WO2018211796A1 - Stent - Google Patents

Stent Download PDF

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Publication number
WO2018211796A1
WO2018211796A1 PCT/JP2018/009100 JP2018009100W WO2018211796A1 WO 2018211796 A1 WO2018211796 A1 WO 2018211796A1 JP 2018009100 W JP2018009100 W JP 2018009100W WO 2018211796 A1 WO2018211796 A1 WO 2018211796A1
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WIPO (PCT)
Prior art keywords
stent
portions
strut
dense
axis
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Application number
PCT/JP2018/009100
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French (fr)
Japanese (ja)
Inventor
翔平 海田
亮輔 上田
有真 河本
Original Assignee
テルモ株式会社
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Publication of WO2018211796A1 publication Critical patent/WO2018211796A1/en

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    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
    • A61F2/82—Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
    • A61F2/86—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure
    • A61F2/90—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure characterised by a net-like or mesh-like structure
    • A61F2/91—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure characterised by a net-like or mesh-like structure made from perforated sheet material or tubes, e.g. perforated by laser cuts or etched holes
    • A61F2/915—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure characterised by a net-like or mesh-like structure made from perforated sheet material or tubes, e.g. perforated by laser cuts or etched holes with bands having a meander structure, adjacent bands being connected to each other

Definitions

  • the present invention relates to a stent used for improving a stenosis or occlusion occurring in a body lumen such as a blood vessel, a bile duct, a trachea, an esophagus, or a urethra.
  • Patent Document 1 discloses a stent delivery system including a stent having a dense portion occupied by a wire member having a large occupation density and a sparse portion occupied by a wire member having a small occupation density.
  • Stents are used to treat various diseases caused by stenosis or occlusion of blood vessels or other biological lumens, to expand the stenosis or occlusion, and to ensure the patency of the biological lumen. Or it is a medical device detained in an obstruction
  • the stent is attached in a contracted state to, for example, a stent delivery system disclosed in Patent Document 1 and the like, inserted from outside the living body into the living body, and delivered to the target site.
  • the stent When the stent passes through the living body lumen and is delivered to the target site, the stent is required to be able to pass through the living body lumen flexibly following the bending of the living body lumen. . For example, a higher passability is required for a stent that expands a stenosis or occlusion in a coronary artery.
  • One of the physical properties that contributes to the passage of the stent is the bending rigidity of the stent. That is, if the bending rigidity of the stent is relatively low, the passage of the stent is relatively high. Bending stiffness is proportional to the cross-sectional second moment when the material is a single material and represents resistance to bending deformation.
  • a measure for reducing the bending rigidity of the stent there is a method of reducing the amount of the constituent material of the stent.
  • the stent is required to have strength (radial force: radial force) for maintaining the state in which the stenosis portion is pushed and expanded.
  • radial force radial force
  • the amount of the constituent material of the stent is reduced, the bending rigidity of the stent is lowered, while the radial force required for the stent may not be maintained.
  • the present invention has been made to solve the above-described problems, and an object of the present invention is to provide a stent capable of improving the passage through a living body lumen while maintaining a radial force.
  • the subject is a stent that is placed in a living body lumen, and includes a plurality of orbiting portions having linear struts that are formed around a shaft and formed in a cylindrical shape,
  • the plurality of circulation parts are arranged side by side along the axial direction, and each of the plurality of circulation parts is provided with a plurality of first portions provided at positions facing each other with respect to the axis in the circumferential direction;
  • a plurality of second portions provided at positions facing each other in the circumferential direction and having a rigidity smaller than the rigidity of the struts of the first portion in a state where at least a part of the plurality of rotating portions is bent.
  • the plurality of circular portions provided in the stent are arranged side by side along the axis of the stent.
  • Each circulating portion has a plurality of first portions and a plurality of second portions.
  • the plurality of first portions are provided at positions facing each other with respect to the axis of the stent in the circumferential direction.
  • the plurality of second portions are provided at positions facing each other with respect to the stent axis in the circumferential direction, and have a rigidity smaller than the rigidity of the struts of the first portion in a state where at least a part of the plurality of circulation portions is bent. .
  • the rigidity of the struts of the second part is smaller than the rigidity of the struts of the first part in a state where at least a part of the plurality of circulation parts is bent.
  • the plurality of first portions are continuously arranged along the axial direction of the stent over the plurality of rotating portions in a state in which the positional relationship facing each other with respect to the axis of the stent is maintained in the circumferential direction. Therefore, the bending stiffness when the stent bends in a posture in which the first part is arranged at the position of the neutral surface is smaller than the bending stiffness when the stent bends in another posture.
  • the stent is easily bent in a posture in which the first part is disposed at the position of the neutral surface. That is, directivity can be given to the bending rigidity of the stent. Therefore, the stent can pass through the bent portion of the living body lumen in a posture in which the bending rigidity is minimized more reliably. Thereby, the passage of the stent in the living body lumen can be improved.
  • the stent can be easily bent. Thereby, the amount of struts in the entire stent can be secured, and the radial force required for the stent can be maintained.
  • the circumferential portion is a corrugated body in which the strut is bent, and a distal-end bending portion having a vertex on the distal end side in the axial direction and a proximal-side bending having a vertex on the proximal end side in the axial direction. And a wavy body having a portion.
  • the orbiting portion is a wavy body in which the strut is bent.
  • the corrugated body has a distal-end bending portion having a vertex on the distal end side in the axial direction of the stent and a proximal-end bending portion having a vertex on the proximal end side in the axial direction of the stent. Accordingly, the stent can follow the bending of the living body lumen more flexibly and pass through the living body lumen. That is, the passage of the stent in the living body lumen can be further improved.
  • the plurality of first portions are arranged on a straight line along the axial direction over the plurality of circulation portions in a state in which a positional relationship facing each other with respect to the axis is maintained in the circumferential direction. It is characterized by.
  • the neutral surface when the stent is bent is formed on a straight line along the axial direction of the stent. Therefore, the stent is easy to bend in a certain direction in a posture in which the first portion is disposed at the position of the neutral surface formed linearly over the entire length of the stent. Thereby, the directivity of the bending rigidity of the stent is improved, and the passing property of the stent in the living body lumen is further improved.
  • the plurality of first portions are arranged in a spiral shape along the axial direction over the plurality of circulation portions in a state in which a positional relationship facing each other with respect to the axis is maintained in the circumferential direction. It is characterized by.
  • the neutral surface when the stent is bent is formed in a spiral shape along the axial direction of the stent. Therefore, the stent can be easily bent in a posture in which the first portion is disposed at the position of the neutral surface formed in a spiral shape, and the directivity can be improved. In other words, the neutral surface of the stent changes along each of the plurality of rotating portions along the axial direction.
  • the stent when the stent passes through a meandering blood vessel site, the stent can pass through the blood vessel site while taking a posture in which the bending rigidity is locally minimized. Thereby, the passage of the stent in the living body lumen is further improved.
  • the plurality of first portions includes a first dense portion in which a proportion of the volume of the struts in a unit volume of the space including the struts is higher than the proportion in the second portions;
  • a second dense portion provided at a position facing the first dense portion and the axis in the circumferential direction, wherein the proportion is higher than the proportion of the second portion. It is characterized by that.
  • the plurality of first portions have the first dense portion and the second dense portion.
  • the proportion (volume density) of the strut volume in the unit volume of the space including the struts in the first dense portion is higher than the strut volume density in the second region.
  • the volume density of the struts in the second dense portion is higher than the volume density of the struts in the second region.
  • the first dense portion and the second dense portion are provided at positions facing each other with respect to the stent axis in the circumferential direction. Therefore, the bending rigidity when the stent bends in a posture in which the first dense portion and the second dense portion are arranged at the position of the neutral surface is smaller than the bending stiffness when the stent bends in another posture. Therefore, the stent is easily bent in a posture in which the first dense portion and the second dense portion are arranged at the position of the neutral surface. That is, directivity can be given to the bending rigidity of the stent. Therefore, the stent can pass through the bent portion of the living body lumen in a posture in which the bending rigidity is minimized.
  • the passage of the stent in the living body lumen can be improved.
  • the first dense portion and the second dense portion are arranged at the position of the neutral surface that has little influence on the bending rigidity of the stent. That is, in the bending deformation of the stent, the first dense portion and the second dense portion, in which the amount of struts forming the circumference of the stent is larger than the amount of struts in the second portion, have little influence on the bending rigidity of the stent.
  • Arranged at the position of the elevation Thereby, the amount of struts in the entire stent can be secured, and the radial force required for the stent can be maintained.
  • the circumferential interval between the struts in each of the first dense portion and the second dense portion is narrower than the circumferential interval between the struts in the second portion.
  • part are formed because the space
  • the first dense portion and the second dense portion can be formed relatively easily, and the passage of the stent in the living body lumen can be improved while maintaining the radial force of the stent.
  • the axial length of the strut in each of the first dense portion and the second dense portion is longer than the axial length of the strut in the second portion.
  • the length (amplitude) of the strut in the axial direction of the stent changes, so that the first dense portion and the second dense portion in which the volume density of the strut is higher than the volume density of the strut in the second portion. Is formed.
  • the first dense portion and the second dense portion can be formed relatively easily, and the passage of the stent in the living body lumen can be improved while maintaining the radial force of the stent.
  • a line width of the strut in each of the first dense portion and the second dense portion is larger than a line width of the strut in the second portion.
  • the first dense portion and the second dense portion in which the volume density of the strut is higher than the volume density of the strut in the second portion are formed by changing the line width of the strut.
  • the thickness of the strut in each of the first dense portion and the second dense portion is larger than the thickness of the strut in the second portion.
  • the first dense portion and the second dense portion in which the volume density of the strut is higher than the volume density of the strut in the second portion are formed by changing the thickness (the length in the radial direction) of the strut.
  • the first dense portion and the second dense portion are formed by the change in the thickness of the strut, and the passage of the stent in the living body lumen can be improved while maintaining the radial force of the stent.
  • the material property of the strut in the first part is different from the material property of the strut in the second part.
  • the material properties of the struts of the first part are different from the material properties of the struts of the second part.
  • the rigidity of the struts of the second part is different from the rigidity of the struts of the first part. Accordingly, the first portion and the second portion are formed by the difference in the material characteristics of the strut, and the passage of the stent in the living body lumen can be improved while maintaining the radial force of the stent.
  • the surrounding portion is an annular body in which the struts extend in an annular shape, and at least one of the plurality of first portions is a connecting portion that connects the surrounding portions adjacent to each other in the axial direction. It is characterized by having.
  • the circulating portion is an annular body in which struts extend in an annular shape.
  • At least one of the plurality of first portions has a connecting portion that connects the circumferential portions adjacent to each other in the axial direction of the stent. Therefore, the 1st site
  • part are formed by arrange
  • the circulating portion is a spiral body in which the struts extend spirally.
  • the circulating portion is a spiral body in which the struts extend spirally. Therefore, even if the connection part which connects the mutually adjacent surrounding parts is not provided, the surrounding parts are continuing spirally. And a some 1st site
  • a stent that can improve the passage through a living body lumen while maintaining a radial force.
  • the stent according to the embodiment of the present invention is used to treat a stenosis (treatment site) generated in a blood vessel that is a living body lumen.
  • the stent is configured as an indwelling member that is expanded and placed in a blood vessel and pushes the stenosis part by supporting the inside of the stenosis part.
  • the stent is not limited to the application to blood vessels, but is applied to the treatment of various biological lumens (for example, bile duct, trachea, esophagus, urethra, nasal cavity, other organs, etc.).
  • the side to be inserted into the lumen left side in FIGS.
  • FIG. 1 to 4, 6 to 8, and 10 to 12 is the “tip” or “tip side”, and the proximal side (FIG. 1 to FIG. 4, FIG. 6 to FIG. 8, and FIG. 10 to FIG. 12 are referred to as “base end” or “base end side”.
  • FIG. 1 is a front view showing a stent delivery system for delivering a stent according to an embodiment of the present invention.
  • FIG. 2 is a partial cross-sectional view of the distal end portion of the stent delivery system shown in FIG.
  • FIG. 3 is a partial cross-sectional view for explaining the operation of the stent delivery system shown in FIG.
  • the stent delivery system 2 shown in FIG. 1 includes a balloon catheter 3 having a balloon 32 and a stent 4 attached to the balloon 32.
  • the balloon catheter 3 has a tube-shaped shaft main body 31 and a foldable and expandable balloon 32 provided at the distal end of the shaft main body 31. That is, the balloon 32 is provided at the distal end portion of the shaft main body 31 so that it can be expanded and contracted.
  • the stent 4 is attached to the balloon 32 so as to encapsulate the deflated balloon 32, and is expanded by the expansion of the balloon 32.
  • the stent 4 is a so-called balloon-expandable stent that has a diameter for insertion into a lumen in a living body and is expandable when a force spreading in the radial direction from the inside of the tubular body is applied.
  • the stent 4 according to the present embodiment is not necessarily limited to a balloon expandable stent, and may be a self-expandable stent that automatically shifts from a contracted state to an expanded state by elastic recovery. In the following description, a case where the stent 4 is a balloon expandable stent will be described as an example.
  • the shaft main body 31 has a guide wire lumen 314.
  • One end of the guide wire lumen 314 is open at the tip of the shaft body 31.
  • the other end of the guide wire lumen 314 is open at the base end of the shaft body 31.
  • the shaft main body 31 includes an inner tube 311, an outer tube 312, and a branch hub 313.
  • the inner tube 311 is a tube body having a guide wire lumen 314 for inserting a guide wire therein.
  • the length of the inner tube 311 is 100 to 2500 mm, more preferably 250 to 2000 mm.
  • the outer diameter of the inner tube 311 is 0.1 to 1.0 mm, more preferably 0.3 to 0.7 mm.
  • the wall thickness of the inner tube 311 is 10 to 250 ⁇ m, more preferably 20 to 100 ⁇ m.
  • the inner tube 311 is inserted into the outer tube 312. The distal end portion of the inner tube 311 protrudes more distally than the outer tube 312.
  • a balloon expansion lumen 315 is formed between the outer surface of the inner tube 311 and the inner surface of the outer tube 312 and has a sufficient volume.
  • the outer tube 312 is a tube body in which the inner tube 311 is inserted.
  • the distal end of the outer tube 312 is located at a portion slightly retracted from the distal end of the inner tube 311.
  • the length of the outer tube 312 is 100 to 2500 mm, more preferably 250 to 2000 mm.
  • the outer diameter of the outer tube 312 is 0.5 to 1.5 mm, more preferably 0.7 to 1.1 mm.
  • the wall thickness of the outer tube 312 is 25 to 200 ⁇ m, more preferably 50 to 100 ⁇ m.
  • the outer tube 312 includes a distal end side outer tube 312a and a proximal end side outer tube 312b.
  • the distal end side outer tube 312a and the proximal end side outer tube 312b are joined to each other.
  • the distal end side outer tube 312a is tapered in the vicinity of the joint between the distal end side outer tube 312a and the proximal end side outer tube 312b. Therefore, the diameter of the distal outer tube 312a on the distal end side with respect to the tapered portion is smaller than the diameter of the proximal outer tube 312b on the proximal end side with respect to the tapered portion.
  • the outer diameter of the small-diameter portion (the portion closer to the tip side than the taper portion) of the tip-side outer tube 312a is 0.5 to 1.5 mm, preferably 0.6 to 1.1 mm. Further, the outer diameter of the proximal end portion of the distal end side outer tube 312a (the portion closer to the proximal end than the tapered portion) and the proximal end side outer tube 312b is 0.75 to 1.5 mm, preferably 0.9 to 1.. 1 mm.
  • the outer tube 312 does not necessarily have to have the distal end side outer tube 312a and the proximal end side outer tube 312b. That is, the outer tube 312 may be formed as a tube body having substantially the same diameter over the entire length.
  • the material for forming the inner tube 311 and the outer tube 312 is preferably a material having a certain degree of flexibility.
  • polyolefin for example, polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, etc.
  • Polyvinyl chloride polyamide, polyamide elastomer, polyester, polyester elastomer, polyurethane and other thermoplastic resins, silicone rubber, latex rubber and the like.
  • the material for forming the inner tube 311 and the outer tube 312 is preferably the above-described thermoplastic resin, and more preferably polyamide or polyamide elastomer.
  • the balloon 32 is foldable, and is folded on the outer periphery of the inner tube 311 when not expanded.
  • the balloon 32 has an expandable portion that exhibits a cylindrical portion (preferably, a cylindrical portion) having substantially the same diameter so that the attached stent 4 can be expanded.
  • the substantially cylindrical portion may not be a complete cylinder but may be a polygonal column.
  • the balloon 32 has a distal end side joint portion 32a and a proximal end side joint portion 32b.
  • the distal end side joint portion 32 a is fixed at a position slightly proximal to the distal end of the inner tube 311. Specifically, the distal end side joint portion 32a is fixed to the inner tube 311 in a liquid-tight manner by an adhesive or heat fusion.
  • the proximal end joint portion 32 b is fixed to the distal end of the outer tube 312. Specifically, the proximal end side joining portion 32b is liquid-tightly fixed to the distal end of the outer tube 312 with an adhesive or heat fusion.
  • the balloon 32 is liquid-tightly fixed to the inner tube 311 and the outer tube 312 by an adhesive or heat fusion.
  • the balloon 32 communicates with the balloon expansion lumen 315 in the vicinity of the proximal end portion.
  • interval between the expandable part and the front end side junction part 32a and the base end side junction part 32b is formed in the taper shape.
  • the balloon 32 has an expansion space 32c formed between the inner surface of the balloon 32 and the outer surface of the inner tube 311.
  • the base end portion of the expansion space 32c communicates with the balloon expansion lumen 315 on the entire circumference.
  • the proximal end of the balloon 32 communicates with the balloon expansion lumen 315 having a relatively large volume. Therefore, the expansion fluid can be reliably injected from the balloon expansion lumen 315 into the balloon 32.
  • the expansion fluid may be a gas or a liquid. Examples of the expansion fluid include gases such as helium gas, CO 2 gas, and O 2 gas, and liquids such as physiological saline and contrast medium.
  • a material for forming the balloon 32 As a material for forming the balloon 32, a material having a certain degree of flexibility is preferable.
  • polyolefin for example, polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, cross-linked ethylene-vinyl acetate). Copolymer), polyvinyl chloride, polyamide, polyamide elastomer, polyurethane, polyester (for example, polyethylene terephthalate), polyester elastomer, polyarylene sulfide (for example, polyphenylene sulfide), thermoplastic resin, silicone rubber, latex rubber, etc.
  • the forming material of the balloon 32 is preferably a stretchable material.
  • the forming material of the balloon 32 is a biaxially stretched material having high strength and expansion force.
  • the outer diameter of the cylindrical portion (expandable portion) of the balloon 32 when the balloon 32 is expanded is 2 to 6 mm, preferably 2.5 to 5.5 mm.
  • the length of the balloon 32 is 5 to 50 mm, preferably 10 to 40 mm.
  • the outer diameter of the distal end side joint portion 32a is 0.9 to 1.5 mm, preferably 1 to 1.3 mm.
  • the length of the distal end side joint portion 32a is 1 to 5 mm, preferably 1 to 3 mm.
  • the outer diameter of the base end side joint portion 32b is 1 to 1.6 mm, preferably 1.1 to 1.5 mm.
  • the length of the base end side joining portion 32b is 1 to 5 mm, preferably 2 to 4 mm.
  • the stent delivery system 2 has two X-ray contrast members 316 and 317.
  • the X-ray contrast members 316 and 317 are fixed to the outer surface of the inner tube 311 at positions corresponding to both ends of the cylindrical portion (expandable portion) when the balloon 32 is expanded.
  • the two X-ray contrast members may be fixed at positions on the outer surface of the inner tube 311 at both ends of a predetermined length in the central portion of the stent 4.
  • a single X-ray contrast member may be fixed to a position that is the central portion of the stent 4 in the outer surface of the shaft main body 31.
  • a ring-shaped member having a predetermined length or a member obtained by winding a linear member in a coil shape is suitable.
  • a material for forming the X-ray contrast members 316 and 317 for example, gold, platinum, tungsten, iridium or an alloy thereof, or a silver-palladium alloy is preferable.
  • a branch hub 313 is fixed to the proximal end of the stent delivery system 2.
  • the branch hub 313 has an inner tube hub and an outer tube hub.
  • the inner tube hub is fixed to the inner tube 311 and has a guide wire port 313 a communicating with the guide wire lumen 314.
  • the outer tube hub is fixed to the outer tube 312 and has an injection port 313 b that communicates with the balloon expansion lumen 315.
  • the outer tube hub and the inner tube hub are fixed to each other.
  • the outer tube hub and the inner tube hub are fixed by inserting and joining the distal end of the inner tube 311 from the proximal end of the outer tube hub attached to the proximal end portion of the outer tube 312.
  • the inner tube hub and the outer tube hub can be securely fixed by applying and bonding an adhesive to the joint portion between the inner tube hub and the outer tube hub.
  • the material for forming the branch hub 313 examples include thermoplastic resins such as polycarbonate, polyamide, polysulfone, polyarylate, and methacrylate-butylene-styrene copolymer.
  • thermoplastic resins such as polycarbonate, polyamide, polysulfone, polyarylate, and methacrylate-butylene-styrene copolymer.
  • the structure of the proximal end of the stent delivery system 2 is not limited to the above structure.
  • a tube having a port member that forms an opening at the proximal end is attached to each of the guide wire lumen 314 and the balloon expansion lumen 315 in a liquid-tight manner.
  • a guide wire insertion port that communicates with the guide wire lumen may be provided in an intermediate portion of the stent delivery system.
  • the structure of the guide wire lumen 314 is not limited to the over-the-wire structure in which the proximal-side guide wire port 313a exists outside the patient's body, and the proximal-side guide wire port 313a is not the patient.
  • a rapid exchange structure existing in the body may be adopted.
  • the stent 4 is attached to the balloon 32 so as to encapsulate the balloon 32.
  • the stent 4 is manufactured by processing, for example, a tube or a pipe having an inner diameter smaller than that of the expanded stent 4 and an inner diameter larger than the outer diameter of the folded balloon 32. Then, the balloon 32 is inserted into the manufactured stent 4, and a uniform force is applied to the outer surface of the stent 4 inward to reduce the diameter, thereby forming the product-state stent 4. That is, the stent 4 is completed by compression mounting on the balloon 32.
  • the material for forming the stent 4 synthetic resin or metal is used.
  • the synthetic resin include synthetic resins having a certain degree of hardness and elasticity, and biocompatible synthetic resins are preferable.
  • the synthetic resin is a polyolefin (eg, polyethylene, polypropylene), polyester (eg, polyethylene terephthalate), fluororesin (eg, PTFE, ETFE), or polylactic acid, polyglycolic acid that is a bioabsorbable material, Or a copolymer of polylactic acid and polyglycolic acid.
  • the metal used as the material for forming the stent 4 is preferably a metal having biocompatibility, for example, a cobalt base alloy such as stainless steel, tantalum or tantalum alloy, platinum or platinum alloy, gold or gold alloy, or cobalt chromium alloy. And nickel titanium alloy. Moreover, after producing the shape of the stent 4, noble metal plating (gold, platinum) may be applied.
  • FIG. 4 is a developed view showing the stent according to the present embodiment.
  • FIG. 5 is a cross-sectional view illustrating a contracted state of the stent according to the present embodiment.
  • FIG. 6 is a front view illustrating the stent according to the present embodiment.
  • FIG. 5 is a cross-sectional view of the stent taken along section plane C1-C1 shown in FIG.
  • the stent 4 includes a plurality of rotating portions 41 arranged side by side along the direction of the axis X1 (see FIGS. 2 and 3).
  • the circulating portion 41 has a linear strut 411 as a strand, and is formed into a cylindrical skeleton as a whole by the strut 411.
  • the orbiting portion 41 has a linear strut 411 formed around the axis X ⁇ b> 1 of the stent 4 and formed in a cylindrical shape.
  • the circumferential portion 41 is formed as a wave-like body in which the strut 411 extends in the circumferential direction of the stent 4 and has a plurality of bent portions, and has a distal end side bent portion 412, a proximal end side bent portion 413, and a linear portion 414. .
  • the orbiting portion 41 is formed as an annular body in which the struts 411 extend in an annular shape.
  • the distal end side bent portion 412 has a vertex on the distal end side in the axial direction of the stent 4.
  • the proximal side bent portion 413 has a vertex on the proximal side in the axial direction of the stent 4.
  • the linear portion 414 is a linear portion that connects the distal end side bent portion 412 and the proximal end side bent portion 413.
  • the distal end side bent portion 412 and the proximal end side bent portion 413 correspond to the “bent portion” of the present invention, and are deformed when the stent 4 is expanded.
  • at least one of the distal end side bent portion 412 and the proximal end side bent portion 413 may be simply referred to as a “bent portion”.
  • the length of one rotating portion 41 is preferably about 0.7 to 2.0 mm.
  • the number of each of the distal end side bent portion 412 and the proximal end side bent portion 413 of one circumference portion is preferably 6 to 20, and particularly preferably 8 to 12.
  • the number of the circulating portions 41 is preferably 4-20. However, the number of each of the distal end side bent portion 412 and the proximal end side bent portion 413 and the number of the surrounding portions 41 are not limited to this.
  • the orbiting portion 41 of the stent 4 has a plurality of first portions 45 and a plurality of second portions 46.
  • the plurality of first portions 45 are provided at positions facing each other with respect to the axis X1 of the stent 4 in the circumferential direction.
  • the plurality of second portions are provided at positions facing each other with respect to the axis X1 of the stent 4 in the circumferential direction.
  • the rigidity of the struts 411 in the second part 46 is smaller than the rigidity of the struts 411 in the first part 45 in a state in which at least a part of the plurality of circulation parts is bent as indicated by an arrow A1 shown in FIG.
  • the “second portion” is a portion having a rigidity smaller than the rigidity of the strut of the first portion in a state where at least some of the plurality of surrounding portions are bent. And other than the first part.
  • the plurality of first portions 45 are arranged over the plurality of circumferential portions 41 in a state in which the first portions 45 maintain the positional relationship facing each other with respect to the axis X1 of the stent 4 in the circumferential direction. It arrange
  • the plurality of first portions 45 include a first dense portion 42 and a second dense portion 43.
  • the first dense portion 42 has a proportion (volume density) occupied by the volume of the strut 411 in the unit volume (compartment frame) V ⁇ b> 1 of the space including the strut 411 in comparison with the volume density of the strut 411 in the second portion 46.
  • the second dense portion 43 is a portion in which the proportion (volume density) of the volume of the strut 411 in the unit volume V1 of the space including the strut 411 is higher than the volume density of the strut 411 in the second portion.
  • the unit volume (compartment frame) V ⁇ b> 1 preferably includes a distal end side bent portion 412 of the strut 411 and a proximal end side bent portion 413 of the strut 411.
  • the second dense portion 43 is provided at a position facing the first dense portion 42 and the axis X ⁇ b> 1 of the stent 4 in the circumferential direction. 4 and 5, the first dense portion 42 is provided at a position of 90 degrees when the lower end portion of the circumferential portion 41 is set to 0 degree and is rotated counterclockwise. 43 is provided at a position of 270 degrees.
  • the positions of the first dense portion 42 and the second dense portion 43 are not limited to the examples shown in FIGS. 4 and 5, and the first dense portion 42 and the second dense portion 43 are arranged in the circumferential direction of the stent 4. There is no particular limitation as long as they are provided at positions facing each other with respect to the axis X1.
  • the circumferential interval (pitch) D1 between the struts 411 in the first dense portion 42 is narrower than the circumferential interval D3 between the struts 411 in the second portion 46.
  • the volume density of the struts 411 in the first dense portion 42 is higher than the volume density of the struts 411 in the second portion 46.
  • the circumferential interval D2 between the struts 411 in the second dense portion 43 is narrower than the circumferential interval D3 between the struts 411 in the second portion 46.
  • the volume density of the struts 411 in the second dense portion 43 is higher than the volume density of the struts 411 in the second portion 46.
  • the circumferential interval between the struts 411 in the vicinity of the lower end portion (around 0 degrees) of the rotating portion 41 is taken as an example as the circumferential interval D3 between the struts 411 in the second portion 46.
