WO2019189129A1 - Stent delivery system - Google Patents

Stent delivery system Download PDF

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Publication number
WO2019189129A1
WO2019189129A1 PCT/JP2019/012781 JP2019012781W WO2019189129A1 WO 2019189129 A1 WO2019189129 A1 WO 2019189129A1 JP 2019012781 W JP2019012781 W JP 2019012781W WO 2019189129 A1 WO2019189129 A1 WO 2019189129A1
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WO
WIPO (PCT)
Prior art keywords
stent
delivery system
stent delivery
outer diameter
distal end
Prior art date
Application number
PCT/JP2019/012781
Other languages
French (fr)
Japanese (ja)
Inventor
亮子 西岡
Original Assignee
日本ゼオン株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 日本ゼオン株式会社 filed Critical 日本ゼオン株式会社
Priority to JP2020510879A priority Critical patent/JP7298598B2/en
Publication of WO2019189129A1 publication Critical patent/WO2019189129A1/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
    • A61F2/95—Instruments specially adapted for placement or removal of stents or stent-grafts
    • A61F2/962—Instruments specially adapted for placement or removal of stents or stent-grafts having an outer sleeve
    • A61F2/966—Instruments specially adapted for placement or removal of stents or stent-grafts having an outer sleeve with relative longitudinal movement between outer sleeve and prosthesis, e.g. using a push rod

Definitions

  • the present invention relates to a stent delivery system for transporting a stent to be placed in the body to an indwelling position.
  • stents For the treatment of bile ducts and other gastrointestinal luminal organs, various stents are inserted and placed in the body. There are two types of stents, a self-expandable type and a balloon-expandable type depending on the type of expansion, and a covered stent and a bare stent depending on the presence or absence of resin coating. In addition, as for the shape and the like of the stent, not only a simple cylindrical shape but also various shapes are used.
  • a luminal organ eg, a digestive tract such as the stomach or duodenum
  • another luminal organ eg, bile duct or gallbladder
  • a stent having a flexible portion such as a hook at the end has been proposed (see Patent Document 1).
  • the self-expanding stent is mounted on the distal end of the stent delivery system, and is delivered to the indwelling position, and then released from the stent delivery system.
  • the stent mounted between the inner shaft and the outer sheath is released by moving the outer sheath relative to the proximal end side and exposing the distal end of the inner shaft. Is mentioned.
  • the stent needs to remain in place on the inner shaft against the axial force generated by the frictional force with the outer sheath.
  • the flexible portion of the stent is accommodated in the groove, and the portion (cylindrical portion) other than the flexible portion of the stent is brought into contact with the end surface of the inner shaft, whereby the flexible portion is formed at the end portion.
  • the present invention has been made in view of such a situation, and an object thereof is to provide a stent delivery system capable of installing a stent having a flexible portion at an end portion with good workability.
  • a stent delivery system comprises: A first portion having a first outer diameter; and a second portion connected to a distal end of the first portion and having a second outer diameter that is smaller than the first outer diameter.
  • An inner shaft From the first state that is inserted through the first part and the second part and covers the second part, to the second state that exposes the second part from the distal end, the inner part An outer sheath that can move relative to the shaft in the axial direction; A cylindrical portion accommodated between the second portion and the outer sheath, and a flexible portion that is connected to the proximal end of the cylindrical portion and is more easily deformed than the cylindrical portion with respect to a force from the axial direction.
  • a stent having The inner shaft has a contact portion that contacts the stent at a boundary position between the first portion and the second portion;
  • the contact portion includes a plurality of top portions having an outer diameter equal to or larger than the first outer diameter, and a plurality of side portions linearly connecting the plurality of top portions.
  • the inner shaft has a contact portion that contacts the stent, and the contact portion has a top portion and a side portion. Since the side part is linearly connected to the top part, the flexible part of the stent can pass through the gap formed between the side part and the outer sheath when installing a stent having a flexible part at the end part. . Thereby, when pushing out a stent, the top part of a contact part can contact the proximal end of the cylindrical part of a stent directly, and can push out a stent from an outer sheath. At this time, the plurality of tops push the cylindrical part, so that the stent can be pushed reliably and in a balanced manner.
  • the flexible part passes through the gap between the side part and the outer sheath, so that the problem that the flexible part is sandwiched between the outer sheath and the inner shaft can be suitably prevented.
  • the work for housing the is easier than the work for housing the flexible portion in the groove provided in the inner shaft, and the workability is good. Furthermore, since it is not necessary to form a groove in the connection portion, the connection portion can be easily manufactured, and manufacturing variations can be suppressed.
  • an angle ⁇ 1 formed by both ends of the top and the center position of the inner shaft is smaller than an angle ⁇ 2 formed by both ends of the side and the center position. Also good.
  • the flexible portion of the stent can be easily disposed between the side portion and the outer sheath.
  • the inner shaft has a resin outer tube having the first outer diameter and the second outer diameter, and the distal end of the outer tube is inserted through the outer tube. A distal end exposed from the inner tube may constitute the second portion.
  • the inner shaft which is a double tube structure with an inner tube and an outer tube, is manufactured so that the distal end of the outer tube is processed or a metal ring is disposed at the distal end of the outer tube, so that a contact portion can be easily formed. Is easy.
  • the contact portion may be formed of a metal ring.
  • the stent cylindrical portion comes into contact with the top of the metal ring, which is a relatively hard material, during the stent release operation, so that the second portion can be more reliably and stably provided. Can stay in.
  • the contact portion is a metal ring, the frictional force generated between the top of the contact portion and the outer sheath can be suppressed during stent release. Are better.
  • FIG. 1 is an external view of a stent delivery system according to an embodiment of the present invention.
  • FIG. 2 is an external view showing an example of a stent provided in the stent delivery system of FIG.
  • FIG. 3 is a partially enlarged view of the stent delivery system shown in FIG. 1 and shows the stent housed in the stent delivery system and its peripheral portion.
  • FIG. 4 shows the stent accommodation part in the stent delivery system with the stent hidden.
  • FIG. 5 is a cross-sectional view of the stent delivery system shown in FIG. 6 is an external view of a contact portion included in the stent delivery system shown in FIG. FIG.
  • FIG. 7 is a partially enlarged view showing the periphery of the contact portion of the inner shaft included in the stent delivery system shown in FIG.
  • FIG. 8 is a cross-sectional view illustrating a cross-sectional shape of the contact portion according to the embodiment and the modification.
  • FIG. 1 is an external view of a stent delivery system 10 according to an embodiment of the present invention
  • FIG. 1A shows a stent delivery system 10 in a first state in which a stent 20 is accommodated
  • FIG. Represents the distal end portion of the second state stent delivery system 10 that releases the stent 20.
  • the stent delivery system 10 for placing a stent inserted into the digestive tract via the treatment instrument channel of the endoscope and bypassing the stomach or duodenum and the bile duct or gallbladder will be described as an example.
  • the application of the stent delivery system 10 is not limited to this.
  • the direction in which the stent delivery system 10 extends from the proximal end where the operation unit 30 is arranged to the distal end where the tip tip 80 is arranged is an axial direction. Do.
  • the stent delivery system 10 includes a stent 20, an operation unit 30, an outermost tube 40, an outer sheath 50, an inner shaft 60, a distal tip 80, and the like.
  • the total length of the stent delivery system 10 is, for example, about 300 to 2500 mm, although it varies depending on the placement position of the stent 20 and the transport route.
  • the stent 20 is housed near the distal end of the stent delivery system 10.
  • the operator of the stent delivery system 10 sets the stent delivery system 10 to the second state shown in FIG. 1B after transporting the stent 20 to the indwelling position in the body in the first state shown in FIG.
  • the stent 20 is released and placed at the placement position.
  • the inner shaft 60 extends in the axial direction from the operation unit 30 provided at the proximal end of the stent delivery system 10 to the tip tip 80 provided at the distal end of the stent delivery system 10. In the first state shown in FIG. 1A, the inner shaft 60 is accommodated inside the outer sheath 50 and the housing 31 of the operation unit 30.
  • the inner shaft 60 includes a first portion 60a having a first outer diameter and a second portion having a second outer diameter smaller than the outer diameter of the first portion 60a. 60b.
  • the second portion 60b at the distal end is exposed.
  • FIG. 5 is a cross-sectional view of the stent delivery system 10 with a cross section perpendicular to the axial direction, and shows a cross section at a position closer to the proximal end side than a connecting portion 66 (see FIG. 3) described later.
  • the inner shaft 60 includes a resin outer tube 64 having a first outer diameter and a resin inner tube 62 having a second outer diameter. It has a double pipe structure in which the inner pipe 62 is inserted through the lumen.
  • FIG. 1 (b) and FIG. 4 which is a partially enlarged view, the distal end of the inner tube 62 is exposed from the distal end of the outer tube 64 and the contact portion 66, and the second end of the inner shaft 60.
  • a portion 60b is formed.
  • a guide wire lumen 62a through which a guide wire is inserted when the stent delivery system 10 is guided in the body using a guide wire is formed inside the inner tube 62.
  • a distal end tip 80 is provided at the distal end of the inner shaft 60, and a through hole communicating with the guide wire lumen 62a is formed in the distal end tip 80.
  • the distal tip 80 is made of resin or the like, and has a rounded outer shape so that it can be prevented from being damaged when it contacts the tube wall of the body lumen.
  • the inner shaft 60 has a contact portion 66 that contacts the stent 20 accommodated in the stent delivery system 10 at the boundary position between the first portion 60 a and the second portion 60 b.
  • the contact portion 66 shown in FIG. 4 is disposed at the distal end of the first portion 60a, and is configured by a metal ring through which the inner tube 62 is inserted.
  • the outer diameter (radius) of the contact portion 66 is represented by the length from the surface of the top portion 66a shown in FIG. 8 to the center position 60c of the inner shaft 60, and in this embodiment, the outer tube 64 (first portion 60a). This coincides with the outer diameter (first outer diameter).
  • the outer diameter of the contact portion 66 does not have to completely match the outer diameter (first outer diameter) of the outer tube 64 (first portion 60a), and the outer tube 64 (first portion). You may have an outer diameter larger than the outer diameter (1st outer diameter) of 60a).
  • the detailed structure of the inner shaft 60 including the contact portion 66 will be described later.
  • the inner tube 62 and the outer tube 64 have flexibility, and a thermoplastic resin having a certain degree of rigidity and slidability is preferably used as the material thereof.
  • the inner tube 62 is formed of a high-rigidity thermoplastic resin
  • the outer tube 64 is formed of a thermoplastic resin that is excellent in slidability.
  • the surface of the outer tube 64 may be coated to improve the slidability with the outer sheath 50 and the rigidity of the inner shaft 60.
  • the outer diameter of the outer tube 64 is about 0.5 to 3.0 mm, but is not particularly limited.
  • the total length of the inner shaft 60 is substantially the same as the total length of the stent delivery system 10.
  • the outer sheath 50 is inserted through the first portion 60a and the second portion 60b of the inner shaft 60.
  • FIG. 5 which is a cross-sectional view
  • An inner tube 62 and an outer tube 64 of the inner shaft 60 are inserted through the lumen of the outer sheath 50.
  • a gap is formed between the outer peripheral surface of the inner tube 62 and the inner wall of the outer sheath 50 in the second portion 60 b of the inner shaft 60 where the outer tube 64 and the contact portion 66 do not exist.
  • the cylindrical portion 22 (see FIG. 2) of the stent 20 is accommodated in the gap.
  • the outer sheath 50 is movable relative to the inner shaft 60 in the axial direction from the first state shown in FIG. 1A to the second state shown in FIG.
  • the proximal end of the outer sheath 50 is accommodated in the housing 31 of the operation unit 30.
  • the operation unit 30 moves the outer sheath 50 relative to the inner shaft 60 toward the proximal end side in the axial direction in conjunction with the operation of the operation lever 33 attached to the housing 31.
  • the stent delivery system 10 is configured to expose the stent 20 and the second portion 60b from the first state in which the outer sheath 50 covers the second portion 60b of the inner shaft 60 (FIG. 1A). (FIG. 1 (b)).
  • An outermost tube 40 that further covers the outer periphery of the outer sheath 50 is provided in the vicinity of the operation unit 30.
  • the outermost tube 40 covers the outer sheath 50, so that such a problem can be prevented.
  • the outer sheath 50 has flexibility, and is formed by embedding a resin layer 51 made of a polymer material and a plurality of wires embedded in the resin layer 51 in a spiral shape.
  • a braided body 52 is provided in a portion of the outer sheath 50 excluding the distal end portion that covers the second portion 60 b of the inner shaft 60.
  • the material constituting the resin layer 51 is preferably a transparent polymer material through which the outer sheath 50 can be seen and the stent 20 inside thereof can be visually observed.
  • polyolefins such as polyethylene and polypropylene, polyvinyl chloride, polyurethane, ethylene-vinyl acetate copolymer, polyesters such as polyethylene terephthalate and polybutylene terephthalate, fluorine-based materials such as polyamide, polyether polyamide, polyester polyamide, and polytetrafluoroethylene
  • resin materials such as resin, and various thermoplastic elastomers such as styrene, polyolefin, polyurethane, polyester, polyamide, and polybutadiene can be used. Two or more of these can be used in combination.
  • the braided body 52 is configured by braiding a plurality of metal wire rods, and forms a tubular body as a whole.
  • each wire has a shape wound spirally.
  • the material of the wire constituting the braided body 52 is, for example, a simple metal such as gold, silver, platinum, copper, iridium, nickel, titanium, tungsten, iron, aluminum, tin, zinc, stainless steel, nichrome steel, nickel-titanium.
  • An alloy such as an alloy or a titanium-based alloy may be used.
  • stainless steel such as SUS304 and SUS316, from a viewpoint of workability, strength, and corrosion resistance.
  • FIG. 2 is an external view of the stent 20 accommodated in the stent delivery system 10.
  • the stent 20 is a self-expanding stent that contracts in the radial direction by applying a force in the radial direction and elastically deforms, and expands in the radial direction from its contracted state by its own elastic force when the force is released. It is.
  • the stent 20 is described as an example of a covered stent for bypassing a luminal organ that bypasses the stomach or duodenum and the bile duct or gallbladder. It is not limited to this.
  • the stent housed in the stent delivery system 10 may be a bare stent.
  • the stent 20 includes a cylindrical portion 22 and flexible portions 24 and 28 connected to the proximal end and the distal end of the cylindrical portion 22.
  • the cylindrical portion 22 includes a frame portion 22a formed by connecting zigzag annular struts in the axial direction with a bridge, and a cover film 22b covering the outer peripheral surfaces of the frame portion 22a and the cylindrical frame portion 22a. And have.
  • the frame portion 22a is made of, for example, a superelastic alloy such as a nickel titanium alloy or a cobalt chromium alloy, a shape memory alloy, or the like, but may be made of another metal or resin.
  • the material of the cover film 22b is not particularly limited, but a polymer material that is soluble in an organic solvent and has little toxicity is preferable.
  • examples of the polymer material used for the cover film 22b include non-biodegradable polymers and biodegradable polymers, and non-biodegradable polymers such as polyurethane or silicone resin are particularly preferable.