  • the second portion 46 is not limited to the vicinity of the lower end portion of the rotating portion 41, and refers to a portion other than the first portion 45 in the rotating portion 41 of the stent 4. Therefore, the circumferential interval between the struts 411 in the second portion 46 is not limited to the interval D3 illustrated in FIG.
  • the circumferential distance D3 between the struts 411 in the second portion 46 is larger than the circumferential distances D1 and D2 between the struts 411 in the first dense portion 42 and the second dense portion 43, respectively. As long as it is, it may be changed.
  • the circumferential distance D3 between the struts 411 changes, it greatly affects the bending rigidity of the neutral plane X2 (see FIG. 6) and is arranged at the position of the neutral plane X2 (see FIG. 6).
  • the distance D3 in the circumferential direction between the struts 411 at positions rotated 90 degrees from each of the first dense portion 42 and the second dense portion 43 is the largest. With such a configuration, the stent 4 is easily bent in a posture in which the first dense portion 42 and the second dense portion 43 are disposed on the neutral plane X2. That is, directivity can be given to the bending rigidity of the stent 4.
  • the plurality of circumferential portions 41 are arranged side by side along the direction of the axis X1 of the stent 4.
  • the plurality of first dense portions 42 are linearly along the axis X1 direction of the stent 4 over the plurality of surrounding portions 41.
  • the first dense portion 42 has a connecting portion 44.
  • the connecting portion 44 connects the surrounding portions 41 adjacent to each other in the axis X1 direction of the stent 4.
  • the surrounding portions 41 adjacent to each other in the axis X1 direction of the stent 4 are connected by the connecting portion 44 included in the first dense portion 42.
  • the plurality of second dense portions 43 are continuously linearly along the axis X1 direction of the stent 4 over the plurality of surrounding portions 41.
  • the second dense portion 43 has a connecting portion 44.
  • the connecting portion 44 connects the surrounding portions 41 adjacent to each other in the axis X1 direction of the stent 4.
  • the surrounding portions 41 adjacent to each other in the direction of the axis X ⁇ b> 1 of the stent 4 are connected by the connecting portion 44 included in the second dense portion 43.
  • the surrounding portions 41 adjacent to each other in the axis X1 direction of the stent 4 are connected by the connecting portion 44, so that the stent 4 has a cylindrical shape whose peripheral side surface is continuous in the axis X1 direction and exhibits a mesh shape. .
  • the stent 4 when the stent 4 passes through the living body lumen and is delivered to the target site, the stent 4 can pass through the living body lumen flexibly following the bending of the living body lumen. Is required. Further, the stent 4 is required to have strength (radial force: radial force) for maintaining the state in which the stenosis portion is expanded.
  • each of the plurality of rotating portions 41 has a plurality of first portions 45 and a plurality of second portions 46.
  • the plurality of first portions 45 are provided at positions facing each other with respect to the axis X1 of the stent 4 in the circumferential direction.
  • the plurality of second portions 46 are provided at positions facing each other with respect to the axis X1 of the stent 4 in the circumferential direction, and the rigidity of the strut 411 of the first portion 45 is in a state where at least a part of the plurality of surrounding portions 41 is bent. Less rigid.
  • the rigidity of the struts 411 in the second part 46 is smaller than the rigidity of the struts 411 in the first part 45 in a state in which at least a part of the plurality of circumferential portions 41 is bent.
  • the plurality of first portions 45 are continuously provided along the axis X1 direction of the stent 4 over the plurality of rotating portions 41 while maintaining a positional relationship facing each other with respect to the axis X1 of the stent 4 in the circumferential direction. Has been placed.
  • the bending stiffness when the stent 4 bends in a posture in which the first portion 45 is disposed at the position of the neutral plane X2 (see FIG. 6) is smaller than the bending stiffness when the stent 4 bends in another posture. Therefore, the stent 4 is easily bent in a posture in which the first portion 45 is disposed at the position of the neutral plane X2. That is, directivity can be given to the bending rigidity of the stent 4.
  • the “directivity” of the bending rigidity of the stent 4 means that the stent 4 has a relatively large rigidity in the strut 411 and a portion having a relatively large rigidity (the first portion 45 in the present embodiment).
  • the stent 4 having the directivity of bending rigidity has a portion that is relatively easily bent and a portion that is not easily bent in the strut 411 when bending.
  • the directivity of the stent 4 can be improved by increasing the difference between the rigidity of the portion having high rigidity and the rigidity of the portion having low rigidity in the strut 411. The stent 4 having such high directivity is surely bent in a posture where the bending rigidity is minimized.
  • the stent 4 since the stent 4 according to the present embodiment has high bending rigidity directivity, the stent 4 can pass through the bent portion of the living body lumen in a posture in which the bending rigidity is more surely minimized. Thereby, the passage property of the stent 4 in the living body lumen can be improved. Further, by giving directivity to the bending rigidity of the stent 4 without reducing the amount of the constituent material of the stent 4, the stent 4 can take a posture that is easy to bend. Thereby, the amount of struts 411 in the entire stent 4 can be secured, and the radial force required for the stent 4 can be maintained.
  • the circumferential portion 41 of the stent 4 has a first dense portion 42 in which the volume density of the struts 411 is higher than the volume density of the struts 411 in the second region 46, and the volume density of the struts 411. And a second dense portion 43 that is higher than the volume density of the struts 411 in the second portion 46.
  • the first dense portion 42 and the second dense portion 43 are provided at positions facing each other with respect to the axis X1 of the stent 4 in the circumferential direction.
  • the plurality of first dense portions 42 are continuously linearly extended along the axis X1 direction of the stent 4 over the plurality of surrounding portions 41.
  • the plurality of second dense portions 43 are continuously arranged on the straight line along the axis X1 direction of the stent 4 over the plurality of rotating portions 41.
  • the bending stiffness when the stent 4 bends in a posture in which the first dense portion 42 and the second dense portion 43 are arranged at the position of the neutral plane X2 is more than the bending stiffness when the stent 4 bends in another posture. small. Therefore, as indicated by an arrow A1 illustrated in FIG. 6, the stent 4 is easily bent in a posture in which the first dense portion 42 and the second dense portion 43 are disposed at the position of the neutral plane X2. That is, the directivity can be given to the bending rigidity of the stent 4 and the directivity of the bending rigidity of the stent 4 can be improved.
  • Bending stiffness is proportional to the cross-sectional second moment when the material is a single material and represents resistance to bending deformation. Therefore, when the material receives a bending moment, the material bends in a posture that minimizes the bending rigidity. Therefore, when the bending rigidity of the stent 4 has directivity, the member is easily bent in a posture in which the bending rigidity is minimized.
  • the stent 4 according to this embodiment can pass through the bent portion of the living body lumen in a posture in which the bending rigidity is more surely minimized. Thereby, the passage property of the stent 4 in the living body lumen can be improved.
  • the first dense portion 42 and the second dense portion 43 are disposed at the position of the neutral surface X ⁇ b> 2 that has little influence on the bending rigidity of the stent 4.
  • the first dense portion 42 and the second dense portion 43 in which the amount of the struts 411 forming the circumferential portion 41 of the stent 4 is larger than the amount of the struts 411 in the other portions are neutral surfaces. It is arranged at the position of X2. Thereby, the amount of struts 411 in the entire stent 4 can be secured, and the radial force required for the stent 4 can be maintained.
  • the circulating portion 41 is formed as a wave-like body in which the strut 411 has a plurality of bent portions.
  • the stent 4 can follow the bending of the living body lumen more flexibly and pass through the living body lumen. That is, the passability of the stent 4 in the living body lumen can be further improved.
  • the circumferential density (pitch) between the struts 411 is changed, so that the volume density of the struts 411 is higher than the volume density of the struts 411 in the second portion 46 and the first dense portions 42 and the first.
  • Two dense portions 43 are formed. Thereby, the 1st dense part 42 and the 2nd dense part 43 can be formed comparatively easily, and the passage nature of the stent 4 in a living body lumen can be improved, maintaining the radial force of the stent 4.
  • each of the first dense portion 42 and the second dense portion 43 has the connecting portion 44 that connects the circumferential portions 41 adjacent to each other in the axis X1 direction of the stent 4. Therefore, as compared with the case where the connecting portion 44 is not provided, the amount of the strut 411 in each of the first dense portion 42 and the second dense portion 43 is further larger than the amount of the strut 411 in the second portion 46. Thereby, the directivity of the bending rigidity of the stent 4 can be further improved, and the passage of the stent 4 in the living body lumen can be further improved while maintaining the radial force of the stent 4.
  • both the first dense portion 42 and the second dense portion 43 do not necessarily have the connecting portion 44.
  • only the first dense portion 42 may have the connecting portion 44.
  • only the second dense portion 43 may have the connecting portion 44. That is, it is sufficient that at least one of the first dense portion 42 and the second dense portion 43 has the connecting portion 44.
  • the connection part 44 does not need to connect all the surrounding parts 41 adjacent to each other in the axis X1 direction of the stent 4.
  • the connecting portions 44 included in each of the first dense portion 42 and the second dense portion 43 are provided alternately between the circumferential portions 41 adjacent to each other, and the connecting portions included in the first dense portion 42. 44 and the connecting portions 44 included in the second dense portion 43 may be alternately arranged along the axis X ⁇ b> 1 of the stent 4.
  • FIG. 7 is a development view showing the stent according to the first modification of the present embodiment.
  • the stent 4A according to the present modification includes a plurality of rotating portions 41A arranged side by side along the direction of the axis X1 (see FIGS. 2 and 3).
  • the orbiting portion 41A is formed as a wave-like body in which the strut 411 extends in the circumferential direction of the stent 4A and has a plurality of bent portions, and has a distal end side bent portion 412, a proximal end side bent portion 413, and a linear portion 414. .
  • the plurality of first portions 45A of the stent 4A includes a first dense portion 42A and a second dense portion 43A.
  • the length (amplitude) D4 of the strut 411 in the axis X1 direction at the first dense portion 42A is longer than the length D6 of the strut 411 in the axis X1 direction at the second portion 46A.
  • the volume density of the strut 411 in the first dense portion 42A is higher than the volume density of the strut 411 in the second portion 46A.
  • the length (amplitude) D5 of the strut 411 in the second dense portion 43A in the axis X1 direction is longer than the length D6 in the axis X1 direction of the strut 411 in the second portion 46A.
  • the volume density of the strut 411 in the 2nd dense part 43A is higher than the volume density of the strut 411 in the 2nd site
  • the “second portion 46A” means a rigidity smaller than the rigidity of the strut 411 of the first portion 45A in a state where at least a part of the plurality of rotating portions 41A is bent. It is a part which has and refers to parts other than the 1st site
  • the amplitude D6 of the strut 411 in the second portion 46A only needs to be shorter than the amplitude D4 of the strut 411 of the first dense portion 42A and the amplitude D5 of the strut 411 of the second dense portion 43A, and changes. You may do it.
  • the amplitude D6 of the strut 411 changes, it greatly affects the magnitude of the bending rigidity in the neutral plane X2, and from each of the first dense portion 42A and the second dense portion 43A arranged at the position of the neutral plane X2. It is preferable that the amplitude D6 of the strut 411 at the position rotated by 90 degrees is the shortest.
  • the stent 4A is easily bent in a posture in which the first dense portion 42A and the second dense portion 43A are disposed on the neutral plane X2. That is, directivity can be given to the bending rigidity of the stent 4A.
  • the length (amplitude) of the strut 411 in the axis X1 direction of the stent 4A changes, so that the volume density of the strut 411 is larger than the volume density of the strut 411 in the second portion 46A.
  • a high first dense portion 42A and a second dense portion 43A are formed.
  • the first dense portion 42A and the second dense portion 43A can be formed relatively easily, and the passage of the stent 4A in the living body lumen can be improved while maintaining the radial force of the stent 4A.
  • the same effects as those described above with reference to FIGS. 4 to 6 can be obtained.
  • FIG. 8 is a development view showing the stent according to the second modification of the present embodiment.
  • the stent 4B according to the present modification includes a plurality of rotating portions 41B arranged side by side along the direction of the axis X1 (see FIGS. 2 and 3).
  • the circumferential portion 41B is formed as a wave-like body in which the strut 411 extends in the circumferential direction of the stent 4B and has a plurality of bent portions, and has a distal end side bent portion 412, a proximal end side bent portion 413, and a linear portion 414. .
  • the plurality of first portions 45B of the stent 4B includes a first dense portion 42B and a second dense portion 43B.
  • the line width D7 of the strut 411 in the first dense portion 42B is thicker than the line width D9 of the strut 411 in the second portion 46B.
  • the volume density of the strut 411 in the 1st dense part 42B is higher than the volume density of the strut 411 in the 2nd site
  • the line width D8 of the strut 411 in the second dense portion 43B is larger than the line width D9 of the strut 411 in the second portion 46B.
  • the volume density of the strut 411 in the 2nd dense part 43B is higher than the volume density of the strut 411 in the 2nd site
  • the “second portion 46B” means a rigidity smaller than the rigidity of the strut 411 of the first portion 45B in a state where at least a part of the plurality of rotating portions 41B is bent. It is a part which has, and says parts other than the 1st site
  • the line width D9 of the strut 411 in the second portion 46B only needs to be narrower than the line widths D7 and D8 of the strut 411 in each of the first dense portion 42B and the second dense portion 43B, and changes. You may do it.
  • the line width D9 of the strut 411 changes, the magnitude of the bending rigidity in the neutral plane X2 is greatly affected, and each of the first dense portion 42B and the second dense portion 43B disposed at the position of the neutral plane X2 It is preferable that the line width D9 of the strut 411 at a position rotated 90 degrees from the narrowest is the narrowest.
  • the stent 4B is easily bent in a posture in which the first dense portion 42B and the second dense portion 43B are disposed on the neutral plane X2. That is, directivity can be given to the bending rigidity of the stent 4B.
  • a portion 43B is formed.
  • the 1st dense part 42B and the 2nd dense part 43B can be formed comparatively easily, and the passage nature of stent 4B in a living body lumen can be improved, maintaining the radial force of stent 4B.
  • the same effects as those described above with reference to FIGS. 4 to 6 can be obtained.
  • FIG. 9 is a cross-sectional view illustrating a contracted state of the stent according to the third modification of the present embodiment.
  • FIG. 9 corresponds to a cross-sectional view of the stent taken along section plane C1-C1 shown in FIG.
  • the stent 4C according to the present modification includes a plurality of rotating portions 41C arranged side by side along the direction of the axis X1 (see FIGS. 2 and 3).
  • the circumferential portion 41C is formed as a wave-like body in which the strut 411 extends in the circumferential direction of the stent 4C and has a plurality of bent portions, and includes a distal end side bent portion 412 (see FIG. 4) and a proximal end side bent portion 413 (see FIG. 4). And a linear portion 414 (see FIG. 4).
  • the plurality of first portions 45C of the stent 4C according to this modification includes a first dense portion 42C and a second dense portion 43C.
  • the thickness (diameter length) t1 of the strut 411 in the first dense portion 42C is thicker than the thickness t3 of the strut 411 in the second portion 46C.
  • the volume density of the strut 411 in the first dense portion 42C is higher than the volume density of the strut 411 in the second portion 46C.
  • the thickness t2 of the strut 411 in the second dense portion 43C is thicker than the thickness t3 of the strut 411 in the second portion 46C.
  • the volume density of the strut 411 in the 2nd dense part 43C is higher than the volume density of the strut 411 in the 2nd site
  • the “second portion 46C” means a rigidity smaller than the rigidity of the strut 411 of the first portion 45C in a state where at least a part of the plurality of rotating portions 41C is bent. It is a part which has, and says parts other than the 1st site
  • the thickness t3 of the strut 411 changes, the bending rigidity at the neutral plane X2 is greatly affected, and each of the first dense portion 42C and the second dense portion 43C disposed at the position of the neutral plane X2 It is preferable that the thickness t3 of the strut 411 at the position rotated 90 degrees from the smallest is the thinnest. With such a configuration, the stent 4C is easily bent in a posture in which the first dense portion 42C and the second dense portion 43C are disposed on the neutral plane X2. That is, directivity can be given to the bending rigidity of the stent 4C.
  • the thickness (the length in the radial direction) of the strut 411 is changed, so that the first density is higher than the volume density of the strut in the second portion 46C.
  • a portion 42C and a second dense portion 43C are formed.
  • the first dense portion 42C and the second dense portion 43C are formed by the change in the thickness of the strut 411, and the passage of the stent 4C in the living body lumen can be improved while maintaining the radial force of the stent 4C. it can.
  • the same effects as those described above with reference to FIGS. 4 to 6 can be obtained.
  • FIG. 10 is a developed view showing a stent according to a fourth modification of the present embodiment.
  • the stent 4D according to this modification includes a plurality of rotating portions 41D arranged side by side along the direction of the axis X1 (see FIGS. 2 and 3).
  • the orbiting portion 41D is formed as a wave-like body in which the strut 411 extends in the circumferential direction of the stent 4D and has a plurality of bent portions, and has a distal end side bent portion 412, a proximal end side bent portion 413, and a linear portion 414. .
  • the plurality of first portions 45D of the stent 4D according to this modification include a first dense portion 42D and a second dense portion 43D.
  • the first dense portion 42D has the connecting portion 44 described above with reference to FIGS. Therefore, the amount of struts 411 in the first dense portion 42D is larger than the amount of struts 411 in the second portion 46D. Thereby, the volume density of the strut 411 in the 1st dense part 42D is higher than the volume density of the strut 411 in the 2nd site
  • the second dense portion 43D has the connecting portion 44 described above with reference to FIGS. Therefore, the amount of struts 411 in the second dense portion 43D is larger than the amount of struts 411 in the second portion 46D. Thereby, the volume density of the strut 411 in the 2nd dense part 43D is higher than the volume density of the strut 411 in the 2nd site
  • each of the first dense portion 42D and the second dense portion 43D has the connecting portion 44, and thus the first dense portion 42D and the second dense portion 42D.
  • the amount of struts 411 in each of the dense portions 43D is larger than the amount of struts 411 in the second portion 46D.
  • the connecting portion 44 connects all the surrounding portions 41D adjacent to each other in the axis X1 direction of the stent 4D. Therefore, directivity can be given to the bending rigidity of the stent 4D. Further, with respect to other effects, the same effects as those described above with reference to FIGS. 4 to 6 can be obtained.
  • FIG. 11 is a developed view showing a stent according to a fifth modification of the present embodiment.
  • the stent 4E according to this modification includes a plurality of circumferential portions 41E arranged side by side along the direction of the axis X1 (see FIGS. 2 and 3).
  • the circumferential portion 41E is formed as a wave-like body in which the strut 411 extends in the circumferential direction of the stent 4E and has a plurality of bent portions, and has a distal end side bent portion 412, a proximal end side bent portion 413, and a linear portion 414. .
  • the plurality of first portions 45E of the stent 4E according to this modification include a first dense portion 42E and a second dense portion 43E.
  • the connecting portions 44 included in the first dense portions 42E are provided alternately between the surrounding portions 41E adjacent to each other in the axis X1 direction of the stent 4E.
  • the connection part 44 which the 2nd dense part 43E has is provided every other between the surrounding parts 41E mutually adjacent in the axis
  • the connection part 44 which the 1st dense part 42E has, and the connection part 44 which the 2nd dense part 43E has are alternately arrange
  • the connecting portions 44 included in the first dense portion 42E and the connecting portions 44 included in the second dense portion 43E are alternately arranged along the axis X1 of the stent 4E.
  • the stent 4E according to this modification is different from the stent 4D described above with reference to FIG.
  • the other structure is the same as the stent 4D described above with reference to FIG.
  • the connecting portions 44 are provided alternately between the surrounding portions 41E adjacent to each other in the axis X1 direction of the stent 4E, the flexibility with respect to the bending of the biological lumen is provided. While ensuring, directivity can be given to the bending rigidity of the stent 4E. As for other effects, the same effects as those described above with reference to FIGS. 4 to 6 and 10 can be obtained.
  • FIG. 12 is a developed view showing a stent according to a sixth modification of the present embodiment.
  • the orbiting portion 41F of the stent 4F according to this modification is a spiral body in which the struts 411 extend spirally. That is, in the stent 4F illustrated in FIG. 12, the lower end portion (the end portion at the 0 degree position) of the orbiting portion 41F is the adjacent orbiting portion 41F (the adjacent orbiting portion on the left in FIG. 12) in the axis X1 direction of the stent 4F. 41F) is connected to the upper end portion (the end portion at a position of 360 degrees).
  • the surrounding portions 41F adjacent to each other in the axis X1 direction of the stent 4F are connected as a spiral body, so that the stent 4F has a cylindrical shape whose peripheral side surface is continuous in the axis X1 direction and exhibits a spiral shape. .
  • the plurality of first portions 45F of the stent 4F includes a first dense portion 42F and a second dense portion 43F.
  • the circumferential distance D11 between the struts 411 in the first dense portion 42F is narrower than the circumferential distance D12 between the struts 411 in the second part 46F.
  • the volume density of the strut 411 in the 1st dense part 42F is higher than the volume density of the strut 411 in the 2nd site
  • the circumferential interval D11 between the struts 411 in the second dense portion 43F is narrower than the circumferential interval D12 between the struts 411 in the second portion 46F.
  • the volume density of the strut 411 in the 2nd dense part 43F is higher than the volume density of the strut 411 in the 2nd site
  • the “second portion 46F” means a rigidity smaller than the rigidity of the strut 411 of the first portion 45F in a state in which at least a part of the plurality of rotating portions 41F is bent. It is a part which has, and says parts other than the 1st site
  • the orbiting portion 41F is a spiral body, the orbiting portion 41F is spirally continuous even if a connecting portion that connects the adjacent surrounding portion 41F is not provided. is doing.
  • the first dense portion 42F and the second dense portion 43F are provided at positions facing each other with respect to the axis X1 of the stent 4 in the circumferential direction. Thereby, the stent 4F can improve the passage property in a living body lumen, maintaining a radial force.
  • the surrounding portion 41 of the stent 4 described above with reference to FIGS. 4 to 6 is a spiral body is taken as an example.
  • the present invention is not limited to this, and the orbiting portions 41A, 41B, and 41C of the stents 4A, 4B, and 4C described above with reference to FIGS. 7 to 9 may be formed as a spiral body. Even in this case, the same effect can be obtained.
  • FIG. 13 is a developed view showing a stent according to a seventh modification of the present embodiment.
  • the stent 4G according to this modification includes a plurality of rotating portions 41G arranged side by side along the direction of the axis X1 (see FIGS. 2 and 3).
  • the circumferential portion 41G is formed as a wave-like body in which the strut 411 extends in the circumferential direction of the stent 4G and has a plurality of bent portions, and has a distal end side bent portion 412, a proximal end side bent portion 413, and a linear portion 414. .
  • the orbiting portion 41G of the stent 4G has a plurality of first portions 45G and a plurality of second portions 46G.
  • the plurality of first portions 45G are spirally arranged along the axis X1 direction of the stent 4G over the plurality of surrounding portions 41G while maintaining a positional relationship facing each other with respect to the axis X1 of the stent 4G in the circumferential direction. ing.
  • the plurality of first portions 45G have a first dense portion 42G and a second dense portion 43G.
  • the plurality of first dense portions 42G are continuously spiraled along the axis X1 direction of the stent 4G over the plurality of surrounding portions 41G. Is arranged.
  • the circumferential angle between one first dense portion 42G and the other first dense portion 42G is 45 degrees.
  • the angle in the circumferential direction between one first dense portion 42G and the other first dense portion 42G is not limited to 45 degrees, and may be 30 degrees, for example, 60 degrees. May be.
  • the plurality of second dense portions 43G are spirally continuous along the axis X1 direction of the stent 4G over the plurality of surrounding portions 41G.
  • the circumferential angle between one second dense portion 43G and the other second dense portion 43G is 45 degrees.
  • the circumferential angle between one second dense portion 43G and the other second dense portion 43G is not limited to 45 degrees, and may be, for example, 30 degrees, for example, 60 degrees. May be.
  • the plurality of first portions 45G spirals along the axis X1 direction of the stent 4G over the plurality of rotating portions 41G in a state in which the positional relationship facing each other with respect to the axis X1 of the stent 4G is maintained in the circumferential direction.
  • the stent 4G according to the present embodiment is different from the stent 4 described above with reference to FIGS.
  • Other structures are similar to the stent 4 described above with respect to FIGS.
  • the neutral plane X2 (see FIG. 6) when the stent 4G is bent is formed in a spiral shape along the axis X1 direction of the stent 4G. Therefore, the stent 4G is easily bent in a posture in which the first portion 45G is disposed at the position of the neutral surface X2 formed in a spiral shape. That is, the neutral plane X2 of the stent 4G changes along each of the plurality of rotating portions 41G along the direction of the axis X1.
  • the stent 4G when the stent 4G passes through a meandering blood vessel portion, the stent 4G can pass through the blood vessel portion while taking a posture in which the bending rigidity is locally minimized with respect to the blood vessel portion. Thereby, the passage of the stent 4G in the living body lumen is further improved.
  • FIG. 14 is a cross-sectional view showing a tube for producing a stent according to an eighth modification of the present embodiment. Note that FIG. 14 corresponds to a cross-sectional view taken along a plane perpendicular to the axis of the stent.
  • the stent according to the present embodiment is manufactured by processing, for example, a tube or a pipe.
  • a stent is partially removed by cutting (for example, mechanical cutting, laser cutting), chemical etching, or the like on a side surface of a synthetic resin tube or a metal tube, and a plurality of notches are formed on the side surface.
  • it is produced by forming a plurality of openings.
  • a tube 5 shown in FIG. 14 is an example of a tube for producing a stent according to this modification.
  • the tube 5 is formed in a cylindrical shape or a tubular shape by, for example, a biodegradable biodegradable polymer, and includes a first forming portion 51 and a second forming portion 52.
  • the first forming portion 51 is a portion that becomes the first portion of the strut (for example, the first portion 45 described above with reference to FIG. 4) after the stent according to the present modification is manufactured.
  • the second formation portion 52 is a portion that becomes the second portion of the strut (for example, the second portion 46 described above with reference to FIG. 4) after the stent according to the present modification is manufactured.
  • the material property of the first formation part 51 is different from the material property of the second formation part 52.
  • the tube 5 is formed by extrusion molding using different biodegradable polymers at the first forming portion 51 and the second forming portion 52.
  • the material of the first formation site 51 include polylactic acid.
  • the material of the second formation site 52 include polycaprolactan.
  • the tube 5 is formed in a cylindrical shape or a tubular shape from a metal having biocompatibility, and has a first forming portion 51 and a second forming portion 52. Even in this case, the material characteristics of the first formation site 51 are different from the material characteristics of the second formation site 52. For example, heat treatment such as annealing is performed on at least one of the first formation portion 51 and the second formation portion 52. Alternatively, for example, processing such as shot peening is performed on at least one of the first formation portion 51 and the second formation portion 52.
  • part differs from the material property of the strut of the 2nd site
  • the tube 5 may have a structure in which different metals are bonded to each other at the first forming portion 51 and the second forming portion 52.
  • examples of the material of the first forming portion 51 include stainless steel.
  • An example of the material of the second formation portion 52 is gold.
  • the tube 5 may have a structure in which a metal and a biodegradable polymer are bonded to each other at the first formation site 51 and the second formation site 52.
  • the material of the strut of the first part Because the properties are different from the material properties of the struts in the second part, the stiffness of the struts in the second part is different from the rigidity of the struts in the first part. Specifically, it is possible to make the rigidity of the struts of the second part smaller than the rigidity of the struts of the first part in a state where at least some of the plurality of circulation parts are bent. Accordingly, the first portion and the second portion are formed by the difference in the material characteristics of the strut, and the passage of the stent in the living body lumen can be improved while maintaining the radial force of the stent.
  • the present invention has been described above. However, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the claims. A part of the configuration of the above embodiment can be omitted, or can be arbitrarily combined so as to be different from the above. For example, in the description of the present embodiment, the direction of the bending rigidity is given to the stent by changing the strut or the connecting portion of the stent. However, the present invention is not limited to this.
  • the struts or connecting portions of the stent do not change, and by providing a member that continuously extends and is fixed on the outer circumference of the stent over the entire length of the stent, the direction of the bending rigidity is given to the stent. May be.
  • 2 ... Stent delivery system, 3 ... Balloon catheter, 4, 4A, 4B, 4C, 4D, 4E, 4F, 4G ... Stent, 5 ... Tube, 31 ... Shaft body, 32 ... Balloon, 32a ... Tip side joint, 32b ... Base end side joint, 32c ... Expansion space, 41, 41A, 41B, 41C, 41D, 41E, 41F, 41G ... Circulation 42, 42A, 42B, 42C, 42D, 42E, 42F, 42G ... first dense part, 43, 43A, 43B, 43C, 43D, 43E, 43F, 43G ... second dense part, 44.