  • the axial length of the cylindrical portion 22 is appropriately determined depending on the application of the stent 20, but may be, for example, 10 to 200 mm. Further, the outer diameter of the cylindrical portion 22 at the time of expansion is also appropriately determined according to the location where the stent 20 is placed, but can be, for example, about ⁇ 2 to 20 mm. Note that the outer diameter of the cylindrical portion 22 when the diameter is reduced (when accommodated in the stent delivery system 10) is 1/2 of the outer diameter when the diameter is expanded (when released from the stent delivery system 10). About 1/10.
  • the flexible portion 24 connected to the proximal end of the cylindrical portion 22 is more flexible than the cylindrical portion 22 and is more easily deformed than the cylindrical portion 22 with respect to a force from the axial direction.
  • the flexible portion 24 has a plurality of linear members 25 extending from the proximal end of the cylindrical portion 22.
  • the base end 25a, which is one end of the linear member 25, is connected to the frame portion 22a of the cylindrical portion 22, and the tip 25b, which is the other end, extends from the base end 25a toward the outside of the cylindrical portion 22. It extends to bend.
  • the flexible portion 24 on the proximal end side of the stent 20 is such that the distal end 25b of the linear member 25 is extended in the axial direction while the stent 20 is housed in the stent delivery system 10.
  • the distal end 25b of the linear member 25 is elastically deformed so as to bend from the proximal end 25a to the outer side of the cylindrical portion 22, It becomes in the state shown in 2 and is left in the body.
  • a round tip protection portion 26 is connected to the tip 25 b of the linear member 25.
  • the tip protector 26 is connected to the tips 25 b of the two linear members 25.
  • the flexible portion 24 connected to the proximal end of the cylindrical portion 22 has a total of six linear members 25 connected at substantially equal intervals along the circumferential direction of the cylindrical portion 22.
  • the number of 25 is not particularly limited.
  • the linear member 25 is made of an elastically deformable material, for example, the same material as the frame portion 22a of the cylindrical portion 22.
  • the length of the linear member 25 is not particularly limited, but is preferably selected in the range of 10 to 50 mm, for example.
  • the wire diameter of the linear member 25 is thinner than the wire diameter of the strut which comprises the flame
  • the tip protection part 26 may be made of the same material as that of the linear member 25 or may be made of an X-ray opaque material. When the tip protector 26 is made of an X-ray opaque material, the tip protector 26 functions as an X-ray marker.
  • the flexible part 28 connected to the distal end of the cylindrical part 22 is the same as the flexible part 24 connected to the proximal end of the cylindrical part 22 except that its connection position and shape are symmetrical.
  • the flexible portions 24 and 28 of the stent 20 come into contact with the inner wall of the luminal organ by spreading in the radial direction.
  • the flexible parts 24 and 28 can effectively prevent migration of the stent 20 by supporting the stent 20 by its elastic force.
  • the flexible portions 24 and 28 serve as buffer portions that prevent the distal end or proximal end of the relatively rigid cylindrical portion 22 from coming into strong contact with the body lumen during and after placement of the stent 20. It can function and prevent the problem that the stent 20 damages the body lumen.
  • the manufacturing method of the stent 20 shown in FIG. 2 is not particularly limited.
  • the frame portion 22a and the flexible portions 24, 28 connected to both ends thereof are formed.
  • the cover film 22b can be covered only on the frame portion 22a.
  • the curved shape of the linear member 25 is formed by brazing after processing.
  • the linear members 25 constituting the flexible portions 24 and 28 may be formed separately from the frame portion 22a and then fixed to the distal end and the proximal end of the frame portion 22a by welding or the like.
  • FIG. 3 is a partially enlarged view showing a peripheral portion of the stent 20 accommodated in the stent delivery system 10 in the first state shown in FIG.
  • the outer sheath 50 is seen through for easy explanation.
  • the cylindrical portion 22 of the stent 20 is accommodated between the second portion 60 b of the inner shaft 60 and the outer sheath 50.
  • the flexible portion 28 (distal end flexible portion) connected to the distal end of the cylindrical portion 22 is also accommodated between the second portion 60 b and the outer sheath 50, similarly to the cylindrical portion 22.
  • the flexible part 24 connected to the proximal end of the stent 20 is connected to the side part 66b (see FIG. 3) of the contact part 66 disposed at the distal end of the first part 60a of the inner shaft 60. It is accommodated between the outer sheath 50.
  • FIG. 4 shows the accommodation portion of the stent 20 shown in FIG. 3 with the stent 20 hidden. By comparing FIG. 4 and FIG. It can be understood that it is accommodated between the side portion 66b (see FIG. 3) and the outer sheath 50.
  • FIG. 6 is an external view of a metal ring constituting the contact portion 66.
  • the contact part 66 has a substantially polygonal columnar outer shape extending in the axial direction. In the center of the contact portion 66, a through hole 66c penetrating in the axial direction is formed. As shown in FIG. 7, the through hole 66 c of the contact portion 66 is inserted through the inner tube 62 of the inner shaft 60.
  • the contact portion 66 is attached to a ring installation portion 62 b formed on the outer peripheral surface of the proximal end of the inner tube 62 exposed from the distal end of the outer tube 64.
  • the end surface on the proximal end side of the contact portion 66 is in contact with the outer tube distal end surface 64 b that is the end surface on the distal end side of the outer tube 64.
  • FIG. 8A shows a cross section perpendicular to the axial direction of the contact portion 66.
  • the contact portion 66 has three top portions 66a having an outer diameter substantially coincident with the outer diameter of the outer tube 64 (first portion 60a) in a cross section perpendicular to the axial direction.
  • the outer surface of the top portion 66a has an arc shape that substantially matches the outer peripheral surface of the outer tube 64 when viewed from the axial direction, and the three top portions 66a are arranged at equal intervals (120 ° intervals) in the circumferential direction. Yes.
  • the contact portion 66 has three side portions 66b that linearly connect the three top portions 66a.
  • An angle ⁇ 1 formed between both ends of the top 66a and the center position 60c is smaller than an angle ⁇ 2 formed between both ends of the side 66b and the center position 60c, and when the stent delivery system 10 is in the first state, A large gap is secured between the portion 66b and the outer sheath 50.
  • the value of ⁇ 1 / ⁇ 2 can be set to 0.1 to 0.9, for example.
  • “straightly connected” in “straightly connected” does not mean that the side portion is linear in a strict sense, and in a range not departing from the present invention. Specifically, as long as the flexible part of the stent can be easily accommodated in the gap formed between the side part and the outer sheath, it does not prevent part or all of the side part from being a polygonal line or a curved line. .
  • the some top part 66a of the contact part 66 has the mutually same shape.
  • the plurality of side portions 66b also have the same shape as each other, although the arrangement with respect to the center position 60c is different, similarly to the top portion 66a.
  • the plurality of top portions 66a or the plurality of side portions 66b may have different shapes.
  • the flexible portion 24 connected to the proximal end of the cylindrical portion 22 is formed by the three side portions 66 b of the contact portion 66 and the outer sheath 50. Each of the gaps formed between them extends through the proximal end side.
  • the outer side of the contact portion 66 is covered with the outer sheath 50, and therefore, the linear member 25 that is brazed to curve outward as shown in FIG.
  • the linear member 25 is stretched by elastic deformation and brought close to the side portion 66b, and its restoration is pressed by the outer sheath 50 from the outside, so that it is suitably accommodated between the side portion 66b and the outer sheath 50.
  • the six linear members 25 constituting the flexible portion 24 on the proximal end side are equally accommodated two by two in the gaps between the side portions 66b and the outer sheath 50.
  • the number of the linear members 25 accommodated in the gaps between the side portions 66b and the outer sheath 50 may be different from each other.
  • the flexible portion 24 connected to the proximal end of the cylindrical portion 22 passes through a gap formed between the side portion 66 b and the outer sheath 50, so that the contact portion 66 becomes free from the stent 20. Can directly contact the proximal end of the cylindrical portion 22. That is, the top portion 66 a of the contact portion 66 shown in FIG. 7 has an outer diameter that is substantially equal to the outer diameter of the cylindrical portion 22 of the stent 20 that is maintained in a contracted state by the outer sheath 50.
  • the contact portion distal end surface 66d around the top portion 66a of the contact portion 66 contacts the proximal end of the cylindrical portion 22 of the stent 20 when the stent delivery system 10 releases the stent 20, and the Thus, a force for pushing the stent 20 toward the distal end side can be directly applied.
  • the material of the metal ring constituting the contact portion 66 is not particularly limited as long as it is a metal or alloy harder than the resin constituting the outer tube 64, and may be stainless steel, gold, platinum, tungsten, etc. It is preferable to use an X-ray opaque material such as platinum or tungsten because the contact portion 66 becomes an X-ray opaque marker.
  • the top portion 66a, the side portion 66b and the through hole 66c are formed by machining the material, or a metal ring having the shape shown in FIG. 6 is cast.
  • the manufacturing method of the contact portion 66 is not particularly limited.
  • the contact portion 66 is fixed to the ring installation portion 62b of the inner tube 62 by, for example, adhesion, but the fixing method of the contact portion 66 is not particularly limited.
  • the contact portion 66 disposed on the proximal end side of the second portion 60b where the cylindrical portion 22 of the stent 20 is installed has the plurality of top portions 66a and the plurality of side portions 66b.
  • the flexible part 24 can pass through a gap formed between the side part 66b and the outer sheath 50.
  • the top portion 66 a of the contact portion 66 can directly contact the proximal end of the cylindrical portion 22 of the stent 20 to push the stent 20 out of the outer sheath 50.
  • the plurality of top portions 66a press the cylindrical portion 22, whereby the stent 20 can be pressed reliably and in a well-balanced manner.
  • the flexible portion 24 on the proximal end side of the stent 20 is disposed between the side portion 66 b of the contact portion 66 disposed at the distal end portion of the first portion 60 a of the inner shaft 60 and the outer sheath 50. It can be accommodated in the gap formed in.
  • the linear member 25 included in the flexible portion 24 may be accommodated in a state of being stretched along the axial direction as shown in FIG. 3, but the linear member 25 is curved or folded. In this state, it may be accommodated between the side portion 66b and the outer sheath 50. Further, the tip 25b of the linear member 25 may be positioned closer to the proximal end side than the contact portion 66. In this case, the linear member 25 and the tip protector 26 are provided at the distal end of the outer tube 64. A groove or a notch to be accommodated may be formed.
  • the contact portion 66 as shown in FIG. 7 has a simple shape, it can be easily manufactured by molding or machining, and has good dimensional accuracy.
  • the shape of the contact part 66 is not limited to this.
  • another R shape, chamfering shape, or groove shape may be formed between the top portion 66a and the side portion 66b of the contact portion 66.
  • the proximal end side end surface of the cylindrical portion 22 has the contact portion 66.
  • the cylindrical portion 22 can remain in the second portion 60b. Therefore, in the stent delivery system 10, the releasing operation of the stent 20 can be performed smoothly without crushing the flexible portion 24.
  • the contact portion 66 in contact with the outer tube distal end surface 64 b of the outer tube 64, the force from the cylindrical portion 22 is applied to the contact portion 66 in the releasing operation of the stent 20. And the outer tube 64 can be received stably.
  • the stent delivery system 10 can smoothly perform the releasing operation of the stent 20. Moreover, when installing the stent 20 in the stent delivery system 10, the operation
  • the contact portion 66 is configured by a metal ring.
  • the contact portion 66 is not limited to this, and the contact portion is configured by using a resin ring.
  • the contact portion may be formed by processing the distal end of a member included in the first portion 60a such as the outer tube 64.
  • the shape of the contact portion 66 is not limited to the shape having three top portions 66a and three side portions 66b as shown in FIGS. 6 and 8A, and the contact portion has a prismatic shape other than the triangular prism shape. It may have the outer shape.
  • FIG. 8B shows a cross section perpendicular to the axial direction of the contact portion 166 according to the first modification.
  • the contact portion 166 has two top portions 166a and two side portions 166b.
  • FIG. 8C shows a cross section perpendicular to the axial direction of the contact portion 266 according to the second modification.
  • the contact portion 266 has four top portions 266a and four side portions 266b.
  • the stent delivery system using the contact portions 166 and 266 according to the first or second modification instead of the contact portion 66 also has the same effect as the stent delivery system 10 shown in FIGS.
  • FIG. 8D shows a cross section perpendicular to the axial direction of the contact portion 366 according to the third modification.
  • the contact portion 366 has six top portions 366a and six side portions 366b.
  • the top portion 366a of the contact portion 366 is a connection point between two adjacent side portions 366b.
  • Such a contact portion 366 can be applied to the stent delivery system 10 instead of the contact portion 66.

Abstract

Provided is a stent delivery system with which a stent having a flexible portion on an end thereof can be placed with good operability. The stent delivery system comprises: an inner shaft having a first portion with a first outer diameter and a second portion that is connected to the distal end of the first portion; and a stent including an outer sheath that is inserted into the first portion and the second portion and that can relatively move from a first state in which the second portion is covered to a second state in which the second portion is exposed from the distal end, a cylindrical part that is accommodated between the second portion and the outer sheath, and a flexible part that is connected to the proximal end of the cylindrical part. The stent delivery system is characterized in that the inner shaft has a contact part (66) that contacts the stent at a boundary position between the first portion and the second portion, and the contact part (66) includes, in a cross-section perpendicular to the axial direction, a plurality of apex sections (66a) having an outer diameter that is equal to or greater than the first outer diameter, and a plurality of side sections (66b) that linearly connect the plurality of apex sections (66a).

Description

ステントデリバリーシステムStent delivery system
　本発明は、体内に留置するステントを留置位置まで搬送するためのステントデリバリーシステムに関する。 The present invention relates to a stent delivery system for transporting a stent to be placed in the body to an indwelling position.
　胆管その他の消化器系管腔臓器の治療を目的として、各種のステントを体内に挿入・留置する手技が行われている。ステントには、拡張のタイプにより自己拡張型とバルーン拡張型があり、また、樹脂被覆の有無によりカバードステントとベアステントがあり、用途に応じて使い分けられる。また、ステントの形状等についても、単純な円筒状のものだけではなく、種々の形状を有するものが用いられている。たとえば、超音波内視鏡ガイド下胆道ドレナージ（ＥＵＳ－ＢＤ）を施行する場合などにおいて、管腔臓器（たとえば、胃や十二指腸等の消化管）と他の管腔臓器（たとえば、胆管または胆嚢等）をバイパス接続するために用いられるステントにおいて、マイグレーションや体内管腔への穿孔を防止するために、端部にフック等の柔軟な部分を有するものが提案されている（特許文献１参照）。 For the treatment of bile ducts and other gastrointestinal luminal organs, various stents are inserted and placed in the body. There are two types of stents, a self-expandable type and a balloon-expandable type depending on the type of expansion, and a covered stent and a bare stent depending on the presence or absence of resin coating. In addition, as for the shape and the like of the stent, not only a simple cylindrical shape but also various shapes are used. For example, when performing endoscopic ultrasound-guided biliary drainage (EUS-BD), a luminal organ (eg, a digestive tract such as the stomach or duodenum) and another luminal organ (eg, bile duct or gallbladder) In order to prevent migration and perforation into the body lumen, a stent having a flexible portion such as a hook at the end has been proposed (see Patent Document 1).