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Abstract

[Problem] To provide a stent with which it is possible to improve passage in a lumen of a living body while maintaining radial force. [Solution] A stent 4 comprises a plurality of coiling portions 41 having linear struts 411 formed in a tubular shape and coiling around an axis. The plurality of coiling portions 41 are arranged side-by-side along the axial direction. Each of the plurality of coiling portions 41 has a plurality of first parts 45 provided at positions opposite each other with respect to the axis in the circumferential direction, and a plurality of second parts 46 having rigidity less than the rigidity of the struts 411 of the first parts 45 in a state in which at least some of the plurality of coiling portions 41 are bent, the second parts being provided at positions opposite each other with respect to the axis in the circumferential direction. The plurality of first portions 45 are arranged continuously along the axial direction across the plurality of coiling portions 41 in a state that maintains the positional relationships opposite each other with respect to the axis in the circumferential direction.

Description

ステントStent
　本発明は、血管、胆管、気管、食道、尿道等の生体管腔内に生じた狭窄部もしくは閉塞部の改善に使用されるステントに関する。 The present invention relates to a stent used for improving a stenosis or occlusion occurring in a body lumen such as a blood vessel, a bile duct, a trachea, an esophagus, or a urethra.
　特許文献１には、線材部材が占有する占有密度が大きい密部と、線材部材が占有する占有密度が小さい疎部と、を有するステントを備えたステントデリバリーシステムが開示されている。ステントは、血管あるいは他の生体管腔が狭窄もしくは閉塞することによって生じる様々な疾患を治療するために、狭窄部もしくは閉塞部を拡張し、生体管腔の開存状態を確保するために狭窄部もしくは閉塞部に留置される医療用具である。ステントは、例えば特許文献１などに開示されたステントデリバリーシステムに収縮した状態で装着され、生体外から生体内に挿入され、目的部位まで送達される。 Patent Document 1 discloses a stent delivery system including a stent having a dense portion occupied by a wire member having a large occupation density and a sparse portion occupied by a wire member having a small occupation density. Stents are used to treat various diseases caused by stenosis or occlusion of blood vessels or other biological lumens, to expand the stenosis or occlusion, and to ensure the patency of the biological lumen. Or it is a medical device detained in an obstruction | occlusion part. The stent is attached in a contracted state to, for example, a stent delivery system disclosed in Patent Document 1 and the like, inserted from outside the living body into the living body, and delivered to the target site.
　ステントが生体管腔内を通過し目的部位まで送達される際には、生体管腔の屈曲に対して柔軟に追従し生体管腔内を通過することができる通過性がステントに対して求められる。例えば冠動脈血管に生じた狭窄部もしくは閉塞部を拡張するステントに対しては、より高い通過性が求められる。 When the stent passes through the living body lumen and is delivered to the target site, the stent is required to be able to pass through the living body lumen flexibly following the bending of the living body lumen. . For example, a higher passability is required for a stent that expands a stenosis or occlusion in a coronary artery.
　ステントの通過性に寄与する物性のうちのひとつとして、ステントの曲げ剛性が挙げられる。つまり、ステントの曲げ剛性が相対的に低いと、ステントの通過性は相対的に高くなる。曲げ剛性は、材料が単一材料である場合において断面二次モーメントに比例し、曲げ変形に対する抵抗を表す。ここで、ステントの曲げ剛性を低下させる一策として、ステントの構成材料の量を減らす方法が挙げられる。 One of the physical properties that contributes to the passage of the stent is the bending rigidity of the stent. That is, if the bending rigidity of the stent is relatively low, the passage of the stent is relatively high. Bending stiffness is proportional to the cross-sectional second moment when the material is a single material and represents resistance to bending deformation. Here, as a measure for reducing the bending rigidity of the stent, there is a method of reducing the amount of the constituent material of the stent.
　しかし、ステントの構成材料の量を減らすと、ステントに対して求められるラジアルフォースが低下することが一般的に知られている。すなわち、ステントには、狭窄部を押し広げた状態を維持するための強度（ラジアルフォース：径方向の力）が求められる。しかし、ステントの構成材料の量を減らすと、ステントの曲げ剛性が低下する一方で、ステントに対して求められるラジアルフォースを維持することができないおそれがある。 However, it is generally known that when the amount of the constituent material of the stent is reduced, the radial force required for the stent is lowered. That is, the stent is required to have strength (radial force: radial force) for maintaining the state in which the stenosis portion is pushed and expanded. However, when the amount of the constituent material of the stent is reduced, the bending rigidity of the stent is lowered, while the radial force required for the stent may not be maintained.
特開２０１５－１５６９６７号公報Japanese Patent Laying-Open No. 2015-156967
　本発明は、前記課題を解決するためになされたものであり、ラジアルフォースを維持しつつ生体管腔内における通過性を向上させることができるステントを提供することを目的とする。 The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a stent capable of improving the passage through a living body lumen while maintaining a radial force.
　前記課題は、本発明によれば、生体管腔内に留置されるステントであって、軸を中心に周回して筒状に形成された線状のストラットを有する複数の周回部を備え、前記複数の周回部は、前記軸方向に沿って並んで配置され、前記複数の周回部のそれぞれは、周方向において前記軸に対して互いに対向する位置に設けられた複数の第１部位と、前記周方向において前記軸に対して互いに対向する位置に設けられ、前記複数の周回部の少なくとも一部が曲がった状態において前記第１部位の前記ストラットの剛性よりも小さい剛性を有する複数の第２部位と、を有し、前記複数の第１部位は、前記周方向において前記軸に対して互いに対向する位置関係を維持した状態で、前記複数の周回部にわたって前記軸方向に沿って連続的に配置されたことを特徴とするステントにより解決される。 According to the present invention, the subject is a stent that is placed in a living body lumen, and includes a plurality of orbiting portions having linear struts that are formed around a shaft and formed in a cylindrical shape, The plurality of circulation parts are arranged side by side along the axial direction, and each of the plurality of circulation parts is provided with a plurality of first portions provided at positions facing each other with respect to the axis in the circumferential direction; A plurality of second portions provided at positions facing each other in the circumferential direction and having a rigidity smaller than the rigidity of the struts of the first portion in a state where at least a part of the plurality of rotating portions is bent. And the plurality of first portions are continuously arranged along the axial direction over the plurality of rotating portions in a state in which a positional relationship facing each other with respect to the axis is maintained in the circumferential direction. Octopus It is solved by a stent according to claim.
　前記構成によれば、ステントが備える複数の周回部は、ステントの軸に沿って並んで配置されている。各周回部は、複数の第１部位と、複数の第２部位と、を有する。複数の第１部位は、周方向においてステントの軸に対して互いに対向する位置に設けられている。複数の第２部位は、周方向においてステントの軸に対して互いに対向する位置に設けられ、複数の周回部の少なくとも一部が曲がった状態において第１部位のストラットの剛性よりも小さい剛性を有する。すなわち、複数の周回部の少なくとも一部が曲がった状態において、第２部位のストラットの剛性は、第１部位のストラットの剛性よりも小さい。そして、複数の第１部位は、周方向においてステントの軸に対して互いに対向する位置関係を維持した状態で、複数の周回部にわたってステントの軸方向に沿って連続的に配置されている。そのため、第１部位が中立面の位置に配置される姿勢でステントが曲がるときの曲げ剛性は、他の姿勢でステントが曲がるときの曲げ剛性よりも小さい。そのため、ステントは、第１部位が中立面の位置に配置される姿勢で曲がりやすい。つまり、ステントの曲げ剛性に指向性を持たせることができる。そのため、ステントは、曲げ剛性がより確実に最小となる姿勢で生体管腔の屈曲部を通過することができる。これにより、生体管腔内におけるステントの通過性を向上させることができる。また、ステントの構成材料の量を減らすことなくステントの曲げ剛性に指向性を持たせることにより、ステントは、曲がりやすい姿勢をとることができる。これにより、ステント全体におけるストラットの量を確保し、ステントに対して求められるラジアルフォースを維持することができる。 According to the above-described configuration, the plurality of circular portions provided in the stent are arranged side by side along the axis of the stent. Each circulating portion has a plurality of first portions and a plurality of second portions. The plurality of first portions are provided at positions facing each other with respect to the axis of the stent in the circumferential direction. The plurality of second portions are provided at positions facing each other with respect to the stent axis in the circumferential direction, and have a rigidity smaller than the rigidity of the struts of the first portion in a state where at least a part of the plurality of circulation portions is bent. . That is, the rigidity of the struts of the second part is smaller than the rigidity of the struts of the first part in a state where at least a part of the plurality of circulation parts is bent. The plurality of first portions are continuously arranged along the axial direction of the stent over the plurality of rotating portions in a state in which the positional relationship facing each other with respect to the axis of the stent is maintained in the circumferential direction. Therefore, the bending stiffness when the stent bends in a posture in which the first part is arranged at the position of the neutral surface is smaller than the bending stiffness when the stent bends in another posture. Therefore, the stent is easily bent in a posture in which the first part is disposed at the position of the neutral surface. That is, directivity can be given to the bending rigidity of the stent. Therefore, the stent can pass through the bent portion of the living body lumen in a posture in which the bending rigidity is minimized more reliably. Thereby, the passage of the stent in the living body lumen can be improved. In addition, by giving directivity to the bending rigidity of the stent without reducing the amount of the constituent material of the stent, the stent can be easily bent. Thereby, the amount of struts in the entire stent can be secured, and the radial force required for the stent can be maintained.
　好ましくは、前記周回部は、前記ストラットが屈曲した波状体であって、前記軸方向の先端側に頂点を有する先端側屈曲部と、前記軸方向の基端側に頂点を有する基端側屈曲部と、を有する波状体であることを特徴とする。 Preferably, the circumferential portion is a corrugated body in which the strut is bent, and a distal-end bending portion having a vertex on the distal end side in the axial direction and a proximal-side bending having a vertex on the proximal end side in the axial direction. And a wavy body having a portion.
　前記構成によれば、周回部は、ストラットが屈曲した波状体である。波状体は、ステントの軸方向の先端側に頂点を有する先端側屈曲部と、ステントの軸方向の基端側に頂点を有する基端側屈曲部と、を有する。これにより、ステントは、生体管腔の屈曲に対してより柔軟に追従し、生体管腔内を通過することができる。つまり、生体管腔内におけるステントの通過性をより向上させることができる。 According to the above configuration, the orbiting portion is a wavy body in which the strut is bent. The corrugated body has a distal-end bending portion having a vertex on the distal end side in the axial direction of the stent and a proximal-end bending portion having a vertex on the proximal end side in the axial direction of the stent. Accordingly, the stent can follow the bending of the living body lumen more flexibly and pass through the living body lumen. That is, the passage of the stent in the living body lumen can be further improved.
　好ましくは、前記複数の第１部位は、前記周方向において前記軸に対して互いに対向する位置関係を維持した状態で、前記複数の周回部にわたって前記軸方向に沿って直線上に配置されたことを特徴とする。 Preferably, the plurality of first portions are arranged on a straight line along the axial direction over the plurality of circulation portions in a state in which a positional relationship facing each other with respect to the axis is maintained in the circumferential direction. It is characterized by.
　前記構成によれば、ステントが曲がるときの中立面がステントの軸方向に沿って直線上に形成される。そのため、ステントは、ステントの全長に亘って直線上に形成される中立面の位置に第１部位が配置される姿勢で、一定方向に曲がりやすい。これにより、ステントの曲げ剛性の指向性が向上し、生体管腔内におけるステントの通過性がより向上する。 According to the above configuration, the neutral surface when the stent is bent is formed on a straight line along the axial direction of the stent. Therefore, the stent is easy to bend in a certain direction in a posture in which the first portion is disposed at the position of the neutral surface formed linearly over the entire length of the stent. Thereby, the directivity of the bending rigidity of the stent is improved, and the passing property of the stent in the living body lumen is further improved.
　好ましくは、前記複数の第１部位は、前記周方向において前記軸に対して互いに対向する位置関係を維持した状態で、前記複数の周回部にわたって前記軸方向に沿って螺旋状に配置されたことを特徴とする。 Preferably, the plurality of first portions are arranged in a spiral shape along the axial direction over the plurality of circulation portions in a state in which a positional relationship facing each other with respect to the axis is maintained in the circumferential direction. It is characterized by.
　前記構成によれば、ステントが曲がるときの中立面がステントの軸方向に沿って螺旋状に形成される。そのため、ステントは、螺旋状に形成される中立面の位置に第１部位が配置される姿勢で曲がりやすく、指向性を向上することができる。すなわち、ステントの中立面は、軸方向に沿って、複数の周回部のそれぞれで変化する。これにより、ステントは、例えば蛇行した血管部位を通過する場合、局所的に曲げ剛性が最小となる姿勢をとりながら、血管部位を通過することができる。これにより、生体管腔内におけるステントの通過性がより向上する。 According to the above configuration, the neutral surface when the stent is bent is formed in a spiral shape along the axial direction of the stent. Therefore, the stent can be easily bent in a posture in which the first portion is disposed at the position of the neutral surface formed in a spiral shape, and the directivity can be improved. In other words, the neutral surface of the stent changes along each of the plurality of rotating portions along the axial direction. Thus, for example, when the stent passes through a meandering blood vessel site, the stent can pass through the blood vessel site while taking a posture in which the bending rigidity is locally minimized. Thereby, the passage of the stent in the living body lumen is further improved.
　好ましくは、前記複数の第１部位は、前記周方向において、前記ストラットを含む空間の単位体積のうち前記ストラットの体積が占める割合が前記第２部位における前記割合よりも高い第１密部と、前記周方向において前記第１密部と前記軸に対して対向する位置に設けられた第２密部であって前記割合が前記第２部位における前記割合よりも高い第２密部と、を有することを特徴とする。 Preferably, in the circumferential direction, the plurality of first portions includes a first dense portion in which a proportion of the volume of the struts in a unit volume of the space including the struts is higher than the proportion in the second portions; A second dense portion provided at a position facing the first dense portion and the axis in the circumferential direction, wherein the proportion is higher than the proportion of the second portion. It is characterized by that.
　前記構成によれば、複数の第１部位は、第１密部と、第２密部と、を有する。周方向において、第１密部におけるストラットを含む空間の単位体積のうちストラットの体積が占める割合（体積密度）は、第２部位におけるストラットの体積密度よりも高い。また、周方向において、第２密部におけるストラットの体積密度は、第２部位におけるストラットの体積密度よりも高い。複数の周回部がステントの軸に沿って設けられた状態において、複数の第１密部は、軸方向に沿って連続的に配置されている。また、複数の第２密部は、軸方向に沿って連続的に配置されている。そして、第１密部および第２密部は、周方向においてステントの軸に対して互いに対向する位置に設けられている。そのため、第１密部および第２密部が中立面の位置に配置される姿勢でステントが曲がるときの曲げ剛性は、他の姿勢でステントが曲がるときの曲げ剛性よりも小さい。そのため、ステントは、第１密部および第２密部が中立面の位置に配置される姿勢で曲がりやすい。つまり、ステントの曲げ剛性に指向性を持たせることができる。そのため、ステントは、曲げ剛性が最小となる姿勢で生体管腔の屈曲部を通過することができる。これにより、生体管腔内におけるステントの通過性を向上させることができる。また、ステントの曲げ変形において、ステントの曲げ剛性に与える影響が少ない中立面の位置に、第１密部および第２密部が配置される。すなわち、ステントの曲げ変形において、ステントの周回部を形成するストラットの量が第２部位におけるストラットの量よりも多い第１密部および第２密部が、ステントの曲げ剛性に与える影響が少ない中立面の位置に配置される。これにより、ステント全体におけるストラットの量を確保し、ステントに対して求められるラジアルフォースを維持することができる。 According to the configuration, the plurality of first portions have the first dense portion and the second dense portion. In the circumferential direction, the proportion (volume density) of the strut volume in the unit volume of the space including the struts in the first dense portion is higher than the strut volume density in the second region. In the circumferential direction, the volume density of the struts in the second dense portion is higher than the volume density of the struts in the second region. In a state where the plurality of circular portions are provided along the axis of the stent, the plurality of first dense portions are continuously arranged along the axial direction. Further, the plurality of second dense portions are continuously arranged along the axial direction. The first dense portion and the second dense portion are provided at positions facing each other with respect to the stent axis in the circumferential direction. Therefore, the bending rigidity when the stent bends in a posture in which the first dense portion and the second dense portion are arranged at the position of the neutral surface is smaller than the bending stiffness when the stent bends in another posture. Therefore, the stent is easily bent in a posture in which the first dense portion and the second dense portion are arranged at the position of the neutral surface. That is, directivity can be given to the bending rigidity of the stent. Therefore, the stent can pass through the bent portion of the living body lumen in a posture in which the bending rigidity is minimized. Thereby, the passage of the stent in the living body lumen can be improved. Further, in the bending deformation of the stent, the first dense portion and the second dense portion are arranged at the position of the neutral surface that has little influence on the bending rigidity of the stent. That is, in the bending deformation of the stent, the first dense portion and the second dense portion, in which the amount of struts forming the circumference of the stent is larger than the amount of struts in the second portion, have little influence on the bending rigidity of the stent. Arranged at the position of the elevation. Thereby, the amount of struts in the entire stent can be secured, and the radial force required for the stent can be maintained.
　好ましくは、前記第１密部および前記第２密部のそれぞれにおける前記ストラット同士の前記周方向の間隔は、前記第２部位における前記ストラット同士の前記周方向の間隔よりも狭いことを特徴とする。 Preferably, the circumferential interval between the struts in each of the first dense portion and the second dense portion is narrower than the circumferential interval between the struts in the second portion. .
　前記構成によれば、ストラット同士の周方向の間隔（ピッチ）が変化することで、ストラットの体積密度が第２部位におけるストラットの体積密度よりも高い第１密部および第２密部が形成されている。これにより、第１密部および第２密部を比較的容易に形成し、ステントのラジアルフォースを維持しつつ生体管腔内におけるステントの通過性を向上させることができる。 According to the said structure, the 1st dense part and 2nd dense part whose volume density of struts is higher than the volume density of struts in a 2nd site | part are formed because the space | interval (pitch) of the struts in the circumferential direction changes. ing. Thereby, the first dense portion and the second dense portion can be formed relatively easily, and the passage of the stent in the living body lumen can be improved while maintaining the radial force of the stent.
　好ましくは、前記第１密部および前記第２密部のそれぞれにおける前記ストラットの前記軸方向の長さは、前記第２部位における前記ストラットの前記軸方向の長さよりも長いことを特徴とする。 Preferably, the axial length of the strut in each of the first dense portion and the second dense portion is longer than the axial length of the strut in the second portion.
　前記構成によれば、ステントの軸方向におけるストラットの長さ（振幅）が変化することで、ストラットの体積密度が第２部位におけるストラットの体積密度よりも高い第１密部および第２密部が形成されている。これにより、第１密部および第２密部を比較的容易に形成し、ステントのラジアルフォースを維持しつつ生体管腔内におけるステントの通過性を向上させることができる。 According to the above configuration, the length (amplitude) of the strut in the axial direction of the stent changes, so that the first dense portion and the second dense portion in which the volume density of the strut is higher than the volume density of the strut in the second portion. Is formed. Thereby, the first dense portion and the second dense portion can be formed relatively easily, and the passage of the stent in the living body lumen can be improved while maintaining the radial force of the stent.
　好ましくは、前記第１密部および前記第２密部のそれぞれにおける前記ストラットの線幅は、前記第２部位における前記ストラットの線幅よりも太いことを特徴とする。 Preferably, a line width of the strut in each of the first dense portion and the second dense portion is larger than a line width of the strut in the second portion.
　前記構成によれば、ストラットの線幅が変化することで、ストラットの体積密度が第２部位におけるストラットの体積密度よりも高い第１密部および第２密部が形成されている。これにより、第１密部および第２密部を比較的容易に形成し、ステントのラジアルフォースを維持しつつ生体管腔内におけるステントの通過性を向上させることができる。 According to the above configuration, the first dense portion and the second dense portion in which the volume density of the strut is higher than the volume density of the strut in the second portion are formed by changing the line width of the strut. Thereby, the first dense portion and the second dense portion can be formed relatively easily, and the passage of the stent in the living body lumen can be improved while maintaining the radial force of the stent.
　好ましくは、前記第１密部および前記第２密部のそれぞれにおける前記ストラットの肉厚は、前記第２部位における前記ストラットの肉厚よりも厚いことを特徴とする。 Preferably, the thickness of the strut in each of the first dense portion and the second dense portion is larger than the thickness of the strut in the second portion.
　前記構成によれば、ストラットの肉厚（径方向の長さ）が変化することで、ストラットの体積密度が第２部位におけるストラットの体積密度よりも高い第１密部および第２密部が形成されている。これにより、ストラットの肉厚の変化により第１密部および第２密部を形成し、ステントのラジアルフォースを維持しつつ生体管腔内におけるステントの通過性を向上させることができる。 According to the above configuration, the first dense portion and the second dense portion in which the volume density of the strut is higher than the volume density of the strut in the second portion are formed by changing the thickness (the length in the radial direction) of the strut. Has been. Thereby, the first dense portion and the second dense portion are formed by the change in the thickness of the strut, and the passage of the stent in the living body lumen can be improved while maintaining the radial force of the stent.
　好ましくは、前記第１部位の前記ストラットの材料特性は、前記第２部位の前記ストラットの材料特性とは異なることを特徴とする。 Preferably, the material property of the strut in the first part is different from the material property of the strut in the second part.
　前記構成によれば、第１部位のストラットの形状が第２部位のストラットの形状と同じである場合であっても、第１部位のストラットの材料特性が第２部位のストラットの材料特性と異なることで、第２部位のストラットの剛性は、第１部位のストラットの剛性とは異なる。これにより、ストラットの材料特性の違いにより第１部位および第２部位を形成し、ステントのラジアルフォースを維持しつつ生体管腔内におけるステントの通過性を向上させることができる。 According to the above configuration, even if the shape of the struts of the first part is the same as the shape of the struts of the second part, the material properties of the struts of the first part are different from the material properties of the struts of the second part. Thus, the rigidity of the struts of the second part is different from the rigidity of the struts of the first part. Accordingly, the first portion and the second portion are formed by the difference in the material characteristics of the strut, and the passage of the stent in the living body lumen can be improved while maintaining the radial force of the stent.
　好ましくは、前記周回部は、前記ストラットが環状に延びた環状体であり、前記複数の第１部位のうちの少なくともいずれかは、前記軸方向において互いに隣り合う前記周回部同士を連結する連結部を有することを特徴とする。 Preferably, the surrounding portion is an annular body in which the struts extend in an annular shape, and at least one of the plurality of first portions is a connecting portion that connects the surrounding portions adjacent to each other in the axial direction. It is characterized by having.
　前記構成によれば、周回部は、ストラットが環状に延びた環状体である。複数の第１部位のうちの少なくともいずれかは、ステントの軸方向において互いに隣り合う周回部同士を連結する連結部を有する。そのため、互いに隣り合う周回部同士を連結する連結部が配置されることにより、第１部位と、第１部位の剛性よりも小さい剛性を有する第２部位と、が形成されている。これにより、第１部位および第２部位を比較的容易に形成し、ステントのラジアルフォースを維持しつつ生体管腔内におけるステントの通過性を向上させることができる。 According to the above configuration, the circulating portion is an annular body in which struts extend in an annular shape. At least one of the plurality of first portions has a connecting portion that connects the circumferential portions adjacent to each other in the axial direction of the stent. Therefore, the 1st site | part and the 2nd site | part which has rigidity smaller than the rigidity of a 1st site | part are formed by arrange | positioning the connection part which connects the mutually adjacent surrounding parts. Thereby, the 1st site | part and the 2nd site | part can be formed comparatively easily, and the passage property of the stent in a biological lumen can be improved, maintaining the radial force of a stent.