　ところで、自己拡張型のステントは、ステントデリバリーシステムの遠位端に搭載され、留置位置まで運ばれた後に、ステントデリバリーシステムから放出される。ステントデリバリーシステムの構造としては、たとえば、アウターシースを近位端側に相対移動させ、インナーシャフトの遠位端を露出させることで、インナーシャフトとアウターシースの間に搭載されたステントを放出するものが挙げられる。このようなステントデリバリーシステムからステントを放出する際、ステントは、アウターシースとの摩擦力によって生じる軸方向の力に抗して、インナーシャフトの所定位置に留まる必要がある。 By the way, the self-expanding stent is mounted on the distal end of the stent delivery system, and is delivered to the indwelling position, and then released from the stent delivery system. As the structure of the stent delivery system, for example, the stent mounted between the inner shaft and the outer sheath is released by moving the outer sheath relative to the proximal end side and exposing the distal end of the inner shaft. Is mentioned. When releasing a stent from such a stent delivery system, the stent needs to remain in place on the inner shaft against the axial force generated by the frictional force with the outer sheath.
　しかし、特許文献１に記載されるような端部に柔軟な部分を有するステントをステントデリバリーシステムから放出しようとすると、放出動作の際に柔軟な部分が押しつぶされ、または、アウターシースとインナーシャフトの間に柔軟な部分が引っ掛かり、ステントが本来意図した位置に、適切な形状で放出できない問題が生じ得る。そこで、この問題を解決するためのステントデリバリーシステムとして、インナーシャフトに柔軟な部分を収容するための溝を形成したものが提案されている（特許文献２参照）。このステントデリバリーシステムによれば、ステントの柔軟な部分を溝に収容して、ステントの柔軟な部分以外の部分（円筒部）をインナーシャフトの端面に接触させることによって、端部に柔軟な部分を有するステントを適切に放出することができる。 However, when a stent having a flexible part at the end as described in Patent Document 1 is to be released from the stent delivery system, the flexible part is crushed during the releasing operation, or the outer sheath and the inner shaft There may be a problem that the flexible part is caught between them, and the stent cannot be released in an appropriate shape at the originally intended position. Thus, as a stent delivery system for solving this problem, a system in which a groove for accommodating a flexible portion is formed in an inner shaft has been proposed (see Patent Document 2). According to this stent delivery system, the flexible portion of the stent is accommodated in the groove, and the portion (cylindrical portion) other than the flexible portion of the stent is brought into contact with the end surface of the inner shaft, whereby the flexible portion is formed at the end portion. The stent it has can be released appropriately.
特開２０１５－６６２２１号公報Japanese Patent Laying-Open No. 2015-66221 特開２０１７－１７６６６６号公報JP 2017-176666 A
　しかしながら、特許文献２に記載されたステントデリバリーシステムに端部に柔軟な部分を有するステントを設置しようとするとき、インナーシャフトの溝にステントの柔軟な部分を収容する作業の困難性が高く、作業性の観点において、改良の余地があった。 However, when a stent having a flexible portion at the end is to be installed in the stent delivery system described in Patent Document 2, it is highly difficult to accommodate the flexible portion of the stent in the groove of the inner shaft. There was room for improvement in terms of sex.
　本発明は、このような実状に鑑みてなされ、その目的は、端部に柔軟な部分を有するステントを良好な作業性で設置することができるステントデリバリーシステムを提供することである。 The present invention has been made in view of such a situation, and an object thereof is to provide a stent delivery system capable of installing a stent having a flexible portion at an end portion with good workability.
　上記目的を達成するために、本発明に係るステントデリバリーシステムは、
　第１の外径を有する第１の部分と、前記第１の部分の遠位端に接続しており前記第１の外径より小さい第２の外径を有する第２の部分と、を有するインナーシャフトと、
　前記第１の部分および前記第２の部分に挿通されており、前記第２の部分を覆う第１の状態から、前記第２の部分を遠位端から露出させる第２の状態へ、前記インナーシャフトに対して軸方向に相対移動可能なアウターシースと、
　前記第２の部分と前記アウターシースとの間に収容される円筒部と、前記円筒部の近位端に接続しており前記軸方向からの力に対して前記円筒部より変形しやすい柔軟部と、を有するステントと、を有しており、
　前記インナーシャフトは、前記第１の部分と前記第２の部分との境界位置に、前記ステントに接触する接触部を有し、
　前記接触部は、前記軸方向に垂直な断面において、前記第１の外径以上の外径を有する複数の頂部と、複数の前記頂部の間を直線的に接続する複数の辺部と、を有する。 In order to achieve the above object, a stent delivery system according to the present invention comprises:
A first portion having a first outer diameter; and a second portion connected to a distal end of the first portion and having a second outer diameter that is smaller than the first outer diameter. An inner shaft,
From the first state that is inserted through the first part and the second part and covers the second part, to the second state that exposes the second part from the distal end, the inner part An outer sheath that can move relative to the shaft in the axial direction;
A cylindrical portion accommodated between the second portion and the outer sheath, and a flexible portion that is connected to the proximal end of the cylindrical portion and is more easily deformed than the cylindrical portion with respect to a force from the axial direction. And a stent having
The inner shaft has a contact portion that contacts the stent at a boundary position between the first portion and the second portion;
In the cross section perpendicular to the axial direction, the contact portion includes a plurality of top portions having an outer diameter equal to or larger than the first outer diameter, and a plurality of side portions linearly connecting the plurality of top portions. Have.
　本発明に係るステントデリバリーシステムは、インナーシャフトがステントに接触する接触部を有しており、接触部が頂部と辺部とを有する。辺部は頂部を直線的に接続しているため、端部に柔軟部を有するステントを設置する際に、辺部とアウターシースとの間に形成される隙間を、ステントの柔軟部が通過できる。これにより、ステントを押し出す際に、接触部の頂部は、ステントの円筒部の近位端に直接接触して、ステントをアウターシースから押し出すことができる。この際、複数の頂部が円筒部を押すことにより、確実かつバランス良くステントを押すことができる。また、辺部とアウターシースとの隙間を柔軟部が通過することにより、柔軟部がアウターシースとインナーシャフトに挟まれる問題を好適に防止でき、しかも、辺部とアウターシースとの隙間に柔軟部を収容する作業は、柔軟部をインナーシャフトに設けた溝に収容する作業等に比して容易であり、作業性が良好である。さらに、接続部に溝を形成する必要がないため、接続部の製造が容易であり、製造バラツキも抑制できる。 In the stent delivery system according to the present invention, the inner shaft has a contact portion that contacts the stent, and the contact portion has a top portion and a side portion. Since the side part is linearly connected to the top part, the flexible part of the stent can pass through the gap formed between the side part and the outer sheath when installing a stent having a flexible part at the end part. . Thereby, when pushing out a stent, the top part of a contact part can contact the proximal end of the cylindrical part of a stent directly, and can push out a stent from an outer sheath. At this time, the plurality of tops push the cylindrical part, so that the stent can be pushed reliably and in a balanced manner. Further, the flexible part passes through the gap between the side part and the outer sheath, so that the problem that the flexible part is sandwiched between the outer sheath and the inner shaft can be suitably prevented. The work for housing the is easier than the work for housing the flexible portion in the groove provided in the inner shaft, and the workability is good. Furthermore, since it is not necessary to form a groove in the connection portion, the connection portion can be easily manufactured, and manufacturing variations can be suppressed.
　また、たとえば、前記軸方向に垂直な断面において、前記頂部の両端部と前記インナーシャフトの中心位置とがなす角θ１は、前記辺部の両端部と前記中心位置とがなす角θ２より小さくてもよい。 Further, for example, in a cross section perpendicular to the axial direction, an angle θ1 formed by both ends of the top and the center position of the inner shaft is smaller than an angle θ2 formed by both ends of the side and the center position. Also good.