　好ましくは、前記周回部は、前記ストラットが螺旋状に延びた螺旋状体であることを特徴とする。 Preferably, the circulating portion is a spiral body in which the struts extend spirally.
　前記構成によれば、周回部は、ストラットが螺旋状に延びた螺旋状体である。そのため、互いに隣り合う周回部同士を連結する連結部が設けられていなくとも、周回部は、螺旋状に連続している。そして、複数の第１部位は、周方向においてステントの軸に対して互いに対向する位置に設けられる。これにより、ステントは、ラジアルフォースを維持しつつ生体管腔内における通過性を向上させることができる。 According to the above configuration, the circulating portion is a spiral body in which the struts extend spirally. Therefore, even if the connection part which connects the mutually adjacent surrounding parts is not provided, the surrounding parts are continuing spirally. And a some 1st site | part is provided in the position which mutually opposes with respect to the axis | shaft of a stent in the circumferential direction. Thereby, the stent can improve the passage property in a living body lumen, maintaining a radial force.
　本発明によれば、ラジアルフォースを維持しつつ生体管腔内における通過性を向上させることができるステントを提供することができる。 According to the present invention, it is possible to provide a stent that can improve the passage through a living body lumen while maintaining a radial force.
本発明の実施形態に係るステントを送達するステントデリバリーシステムを表す正面図である。It is a front view showing the stent delivery system which delivers the stent which concerns on embodiment of this invention. 図１に表したステントデリバリーシステムの先端部の部分断面図である。It is a fragmentary sectional view of the front-end | tip part of the stent delivery system represented to FIG. 図１に表したステントデリバリーシステムの作用を説明する部分断面図である。It is a fragmentary sectional view explaining the effect | action of the stent delivery system represented to FIG. 本実施形態に係るステントを展開して表した展開図である。It is the expanded view which expanded and represented the stent which concerns on this embodiment. 本実施形態に係るステントの収縮状態を表す断面図である。It is sectional drawing showing the contracted state of the stent which concerns on this embodiment. 本実施形態に係るステントを表す正面図である。It is a front view showing the stent which concerns on this embodiment. 本実施形態の第１変形例に係るステントを展開して表した展開図である。It is the expanded view which expanded and represented the stent which concerns on the 1st modification of this embodiment. 本実施形態の第２変形例に係るステントを展開して表した展開図である。It is the expanded view which expanded and represented the stent which concerns on the 2nd modification of this embodiment. 本実施形態の第３変形例に係るステントの収縮状態を表す断面図である。It is sectional drawing showing the contraction state of the stent which concerns on the 3rd modification of this embodiment. 本実施形態の第４変形例に係るステントを展開して表した展開図である。It is the expanded view which expanded and represented the stent which concerns on the 4th modification of this embodiment. 本実施形態の第５変形例に係るステントを展開して表した展開図である。It is the expanded view which expanded and represented the stent which concerns on the 5th modification of this embodiment. 本実施形態の第６変形例に係るステントを展開して表した展開図である。It is the expanded view which expanded and represented the stent which concerns on the 6th modification of this embodiment. 本実施形態の第７変形例に係るステントを展開して表した展開図である。It is the expanded view which expanded and represented the stent which concerns on the 7th modification of this embodiment. 本実施形態の第８変形例に係るステントを作製するためのチューブを表す断面図である。It is sectional drawing showing the tube for producing the stent which concerns on the 8th modification of this embodiment.
　以下に、本発明の好ましい実施形態を、図面を参照して詳しく説明する。
　なお、以下に説明する実施形態は、本発明の好適な具体例であるから、技術的に好ましい種々の限定が付されているが、本発明の範囲は、以下の説明において特に本発明を限定する旨の記載がない限り、これらの態様に限られるものではない。また、各図面中、同様の構成要素には同一の符号を付して詳細な説明は適宜省略する。 Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.
The embodiments described below are preferable specific examples of the present invention, and thus various technically preferable limitations are given. However, the scope of the present invention is particularly limited in the following description. Unless otherwise stated, the present invention is not limited to these embodiments. Moreover, in each drawing, the same code | symbol is attached | subjected to the same component and detailed description is abbreviate | omitted suitably.
　本発明の実施形態に係るステントは、生体管腔である血管に生じた狭窄部（治療部位）を治療するために使用される。ステントは、血管内で拡張及び留置され、狭窄部の内側を支持することで狭窄部を押し広げる留置部材として構成される。なお、ステントは、血管への適用に限定されるものではなく、種々の生体管腔（例えば、胆管、気管、食道、尿道、鼻腔、その他の臓器等）の治療に適用される。なお、本願明細書では、管腔に挿入する側（図１～図４、図６～図８、図１０～図１２において左側）を「先端」若しくは「先端側」、操作する手元側（図１～図４、図６～図８、図１０～図１２において右側）を「基端」若しくは「基端側」と称する。 The stent according to the embodiment of the present invention is used to treat a stenosis (treatment site) generated in a blood vessel that is a living body lumen. The stent is configured as an indwelling member that is expanded and placed in a blood vessel and pushes the stenosis part by supporting the inside of the stenosis part. The stent is not limited to the application to blood vessels, but is applied to the treatment of various biological lumens (for example, bile duct, trachea, esophagus, urethra, nasal cavity, other organs, etc.). In the specification of the present application, the side to be inserted into the lumen (left side in FIGS. 1 to 4, 6 to 8, and 10 to 12) is the “tip” or “tip side”, and the proximal side (FIG. 1 to FIG. 4, FIG. 6 to FIG. 8, and FIG. 10 to FIG. 12 are referred to as “base end” or “base end side”.
　図１は、本発明の実施形態に係るステントを送達するステントデリバリーシステムを表す正面図である。
　図２は、図１に表したステントデリバリーシステムの先端部の部分断面図である。
　図３は、図１に表したステントデリバリーシステムの作用を説明する部分断面図である。 FIG. 1 is a front view showing a stent delivery system for delivering a stent according to an embodiment of the present invention.
FIG. 2 is a partial cross-sectional view of the distal end portion of the stent delivery system shown in FIG.
FIG. 3 is a partial cross-sectional view for explaining the operation of the stent delivery system shown in FIG.
　本実施形態の説明では、本実施形態に係るステントを送達するステントデリバリーシステムを説明した後に、本実施形態に係るステントの詳細を説明する。図１に表したステントデリバリーシステム２は、バルーン３２を有するバルーンカテーテル３と、バルーン３２に装着されたステント４と、を備える。バルーンカテーテル３は、チューブ状のシャフト本体部３１と、シャフト本体部３１の先端部に設けられた折り畳みおよび拡張可能なバルーン３２と、を有する。すなわち、バルーン３２は、シャフト本体部３１の先端部において拡張および収縮可能に設けられている。 In the description of the present embodiment, the stent delivery system for delivering the stent according to the present embodiment will be described, and then the details of the stent according to the present embodiment will be described. The stent delivery system 2 shown in FIG. 1 includes a balloon catheter 3 having a balloon 32 and a stent 4 attached to the balloon 32. The balloon catheter 3 has a tube-shaped shaft main body 31 and a foldable and expandable balloon 32 provided at the distal end of the shaft main body 31. That is, the balloon 32 is provided at the distal end portion of the shaft main body 31 so that it can be expanded and contracted.
　ステント４は、収縮状態のバルーン３２を被包するようにバルーン３２に装着され、バルーン３２の拡張により拡張する。ステント４は、生体内管腔への挿入のための直径を有し、管状体の内部より半径方向に広がる力が付加されたときに拡張可能ないわゆるバルーン拡張型ステントである。なお、本実施形態に係るステント４は、必ずしもバルーン拡張型ステントには限定されず、弾性復元することにより収縮状態から拡張状態に自動的に移行する自己拡張型ステントであってもよい。以下の説明では、ステント４がバルーン拡張型ステントである場合を例に挙げる。 The stent 4 is attached to the balloon 32 so as to encapsulate the deflated balloon 32, and is expanded by the expansion of the balloon 32. The stent 4 is a so-called balloon-expandable stent that has a diameter for insertion into a lumen in a living body and is expandable when a force spreading in the radial direction from the inside of the tubular body is applied. The stent 4 according to the present embodiment is not necessarily limited to a balloon expandable stent, and may be a self-expandable stent that automatically shifts from a contracted state to an expanded state by elastic recovery. In the following description, a case where the stent 4 is a balloon expandable stent will be described as an example.
　図２および図３に示すように、シャフト本体部３１は、ガイドワイヤルーメン３１４を有する。ガイドワイヤルーメン３１４の一方の端部は、シャフト本体部３１の先端において開口している。また、ガイドワイヤルーメン３１４の他方の端部は、シャフト本体部３１の基端において開口している。 2 and 3, the shaft main body 31 has a guide wire lumen 314. One end of the guide wire lumen 314 is open at the tip of the shaft body 31. The other end of the guide wire lumen 314 is open at the base end of the shaft body 31.
　具体的に説明すると、シャフト本体部３１は、内管３１１と、外管３１２と、分岐ハブ３１３と、を有する。内管３１１は、図３に示すように、内部にガイドワイヤを挿通するためのガイドワイヤルーメン３１４を有するチューブ体である。内管３１１の長さは、１００～２５００ｍｍ、より好ましくは、２５０～２０００ｍｍである。内管３１１の外径は、０．１～１．０ｍｍ、より好ましくは、０．３～０．７ｍｍである。内管３１１の肉厚は、１０～２５０μｍ、より好ましくは、２０～１００μｍである。内管３１１は、外管３１２の内部に挿通されている。内管３１１の先端部は、外管３１２よりも先端側に突出している。 More specifically, the shaft main body 31 includes an inner tube 311, an outer tube 312, and a branch hub 313. As shown in FIG. 3, the inner tube 311 is a tube body having a guide wire lumen 314 for inserting a guide wire therein. The length of the inner tube 311 is 100 to 2500 mm, more preferably 250 to 2000 mm. The outer diameter of the inner tube 311 is 0.1 to 1.0 mm, more preferably 0.3 to 0.7 mm. The wall thickness of the inner tube 311 is 10 to 250 μm, more preferably 20 to 100 μm. The inner tube 311 is inserted into the outer tube 312. The distal end portion of the inner tube 311 protrudes more distally than the outer tube 312.
　内管３１１の外面と、外管３１２の内面と、の間には、バルーン拡張用ルーメン３１５が形成されており、十分な容積を有している。 A balloon expansion lumen 315 is formed between the outer surface of the inner tube 311 and the inner surface of the outer tube 312 and has a sufficient volume.
　外管３１２は、内部に内管３１１を挿通しているチューブ体である。外管３１２の先端は、内管３１１の先端よりもやや後退した部分に位置している。外管３１２の長さは、１００～２５００ｍｍ、より好ましくは、２５０～２０００ｍｍである。外管３１２の外径は、０．５～１．５ｍｍ、より好ましくは、０．７～１．１ｍｍである。外管３１２の肉厚は、２５～２００μｍ、より好ましくは、５０～１００μｍである。 The outer tube 312 is a tube body in which the inner tube 311 is inserted. The distal end of the outer tube 312 is located at a portion slightly retracted from the distal end of the inner tube 311. The length of the outer tube 312 is 100 to 2500 mm, more preferably 250 to 2000 mm. The outer diameter of the outer tube 312 is 0.5 to 1.5 mm, more preferably 0.7 to 1.1 mm. The wall thickness of the outer tube 312 is 25 to 200 μm, more preferably 50 to 100 μm.
　図１に表したステントデリバリーシステム２では、外管３１２は、先端側外管３１２ａと、基端側外管３１２ｂと、を有する。先端側外管３１２ａおよび基端側外管３１２ｂは、互いに接合されている。先端側外管３１２ａは、先端側外管３１２ａと基端側外管３１２ｂとの接合部近傍において、テーパー状に縮径している。そのため、テーパー部よりも先端側における先端側外管３１２ａの径は、テーパー部よりも基端側における基端側外管３１２ｂの径よりも細い。 In the stent delivery system 2 shown in FIG. 1, the outer tube 312 includes a distal end side outer tube 312a and a proximal end side outer tube 312b. The distal end side outer tube 312a and the proximal end side outer tube 312b are joined to each other. The distal end side outer tube 312a is tapered in the vicinity of the joint between the distal end side outer tube 312a and the proximal end side outer tube 312b. Therefore, the diameter of the distal outer tube 312a on the distal end side with respect to the tapered portion is smaller than the diameter of the proximal outer tube 312b on the proximal end side with respect to the tapered portion.
　先端側外管３１２ａの細径部（テーパー部よりも先端側の部分）の外径は、０．５～１．５ｍｍ、好ましくは０．６～１．１ｍｍである。また、先端側外管３１２ａの基端部（テーパー部よりも基端側の部分）および基端側外管３１２ｂの外径は、０．７５～１．５ｍｍ、好ましくは０．９～１．１ｍｍである。なお、外管３１２は、必ずしも先端側外管３１２ａと基端側外管３１２ｂとを有していなくともよい。つまり、外管３１２は、全長にわたって略同じ径を有するチューブ体として形成されていてもよい。 The outer diameter of the small-diameter portion (the portion closer to the tip side than the taper portion) of the tip-side outer tube 312a is 0.5 to 1.5 mm, preferably 0.6 to 1.1 mm. Further, the outer diameter of the proximal end portion of the distal end side outer tube 312a (the portion closer to the proximal end than the tapered portion) and the proximal end side outer tube 312b is 0.75 to 1.5 mm, preferably 0.9 to 1.. 1 mm. The outer tube 312 does not necessarily have to have the distal end side outer tube 312a and the proximal end side outer tube 312b. That is, the outer tube 312 may be formed as a tube body having substantially the same diameter over the entire length.
　内管３１１および外管３１２の形成材料としては、ある程度の可撓性を有するものが好ましく、例えば、ポリオレフィン（例えば、ポリエチレン、ポリプロピレン、エチレン－プロピレン共重合体、エチレン－酢酸ビニル共重合体など）、ポリ塩化ビニル、ポリアミド、ポリアミドエラストマー、ポリエステル、ポリエステルエラストマー、ポリウレタン等の熱可塑性樹脂、シリコーンゴム、ラテックスゴム等が挙げられる。内管３１１および外管３１２の形成材料は、好ましくは上記の熱可塑性樹脂であり、より好ましくは、ポリアミド、ポリアミドエラストマーである。 The material for forming the inner tube 311 and the outer tube 312 is preferably a material having a certain degree of flexibility. For example, polyolefin (for example, polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, etc.) , Polyvinyl chloride, polyamide, polyamide elastomer, polyester, polyester elastomer, polyurethane and other thermoplastic resins, silicone rubber, latex rubber and the like. The material for forming the inner tube 311 and the outer tube 312 is preferably the above-described thermoplastic resin, and more preferably polyamide or polyamide elastomer.
　バルーン３２は、折り畳み可能であり、拡張しない状態では、内管３１１の外周に折り畳まれた状態となる。バルーン３２は、装着されるステント４を拡張できるようにほぼ同一径の筒状部分（好ましくは、円筒部分）を呈する拡張可能部を有している。略円筒部分は、完全な円筒でなくてもよく、多角柱状であってもよい。 The balloon 32 is foldable, and is folded on the outer periphery of the inner tube 311 when not expanded. The balloon 32 has an expandable portion that exhibits a cylindrical portion (preferably, a cylindrical portion) having substantially the same diameter so that the attached stent 4 can be expanded. The substantially cylindrical portion may not be a complete cylinder but may be a polygonal column.
　バルーン３２は、先端側接合部３２ａと、基端側接合部３２ｂと、を有する。先端側接合部３２ａは、内管３１１の先端よりも若干基端側の位置に固定されている。具体的には、先端側接合部３２ａは、内管３１１に接着剤または熱融着などにより液密に固着されている。基端側接合部３２ｂは、外管３１２の先端に固定されている。具体的には、基端側接合部３２ｂは、外管３１２の先端に接着剤または熱融着などにより液密に固着されている。これにより、バルーン３２は、内管３１１および外管３１２に対して接着剤または熱融着などにより液密に固着されている。バルーン３２は、基端部付近にてバルーン拡張用ルーメン３１５と連通している。また、本実施形態のバルーン３２では、拡張可能部と、先端側接合部３２ａおよび基端側接合部３２ｂと、の間がテーパー状に形成されている。 The balloon 32 has a distal end side joint portion 32a and a proximal end side joint portion 32b. The distal end side joint portion 32 a is fixed at a position slightly proximal to the distal end of the inner tube 311. Specifically, the distal end side joint portion 32a is fixed to the inner tube 311 in a liquid-tight manner by an adhesive or heat fusion. The proximal end joint portion 32 b is fixed to the distal end of the outer tube 312. Specifically, the proximal end side joining portion 32b is liquid-tightly fixed to the distal end of the outer tube 312 with an adhesive or heat fusion. Accordingly, the balloon 32 is liquid-tightly fixed to the inner tube 311 and the outer tube 312 by an adhesive or heat fusion. The balloon 32 communicates with the balloon expansion lumen 315 in the vicinity of the proximal end portion. Moreover, in the balloon 32 of this embodiment, the space | interval between the expandable part and the front end side junction part 32a and the base end side junction part 32b is formed in the taper shape.
　バルーン３２は、バルーン３２の内面と、内管３１１の外面と、の間に形成された拡張空間３２ｃを有する。拡張空間３２ｃの基端部は、全周においてバルーン拡張用ルーメン３１５と連通している。このように、バルーン３２の基端は、比較的大きい容積を有するバルーン拡張用ルーメン３１５と連通している。そのため、バルーン拡張用ルーメン３１５からバルーン３２内へ拡張用流体を確実に注入することができる。拡張用流体は、気体でも液体でもよい。拡張用流体としては、例えば、ヘリウムガス、ＣＯ２ガス、Ｏ２ガス等の気体や、生理食塩水、造影剤等の液体が挙げられる。 The balloon 32 has an expansion space 32c formed between the inner surface of the balloon 32 and the outer surface of the inner tube 311. The base end portion of the expansion space 32c communicates with the balloon expansion lumen 315 on the entire circumference. Thus, the proximal end of the balloon 32 communicates with the balloon expansion lumen 315 having a relatively large volume. Therefore, the expansion fluid can be reliably injected from the balloon expansion lumen 315 into the balloon 32. The expansion fluid may be a gas or a liquid. Examples of the expansion fluid include gases such as helium gas, CO 2 gas, and O 2 gas, and liquids such as physiological saline and contrast medium.
　バルーン３２の形成材料としては、ある程度の可撓性を有するものが好ましく、例えば、ポリオレフィン（例えば、ポリエチレン、ポリプロピレン、エチレン－プロピレン共重合体、エチレン－酢酸ビニル共重合体、架橋型エチレン－酢酸ビニル共重合体など）、ポリ塩化ビニル、ポリアミド、ポリアミドエラストマー、ポリウレタン、ポリエステル（例えば、ポリエチレンテレフタレート）、ポリエステルエラストマー、ポリアリレーンサルファイド（例えば、ポリフェニレンサルファイド）等の熱可塑性樹脂、シリコーンゴム、ラテックスゴム等が挙げられる。特に、バルーン３２の形成材料は、延伸可能な材料であることが好ましい。また、バルーン３２の形成材料は、高い強度および拡張力を有する二軸延伸された材料であることが好ましい。 As a material for forming the balloon 32, a material having a certain degree of flexibility is preferable. For example, polyolefin (for example, polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, cross-linked ethylene-vinyl acetate). Copolymer), polyvinyl chloride, polyamide, polyamide elastomer, polyurethane, polyester (for example, polyethylene terephthalate), polyester elastomer, polyarylene sulfide (for example, polyphenylene sulfide), thermoplastic resin, silicone rubber, latex rubber, etc. Is mentioned. In particular, the forming material of the balloon 32 is preferably a stretchable material. Moreover, it is preferable that the forming material of the balloon 32 is a biaxially stretched material having high strength and expansion force.
　バルーン３２が拡張されたときのバルーン３２の円筒部分（拡張可能部）の外径は、２～６ｍｍ、好ましくは２．５～５．５ｍｍである。バルーン３２の長さは、５～５０ｍｍ、好ましくは１０～４０ｍｍである。先端側接合部３２ａの外径は、０．９～１．５ｍｍ、好ましくは１～１．３ｍｍである。先端側接合部３２ａの長さは、１～５ｍｍ、好ましくは１～３ｍｍである。また、基端側接合部３２ｂの外径は、１～１．６ｍｍ、好ましくは１．１～１．５ｍｍである。基端側接合部３２ｂの長さは、１～５ｍｍ、好ましくは、２～４ｍｍである。 The outer diameter of the cylindrical portion (expandable portion) of the balloon 32 when the balloon 32 is expanded is 2 to 6 mm, preferably 2.5 to 5.5 mm. The length of the balloon 32 is 5 to 50 mm, preferably 10 to 40 mm. The outer diameter of the distal end side joint portion 32a is 0.9 to 1.5 mm, preferably 1 to 1.3 mm. The length of the distal end side joint portion 32a is 1 to 5 mm, preferably 1 to 3 mm. The outer diameter of the base end side joint portion 32b is 1 to 1.6 mm, preferably 1.1 to 1.5 mm. The length of the base end side joining portion 32b is 1 to 5 mm, preferably 2 to 4 mm.
　図２および図３に示すように、ステントデリバリーシステム２は、２つのＸ線造影性部材３１６、３１７を有する。Ｘ線造影性部材３１６、３１７は、バルーン３２が拡張したときの円筒部分（拡張可能部）の両端となる位置の内管３１１の外面に固定されている。なお、２つのＸ線造影性部材は、内管３１１の外面のうちでステント４の中央部分の所定長の両端となる位置に固定されていてもよい。さらに、単独のＸ線造影性部材が、シャフト本体部３１の外面のうちでステント４の中央部となる位置に固定されていてもよい。 2 and 3, the stent delivery system 2 has two X-ray contrast members 316 and 317. The X-ray contrast members 316 and 317 are fixed to the outer surface of the inner tube 311 at positions corresponding to both ends of the cylindrical portion (expandable portion) when the balloon 32 is expanded. Note that the two X-ray contrast members may be fixed at positions on the outer surface of the inner tube 311 at both ends of a predetermined length in the central portion of the stent 4. Further, a single X-ray contrast member may be fixed to a position that is the central portion of the stent 4 in the outer surface of the shaft main body 31.
　Ｘ線造影性部材３１６、３１７としては、所定の長さを有するリング状のもの、もしくは線状体をコイル状に巻き付けたものなどが好適である。Ｘ線造影性部材３１６、３１７の形成材料としては、例えば、金、白金、タングステン、イリジウムあるいはそれらの合金、あるいは銀－パラジウム合金等が好適である。 As the X-ray contrast members 316 and 317, a ring-shaped member having a predetermined length or a member obtained by winding a linear member in a coil shape is suitable. As a material for forming the X-ray contrast members 316 and 317, for example, gold, platinum, tungsten, iridium or an alloy thereof, or a silver-palladium alloy is preferable.
　図１に示すように、ステントデリバリーシステム２の基端には、分岐ハブ３１３が固定されている。分岐ハブ３１３は、内管ハブと、外管ハブと、を有する。内管ハブは、内管３１１に固着され、ガイドワイヤルーメン３１４と連通するガイドワイヤポート３１３ａを有する。外管ハブは、外管３１２に固着され、バルーン拡張用ルーメン３１５と連通するインジェクションポート３１３ｂを有する。外管ハブと内管ハブとは、互いに固着されている。外管ハブと内管ハブとの固定は、外管３１２の基端部に取り付けられた外管ハブの基端から内管３１１の先端を挿入し接合することにより行われている。また、内管ハブと外管ハブとの接合部に接着剤を塗布して接着することにより、内管ハブと外管ハブとを確実に固着することができる。 As shown in FIG. 1, a branch hub 313 is fixed to the proximal end of the stent delivery system 2. The branch hub 313 has an inner tube hub and an outer tube hub. The inner tube hub is fixed to the inner tube 311 and has a guide wire port 313 a communicating with the guide wire lumen 314. The outer tube hub is fixed to the outer tube 312 and has an injection port 313 b that communicates with the balloon expansion lumen 315. The outer tube hub and the inner tube hub are fixed to each other. The outer tube hub and the inner tube hub are fixed by inserting and joining the distal end of the inner tube 311 from the proximal end of the outer tube hub attached to the proximal end portion of the outer tube 312. Moreover, the inner tube hub and the outer tube hub can be securely fixed by applying and bonding an adhesive to the joint portion between the inner tube hub and the outer tube hub.
　分岐ハブ３１３の形成材料としては、ポリカーボネート、ポリアミド、ポリサルホン、ポリアリレート、メタクリレート－ブチレン－スチレン共重合体等の熱可塑性樹脂が挙げられる。なお、ステントデリバリーシステム２の基端の構造は、上記のような構造には限定されない。例えば、分岐ハブ３１３が設けられておらず、ガイドワイヤルーメン３１４、バルーン拡張用ルーメン３１５のそれぞれに対して、基端に開口部を形成するポート部材を有するチューブが液密に取り付けられていてもよい。また、例えば、ステントデリバリーシステムの中間部分にガイドワイヤルーメンと連通するガイドワイヤ挿入口が設けられていてもよい。つまり、ガイドワイヤルーメン３１４の構造として、基端側のガイドワイヤポート３１３ａが患者の体外に存在するオーバーザワイヤ構造が採用されていることには限定されず、基端側のガイドワイヤポート３１３ａが患者の体内に存在するラピッドエクスチェンジ構造が採用されていてもよい。 Examples of the material for forming the branch hub 313 include thermoplastic resins such as polycarbonate, polyamide, polysulfone, polyarylate, and methacrylate-butylene-styrene copolymer. Note that the structure of the proximal end of the stent delivery system 2 is not limited to the above structure. For example, even if the branch hub 313 is not provided and a tube having a port member that forms an opening at the proximal end is attached to each of the guide wire lumen 314 and the balloon expansion lumen 315 in a liquid-tight manner. Good. Further, for example, a guide wire insertion port that communicates with the guide wire lumen may be provided in an intermediate portion of the stent delivery system. That is, the structure of the guide wire lumen 314 is not limited to the over-the-wire structure in which the proximal-side guide wire port 313a exists outside the patient's body, and the proximal-side guide wire port 313a is not the patient. A rapid exchange structure existing in the body may be adopted.
　ステント４は、バルーン３２を被包するようにバルーン３２に装着されている。ステント４は、拡張状態のステント４よりも小さい内径であって折り畳まれたバルーン３２の外径よりも大きい内径の例えばチューブやパイプなどを加工することにより作製される。そして、作製されたステント４内にバルーン３２を挿入し、ステント４の外面に対して均一な力を内側に向けて与え縮径させることにより製品状態のステント４が形成される。つまり、ステント４は、バルーン３２に対する圧縮装着により完成する。 The stent 4 is attached to the balloon 32 so as to encapsulate the balloon 32. The stent 4 is manufactured by processing, for example, a tube or a pipe having an inner diameter smaller than that of the expanded stent 4 and an inner diameter larger than the outer diameter of the folded balloon 32. Then, the balloon 32 is inserted into the manufactured stent 4, and a uniform force is applied to the outer surface of the stent 4 inward to reduce the diameter, thereby forming the product-state stent 4. That is, the stent 4 is completed by compression mounting on the balloon 32.