　角θ１を角θ２より小さくすることにより、辺部とアウターシースとの間に、ステントの柔軟部を配置しやすくなる。 By making the angle θ1 smaller than the angle θ2, the flexible portion of the stent can be easily disposed between the side portion and the outer sheath.
　また、たとえば、前記インナーシャフトは、前記第１の外径を有する樹脂製の外管と、前記第２の外径を有しており、前記外管を挿通し、前記外管の遠位端から露出する遠位端が前記第２の部分を構成する内管と、を有してもよい。 Further, for example, the inner shaft has a resin outer tube having the first outer diameter and the second outer diameter, and the distal end of the outer tube is inserted through the outer tube. A distal end exposed from the inner tube may constitute the second portion.
　内管と外管による２重管構造であるインナーシャフトは、外管の遠位端を加工するか、または外管の遠位端に金属リングを配置することなどにより接触部を形成しやすく製造が容易である。 The inner shaft, which is a double tube structure with an inner tube and an outer tube, is manufactured so that the distal end of the outer tube is processed or a metal ring is disposed at the distal end of the outer tube, so that a contact portion can be easily formed. Is easy.
　また、たとえば、前記接触部は、金属リングで構成されていてもよい。 Further, for example, the contact portion may be formed of a metal ring.
　接触部を金属リングで構成することにより、ステント放出動作時において、ステントの円筒部は、比較的硬質の材料である金属リングの頂部に接触することで、より確実かつ安定的に第２の部分に留まることができる。また、接触部を金属リングとすることにより、ステント放出時において、接触部の頂部とアウターシースとの間に生じる摩擦力を抑制することができるため、このようなステントデリバリーシステムは、操作性に優れている。 By configuring the contact portion with a metal ring, the stent cylindrical portion comes into contact with the top of the metal ring, which is a relatively hard material, during the stent release operation, so that the second portion can be more reliably and stably provided. Can stay in. In addition, since the contact portion is a metal ring, the frictional force generated between the top of the contact portion and the outer sheath can be suppressed during stent release. Are better.
図１は、本発明の一実施形態に係るステントデリバリーシステムの外観図である。FIG. 1 is an external view of a stent delivery system according to an embodiment of the present invention. 図２は、図１のステントデリバリーシステムに備えられるステントの一例を表す外観図である。FIG. 2 is an external view showing an example of a stent provided in the stent delivery system of FIG. 図３は、図１に示すステントデリバリーシステムの部分拡大図であり、ステントデリバリーシステムに収容されたステントおよびその周辺部分を表している。FIG. 3 is a partially enlarged view of the stent delivery system shown in FIG. 1 and shows the stent housed in the stent delivery system and its peripheral portion. 図４は、ステントデリバリーシステムにおけるステントの収容部分を、ステントを非表示状態にして表したものである。FIG. 4 shows the stent accommodation part in the stent delivery system with the stent hidden. 図５は、図１に示すステントデリバリーシステムの断面図である。FIG. 5 is a cross-sectional view of the stent delivery system shown in FIG. 図６は、図１に示すステントデリバリーシステムに含まれる接触部の外観図である。6 is an external view of a contact portion included in the stent delivery system shown in FIG. 図７は、図１に示すステントデリバリーシステムに含まれるインナーシャフトにおける接触部周辺を表す部分拡大図である。FIG. 7 is a partially enlarged view showing the periphery of the contact portion of the inner shaft included in the stent delivery system shown in FIG. 図８は、実施形態および変形例に係る接触部の断面形状を表す断面図である。FIG. 8 is a cross-sectional view illustrating a cross-sectional shape of the contact portion according to the embodiment and the modification.
　本発明のステントデリバリーシステムについて、図１～図８に示す実施形態を参照して説明する。 The stent delivery system of the present invention will be described with reference to the embodiment shown in FIGS.
　図１は本発明の一実施形態に係るステントデリバリーシステム１０の外観図であり、図１（ａ）はステント２０を収容した第１状態のステントデリバリーシステム１０を表しており、図１（ｂ）はステント２０を放出する第２状態のステントデリバリーシステム１０の遠位端部分を表している。なお、本実施形態では、内視鏡の処置具チャネルを介して消化管に挿入されて、胃または十二指腸と胆管または胆嚢とをバイパス接続するステントを留置するためのステントデリバリーシステム１０を例に説明を行うが、ステントデリバリーシステム１０の用途は、これに限定されない。また、ステントデリバリーシステム１０の説明においては、操作部３０が配置される近位端から先端チップ８０が配置される遠位端まで、ステントデリバリーシステム１０が延在する方向を軸方向として、説明を行う。 FIG. 1 is an external view of a stent delivery system 10 according to an embodiment of the present invention, and FIG. 1A shows a stent delivery system 10 in a first state in which a stent 20 is accommodated, and FIG. Represents the distal end portion of the second state stent delivery system 10 that releases the stent 20. In the present embodiment, the stent delivery system 10 for placing a stent inserted into the digestive tract via the treatment instrument channel of the endoscope and bypassing the stomach or duodenum and the bile duct or gallbladder will be described as an example. However, the application of the stent delivery system 10 is not limited to this. In the description of the stent delivery system 10, the direction in which the stent delivery system 10 extends from the proximal end where the operation unit 30 is arranged to the distal end where the tip tip 80 is arranged is an axial direction. Do.
　図１に示すように、ステントデリバリーシステム１０は、ステント２０、操作部３０、最外管４０、アウターシース５０、インナーシャフト６０および先端チップ８０等を有する。ステントデリバリーシステム１０の全長は、ステント２０の留置位置や搬送経路等によって異なるが、たとえば３００～２５００ｍｍ程度である。 As shown in FIG. 1, the stent delivery system 10 includes a stent 20, an operation unit 30, an outermost tube 40, an outer sheath 50, an inner shaft 60, a distal tip 80, and the like. The total length of the stent delivery system 10 is, for example, about 300 to 2500 mm, although it varies depending on the placement position of the stent 20 and the transport route.
　図１（ａ）に示すように、ステント２０は、ステントデリバリーシステム１０の遠位端近傍に収容されている。ステントデリバリーシステム１０の操作者は、図１（ａ）に示す第１状態でステント２０を体内の留置位置まで搬送した後、ステントデリバリーシステム１０を図１（ｂ）に示す第２状態とすることにより、ステント２０を放出して留置位置に留置する。 As shown in FIG. 1A, the stent 20 is housed near the distal end of the stent delivery system 10. The operator of the stent delivery system 10 sets the stent delivery system 10 to the second state shown in FIG. 1B after transporting the stent 20 to the indwelling position in the body in the first state shown in FIG. Thus, the stent 20 is released and placed at the placement position.
　インナーシャフト６０は、ステントデリバリーシステム１０の近位端に備えられる操作部３０から、ステントデリバリーシステム１０の遠位端に備えられる先端チップ８０まで、軸方向に延びている。図１（ａ）に示す第１の状態において、インナーシャフト６０は、アウターシース５０および操作部３０のハウジング３１等の内部に収容されている。 The inner shaft 60 extends in the axial direction from the operation unit 30 provided at the proximal end of the stent delivery system 10 to the tip tip 80 provided at the distal end of the stent delivery system 10. In the first state shown in FIG. 1A, the inner shaft 60 is accommodated inside the outer sheath 50 and the housing 31 of the operation unit 30.