　ステント４の形成材料としては、合成樹脂または金属が使用される。合成樹脂としては、ある程度の硬度と弾性とを有する合成樹脂が挙げられ、生体適合性合成樹脂が好ましい。具体的には、合成樹脂は、ポリオレフィン（例えば、ポリエチレン、ポリプロピレン）、ポリエステル（例えば、ポリエチレンテレフタレート），フッ素樹脂（例えば、ＰＴＦＥ、ＥＴＦＥ）、若しくは生体内吸収材料であるポリ乳酸、ポリグリコール酸、又はポリ乳酸とポリグリコール酸の共重合体などである。 As the material for forming the stent 4, synthetic resin or metal is used. Examples of the synthetic resin include synthetic resins having a certain degree of hardness and elasticity, and biocompatible synthetic resins are preferable. Specifically, the synthetic resin is a polyolefin (eg, polyethylene, polypropylene), polyester (eg, polyethylene terephthalate), fluororesin (eg, PTFE, ETFE), or polylactic acid, polyglycolic acid that is a bioabsorbable material, Or a copolymer of polylactic acid and polyglycolic acid.
　ステント４の形成材料に使用される金属としては、生体適合性を有する金属が好ましく、例えば、ステンレス鋼、タンタルもしくはタンタル合金、プラチナもしくはプラチナ合金、金もしくは金合金、コバルトクロム合金等のコバルトベース合金、ニッケルチタン合金等が挙げられる。また、ステント４の形状を作製した後に、貴金属メッキ（金、プラチナ）が施されてもよい。 The metal used as the material for forming the stent 4 is preferably a metal having biocompatibility, for example, a cobalt base alloy such as stainless steel, tantalum or tantalum alloy, platinum or platinum alloy, gold or gold alloy, or cobalt chromium alloy. And nickel titanium alloy. Moreover, after producing the shape of the stent 4, noble metal plating (gold, platinum) may be applied.
　次に、本実施形態に係るステント４を、図面を参照してさらに説明する。
　図４は、本実施形態に係るステントを展開して表した展開図である。
　図５は、本実施形態に係るステントの収縮状態を表す断面図である。
　図６は、本実施形態に係るステントを表す正面図である。
　なお、図５は、図２に表した切断面Ｃ１－Ｃ１におけるステントの断面図である。 Next, the stent 4 according to the present embodiment will be further described with reference to the drawings.
FIG. 4 is a developed view showing the stent according to the present embodiment.
FIG. 5 is a cross-sectional view illustrating a contracted state of the stent according to the present embodiment.
FIG. 6 is a front view illustrating the stent according to the present embodiment.
FIG. 5 is a cross-sectional view of the stent taken along section plane C1-C1 shown in FIG.
　本実施形態に係るステント４は、軸Ｘ１（図２および図３参照）の方向に沿って並んで配置された複数の周回部４１を備える。周回部４１は、素線としての線状のストラット４１１を有し、ストラット４１１により全体として筒状の骨格に形成されている。言い換えれば、周回部４１は、ステント４の軸Ｘ１を中心に周回して筒状に形成された線状のストラット４１１を有する。 The stent 4 according to the present embodiment includes a plurality of rotating portions 41 arranged side by side along the direction of the axis X1 (see FIGS. 2 and 3). The circulating portion 41 has a linear strut 411 as a strand, and is formed into a cylindrical skeleton as a whole by the strut 411. In other words, the orbiting portion 41 has a linear strut 411 formed around the axis X <b> 1 of the stent 4 and formed in a cylindrical shape.
　周回部４１は、ストラット４１１がステント４の周方向に延び複数の屈曲部を有する波状体として形成され、先端側屈曲部４１２と、基端側屈曲部４１３と、線状部４１４と、を有する。図４～図６に表したステント４では、周回部４１は、ストラット４１１が環状に延びた環状体として形成されている。先端側屈曲部４１２は、ステント４の軸方向の先端側に頂点を有する。基端側屈曲部４１３は、ステント４の軸方向の基端側に頂点を有する。線状部４１４は、先端側屈曲部４１２と、基端側屈曲部４１３と、を繋ぐ直線状の部分である。先端側屈曲部４１２および基端側屈曲部４１３は、本発明の「屈曲部」に相当し、ステント４の拡張のときに変形する。本願明細書において、先端側屈曲部４１２および基端側屈曲部４１３の少なくともいずれかを単に「屈曲部」と称することがある。 The circumferential portion 41 is formed as a wave-like body in which the strut 411 extends in the circumferential direction of the stent 4 and has a plurality of bent portions, and has a distal end side bent portion 412, a proximal end side bent portion 413, and a linear portion 414. . In the stent 4 shown in FIGS. 4 to 6, the orbiting portion 41 is formed as an annular body in which the struts 411 extend in an annular shape. The distal end side bent portion 412 has a vertex on the distal end side in the axial direction of the stent 4. The proximal side bent portion 413 has a vertex on the proximal side in the axial direction of the stent 4. The linear portion 414 is a linear portion that connects the distal end side bent portion 412 and the proximal end side bent portion 413. The distal end side bent portion 412 and the proximal end side bent portion 413 correspond to the “bent portion” of the present invention, and are deformed when the stent 4 is expanded. In the present specification, at least one of the distal end side bent portion 412 and the proximal end side bent portion 413 may be simply referred to as a “bent portion”.
　１つの周回部４１の長さは、０．７～２．０ｍｍ程度が好適である。１つの周回部の先端側屈曲部４１２および基端側屈曲部４１３のそれぞれの数は、６～２０が好ましく、特に、８～１２が好ましい。周回部４１の数としては、４～２０が好適である。但し、先端側屈曲部４１２および基端側屈曲部４１３のそれぞれの数、および周回部４１の数は、これだけには限定されない。 The length of one rotating portion 41 is preferably about 0.7 to 2.0 mm. The number of each of the distal end side bent portion 412 and the proximal end side bent portion 413 of one circumference portion is preferably 6 to 20, and particularly preferably 8 to 12. The number of the circulating portions 41 is preferably 4-20. However, the number of each of the distal end side bent portion 412 and the proximal end side bent portion 413 and the number of the surrounding portions 41 are not limited to this.
　図４および図５に表したように、本実施形態に係るステント４の周回部４１は、複数の第１部位４５と、複数の第２部位４６と、を有する。複数の第１部位４５は、周方向においてステント４の軸Ｘ１に対して互いに対向する位置に設けられている。複数の第２部位は、周方向においてステント４の軸Ｘ１に対して互いに対向する位置に設けられている。例えば図６に表した矢印Ａ１のように、複数の周回部の少なくとも一部が曲がった状態において、第２部位４６のストラット４１１の剛性は、第１部位４５のストラット４１１の剛性よりも小さい。すなわち、本願明細書において「第２部位」とは、複数の周回部の少なくとも一部が曲がった状態において第１部位のストラットの剛性よりも小さい剛性を有する部分であり、ステントの周回部のうちで第１部位以外の部位をいう。 4 and 5, the orbiting portion 41 of the stent 4 according to the present embodiment has a plurality of first portions 45 and a plurality of second portions 46. The plurality of first portions 45 are provided at positions facing each other with respect to the axis X1 of the stent 4 in the circumferential direction. The plurality of second portions are provided at positions facing each other with respect to the axis X1 of the stent 4 in the circumferential direction. For example, the rigidity of the struts 411 in the second part 46 is smaller than the rigidity of the struts 411 in the first part 45 in a state in which at least a part of the plurality of circulation parts is bent as indicated by an arrow A1 shown in FIG. That is, in the specification of the present application, the “second portion” is a portion having a rigidity smaller than the rigidity of the strut of the first portion in a state where at least some of the plurality of surrounding portions are bent. And other than the first part.
　図４および図６に表したように、複数の第１部位４５は、周方向においてステント４の軸Ｘ１に対して互いに対向する位置関係を維持した状態で、複数の周回部４１にわたってステント４の軸Ｘ１方向に沿って連続的に配置されている。具体的には、図４～図６に表したステント４の複数の第１部位４５は、周方向においてステント４の軸Ｘ１に対して互いに対向する位置関係を維持した状態で、複数の周回部４１にわたってステント４の軸Ｘ１方向に沿って直線上に配置されている。 As shown in FIGS. 4 and 6, the plurality of first portions 45 are arranged over the plurality of circumferential portions 41 in a state in which the first portions 45 maintain the positional relationship facing each other with respect to the axis X1 of the stent 4 in the circumferential direction. It arrange | positions continuously along the axis | shaft X1 direction. Specifically, the plurality of first portions 45 of the stent 4 shown in FIG. 4 to FIG. 6 maintain the positional relationship facing each other with respect to the axis X1 of the stent 4 in the circumferential direction. 41 is arranged linearly along the direction of the axis X1 of the stent 4.
　本実施形態に係るステント４をさらに具体的に説明すると、複数の第１部位４５は、第１密部４２と、第２密部４３と、を有する。第１密部４２は、周方向において、ストラット４１１を含む空間の単位体積（区画枠）Ｖ１のうちストラット４１１の体積が占める割合（体積密度）が第２部位４６におけるストラット４１１の体積密度よりも高い部分である。第２密部４３は、周方向において、ストラット４１１を含む空間の単位体積Ｖ１のうちストラット４１１の体積が占める割合（体積密度）が第２部位におけるストラット４１１の体積密度よりも高い部分である。図４に表したように、単位体積（区画枠）Ｖ１は、ストラット４１１の先端側屈曲部４１２と、ストラット４１１の基端側屈曲部４１３と、を含むことが好ましい。 Describing the stent 4 according to the present embodiment more specifically, the plurality of first portions 45 include a first dense portion 42 and a second dense portion 43. In the circumferential direction, the first dense portion 42 has a proportion (volume density) occupied by the volume of the strut 411 in the unit volume (compartment frame) V <b> 1 of the space including the strut 411 in comparison with the volume density of the strut 411 in the second portion 46. The high part. In the circumferential direction, the second dense portion 43 is a portion in which the proportion (volume density) of the volume of the strut 411 in the unit volume V1 of the space including the strut 411 is higher than the volume density of the strut 411 in the second portion. As shown in FIG. 4, the unit volume (compartment frame) V <b> 1 preferably includes a distal end side bent portion 412 of the strut 411 and a proximal end side bent portion 413 of the strut 411.
　図５に表したように、第２密部４３は、周方向において第１密部４２とステント４の軸Ｘ１に対して対向する位置に設けられている。図４および図５に表した周回部４１では、周回部４１の下端部を０度とし反時計回りに周回した場合において、第１密部４２は９０度の位置に設けられ、第２密部４３は２７０度の位置に設けられている。但し、第１密部４２および第２密部４３の位置は、図４および図５に表した例には限定されず、第１密部４２および第２密部４３が周方向においてステント４の軸Ｘ１に対して互いに対向する位置に設けられている限りにおいて特には限定されない。 As shown in FIG. 5, the second dense portion 43 is provided at a position facing the first dense portion 42 and the axis X <b> 1 of the stent 4 in the circumferential direction. 4 and 5, the first dense portion 42 is provided at a position of 90 degrees when the lower end portion of the circumferential portion 41 is set to 0 degree and is rotated counterclockwise. 43 is provided at a position of 270 degrees. However, the positions of the first dense portion 42 and the second dense portion 43 are not limited to the examples shown in FIGS. 4 and 5, and the first dense portion 42 and the second dense portion 43 are arranged in the circumferential direction of the stent 4. There is no particular limitation as long as they are provided at positions facing each other with respect to the axis X1.
　図４に表したように、第１密部４２におけるストラット４１１同士の周方向の間隔（ピッチ）Ｄ１は、第２部位４６におけるストラット４１１同士の周方向の間隔Ｄ３よりも狭い。これにより、第１密部４２におけるストラット４１１の体積密度は、第２部位４６におけるストラット４１１の体積密度よりも高い。また、第２密部４３におけるストラット４１１同士の周方向の間隔Ｄ２は、第２部位４６におけるストラット４１１同士の周方向の間隔Ｄ３よりも狭い。これにより、第２密部４３におけるストラット４１１の体積密度は、第２部位４６におけるストラット４１１の体積密度よりも高い。 As shown in FIG. 4, the circumferential interval (pitch) D1 between the struts 411 in the first dense portion 42 is narrower than the circumferential interval D3 between the struts 411 in the second portion 46. Thereby, the volume density of the struts 411 in the first dense portion 42 is higher than the volume density of the struts 411 in the second portion 46. Further, the circumferential interval D2 between the struts 411 in the second dense portion 43 is narrower than the circumferential interval D3 between the struts 411 in the second portion 46. Thereby, the volume density of the struts 411 in the second dense portion 43 is higher than the volume density of the struts 411 in the second portion 46.
　なお、図４においては、第２部位４６におけるストラット４１１同士の周方向の間隔Ｄ３として周回部４１の下端部近傍（０度近傍）のストラット４１１同士の周方向の間隔を例に挙げている。但し、前述したように、第２部位４６は、周回部４１の下端部近傍には限定されず、ステント４の周回部４１のうちで第１部位４５以外の部位をいう。そのため、第２部位４６におけるストラット４１１同士の周方向の間隔は、図４に表した間隔Ｄ３には限定されない。具体的には、第２部位４６におけるストラット４１１同士の周方向の間隔Ｄ３は、第１密部４２および第２密部４３のそれぞれにおけるストラット４１１同士の周方向の間隔Ｄ１、Ｄ２よりも大きくなっていればよく、変化していてもよい。ストラット４１１同士の周方向の間隔Ｄ３が変化する場合、中立面Ｘ２（図６参照）における曲げ剛性の大きさに大きい影響を与え、中立面Ｘ２（図６参照）の位置に配置される第１密部４２および第２密部４３のそれぞれから９０度回転した位置にあるストラット４１１同士の周方向の間隔Ｄ３が、最も大きいことが好ましい。このような構成により、ステント４は、第１密部４２および第２密部４３が中立面Ｘ２に配置される姿勢で曲がりやすくなる。つまり、ステント４の曲げ剛性に指向性を持たせることができる。 In FIG. 4, the circumferential interval between the struts 411 in the vicinity of the lower end portion (around 0 degrees) of the rotating portion 41 is taken as an example as the circumferential interval D3 between the struts 411 in the second portion 46. However, as described above, the second portion 46 is not limited to the vicinity of the lower end portion of the rotating portion 41, and refers to a portion other than the first portion 45 in the rotating portion 41 of the stent 4. Therefore, the circumferential interval between the struts 411 in the second portion 46 is not limited to the interval D3 illustrated in FIG. Specifically, the circumferential distance D3 between the struts 411 in the second portion 46 is larger than the circumferential distances D1 and D2 between the struts 411 in the first dense portion 42 and the second dense portion 43, respectively. As long as it is, it may be changed. When the circumferential distance D3 between the struts 411 changes, it greatly affects the bending rigidity of the neutral plane X2 (see FIG. 6) and is arranged at the position of the neutral plane X2 (see FIG. 6). It is preferable that the distance D3 in the circumferential direction between the struts 411 at positions rotated 90 degrees from each of the first dense portion 42 and the second dense portion 43 is the largest. With such a configuration, the stent 4 is easily bent in a posture in which the first dense portion 42 and the second dense portion 43 are disposed on the neutral plane X2. That is, directivity can be given to the bending rigidity of the stent 4.
　複数の周回部４１は、ステント４の軸Ｘ１の方向に沿って並んで配置されている。このように、複数の周回部４１がステント４の軸Ｘ１に沿って設けられた状態において、複数の第１密部４２は、複数の周回部４１にわたってステント４の軸Ｘ１方向に沿って直線上に連続して配置されている。第１密部４２は、連結部４４を有する。連結部４４は、ステント４の軸Ｘ１方向において互いに隣り合う周回部４１同士を連結している。言い換えれば、ステント４の軸Ｘ１方向において互いに隣り合う周回部４１同士は、第１密部４２が有する連結部４４により連結されている。 The plurality of circumferential portions 41 are arranged side by side along the direction of the axis X1 of the stent 4. Thus, in a state where the plurality of surrounding portions 41 are provided along the axis X1 of the stent 4, the plurality of first dense portions 42 are linearly along the axis X1 direction of the stent 4 over the plurality of surrounding portions 41. Are arranged in succession. The first dense portion 42 has a connecting portion 44. The connecting portion 44 connects the surrounding portions 41 adjacent to each other in the axis X1 direction of the stent 4. In other words, the surrounding portions 41 adjacent to each other in the axis X1 direction of the stent 4 are connected by the connecting portion 44 included in the first dense portion 42.
　また、複数の周回部４１がステント４の軸Ｘ１に沿って設けられた状態において、複数の第２密部４３は、複数の周回部４１にわたってステント４の軸Ｘ１方向に沿って直線上に連続して配置されている。第２密部４３は、連結部４４を有する。連結部４４は、ステント４の軸Ｘ１方向において互いに隣り合う周回部４１同士を連結している。言い換えれば、ステント４の軸Ｘ１方向において互いに隣り合う周回部４１同士は、第２密部４３が有する連結部４４により連結されている。 Further, in a state in which the plurality of surrounding portions 41 are provided along the axis X1 of the stent 4, the plurality of second dense portions 43 are continuously linearly along the axis X1 direction of the stent 4 over the plurality of surrounding portions 41. Are arranged. The second dense portion 43 has a connecting portion 44. The connecting portion 44 connects the surrounding portions 41 adjacent to each other in the axis X1 direction of the stent 4. In other words, the surrounding portions 41 adjacent to each other in the direction of the axis X <b> 1 of the stent 4 are connected by the connecting portion 44 included in the second dense portion 43.
　このように、ステント４の軸Ｘ１方向において互いに隣り合う周回部４１同士が連結部４４により連結されることで、ステント４は、周側面が軸Ｘ１方向に連なって網目状を呈する筒状になる。 Thus, the surrounding portions 41 adjacent to each other in the axis X1 direction of the stent 4 are connected by the connecting portion 44, so that the stent 4 has a cylindrical shape whose peripheral side surface is continuous in the axis X1 direction and exhibits a mesh shape. .
　ここで、ステント４が生体管腔内を通過し目的部位まで送達される際には、生体管腔の屈曲に対して柔軟に追従し生体管腔内を通過することができる通過性がステント４に対して求められる。また、ステント４には、狭窄部を押し広げた状態を維持するための強度（ラジアルフォース：径方向の力）が求められる。 Here, when the stent 4 passes through the living body lumen and is delivered to the target site, the stent 4 can pass through the living body lumen flexibly following the bending of the living body lumen. Is required. Further, the stent 4 is required to have strength (radial force: radial force) for maintaining the state in which the stenosis portion is expanded.
　これに対して、複数の周回部４１のそれぞれは、複数の第１部位４５と、複数の第２部位４６と、を有する。複数の第１部位４５は、周方向においてステント４の軸Ｘ１に対して互いに対向する位置に設けられている。複数の第２部位４６は、周方向においてステント４の軸Ｘ１に対して互いに対向する位置に設けられ、複数の周回部４１の少なくとも一部が曲がった状態において第１部位４５のストラット４１１の剛性よりも小さい剛性を有する。すなわち、複数の周回部４１の少なくとも一部が曲がった状態において、第２部位４６のストラット４１１の剛性は、第１部位４５のストラット４１１の剛性よりも小さい。そして、複数の第１部位４５は、周方向においてステント４の軸Ｘ１に対して互いに対向する位置関係を維持した状態で、複数の周回部４１にわたってステント４の軸Ｘ１方向に沿って連続的に配置されている。 On the other hand, each of the plurality of rotating portions 41 has a plurality of first portions 45 and a plurality of second portions 46. The plurality of first portions 45 are provided at positions facing each other with respect to the axis X1 of the stent 4 in the circumferential direction. The plurality of second portions 46 are provided at positions facing each other with respect to the axis X1 of the stent 4 in the circumferential direction, and the rigidity of the strut 411 of the first portion 45 is in a state where at least a part of the plurality of surrounding portions 41 is bent. Less rigid. That is, the rigidity of the struts 411 in the second part 46 is smaller than the rigidity of the struts 411 in the first part 45 in a state in which at least a part of the plurality of circumferential portions 41 is bent. The plurality of first portions 45 are continuously provided along the axis X1 direction of the stent 4 over the plurality of rotating portions 41 while maintaining a positional relationship facing each other with respect to the axis X1 of the stent 4 in the circumferential direction. Has been placed.
　そのため、第１部位４５が中立面Ｘ２（図６参照）の位置に配置される姿勢でステント４が曲がるときの曲げ剛性は、他の姿勢でステント４が曲がるときの曲げ剛性よりも小さい。そのため、ステント４は、第１部位４５が中立面Ｘ２の位置に配置される姿勢で曲がりやすい。つまり、ステント４の曲げ剛性に指向性を持たせることができる。本願明細書において、ステント４の曲げ剛性の「指向性」とは、ステント４が、ストラット４１１において、剛性が相対的に大きい部位（本実施形態では第１部位４５）と、剛性が相対的に小さい部位（本実施形態では第２部位４６）と、を有する性質をいう。このため、曲げ剛性の指向性を有するステント４は、曲がる際に、ストラット４１１において相対的に曲がり易い部位と曲がりにくい部位とを有する。また、ステント４の指向性は、ストラット４１１において、剛性が大きい部位の剛性と、剛性が小さい部位の剛性と、の間の差を大きくすることにより、向上することができる。このような高い指向性を有するステント４は、曲げ剛性が最小になる姿勢で確実に曲がる。 Therefore, the bending stiffness when the stent 4 bends in a posture in which the first portion 45 is disposed at the position of the neutral plane X2 (see FIG. 6) is smaller than the bending stiffness when the stent 4 bends in another posture. Therefore, the stent 4 is easily bent in a posture in which the first portion 45 is disposed at the position of the neutral plane X2. That is, directivity can be given to the bending rigidity of the stent 4. In this specification, the “directivity” of the bending rigidity of the stent 4 means that the stent 4 has a relatively large rigidity in the strut 411 and a portion having a relatively large rigidity (the first portion 45 in the present embodiment). And a small part (second part 46 in the present embodiment). For this reason, the stent 4 having the directivity of bending rigidity has a portion that is relatively easily bent and a portion that is not easily bent in the strut 411 when bending. In addition, the directivity of the stent 4 can be improved by increasing the difference between the rigidity of the portion having high rigidity and the rigidity of the portion having low rigidity in the strut 411. The stent 4 having such high directivity is surely bent in a posture where the bending rigidity is minimized.
　このように、本実施形態に係るステント４は、高い曲げ剛性の指向性を有するため、曲げ剛性がより確実に最小となる姿勢で生体管腔の屈曲部を通過することができる。これにより、生体管腔内におけるステント４の通過性を向上させることができる。また、ステント４の構成材料の量を減らすことなくステント４の曲げ剛性に指向性を持たせることにより、ステント４は、曲がりやすい姿勢をとることができる。これにより、ステント４全体におけるストラット４１１の量を確保し、ステント４に対して求められるラジアルフォースを維持することができる。 Thus, since the stent 4 according to the present embodiment has high bending rigidity directivity, the stent 4 can pass through the bent portion of the living body lumen in a posture in which the bending rigidity is more surely minimized. Thereby, the passage property of the stent 4 in the living body lumen can be improved. Further, by giving directivity to the bending rigidity of the stent 4 without reducing the amount of the constituent material of the stent 4, the stent 4 can take a posture that is easy to bend. Thereby, the amount of struts 411 in the entire stent 4 can be secured, and the radial force required for the stent 4 can be maintained.
　具体的には、本実施形態に係るステント４の周回部４１は、ストラット４１１の体積密度が第２部位４６におけるストラット４１１の体積密度よりも高い第１密部４２と、ストラット４１１の体積密度が第２部位４６におけるストラット４１１の体積密度よりも高い第２密部４３と、を有する。第１密部４２および第２密部４３は、周方向においてステント４の軸Ｘ１に対して互いに対向する位置に設けられている。そして、複数の周回部４１がステント４の軸Ｘ１に沿って設けられた状態において、複数の第１密部４２が複数の周回部４１にわたってステント４の軸Ｘ１方向に沿って直線上に連続して配置され、複数の第２密部４３が複数の周回部４１にわたってステント４の軸Ｘ１方向に沿って直線上に連続して配置されている。 Specifically, the circumferential portion 41 of the stent 4 according to the present embodiment has a first dense portion 42 in which the volume density of the struts 411 is higher than the volume density of the struts 411 in the second region 46, and the volume density of the struts 411. And a second dense portion 43 that is higher than the volume density of the struts 411 in the second portion 46. The first dense portion 42 and the second dense portion 43 are provided at positions facing each other with respect to the axis X1 of the stent 4 in the circumferential direction. Then, in a state where the plurality of surrounding portions 41 are provided along the axis X1 of the stent 4, the plurality of first dense portions 42 are continuously linearly extended along the axis X1 direction of the stent 4 over the plurality of surrounding portions 41. The plurality of second dense portions 43 are continuously arranged on the straight line along the axis X1 direction of the stent 4 over the plurality of rotating portions 41.
　そのため、第１密部４２および第２密部４３が中立面Ｘ２の位置に配置される姿勢でステント４が曲がるときの曲げ剛性は、他の姿勢でステント４が曲がるときの曲げ剛性よりも小さい。そのため、図６に表した矢印Ａ１のように、ステント４は、第１密部４２および第２密部４３が中立面Ｘ２の位置に配置される姿勢で曲がりやすい。つまり、ステント４の曲げ剛性に指向性を持たせることができるとともに、ステント４の曲げ剛性の指向性を向上させることができる。曲げ剛性は、材料が単一材料である場合において断面二次モーメントに比例し、曲げ変形に対する抵抗を表す。そのため、材料は、曲げモーメントを受けると、曲げ剛性が最小になる姿勢で曲がる。そのため、ステント４の曲げ剛性が指向性を有すると、部材は、曲げ剛性が最小になる姿勢で曲がりやすい。 Therefore, the bending stiffness when the stent 4 bends in a posture in which the first dense portion 42 and the second dense portion 43 are arranged at the position of the neutral plane X2 is more than the bending stiffness when the stent 4 bends in another posture. small. Therefore, as indicated by an arrow A1 illustrated in FIG. 6, the stent 4 is easily bent in a posture in which the first dense portion 42 and the second dense portion 43 are disposed at the position of the neutral plane X2. That is, the directivity can be given to the bending rigidity of the stent 4 and the directivity of the bending rigidity of the stent 4 can be improved. Bending stiffness is proportional to the cross-sectional second moment when the material is a single material and represents resistance to bending deformation. Therefore, when the material receives a bending moment, the material bends in a posture that minimizes the bending rigidity. Therefore, when the bending rigidity of the stent 4 has directivity, the member is easily bent in a posture in which the bending rigidity is minimized.