　図１（ｂ）に示すように、インナーシャフト６０は、第１の外径を有する第１の部分６０ａと、第１の部分６０ａの外径より小さい第２の外径を有する第２の部分６０ｂとを有する。アウターシース５０が近位端側に移動した第２の状態では、遠位端にある第２の部分６０ｂが露出する。 As shown in FIG. 1B, the inner shaft 60 includes a first portion 60a having a first outer diameter and a second portion having a second outer diameter smaller than the outer diameter of the first portion 60a. 60b. In the second state in which the outer sheath 50 moves to the proximal end side, the second portion 60b at the distal end is exposed.
　図５は、軸方向に垂直な断面によるステントデリバリーシステム１０の断面図であり、後述する接続部６６（図３参照）より近位端側の位置の断面を表している。図５に示すように、インナーシャフト６０は、第１の外径を有する樹脂製の外管６４と、第２の外径を有する樹脂製の内管６２とを有しており、外管６４のルーメンを内管６２が挿通する２重管構造を有している。図１（ｂ）および部分拡大図である図４に示すように、内管６２の遠位端は、外管６４の遠位端および接触部６６から露出して、インナーシャフト６０の第２の部分６０ｂを構成している。 FIG. 5 is a cross-sectional view of the stent delivery system 10 with a cross section perpendicular to the axial direction, and shows a cross section at a position closer to the proximal end side than a connecting portion 66 (see FIG. 3) described later. As shown in FIG. 5, the inner shaft 60 includes a resin outer tube 64 having a first outer diameter and a resin inner tube 62 having a second outer diameter. It has a double pipe structure in which the inner pipe 62 is inserted through the lumen. As shown in FIG. 1 (b) and FIG. 4, which is a partially enlarged view, the distal end of the inner tube 62 is exposed from the distal end of the outer tube 64 and the contact portion 66, and the second end of the inner shaft 60. A portion 60b is formed.
　図５に示すように、内管６２の内部には、ステントデリバリーシステム１０を体内でガイドワイヤを用いてガイドする際にガイドワイヤが挿通するガイドワイヤルーメン６２ａが形成されている。図１（ｂ）に示すように、インナーシャフト６０の遠位端には、先端チップ８０が設けられており、先端チップ８０には、ガイドワイヤルーメン６２ａに連通する貫通孔が形成されている。先端チップ８０は樹脂等で作製されており、体内管腔の管壁に接触した際に、これを傷つけることを防止できるように、丸みを帯びた外形状を有している。 As shown in FIG. 5, a guide wire lumen 62a through which a guide wire is inserted when the stent delivery system 10 is guided in the body using a guide wire is formed inside the inner tube 62. As shown in FIG. 1B, a distal end tip 80 is provided at the distal end of the inner shaft 60, and a through hole communicating with the guide wire lumen 62a is formed in the distal end tip 80. The distal tip 80 is made of resin or the like, and has a rounded outer shape so that it can be prevented from being damaged when it contacts the tube wall of the body lumen.
　図１（ｂ）および図４に示すように、インナーシャフト６０は、第１の部分６０ａと第２の部分６０ｂとの境界位置に、ステントデリバリーシステム１０が収容するステント２０に接触する接触部６６を有する。図４に示す接触部６６は、第１の部分６０ａの遠位端に配置されており、内管６２を挿通させる金属リングで構成される。接触部６６の外径（半径）は、図８に示す頂部６６ａの表面からインナーシャフト６０の中心位置６０ｃまでの長さで表わされ、本実施形態では外管６４（第１の部分６０ａ）の外径（第１の外径）と一致している。ただし、接触部６６の外径は、外管６４（第１の部分６０ａ）の外径（第１の外径）に対して、完全に一致する必要はなく、外管６４（第１の部分６０ａ）の外径（第１の外径）よりも大きい外径を有していてもよい。なお、接触部６６を含むインナーシャフト６０の詳細構造については後ほど述べる。 As shown in FIGS. 1B and 4, the inner shaft 60 has a contact portion 66 that contacts the stent 20 accommodated in the stent delivery system 10 at the boundary position between the first portion 60 a and the second portion 60 b. Have The contact portion 66 shown in FIG. 4 is disposed at the distal end of the first portion 60a, and is configured by a metal ring through which the inner tube 62 is inserted. The outer diameter (radius) of the contact portion 66 is represented by the length from the surface of the top portion 66a shown in FIG. 8 to the center position 60c of the inner shaft 60, and in this embodiment, the outer tube 64 (first portion 60a). This coincides with the outer diameter (first outer diameter). However, the outer diameter of the contact portion 66 does not have to completely match the outer diameter (first outer diameter) of the outer tube 64 (first portion 60a), and the outer tube 64 (first portion). You may have an outer diameter larger than the outer diameter (1st outer diameter) of 60a). The detailed structure of the inner shaft 60 including the contact portion 66 will be described later.
　内管６２および外管６４は、可撓性を有しており、その材料としては、ある程度の剛性と摺動性を有する熱可塑性樹脂が好適に用いられる。本実施形態においては、内管６２を高剛性の熱可塑性樹脂で形成して、外管６４は摺動性に優れる熱可塑性樹脂で形成している。外管６４の表面には、アウターシース５０との摺動性の向上や、インナーシャフト６０の剛性向上のために、コーティング等がなされていてもよい。外管６４の外径は０．５～３．０ｍｍ程度であるが、特に限定されない。インナーシャフト６０の全長は、ステントデリバリーシステム１０の全長とほぼ同じである。 The inner tube 62 and the outer tube 64 have flexibility, and a thermoplastic resin having a certain degree of rigidity and slidability is preferably used as the material thereof. In the present embodiment, the inner tube 62 is formed of a high-rigidity thermoplastic resin, and the outer tube 64 is formed of a thermoplastic resin that is excellent in slidability. The surface of the outer tube 64 may be coated to improve the slidability with the outer sheath 50 and the rigidity of the inner shaft 60. The outer diameter of the outer tube 64 is about 0.5 to 3.0 mm, but is not particularly limited. The total length of the inner shaft 60 is substantially the same as the total length of the stent delivery system 10.
　図１（ａ）および図４に示すように、第１の状態において、アウターシース５０は、インナーシャフト６０の第１の部分６０ａおよび第２の部分６０ｂに挿通されている。断面図である図５に示すように、アウターシース５０の内部には、外管６４（第１の部分６０ａ）の外径と略同一か、またはこれより大きい径のルーメンが形成されており、アウターシース５０のルーメン内を、インナーシャフト６０の内管６２および外管６４が挿通している。また、図４に示すように、外管６４および接触部６６が存在しないインナーシャフト６０の第２の部分６０ｂでは、内管６２の外周面とアウターシース５０の内壁との間に隙間が形成され、その隙間にステント２０の円筒部２２（図２参照）が収容される。 As shown in FIG. 1A and FIG. 4, in the first state, the outer sheath 50 is inserted through the first portion 60a and the second portion 60b of the inner shaft 60. As shown in FIG. 5 which is a cross-sectional view, a lumen having a diameter substantially the same as or larger than the outer diameter of the outer tube 64 (first portion 60a) is formed inside the outer sheath 50. An inner tube 62 and an outer tube 64 of the inner shaft 60 are inserted through the lumen of the outer sheath 50. Further, as shown in FIG. 4, a gap is formed between the outer peripheral surface of the inner tube 62 and the inner wall of the outer sheath 50 in the second portion 60 b of the inner shaft 60 where the outer tube 64 and the contact portion 66 do not exist. The cylindrical portion 22 (see FIG. 2) of the stent 20 is accommodated in the gap.