　そのため、本実施形態に係るステント４は、曲げ剛性がより確実に最小となる姿勢で生体管腔の屈曲部を通過することができる。これにより、生体管腔内におけるステント４の通過性を向上させることができる。また、ステント４の曲げ変形において、ステント４の曲げ剛性に与える影響が少ない中立面Ｘ２の位置に、第１密部４２および第２密部４３が配置される。すなわち、ステント４の曲げ変形において、ステント４の周回部４１を形成するストラット４１１の量が他の部分におけるストラット４１１の量よりも多い第１密部４２および第２密部４３が、中立面Ｘ２の位置に配置される。これにより、ステント４全体におけるストラット４１１の量を確保し、ステント４に対して求められるラジアルフォースを維持することができる。 Therefore, the stent 4 according to this embodiment can pass through the bent portion of the living body lumen in a posture in which the bending rigidity is more surely minimized. Thereby, the passage property of the stent 4 in the living body lumen can be improved. In addition, in the bending deformation of the stent 4, the first dense portion 42 and the second dense portion 43 are disposed at the position of the neutral surface X <b> 2 that has little influence on the bending rigidity of the stent 4. That is, in the bending deformation of the stent 4, the first dense portion 42 and the second dense portion 43 in which the amount of the struts 411 forming the circumferential portion 41 of the stent 4 is larger than the amount of the struts 411 in the other portions are neutral surfaces. It is arranged at the position of X2. Thereby, the amount of struts 411 in the entire stent 4 can be secured, and the radial force required for the stent 4 can be maintained.
　また、前述したように、周回部４１は、ストラット４１１が複数の屈曲部を有する波状体として形成されている。これにより、ステント４は、生体管腔の屈曲に対してより柔軟に追従し、生体管腔内を通過することができる。つまり、生体管腔内におけるステント４の通過性をより向上させることができる。 Further, as described above, the circulating portion 41 is formed as a wave-like body in which the strut 411 has a plurality of bent portions. As a result, the stent 4 can follow the bending of the living body lumen more flexibly and pass through the living body lumen. That is, the passability of the stent 4 in the living body lumen can be further improved.
　また、本実施形態では、ストラット４１１同士の周方向の間隔（ピッチ）が変化することで、ストラット４１１の体積密度が第２部位４６におけるストラット４１１の体積密度よりも高い第１密部４２および第２密部４３が形成されている。これにより、第１密部４２および第２密部４３を比較的容易に形成し、ステント４のラジアルフォースを維持しつつ生体管腔内におけるステント４の通過性を向上させることができる。 In the present embodiment, the circumferential density (pitch) between the struts 411 is changed, so that the volume density of the struts 411 is higher than the volume density of the struts 411 in the second portion 46 and the first dense portions 42 and the first. Two dense portions 43 are formed. Thereby, the 1st dense part 42 and the 2nd dense part 43 can be formed comparatively easily, and the passage nature of the stent 4 in a living body lumen can be improved, maintaining the radial force of the stent 4.
　また、前述したように、第１密部４２および第２密部４３のそれぞれは、ステント４の軸Ｘ１方向において互いに隣り合う周回部４１同士を連結する連結部４４を有する。そのため、連結部４４が設けられていない場合と比較すると、第１密部４２および第２密部４３のそれぞれにおけるストラット４１１の量は、第２部位４６におけるストラット４１１の量よりもさらに多くなる。これにより、ステント４の曲げ剛性の指向性をさらに向上させ、ステント４のラジアルフォースを維持しつつ生体管腔内におけるステント４の通過性をさらに向上させることができる。 Further, as described above, each of the first dense portion 42 and the second dense portion 43 has the connecting portion 44 that connects the circumferential portions 41 adjacent to each other in the axis X1 direction of the stent 4. Therefore, as compared with the case where the connecting portion 44 is not provided, the amount of the strut 411 in each of the first dense portion 42 and the second dense portion 43 is further larger than the amount of the strut 411 in the second portion 46. Thereby, the directivity of the bending rigidity of the stent 4 can be further improved, and the passage of the stent 4 in the living body lumen can be further improved while maintaining the radial force of the stent 4.
　なお、必ずしも、第１密部４２および第２密部４３の両方が連結部４４を有していなくともよい。例えば、第１密部４２のみが連結部４４を有していてもよい。あるいは、第２密部４３のみが連結部４４を有していてもよい。すなわち、第１密部４２および第２密部４３の少なくともいずれかが連結部４４を有していればよい。また、連結部４４は、ステント４の軸Ｘ１方向において互いに隣り合う周回部４１同士の全てを連結していなくともよい。例えば、第１密部４２および第２密部４３のそれぞれが有する連結部４４が、互いに隣り合う周回部４１同士の間にひとつ置きに設けられているとともに、第１密部４２が有する連結部４４と、第２密部４３が有する連結部４４と、がステント４の軸Ｘ１に沿って交互に配置されていてもよい。 Note that both the first dense portion 42 and the second dense portion 43 do not necessarily have the connecting portion 44. For example, only the first dense portion 42 may have the connecting portion 44. Alternatively, only the second dense portion 43 may have the connecting portion 44. That is, it is sufficient that at least one of the first dense portion 42 and the second dense portion 43 has the connecting portion 44. Moreover, the connection part 44 does not need to connect all the surrounding parts 41 adjacent to each other in the axis X1 direction of the stent 4. For example, the connecting portions 44 included in each of the first dense portion 42 and the second dense portion 43 are provided alternately between the circumferential portions 41 adjacent to each other, and the connecting portions included in the first dense portion 42. 44 and the connecting portions 44 included in the second dense portion 43 may be alternately arranged along the axis X <b> 1 of the stent 4.
　次に、本実施形態の変形例に係るステントを、図面を参照して説明する。
　なお、以下に説明する変形例に係るステントの構成要素が、図１～図６に関して前述した実施形態に係るステント４の構成要素と同様である場合には、重複する説明は適宜省略し、以下、相違点を中心に説明する。 Next, a stent according to a modification of the present embodiment will be described with reference to the drawings.
If the components of the stent according to the modification described below are the same as the components of the stent 4 according to the embodiment described above with reference to FIGS. The difference will be mainly described.
　図７は、本実施形態の第１変形例に係るステントを展開して表した展開図である。
　本変形例に係るステント４Ａは、軸Ｘ１（図２および図３参照）の方向に沿って並んで配置された複数の周回部４１Ａを備える。周回部４１Ａは、ストラット４１１がステント４Ａの周方向に延び複数の屈曲部を有する波状体として形成され、先端側屈曲部４１２と、基端側屈曲部４１３と、線状部４１４と、を有する。 FIG. 7 is a development view showing the stent according to the first modification of the present embodiment.
The stent 4A according to the present modification includes a plurality of rotating portions 41A arranged side by side along the direction of the axis X1 (see FIGS. 2 and 3). The orbiting portion 41A is formed as a wave-like body in which the strut 411 extends in the circumferential direction of the stent 4A and has a plurality of bent portions, and has a distal end side bent portion 412, a proximal end side bent portion 413, and a linear portion 414. .
　本変形例に係るステント４Ａの複数の第１部位４５Ａは、第１密部４２Ａと、第２密部４３Ａと、を有する。第１密部４２Ａにおけるストラット４１１の軸Ｘ１方向の長さ（振幅）Ｄ４は、第２部位４６Ａにおけるストラット４１１の軸Ｘ１方向の長さＤ６よりも長い。これにより、第１密部４２Ａにおけるストラット４１１の体積密度は、第２部位４６Ａにおけるストラット４１１の体積密度よりも高い。また、第２密部４３Ａにおけるストラット４１１の軸Ｘ１方向の長さ（振幅）Ｄ５は、第２部位４６Ａにおけるストラット４１１の軸Ｘ１方向の長さＤ６よりも長い。これにより、第２密部４３Ａにおけるストラット４１１の体積密度は、第２部位４６Ａにおけるストラット４１１の体積密度よりも高い。 The plurality of first portions 45A of the stent 4A according to this modification includes a first dense portion 42A and a second dense portion 43A. The length (amplitude) D4 of the strut 411 in the axis X1 direction at the first dense portion 42A is longer than the length D6 of the strut 411 in the axis X1 direction at the second portion 46A. Thereby, the volume density of the strut 411 in the first dense portion 42A is higher than the volume density of the strut 411 in the second portion 46A. In addition, the length (amplitude) D5 of the strut 411 in the second dense portion 43A in the axis X1 direction is longer than the length D6 in the axis X1 direction of the strut 411 in the second portion 46A. Thereby, the volume density of the strut 411 in the 2nd dense part 43A is higher than the volume density of the strut 411 in the 2nd site | part 46A.
　なお、図４～図６に関して前述したように、「第２部位４６Ａ」とは、複数の周回部４１Ａの少なくとも一部が曲がった状態において第１部位４５Ａのストラット４１１の剛性よりも小さい剛性を有する部分であり、ステント４Ａの周回部４１Ａのうちで第１部位４５Ａ以外の部位をいう。そのため、第２部位４６Ａにおけるストラット４１１の軸Ｘ１方向の長さは、図７に表した長さＤ６には限定されない。具体的には、第２部位４６Ａにおけるストラット４１１の振幅Ｄ６は、第１密部４２Ａのストラット４１１の振幅Ｄ４および第２密部４３Ａのストラット４１１の振幅Ｄ５よりも短くなっていればよく、変化していてもよい。ストラット４１１の振幅Ｄ６が変化する場合、中立面Ｘ２における曲げ剛性の大きさに大きい影響を与え、中立面Ｘ２の位置に配置される第１密部４２Ａおよび第２密部４３Ａのそれぞれから９０度回転した位置にあるストラット４１１の振幅Ｄ６が、最も短いことが好ましい。このような構成により、ステント４Ａは、第１密部４２Ａおよび第２密部４３Ａが中立面Ｘ２に配置される姿勢で曲がりやすくなる。つまり、ステント４Ａの曲げ剛性に指向性を持たせることができる。 As described above with reference to FIGS. 4 to 6, the “second portion 46A” means a rigidity smaller than the rigidity of the strut 411 of the first portion 45A in a state where at least a part of the plurality of rotating portions 41A is bent. It is a part which has and refers to parts other than the 1st site | part 45A among the surrounding parts 41A of the stent 4A. Therefore, the length of the strut 411 in the axis X1 direction in the second portion 46A is not limited to the length D6 shown in FIG. Specifically, the amplitude D6 of the strut 411 in the second portion 46A only needs to be shorter than the amplitude D4 of the strut 411 of the first dense portion 42A and the amplitude D5 of the strut 411 of the second dense portion 43A, and changes. You may do it. When the amplitude D6 of the strut 411 changes, it greatly affects the magnitude of the bending rigidity in the neutral plane X2, and from each of the first dense portion 42A and the second dense portion 43A arranged at the position of the neutral plane X2. It is preferable that the amplitude D6 of the strut 411 at the position rotated by 90 degrees is the shortest. With such a configuration, the stent 4A is easily bent in a posture in which the first dense portion 42A and the second dense portion 43A are disposed on the neutral plane X2. That is, directivity can be given to the bending rigidity of the stent 4A.
　本変形例に係るステント４Ａによれば、ステント４Ａの軸Ｘ１方向におけるストラット４１１の長さ（振幅）が変化することで、ストラット４１１の体積密度が第２部位４６Ａにおけるストラット４１１の体積密度よりも高い第１密部４２Ａおよび第２密部４３Ａが形成されている。これにより、第１密部４２Ａおよび第２密部４３Ａを比較的容易に形成し、ステント４Ａのラジアルフォースを維持しつつ生体管腔内におけるステント４Ａの通過性を向上させることができる。また、他の効果についても、図４～図６に関して前述した効果と同様の効果が得られる。 According to the stent 4A according to this modified example, the length (amplitude) of the strut 411 in the axis X1 direction of the stent 4A changes, so that the volume density of the strut 411 is larger than the volume density of the strut 411 in the second portion 46A. A high first dense portion 42A and a second dense portion 43A are formed. Thereby, the first dense portion 42A and the second dense portion 43A can be formed relatively easily, and the passage of the stent 4A in the living body lumen can be improved while maintaining the radial force of the stent 4A. As for other effects, the same effects as those described above with reference to FIGS. 4 to 6 can be obtained.
　図８は、本実施形態の第２変形例に係るステントを展開して表した展開図である。
　本変形例に係るステント４Ｂは、軸Ｘ１（図２および図３参照）の方向に沿って並んで配置された複数の周回部４１Ｂを備える。周回部４１Ｂは、ストラット４１１がステント４Ｂの周方向に延び複数の屈曲部を有する波状体として形成され、先端側屈曲部４１２と、基端側屈曲部４１３と、線状部４１４と、を有する。 FIG. 8 is a development view showing the stent according to the second modification of the present embodiment.
The stent 4B according to the present modification includes a plurality of rotating portions 41B arranged side by side along the direction of the axis X1 (see FIGS. 2 and 3). The circumferential portion 41B is formed as a wave-like body in which the strut 411 extends in the circumferential direction of the stent 4B and has a plurality of bent portions, and has a distal end side bent portion 412, a proximal end side bent portion 413, and a linear portion 414. .
　本変形例に係るステント４Ｂの複数の第１部位４５Ｂは、第１密部４２Ｂと、第２密部４３Ｂと、を有する。第１密部４２Ｂにおけるストラット４１１の線幅Ｄ７は、第２部位４６Ｂにおけるストラット４１１の線幅Ｄ９よりも太い。これにより、第１密部４２Ｂにおけるストラット４１１の体積密度は、第２部位４６Ｂにおけるストラット４１１の体積密度よりも高い。また、第２密部４３Ｂにおけるストラット４１１の線幅Ｄ８は、第２部位４６Ｂにおけるストラット４１１の線幅Ｄ９よりも太い。これにより、第２密部４３Ｂにおけるストラット４１１の体積密度は、第２部位４６Ｂにおけるストラット４１１の体積密度よりも高い。 The plurality of first portions 45B of the stent 4B according to this modification includes a first dense portion 42B and a second dense portion 43B. The line width D7 of the strut 411 in the first dense portion 42B is thicker than the line width D9 of the strut 411 in the second portion 46B. Thereby, the volume density of the strut 411 in the 1st dense part 42B is higher than the volume density of the strut 411 in the 2nd site | part 46B. Further, the line width D8 of the strut 411 in the second dense portion 43B is larger than the line width D9 of the strut 411 in the second portion 46B. Thereby, the volume density of the strut 411 in the 2nd dense part 43B is higher than the volume density of the strut 411 in the 2nd site | part 46B.
　なお、図４～図６に関して前述したように、「第２部位４６Ｂ」とは、複数の周回部４１Ｂの少なくとも一部が曲がった状態において第１部位４５Ｂのストラット４１１の剛性よりも小さい剛性を有する部分であり、ステント４Ｂの周回部４１Ｂのうちで第１部位４５Ｂ以外の部位をいう。そのため、第２部位４６Ｂにおけるストラット４１１の線幅は、図８に表した線幅Ｄ９には限定されない。具体的には、第２部位４６Ｂにおけるストラット４１１の線幅Ｄ９は、第１密部４２Ｂおよび第２密部４３Ｂのそれぞれにおけるストラット４１１の線幅Ｄ７、Ｄ８よりも細くなっていればよく、変化していてもよい。ストラット４１１の線幅Ｄ９が変化する場合、中立面Ｘ２における曲げ剛性の大きさに大きい影響を与え、中立面Ｘ２の位置に配置される第１密部４２Ｂおよび第２密部４３Ｂのそれぞれから９０度回転した位置にあるストラット４１１の線幅Ｄ９が、最も細いことが好ましい。このような構成により、ステント４Ｂは、第１密部４２Ｂおよび第２密部４３Ｂが中立面Ｘ２に配置される姿勢で曲がりやすくなる。つまり、ステント４Ｂの曲げ剛性に指向性を持たせることができる。 As described above with reference to FIGS. 4 to 6, the “second portion 46B” means a rigidity smaller than the rigidity of the strut 411 of the first portion 45B in a state where at least a part of the plurality of rotating portions 41B is bent. It is a part which has, and says parts other than the 1st site | part 45B among the surrounding parts 41B of the stent 4B. Therefore, the line width of the strut 411 in the second portion 46B is not limited to the line width D9 shown in FIG. Specifically, the line width D9 of the strut 411 in the second portion 46B only needs to be narrower than the line widths D7 and D8 of the strut 411 in each of the first dense portion 42B and the second dense portion 43B, and changes. You may do it. When the line width D9 of the strut 411 changes, the magnitude of the bending rigidity in the neutral plane X2 is greatly affected, and each of the first dense portion 42B and the second dense portion 43B disposed at the position of the neutral plane X2 It is preferable that the line width D9 of the strut 411 at a position rotated 90 degrees from the narrowest is the narrowest. With such a configuration, the stent 4B is easily bent in a posture in which the first dense portion 42B and the second dense portion 43B are disposed on the neutral plane X2. That is, directivity can be given to the bending rigidity of the stent 4B.
　本変形例に係るステント４Ｂによれば、ストラット４１１の線幅が変化することで、ストラット４１１の体積密度が第２部位４６Ｂにおけるストラット４１１の体積密度よりも高い第１密部４２Ｂおよび第２密部４３Ｂが形成されている。これにより、第１密部４２Ｂおよび第２密部４３Ｂを比較的容易に形成し、ステント４Ｂのラジアルフォースを維持しつつ生体管腔内におけるステント４Ｂの通過性を向上させることができる。また、他の効果についても、図４～図６に関して前述した効果と同様の効果が得られる。 According to the stent 4B according to the present modification, the first dense portion 42B and the second dense portion in which the volume density of the strut 411 is higher than the volume density of the strut 411 in the second portion 46B by changing the line width of the strut 411. A portion 43B is formed. Thereby, the 1st dense part 42B and the 2nd dense part 43B can be formed comparatively easily, and the passage nature of stent 4B in a living body lumen can be improved, maintaining the radial force of stent 4B. As for other effects, the same effects as those described above with reference to FIGS. 4 to 6 can be obtained.
　図９は、本実施形態の第３変形例に係るステントの収縮状態を表す断面図である。
　なお、図９は、図２に表した切断面Ｃ１－Ｃ１におけるステントの断面図に相当する。
　本変形例に係るステント４Ｃは、軸Ｘ１（図２および図３参照）の方向に沿って並んで配置された複数の周回部４１Ｃを備える。周回部４１Ｃは、ストラット４１１がステント４Ｃの周方向に延び複数の屈曲部を有する波状体として形成され、先端側屈曲部４１２（図４参照）と、基端側屈曲部４１３（図４参照）と、線状部４１４（図４参照）と、を有する。 FIG. 9 is a cross-sectional view illustrating a contracted state of the stent according to the third modification of the present embodiment.
Note that FIG. 9 corresponds to a cross-sectional view of the stent taken along section plane C1-C1 shown in FIG.
The stent 4C according to the present modification includes a plurality of rotating portions 41C arranged side by side along the direction of the axis X1 (see FIGS. 2 and 3). The circumferential portion 41C is formed as a wave-like body in which the strut 411 extends in the circumferential direction of the stent 4C and has a plurality of bent portions, and includes a distal end side bent portion 412 (see FIG. 4) and a proximal end side bent portion 413 (see FIG. 4). And a linear portion 414 (see FIG. 4).
　本変形例に係るステント４Ｃの複数の第１部位４５Ｃは、第１密部４２Ｃと、第２密部４３Ｃと、を有する。第１密部４２Ｃにおけるストラット４１１の肉厚（径方向の長さ）ｔ１は、第２部位４６Ｃにおけるストラット４１１の厚さｔ３よりも厚い。これにより、第１密部４２Ｃにおけるストラット４１１の体積密度は、第２部位４６Ｃにおけるストラット４１１の体積密度よりも高い。また、第２密部４３Ｃにおけるストラット４１１の肉厚ｔ２は、第２部位４６Ｃにおけるストラット４１１の厚さｔ３よりも厚い。これにより、第２密部４３Ｃにおけるストラット４１１の体積密度は、第２部位４６Ｃにおけるストラット４１１の体積密度よりも高い。 The plurality of first portions 45C of the stent 4C according to this modification includes a first dense portion 42C and a second dense portion 43C. The thickness (diameter length) t1 of the strut 411 in the first dense portion 42C is thicker than the thickness t3 of the strut 411 in the second portion 46C. Thereby, the volume density of the strut 411 in the first dense portion 42C is higher than the volume density of the strut 411 in the second portion 46C. Further, the thickness t2 of the strut 411 in the second dense portion 43C is thicker than the thickness t3 of the strut 411 in the second portion 46C. Thereby, the volume density of the strut 411 in the 2nd dense part 43C is higher than the volume density of the strut 411 in the 2nd site | part 46C.
　なお、図４～図６に関して前述したように、「第２部位４６Ｃ」とは、複数の周回部４１Ｃの少なくとも一部が曲がった状態において第１部位４５Ｃのストラット４１１の剛性よりも小さい剛性を有する部分であり、ステント４Ｃの周回部４１Ｃのうちで第１部位４５Ｃ以外の部位をいう。そのため、第２部位４６Ｃにおけるストラット４１１の肉厚は、図９に表した肉厚ｔ３には限定されない。具体的には、第２部位４６Ｃにおけるストラット４１１の肉厚ｔ３は、第１密部４２Ｃおよび第２密部４３Ｃのそれぞれのストラット４１１の肉厚ｔ１、ｔ２よりも薄くなっていればよく、変化していてもよい。ストラット４１１の肉厚ｔ３が変化する場合、中立面Ｘ２における曲げ剛性の大きさに大きい影響を与え、中立面Ｘ２の位置に配置される第１密部４２Ｃおよび第２密部４３Ｃのそれぞれから９０度回転した位置にあるストラット４１１の肉厚ｔ３が、最も薄いことが好ましい。このような構成により、ステント４Ｃは、第１密部４２Ｃおよび第２密部４３Ｃが中立面Ｘ２に配置される姿勢で曲がりやすくなる。つまり、ステント４Ｃの曲げ剛性に指向性を持たせることができる。 As described above with reference to FIGS. 4 to 6, the “second portion 46C” means a rigidity smaller than the rigidity of the strut 411 of the first portion 45C in a state where at least a part of the plurality of rotating portions 41C is bent. It is a part which has, and says parts other than the 1st site | part 45C among the surrounding parts 41C of the stent 4C. Therefore, the thickness of the strut 411 in the second portion 46C is not limited to the thickness t3 shown in FIG. Specifically, the thickness t3 of the strut 411 in the second portion 46C only needs to be thinner than the thickness t1, t2 of each strut 411 of the first dense portion 42C and the second dense portion 43C, and changes. You may do it. When the thickness t3 of the strut 411 changes, the bending rigidity at the neutral plane X2 is greatly affected, and each of the first dense portion 42C and the second dense portion 43C disposed at the position of the neutral plane X2 It is preferable that the thickness t3 of the strut 411 at the position rotated 90 degrees from the smallest is the thinnest. With such a configuration, the stent 4C is easily bent in a posture in which the first dense portion 42C and the second dense portion 43C are disposed on the neutral plane X2. That is, directivity can be given to the bending rigidity of the stent 4C.
　本変形例に係るステント４Ｃによれば、ストラット４１１の肉厚（径方向の長さ）が変化することで、ストラット４１１の体積密度が第２部位４６Ｃにおけるストラットの体積密度よりも高い第１密部４２Ｃおよび第２密部４３Ｃが形成されている。これにより、ストラット４１１の肉厚の変化により第１密部４２Ｃおよび第２密部４３Ｃを形成し、ステント４Ｃのラジアルフォースを維持しつつ生体管腔内におけるステント４Ｃの通過性を向上させることができる。また、他の効果についても、図４～図６に関して前述した効果と同様の効果が得られる。 According to the stent 4C according to the present modified example, the thickness (the length in the radial direction) of the strut 411 is changed, so that the first density is higher than the volume density of the strut in the second portion 46C. A portion 42C and a second dense portion 43C are formed. Thereby, the first dense portion 42C and the second dense portion 43C are formed by the change in the thickness of the strut 411, and the passage of the stent 4C in the living body lumen can be improved while maintaining the radial force of the stent 4C. it can. As for other effects, the same effects as those described above with reference to FIGS. 4 to 6 can be obtained.
　図１０は、本実施形態の第４変形例に係るステントを展開して表した展開図である。
　本変形例に係るステント４Ｄは、軸Ｘ１（図２および図３参照）の方向に沿って並んで配置された複数の周回部４１Ｄを備える。周回部４１Ｄは、ストラット４１１がステント４Ｄの周方向に延び複数の屈曲部を有する波状体として形成され、先端側屈曲部４１２と、基端側屈曲部４１３と、線状部４１４と、を有する。 FIG. 10 is a developed view showing a stent according to a fourth modification of the present embodiment.
The stent 4D according to this modification includes a plurality of rotating portions 41D arranged side by side along the direction of the axis X1 (see FIGS. 2 and 3). The orbiting portion 41D is formed as a wave-like body in which the strut 411 extends in the circumferential direction of the stent 4D and has a plurality of bent portions, and has a distal end side bent portion 412, a proximal end side bent portion 413, and a linear portion 414. .
　本変形例に係るステント４Ｄの複数の第１部位４５Ｄは、第１密部４２Ｄと、第２密部４３Ｄと、を有する。第１密部４２Ｄは、図４～図６に関して前述した連結部４４を有する。そのため、第１密部４２Ｄにおけるストラット４１１の量は、第２部位４６Ｄにおけるストラット４１１の量より多い。これにより、第１密部４２Ｄにおけるストラット４１１の体積密度は、第２部位４６Ｄにおけるストラット４１１の体積密度よりも高い。つまり、本具体例では、ストラット４１１の形状の変化により第１密部４２Ｄが形成されているわけではなく、互いに隣り合う周回部４１Ｄ同士を連結する連結部４４が配置されることにより、第１密部４２Ｄが形成されている。 The plurality of first portions 45D of the stent 4D according to this modification include a first dense portion 42D and a second dense portion 43D. The first dense portion 42D has the connecting portion 44 described above with reference to FIGS. Therefore, the amount of struts 411 in the first dense portion 42D is larger than the amount of struts 411 in the second portion 46D. Thereby, the volume density of the strut 411 in the 1st dense part 42D is higher than the volume density of the strut 411 in the 2nd site | part 46D. That is, in this specific example, the first dense portion 42D is not formed by the change in the shape of the strut 411, but the first connecting portion 44 that connects the surrounding portions 41D to each other is arranged. A dense portion 42D is formed.
　また、第２密部４３Ｄは、図４～図６に関して前述した連結部４４を有する。そのため、第２密部４３Ｄにおけるストラット４１１の量は、第２部位４６Ｄにおけるストラット４１１の量より多い。これにより、第２密部４３Ｄにおけるストラット４１１の体積密度は、第２部位４６Ｄにおけるストラット４１１の体積密度よりも高い。つまり、本具体例では、ストラット４１１の形状の変化により第２密部４３Ｄが形成されているわけではなく、互いに隣り合う周回部４１Ｄ同士を連結する連結部４４が配置されることにより、第２密部４３Ｄが形成されている。 Further, the second dense portion 43D has the connecting portion 44 described above with reference to FIGS. Therefore, the amount of struts 411 in the second dense portion 43D is larger than the amount of struts 411 in the second portion 46D. Thereby, the volume density of the strut 411 in the 2nd dense part 43D is higher than the volume density of the strut 411 in the 2nd site | part 46D. That is, in this specific example, the second dense portion 43D is not formed by the change in the shape of the strut 411, but the second connecting portion 44 that connects the surrounding portions 41D to each other is arranged. A dense portion 43D is formed.
　本変形例に係るステント４Ｄによれば、ストラット４１１の形状が変化しなくとも、第１密部４２Ｄおよび第２密部４３Ｄのそれぞれが連結部４４を有するため、第１密部４２Ｄおよび第２密部４３Ｄのそれぞれにおけるストラット４１１の量は、第２部位４６Ｄにおけるストラット４１１の量より多い。これにより、第１密部４２Ｄおよび第２密部４３Ｄを比較的容易に形成し、ステント４Ｄのラジアルフォースを維持しつつ生体管腔内におけるステント４Ｄの通過性を向上させることができる。また、本変形例に係るステント４Ｄでは、連結部４４は、ステント４Ｄの軸Ｘ１方向において互いに隣り合う周回部４１Ｄ同士の全てを連結している。そのため、ステント４Ｄの曲げ剛性に指向性を持たせることができる。さらに、他の効果についても、図４～図６に関して前述した効果と同様の効果が得られる。 According to the stent 4D according to this modified example, even if the shape of the strut 411 does not change, each of the first dense portion 42D and the second dense portion 43D has the connecting portion 44, and thus the first dense portion 42D and the second dense portion 42D. The amount of struts 411 in each of the dense portions 43D is larger than the amount of struts 411 in the second portion 46D. Thereby, the 1st dense part 42D and the 2nd dense part 43D can be formed comparatively easily, and the passage nature of stent 4D in a living body lumen can be improved, maintaining the radial force of stent 4D. Further, in the stent 4D according to this modification, the connecting portion 44 connects all the surrounding portions 41D adjacent to each other in the axis X1 direction of the stent 4D. Therefore, directivity can be given to the bending rigidity of the stent 4D. Further, with respect to other effects, the same effects as those described above with reference to FIGS. 4 to 6 can be obtained.
　図１１は、本実施形態の第５変形例に係るステントを展開して表した展開図である。
　本変形例に係るステント４Ｅは、軸Ｘ１（図２および図３参照）の方向に沿って並んで配置された複数の周回部４１Ｅを備える。周回部４１Ｅは、ストラット４１１がステント４Ｅの周方向に延び複数の屈曲部を有する波状体として形成され、先端側屈曲部４１２と、基端側屈曲部４１３と、線状部４１４と、を有する。 FIG. 11 is a developed view showing a stent according to a fifth modification of the present embodiment.
The stent 4E according to this modification includes a plurality of circumferential portions 41E arranged side by side along the direction of the axis X1 (see FIGS. 2 and 3). The circumferential portion 41E is formed as a wave-like body in which the strut 411 extends in the circumferential direction of the stent 4E and has a plurality of bent portions, and has a distal end side bent portion 412, a proximal end side bent portion 413, and a linear portion 414. .
　本変形例に係るステント４Ｅの複数の第１部位４５Ｅは、第１密部４２Ｅと、第２密部４３Ｅと、を有する。第１密部４２Ｅが有する連結部４４は、ステント４Ｅの軸Ｘ１方向において互いに隣り合う周回部４１Ｅ同士の間にひとつ置きに設けられている。また、第２密部４３Ｅが有する連結部４４は、ステント４Ｅの軸Ｘ１方向において互いに隣り合う周回部４１Ｅ同士の間にひとつ置きに設けられている。そして、第１密部４２Ｅが有する連結部４４と、第２密部４３Ｅが有する連結部４４と、はステント４Ｅの軸Ｘ１に沿って交互に配置されている。すなわち、第１密部４２Ｅが有する連結部４４と、第２密部４３Ｅが有する連結部４４と、はステント４Ｅの軸Ｘ１に沿って互い違いに配置されている。この点において、本変形例に係るステント４Ｅは、図１０に関して前述したステント４Ｄとは相違する。他の構造は、図１０に関して前述したステント４Ｄと同じである。 The plurality of first portions 45E of the stent 4E according to this modification include a first dense portion 42E and a second dense portion 43E. The connecting portions 44 included in the first dense portions 42E are provided alternately between the surrounding portions 41E adjacent to each other in the axis X1 direction of the stent 4E. Moreover, the connection part 44 which the 2nd dense part 43E has is provided every other between the surrounding parts 41E mutually adjacent in the axis | shaft X1 direction of the stent 4E. And the connection part 44 which the 1st dense part 42E has, and the connection part 44 which the 2nd dense part 43E has are alternately arrange | positioned along the axis | shaft X1 of the stent 4E. In other words, the connecting portions 44 included in the first dense portion 42E and the connecting portions 44 included in the second dense portion 43E are alternately arranged along the axis X1 of the stent 4E. In this respect, the stent 4E according to this modification is different from the stent 4D described above with reference to FIG. The other structure is the same as the stent 4D described above with reference to FIG.
　本変形例に係るステント４Ｅによれば、連結部４４がステント４Ｅの軸Ｘ１方向において互いに隣り合う周回部４１Ｅ同士の間にひとつ置きに設けられているため、生体管腔の屈曲に対する柔軟性を確保しつつ、ステント４Ｅの曲げ剛性に指向性を持たせることができる。また、他の効果についても、図４～図６および図１０に関して前述した効果と同様の効果が得られる。 According to the stent 4E according to this modification, since the connecting portions 44 are provided alternately between the surrounding portions 41E adjacent to each other in the axis X1 direction of the stent 4E, the flexibility with respect to the bending of the biological lumen is provided. While ensuring, directivity can be given to the bending rigidity of the stent 4E. As for other effects, the same effects as those described above with reference to FIGS. 4 to 6 and 10 can be obtained.
　図１２は、本実施形態の第６変形例に係るステントを展開して表した展開図である。
　本変形例に係るステント４Ｆの周回部４１Ｆは、ストラット４１１が螺旋状に延びた螺旋状体である。すなわち、図１２に表したステント４Ｆにおいて、周回部４１Ｆの下端部（０度の位置の端部）は、ステント４Ｆの軸Ｘ１方向において互いに隣り合う周回部４１Ｆ（図１２では左隣の周回部４１Ｆ）の上端部（３６０度の位置の端部）に接続されている。このように、ステント４Ｆの軸Ｘ１方向において互いに隣り合う周回部４１Ｆ同士が螺旋状体として接続されることで、ステント４Ｆは、周側面が軸Ｘ１方向に連なって螺旋状を呈する筒状になる。 FIG. 12 is a developed view showing a stent according to a sixth modification of the present embodiment.
The orbiting portion 41F of the stent 4F according to this modification is a spiral body in which the struts 411 extend spirally. That is, in the stent 4F illustrated in FIG. 12, the lower end portion (the end portion at the 0 degree position) of the orbiting portion 41F is the adjacent orbiting portion 41F (the adjacent orbiting portion on the left in FIG. 12) in the axis X1 direction of the stent 4F. 41F) is connected to the upper end portion (the end portion at a position of 360 degrees). Thus, the surrounding portions 41F adjacent to each other in the axis X1 direction of the stent 4F are connected as a spiral body, so that the stent 4F has a cylindrical shape whose peripheral side surface is continuous in the axis X1 direction and exhibits a spiral shape. .
　本変形例に係るステント４Ｆの複数の第１部位４５Ｆは、第１密部４２Ｆと、第２密部４３Ｆと、を有する。第１密部４２Ｆにおけるストラット４１１同士の周方向の間隔Ｄ１１は、第２部位４６Ｆにおけるストラット４１１同士の周方向の間隔Ｄ１２よりも狭い。これにより、第１密部４２Ｆにおけるストラット４１１の体積密度は、第２部位４６Ｆにおけるストラット４１１の体積密度よりも高い。また、第２密部４３Ｆにおけるストラット４１１同士の周方向の間隔Ｄ１１は、第２部位４６Ｆにおけるストラット４１１同士の周方向の間隔Ｄ１２よりも狭い。これにより、第２密部４３Ｆにおけるストラット４１１の体積密度は、第２部位４６Ｆにおけるストラット４１１の体積密度よりも高い。 The plurality of first portions 45F of the stent 4F according to this modification includes a first dense portion 42F and a second dense portion 43F. The circumferential distance D11 between the struts 411 in the first dense portion 42F is narrower than the circumferential distance D12 between the struts 411 in the second part 46F. Thereby, the volume density of the strut 411 in the 1st dense part 42F is higher than the volume density of the strut 411 in the 2nd site | part 46F. Further, the circumferential interval D11 between the struts 411 in the second dense portion 43F is narrower than the circumferential interval D12 between the struts 411 in the second portion 46F. Thereby, the volume density of the strut 411 in the 2nd dense part 43F is higher than the volume density of the strut 411 in the 2nd site | part 46F.
　なお、図４～図６に関して前述したように、「第２部位４６Ｆ」とは、複数の周回部４１Ｆの少なくとも一部が曲がった状態において第１部位４５Ｆのストラット４１１の剛性よりも小さい剛性を有する部分であり、ステント４Ｆの周回部４１Ｆのうちで第１部位４５Ｆ以外の部位をいう。そのため、第２部位４６Ｆにおけるストラット４１１同士の周方向の間隔は、図１２に表した間隔Ｄ１２には限定されない。 As described above with reference to FIGS. 4 to 6, the “second portion 46F” means a rigidity smaller than the rigidity of the strut 411 of the first portion 45F in a state in which at least a part of the plurality of rotating portions 41F is bent. It is a part which has, and says parts other than the 1st site | part 45F among the surrounding parts 41F of the stent 4F. Therefore, the circumferential interval between the struts 411 in the second portion 46F is not limited to the interval D12 illustrated in FIG.
　本変形例に係るステント４Ｆによれば、周回部４１Ｆが螺旋状体であるため、互いに隣り合う周回部４１Ｆ同士を連結する連結部が設けられていなくとも、周回部４１Ｆは、螺旋状に連続している。そして、第１密部４２Ｆおよび第２密部４３Ｆは、周方向においてステント４の軸Ｘ１に対して互いに対向する位置に設けられる。これにより、ステント４Ｆは、ラジアルフォースを維持しつつ生体管腔内における通過性を向上させることができる。 According to the stent 4F according to the present modified example, since the orbiting portion 41F is a spiral body, the orbiting portion 41F is spirally continuous even if a connecting portion that connects the adjacent surrounding portion 41F is not provided. is doing. The first dense portion 42F and the second dense portion 43F are provided at positions facing each other with respect to the axis X1 of the stent 4 in the circumferential direction. Thereby, the stent 4F can improve the passage property in a living body lumen, maintaining a radial force.
　なお、本具体例では、図４～図６に関して前述したステント４の周回部４１が螺旋状体である場合を例に挙げている。但し、これだけには限定されず、図７～図９に関して前述したステント４Ａ、４Ｂ、４Ｃの周回部４１Ａ、４１Ｂ、４１Ｃが螺旋状体として形成されていてもよい。この場合であっても、同様の効果が得られる。 In this specific example, the case where the surrounding portion 41 of the stent 4 described above with reference to FIGS. 4 to 6 is a spiral body is taken as an example. However, the present invention is not limited to this, and the orbiting portions 41A, 41B, and 41C of the stents 4A, 4B, and 4C described above with reference to FIGS. 7 to 9 may be formed as a spiral body. Even in this case, the same effect can be obtained.
　図１３は、本実施形態の第７変形例に係るステントを展開して表した展開図である。
　本変形例に係るステント４Ｇは、軸Ｘ１（図２および図３参照）の方向に沿って並んで配置された複数の周回部４１Ｇを備える。周回部４１Ｇは、ストラット４１１がステント４Ｇの周方向に延び複数の屈曲部を有する波状体として形成され、先端側屈曲部４１２と、基端側屈曲部４１３と、線状部４１４と、を有する。 FIG. 13 is a developed view showing a stent according to a seventh modification of the present embodiment.
The stent 4G according to this modification includes a plurality of rotating portions 41G arranged side by side along the direction of the axis X1 (see FIGS. 2 and 3). The circumferential portion 41G is formed as a wave-like body in which the strut 411 extends in the circumferential direction of the stent 4G and has a plurality of bent portions, and has a distal end side bent portion 412, a proximal end side bent portion 413, and a linear portion 414. .
　本変形例に係るステント４Ｇの周回部４１Ｇは、複数の第１部位４５Ｇと、複数の第２部位４６Ｇと、を有する。複数の第１部位４５Ｇは、周方向においてステント４Ｇの軸Ｘ１に対して互いに対向する位置関係を維持した状態で、複数の周回部４１Ｇにわたってステント４Ｇの軸Ｘ１方向に沿って螺旋状に配置されている。 The orbiting portion 41G of the stent 4G according to this modification has a plurality of first portions 45G and a plurality of second portions 46G. The plurality of first portions 45G are spirally arranged along the axis X1 direction of the stent 4G over the plurality of surrounding portions 41G while maintaining a positional relationship facing each other with respect to the axis X1 of the stent 4G in the circumferential direction. ing.
　具体的に説明すると、複数の第１部位４５Ｇは、第１密部４２Ｇと、第２密部４３Ｇと、を有する。複数の周回部４１Ｇがステント４Ｇの軸Ｘ１に沿って設けられた状態において、複数の第１密部４２Ｇは、複数の周回部４１Ｇにわたってステント４Ｇの軸Ｘ１方向に沿って螺旋状に連続して配置されている。例えば、ステント４Ｇの軸Ｘ１方向において互いに隣り合う周回部４１Ｇ同士において、一方の第１密部４２Ｇと、他方の第１密部４２Ｇと、の間の周方向の角度は４５度である。但し、一方の第１密部４２Ｇと、他方の第１密部４２Ｇと、の間の周方向の角度は、４５度には限定されず、例えば３０度あってもよく、例えば６０度であってもよい。 Specifically, the plurality of first portions 45G have a first dense portion 42G and a second dense portion 43G. In a state where the plurality of surrounding portions 41G are provided along the axis X1 of the stent 4G, the plurality of first dense portions 42G are continuously spiraled along the axis X1 direction of the stent 4G over the plurality of surrounding portions 41G. Is arranged. For example, in the surrounding portions 41G adjacent to each other in the axis X1 direction of the stent 4G, the circumferential angle between one first dense portion 42G and the other first dense portion 42G is 45 degrees. However, the angle in the circumferential direction between one first dense portion 42G and the other first dense portion 42G is not limited to 45 degrees, and may be 30 degrees, for example, 60 degrees. May be.
　また、複数の周回部４１Ｇがステント４Ｇの軸Ｘ１に沿って設けられた状態において、複数の第２密部４３Ｇは、複数の周回部４１Ｇにわたってステント４Ｇの軸Ｘ１方向に沿って螺旋状に連続して配置されている。例えば、ステント４Ｇの軸Ｘ１方向において互いに隣り合う周回部４１Ｇ同士において、一方の第２密部４３Ｇと、他方の第２密部４３Ｇと、の間の周方向の角度は４５度である。但し、一方の第２密部４３Ｇと、他方の第２密部４３Ｇと、の間の周方向の角度は、４５度には限定されず、例えば３０度あってもよく、例えば６０度であってもよい。 In addition, in a state where the plurality of surrounding portions 41G are provided along the axis X1 of the stent 4G, the plurality of second dense portions 43G are spirally continuous along the axis X1 direction of the stent 4G over the plurality of surrounding portions 41G. Are arranged. For example, in the surrounding portions 41G adjacent to each other in the axis X1 direction of the stent 4G, the circumferential angle between one second dense portion 43G and the other second dense portion 43G is 45 degrees. However, the circumferential angle between one second dense portion 43G and the other second dense portion 43G is not limited to 45 degrees, and may be, for example, 30 degrees, for example, 60 degrees. May be.
　このように、複数の第１部位４５Ｇが、周方向においてステント４Ｇの軸Ｘ１に対して互いに対向する位置関係を維持した状態で、複数の周回部４１Ｇにわたってステント４Ｇの軸Ｘ１方向に沿って螺旋状に配置されている点において、本実施形態に係るステント４Ｇは、図４～図６に関して前述したステント４とは異なる。他の構造は、図４～６に関して前述したステント４と同様である。 As described above, the plurality of first portions 45G spirals along the axis X1 direction of the stent 4G over the plurality of rotating portions 41G in a state in which the positional relationship facing each other with respect to the axis X1 of the stent 4G is maintained in the circumferential direction. The stent 4G according to the present embodiment is different from the stent 4 described above with reference to FIGS. Other structures are similar to the stent 4 described above with respect to FIGS.
　本変形例に係るステント４Ｇによれば、ステント４Ｇが曲がるときの中立面Ｘ２（図６参照）がステント４Ｇの軸Ｘ１方向に沿って螺旋状に形成される。そのため、ステント４Ｇは、螺旋状に形成される中立面Ｘ２の位置に第１部位４５Ｇが配置される姿勢で曲がりやすい。すなわち、ステント４Ｇの中立面Ｘ２は、軸Ｘ１方向に沿って、複数の周回部４１Ｇのそれぞれで変化する。これにより、ステント４Ｇは、例えば蛇行した血管部位を通過する場合、その血管部位に対して局所的に曲げ剛性が最小となる姿勢をとりながら、血管部位を通過することができる。これにより、生体管腔内におけるステント４Ｇの通過性がより向上する。 According to the stent 4G according to this modification, the neutral plane X2 (see FIG. 6) when the stent 4G is bent is formed in a spiral shape along the axis X1 direction of the stent 4G. Therefore, the stent 4G is easily bent in a posture in which the first portion 45G is disposed at the position of the neutral surface X2 formed in a spiral shape. That is, the neutral plane X2 of the stent 4G changes along each of the plurality of rotating portions 41G along the direction of the axis X1. Thereby, for example, when the stent 4G passes through a meandering blood vessel portion, the stent 4G can pass through the blood vessel portion while taking a posture in which the bending rigidity is locally minimized with respect to the blood vessel portion. Thereby, the passage of the stent 4G in the living body lumen is further improved.
　図１４は、本実施形態の第８変形例に係るステントを作製するためのチューブを表す断面図である。
　なお、図１４は、ステントの軸に対して垂直な切断面における断面図に相当する。 FIG. 14 is a cross-sectional view showing a tube for producing a stent according to an eighth modification of the present embodiment.
Note that FIG. 14 corresponds to a cross-sectional view taken along a plane perpendicular to the axis of the stent.
　図１～図３に関して前述したように、本実施形態に係るステントは、例えばチューブやパイプなどを加工することにより作製される。例えば、ステントは、合成樹脂製のチューブや金属製のチューブの側面を、切削加工（例えば、機械的切削、レーザ切削）や、化学エッチングなどにより部分的に除去して、側面に複数の切欠部または複数の開口を形成することにより作製される。図１４に表したチューブ５は、本変形例に係るステントを作製するためのチューブの一例である。 As described above with reference to FIGS. 1 to 3, the stent according to the present embodiment is manufactured by processing, for example, a tube or a pipe. For example, a stent is partially removed by cutting (for example, mechanical cutting, laser cutting), chemical etching, or the like on a side surface of a synthetic resin tube or a metal tube, and a plurality of notches are formed on the side surface. Alternatively, it is produced by forming a plurality of openings. A tube 5 shown in FIG. 14 is an example of a tube for producing a stent according to this modification.
　チューブ５は、例えば生体吸収性を有する生分解性ポリマーにより筒状あるいは管状に形成され、第１形成部位５１と、第２形成部位５２と、を有する。第１形成部位５１は、本変形例に係るステントが作製された後に、ストラットの第１部位（例えば図４に関して前述した第１部位４５）になる部位である。第２形成部位５２は、本変形例に係るステントが作製された後に、ストラットの第２部位（例えば図４に関して前述した第２部位４６）になる部位である。 The tube 5 is formed in a cylindrical shape or a tubular shape by, for example, a biodegradable biodegradable polymer, and includes a first forming portion 51 and a second forming portion 52. The first forming portion 51 is a portion that becomes the first portion of the strut (for example, the first portion 45 described above with reference to FIG. 4) after the stent according to the present modification is manufactured. The second formation portion 52 is a portion that becomes the second portion of the strut (for example, the second portion 46 described above with reference to FIG. 4) after the stent according to the present modification is manufactured.
　第１形成部位５１の材料特性は、第２形成部位５２の材料特性とは異なる。例えば、チューブ５は、第１形成部位５１および第２形成部位５２において互いに異なる生分解ポリマーを用いて押出成形により形成される。第１形成部位５１の材料としては、ポリ乳酸などが挙げられる。第２形成部位５２の材料としては、ポリカプロラクタンなどが挙げられる。これにより、チューブ５を用いて作製されたステントにおいて、第１部位のストラットの材料特性は、第２部位のストラットの材料特性とは異なる。 The material property of the first formation part 51 is different from the material property of the second formation part 52. For example, the tube 5 is formed by extrusion molding using different biodegradable polymers at the first forming portion 51 and the second forming portion 52. Examples of the material of the first formation site 51 include polylactic acid. Examples of the material of the second formation site 52 include polycaprolactan. Thereby, in the stent produced using the tube 5, the material property of the strut of the 1st site | part differs from the material property of the strut of the 2nd site | part.
　あるいは、チューブ５は、生体適合性を有する金属により筒状あるいは管状に形成され、第１形成部位５１と、第２形成部位５２と、を有する。この場合であっても、第１形成部位５１の材料特性は、第２形成部位５２の材料特性とは異なる。例えば、焼き鈍しなどの熱処理が、第１形成部位５１および第２形成部位５２の少なくともいずれかに施される。あるいは、例えば、ショットピーニングなどの加工が、第１形成部位５１および第２形成部位５２の少なくともいずれかに施される。これにより、チューブ５を用いて作製されたステントにおいて、第１部位のストラットの材料特性は、第２部位のストラットの材料特性とは異なる。 Alternatively, the tube 5 is formed in a cylindrical shape or a tubular shape from a metal having biocompatibility, and has a first forming portion 51 and a second forming portion 52. Even in this case, the material characteristics of the first formation site 51 are different from the material characteristics of the second formation site 52. For example, heat treatment such as annealing is performed on at least one of the first formation portion 51 and the second formation portion 52. Alternatively, for example, processing such as shot peening is performed on at least one of the first formation portion 51 and the second formation portion 52. Thereby, in the stent produced using the tube 5, the material property of the strut of the 1st site | part differs from the material property of the strut of the 2nd site | part.
　あるいは、チューブ５は、第１形成部位５１および第２形成部位５２において互いに異なる金属が接合された構造を有していてもよい。この場合において、第１形成部位５１の材料としては、ステンレス鋼などが挙げられる。第２形成部位５２の材料としては、金などが挙げられる。また、チューブ５は、第１形成部位５１および第２形成部位５２において金属と生分解ポリマーとが互いに接合された構造を有していてもよい。 Alternatively, the tube 5 may have a structure in which different metals are bonded to each other at the first forming portion 51 and the second forming portion 52. In this case, examples of the material of the first forming portion 51 include stainless steel. An example of the material of the second formation portion 52 is gold. The tube 5 may have a structure in which a metal and a biodegradable polymer are bonded to each other at the first formation site 51 and the second formation site 52.
　チューブ５を用いて作製された本変形例に係るステントによれば、第１部位のストラットの形状が第２部位のストラットの形状と同じである場合であっても、第１部位のストラットの材料特性が第２部位のストラットの材料特性と異なることで、第２部位のストラットの剛性は、第１部位のストラットの剛性とは異なる。具体的には、複数の周回部の少なくとも一部が曲がった状態において、第２部位のストラットの剛性を、第１部位のストラットの剛性よりも小さくすることが可能である。これにより、ストラットの材料特性の違いにより第１部位および第２部位を形成し、ステントのラジアルフォースを維持しつつ生体管腔内におけるステントの通過性を向上させることができる。 According to the stent according to this modification manufactured using the tube 5, even when the shape of the strut of the first part is the same as the shape of the strut of the second part, the material of the strut of the first part Because the properties are different from the material properties of the struts in the second part, the stiffness of the struts in the second part is different from the rigidity of the struts in the first part. Specifically, it is possible to make the rigidity of the struts of the second part smaller than the rigidity of the struts of the first part in a state where at least some of the plurality of circulation parts are bent. Accordingly, the first portion and the second portion are formed by the difference in the material characteristics of the strut, and the passage of the stent in the living body lumen can be improved while maintaining the radial force of the stent.
　以上、本発明の実施形態について説明した。しかし、本発明は、上記実施形態に限定されず、特許請求の範囲を逸脱しない範囲で種々の変更を行うことができる。上記実施形態の構成は、その一部を省略したり、上記とは異なるように任意に組み合わせたりすることができる。例えば、本実施形態の説明では、ステントのストラットまたは連結部を変化させることで、ステントに対して曲げ剛性の指向性を持たせた。但し、本発明は、これだけには限定されない。例えば、ステントのストラットまたは連結部は変化せず、ステントの全長に亘ってステントの外周上に連続的に延びて固定される部材を設けることで、ステントに対して曲げ剛性の指向性を持たせても良い。 The embodiment of the present invention has been described above. However, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the claims. A part of the configuration of the above embodiment can be omitted, or can be arbitrarily combined so as to be different from the above. For example, in the description of the present embodiment, the direction of the bending rigidity is given to the stent by changing the strut or the connecting portion of the stent. However, the present invention is not limited to this. For example, the struts or connecting portions of the stent do not change, and by providing a member that continuously extends and is fixed on the outer circumference of the stent over the entire length of the stent, the direction of the bending rigidity is given to the stent. May be.
　２・・・ステントデリバリーシステム、　３・・・バルーンカテーテル、　４、４Ａ、４Ｂ、４Ｃ、４Ｄ、４Ｅ、４Ｆ、４Ｇ・・・ステント、　５・・・チューブ、　３１・・・シャフト本体部、　３２・・・バルーン、　３２ａ・・・先端側接合部、　３２ｂ・・・基端側接合部、　３２ｃ・・・拡張空間、　４１、４１Ａ、４１Ｂ、４１Ｃ、４１Ｄ、４１Ｅ、４１Ｆ、４１Ｇ・・・周回部、　４２、４２Ａ、４２Ｂ、４２Ｃ、４２Ｄ、４２Ｅ、４２Ｆ、４２Ｇ・・・第１密部、　４３、４３Ａ、４３Ｂ、４３Ｃ、４３Ｄ、４３Ｅ、４３Ｆ、４３Ｇ・・・第２密部、　４４・・・連結部、　４５、４５Ａ、４５Ｂ、４５Ｃ、４５Ｄ、４５Ｅ、４５Ｆ、４５Ｇ・・・第１部位、　４６、４６Ａ、４６Ｂ、４６Ｃ、４６Ｄ、４６Ｅ、４６Ｆ、４６Ｇ・・・第２部位、　５１・・・第１形成部位、　５２・・・第２形成部位、　３１１・・・内管、　３１２・・・外管、　３１２ａ・・・先端側外管、　３１２ｂ・・・基端側外管、　３１３・・・分岐ハブ、　３１３ａ・・・ガイドワイヤポート、　３１３ｂ・・・インジェクションポート、　３１４・・・ガイドワイヤルーメン、　３１５・・・バルーン拡張用ルーメン、　３１６、３１７・・・Ｘ線造影性部材、　４１１・・・ストラット、　４１２・・・先端側屈曲部、　４１３・・・基端側屈曲部、　４１４・・・線状部、　Ｖ１・・・単位体積（区画枠）、　Ｘ１・・・軸、
　Ｘ２・・・中立面 2 ... Stent delivery system, 3 ... Balloon catheter, 4, 4A, 4B, 4C, 4D, 4E, 4F, 4G ... Stent, 5 ... Tube, 31 ... Shaft body, 32 ... Balloon, 32a ... Tip side joint, 32b ... Base end side joint, 32c ... Expansion space, 41, 41A, 41B, 41C, 41D, 41E, 41F, 41G ... Circulation 42, 42A, 42B, 42C, 42D, 42E, 42F, 42G ... first dense part, 43, 43A, 43B, 43C, 43D, 43E, 43F, 43G ... second dense part, 44. ..Connecting part, 45, 45A, 45B, 45C, 45D, 45E, 45F, 45G ... 1st part, 46, 46A, 46B, 46C, 46D, 46E, 46F, 46G ... 2nd part 51 ... 1st formation site, 52 ... 2nd formation site, 311 ... Inner tube, 312 ... Outer tube, 312a ... End side outer tube, 312b ... Base end side outer tube 313 ... Branch hub, 313a ... Guide wire port, 313b ... Injection port, 314 ... Guide wire lumen, 315 ... Lumen for balloon expansion, 316, 317 ... X-ray contrast property 411 ... Strut, 412 ... Front end side bent portion, 413 ... Base end side bent portion, 414 ... Linear portion, V1 ... Unit volume (partition frame), X1 ... axis,
X2 Neutral surface

Claims (12)

  1. 　生体管腔内に留置されるステントであって、
    　軸を中心に周回して筒状に形成された線状のストラットを有する複数の周回部を備え、
    　前記複数の周回部は、前記軸方向に沿って並んで配置され、
    　前記複数の周回部のそれぞれは、
    　周方向において前記軸に対して互いに対向する位置に設けられた複数の第１部位と、
    　前記周方向において前記軸に対して互いに対向する位置に設けられ、前記複数の周回部の少なくとも一部が曲がった状態において前記第１部位の前記ストラットの剛性よりも小さい剛性を有する複数の第２部位と、
    　を有し、
    　前記複数の第１部位は、前記周方向において前記軸に対して互いに対向する位置関係を維持した状態で、前記複数の周回部にわたって前記軸方向に沿って連続的に配置されたことを特徴とするステント。     A stent placed in a body lumen,
    Comprising a plurality of revolving parts having linear struts formed in a cylindrical shape around an axis;
    The plurality of circulation portions are arranged side by side along the axial direction,
    Each of the plurality of circulating portions is
    A plurality of first portions provided at positions facing each other with respect to the axis in the circumferential direction;
    A plurality of second portions provided at positions facing each other with respect to the axis in the circumferential direction and having a rigidity smaller than the rigidity of the struts of the first portion in a state in which at least a part of the plurality of circulation portions is bent. The site,
    Have
    The plurality of first portions are continuously arranged along the axial direction over the plurality of rotating portions in a state in which a positional relationship facing each other with respect to the axis is maintained in the circumferential direction. Stent.
  2. 　前記周回部は、前記ストラットが屈曲した波状体であって、前記軸方向の先端側に頂点を有する先端側屈曲部と、前記軸方向の基端側に頂点を有する基端側屈曲部と、を有する波状体であることを特徴とする請求項１に記載のステント。 The circumferential portion is a wavy body in which the strut is bent, and a distal-side bent portion having a vertex on the distal end side in the axial direction, a proximal-side bent portion having a vertex on the proximal end side in the axial direction, The stent according to claim 1, wherein the stent is a corrugated body.
  3. 　前記複数の第１部位は、前記周方向において前記軸に対して互いに対向する位置関係を維持した状態で、前記複数の周回部にわたって前記軸方向に沿って直線上に配置されたことを特徴とする請求項１または２に記載のステント。 The plurality of first portions are arranged on a straight line along the axial direction over the plurality of rotating portions in a state in which a positional relationship facing each other with respect to the axis is maintained in the circumferential direction. The stent according to claim 1 or 2.
  4. 　前記複数の第１部位は、前記周方向において前記軸に対して互いに対向する位置関係を維持した状態で、前記複数の周回部にわたって前記軸方向に沿って螺旋状に配置されたことを特徴とする請求項１または２に記載のステント。 The plurality of first portions are arranged in a spiral shape along the axial direction over the plurality of circulation portions in a state in which a positional relationship facing each other with respect to the axis is maintained in the circumferential direction. The stent according to claim 1 or 2.
  5. 　前記複数の第１部位は、前記周方向において、前記ストラットを含む空間の単位体積のうち前記ストラットの体積が占める割合が前記第２部位における前記割合よりも高い第１密部と、前記周方向において前記第１密部と前記軸に対して対向する位置に設けられた第２密部であって前記割合が前記第２部位における前記割合よりも高い第２密部と、を有することを特徴とする請求項１～４のいずれか１項に記載のステント。 In the circumferential direction, the plurality of first portions includes a first dense portion in which a proportion of the volume of the strut in a unit volume of the space including the strut is higher than the proportion in the second portion, and the circumferential direction And a second dense portion provided at a position facing the first dense portion and the axis, wherein the ratio is higher than the proportion in the second portion. The stent according to any one of claims 1 to 4.
  6. 　前記第１密部および前記第２密部のそれぞれにおける前記ストラット同士の前記周方向の間隔は、前記第２部位における前記ストラット同士の前記周方向の間隔よりも狭いことを特徴とする請求項５に記載のステント。 6. The circumferential interval between the struts in each of the first dense portion and the second dense portion is narrower than the circumferential interval between the struts in the second portion. The stent according to 1.
  7. 　前記第１密部および前記第２密部のそれぞれにおける前記ストラットの前記軸方向の長さは、前記第２部位における前記ストラットの前記軸方向の長さよりも長いことを特徴とする請求項５または６に記載のステント。 6. The axial length of the strut in each of the first dense portion and the second dense portion is longer than the axial length of the strut in the second portion. 6. The stent according to 6.
  8. 　前記第１密部および前記第２密部のそれぞれにおける前記ストラットの線幅は、前記第２部位における前記ストラットの線幅よりも太いことを特徴とする請求項５または６に記載のステント。 The stent according to claim 5 or 6, wherein a line width of the strut in each of the first dense portion and the second dense portion is larger than a line width of the strut in the second portion.
  9. 　前記第１密部および前記第２密部のそれぞれにおける前記ストラットの肉厚は、前記第２部位における前記ストラットの肉厚よりも厚いことを特徴とする請求項５または６に記載のステント。 The stent according to claim 5 or 6, wherein the thickness of the strut in each of the first dense portion and the second dense portion is thicker than the thickness of the strut in the second portion.
  10. 　前記第１部位の前記ストラットの材料特性は、前記第２部位の前記ストラットの材料特性とは異なることを特徴とする請求項１～３のいずれか１項に記載のステント。 The stent according to any one of claims 1 to 3, wherein a material property of the strut in the first part is different from a material property of the strut in the second part.
  11. 　前記周回部は、前記ストラットが環状に延びた環状体であり、
    　前記複数の第１部位のうちの少なくともいずれかは、前記軸方向において互いに隣り合う前記周回部同士を連結する連結部を有することを特徴とする請求項１～１０のいずれか１項に記載のステント。     The circular portion is an annular body in which the struts extend in an annular shape,
    The at least one of the plurality of first portions has a connecting portion that connects the circumferential portions adjacent to each other in the axial direction. Stent.
  12. 　前記周回部は、前記ストラットが螺旋状に延びた螺旋状体であることを特徴とする請求項１～１０のいずれか１項に記載のステント。 The stent according to any one of claims 1 to 10, wherein the circumferential portion is a spiral body in which the struts extend spirally.
PCT/JP2018/009100 2017-05-17 2018-03-08 Stent WO2018211796A1 (en)

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2023046301A1 (en) * 2021-09-27 2023-03-30 Angiomed Gmbh & Co.Medizintechnik Kg Implant and method of making an implant

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JPH06181993A (en) * 1991-10-28 1994-07-05 Advanced Cardeovascular Syst Inc Expandable stent and its manufacture
JP2001509702A (en) * 1997-01-13 2001-07-24 ゴア エンタープライズ ホールディングス，インコーポレイティド Self-expanding vascular stent with low profile
WO2008112057A2 (en) * 2007-03-09 2008-09-18 Boston Scientific Limited Stent design with struts of various angles and stiffness
JP2008237880A (en) * 2007-01-08 2008-10-09 Cordis Corp Intraluminal medical device having variable axial flexibility about circumference of the device
JP2015156967A (en) * 2014-02-24 2015-09-03 テルモ株式会社 stent delivery system

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH06181993A (en) * 1991-10-28 1994-07-05 Advanced Cardeovascular Syst Inc Expandable stent and its manufacture
JP2001509702A (en) * 1997-01-13 2001-07-24 ゴア エンタープライズ ホールディングス，インコーポレイティド Self-expanding vascular stent with low profile
JP2008237880A (en) * 2007-01-08 2008-10-09 Cordis Corp Intraluminal medical device having variable axial flexibility about circumference of the device
WO2008112057A2 (en) * 2007-03-09 2008-09-18 Boston Scientific Limited Stent design with struts of various angles and stiffness
JP2015156967A (en) * 2014-02-24 2015-09-03 テルモ株式会社 stent delivery system

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2023046301A1 (en) * 2021-09-27 2023-03-30 Angiomed Gmbh & Co.Medizintechnik Kg Implant and method of making an implant

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