　アウターシース５０は、図１（ａ）に示す第１の状態から、図１（ｂ）に示す第２の状態へ、インナーシャフト６０に対して軸方向へ相対移動可能である。アウターシース５０の近位端は、操作部３０におけるハウジング３１の内部に収容されている。操作部３０は、ハウジング３１に取り付けられた操作レバー３３の操作に連動して、アウターシース５０をインナーシャフト６０に対して、軸方向の一方である近位端側に相対移動させる。これにより、ステントデリバリーシステム１０は、アウターシース５０がインナーシャフト６０の第２の部分６０ｂを覆う第１の状態から（図１（ａ））、ステント２０および第２の部分６０ｂを露出する第２の状態へ（図１（ｂ））変化する。なお、操作部３０の近傍には、アウターシース５０の外周をさらに覆う最外管４０が設けられている。操作者がアウターシース５０を直接握ると、操作部３０によるアウターシース５０の移動が妨げられるおそれがあるが、最外管４０がアウターシース５０を覆うことにより、そのような問題を防止できる。 The outer sheath 50 is movable relative to the inner shaft 60 in the axial direction from the first state shown in FIG. 1A to the second state shown in FIG. The proximal end of the outer sheath 50 is accommodated in the housing 31 of the operation unit 30. The operation unit 30 moves the outer sheath 50 relative to the inner shaft 60 toward the proximal end side in the axial direction in conjunction with the operation of the operation lever 33 attached to the housing 31. Thereby, the stent delivery system 10 is configured to expose the stent 20 and the second portion 60b from the first state in which the outer sheath 50 covers the second portion 60b of the inner shaft 60 (FIG. 1A). (FIG. 1 (b)). An outermost tube 40 that further covers the outer periphery of the outer sheath 50 is provided in the vicinity of the operation unit 30. When the operator directly grips the outer sheath 50, the movement of the outer sheath 50 by the operation unit 30 may be hindered. However, the outermost tube 40 covers the outer sheath 50, so that such a problem can be prevented.
　図５に示すように、アウターシース５０は可撓性を有しており、高分子材料からなる樹脂層５１と、この樹脂層５１に埋設され、複数本の線材を螺旋状に編組してなる編組体５２とを有している。編組体５２は、アウターシース５０のうち、インナーシャフト６０の第２の部分６０ｂを覆う遠位端部分を除く部分に設けられている。 As shown in FIG. 5, the outer sheath 50 has flexibility, and is formed by embedding a resin layer 51 made of a polymer material and a plurality of wires embedded in the resin layer 51 in a spiral shape. A braided body 52. The braided body 52 is provided in a portion of the outer sheath 50 excluding the distal end portion that covers the second portion 60 b of the inner shaft 60.
　樹脂層５１を構成する材料としては、アウターシース５０を透かしてその内部にあるステント２０を目視できる透明な高分子材料が好ましい。たとえば、ポリエチレン、ポリプロピレン等のポリオレフィン、ポリ塩化ビニル、ポリウレタン、エチレン－酢酸ビニル共重合体、ポリエチレンテレフタレート、ポリブチレンテレフタレート等のポリエステル、ポリアミド、ポリエーテルポリアミド、ポリエステルポリアミド、ポリテトラフルオロエチレン等のフッ素系樹脂等の各種樹脂材料や、スチレン系、ポリオレフィン系、ポリウレタン系、ポリエステル系、ポリアミド系、ポリブタジエン系等の各種熱可塑性エラストマーを使用することができる。これらのうち２種以上を組み合わせて使用することもできる。 The material constituting the resin layer 51 is preferably a transparent polymer material through which the outer sheath 50 can be seen and the stent 20 inside thereof can be visually observed. For example, polyolefins such as polyethylene and polypropylene, polyvinyl chloride, polyurethane, ethylene-vinyl acetate copolymer, polyesters such as polyethylene terephthalate and polybutylene terephthalate, fluorine-based materials such as polyamide, polyether polyamide, polyester polyamide, and polytetrafluoroethylene Various resin materials such as resin, and various thermoplastic elastomers such as styrene, polyolefin, polyurethane, polyester, polyamide, and polybutadiene can be used. Two or more of these can be used in combination.
　編組体５２は、金属製の線材を複数本編組することにより構成され、全体として管状体をなす。この編組体５２において、各々の線材は、螺旋状に巻回された形状を有している。編組体５２を構成する線材の材料は、たとえば、金、銀、白金、銅、イリジウム、ニッケル、チタン、タングステン、鉄、アルミニウム、錫、亜鉛などの金属単体、ステンレス鋼、ニクロム鋼、ニッケル－チタン合金、チタン系合金などの合金が挙げられる。なかでも、加工性、強度、耐食性の観点より、ＳＵＳ３０４、ＳＵＳ３１６等のステンレス鋼を用いることが好ましい。 The braided body 52 is configured by braiding a plurality of metal wire rods, and forms a tubular body as a whole. In the braided body 52, each wire has a shape wound spirally. The material of the wire constituting the braided body 52 is, for example, a simple metal such as gold, silver, platinum, copper, iridium, nickel, titanium, tungsten, iron, aluminum, tin, zinc, stainless steel, nichrome steel, nickel-titanium. An alloy such as an alloy or a titanium-based alloy may be used. Especially, it is preferable to use stainless steel, such as SUS304 and SUS316, from a viewpoint of workability, strength, and corrosion resistance.
　図２は、ステントデリバリーシステム１０に収容されるステント２０の外観図である。ステント２０は、径方向に向けて力が加えられて弾性変形することによって径方向に収縮し、その力が解除されると収縮状態から自己の弾性力によって径方向に拡張する自己拡張型のステントである。また、本実施形態では、ステント２０として、胃または十二指腸と胆管または胆嚢とをバイパス接続する管腔臓器間バイパス用のカバードステントを例に説明を行うが、ステント２０の用途および詳細形状については、これに限定されない。たとえば、ステントデリバリーシステム１０に収容されるステントは、ベアステントであってもよい。 FIG. 2 is an external view of the stent 20 accommodated in the stent delivery system 10. The stent 20 is a self-expanding stent that contracts in the radial direction by applying a force in the radial direction and elastically deforms, and expands in the radial direction from its contracted state by its own elastic force when the force is released. It is. In the present embodiment, the stent 20 is described as an example of a covered stent for bypassing a luminal organ that bypasses the stomach or duodenum and the bile duct or gallbladder. It is not limited to this. For example, the stent housed in the stent delivery system 10 may be a bare stent.
　ステント２０は、円筒部２２と円筒部２２の近位端および遠位端に接続している柔軟部２４、２８を有している。 The stent 20 includes a cylindrical portion 22 and flexible portions 24 and 28 connected to the proximal end and the distal end of the cylindrical portion 22.
　図２に示すように、円筒部２２は、ジグザグ円環状のストラットをブリッジで軸方向に連結してなるフレーム部２２ａと、フレーム部２２ａおよび円筒状のフレーム部２２ａの外周面を覆うカバー膜２２ｂとを有する。フレーム部２２ａは、たとえばニッケルチタン合金やコバルトクロム合金などの超弾性合金あるいは形状記憶合金等で構成されるが、他の金属または樹脂で構成されてもよい。 As shown in FIG. 2, the cylindrical portion 22 includes a frame portion 22a formed by connecting zigzag annular struts in the axial direction with a bridge, and a cover film 22b covering the outer peripheral surfaces of the frame portion 22a and the cylindrical frame portion 22a. And have. The frame portion 22a is made of, for example, a superelastic alloy such as a nickel titanium alloy or a cobalt chromium alloy, a shape memory alloy, or the like, but may be made of another metal or resin.
　カバー膜２２ｂの材質は特に限定されないが、有機溶媒に溶解し、かつ毒性の少ないポリマー材料が好ましい。カバー膜２２ｂに用いられるポリマー材料としては、たとえば非生体分解性ポリマーや生体分解性ポリマー等が挙げられ、ポリウレタンまたはシリコーン樹脂等の非生体分解性ポリマーが特に好ましい。 The material of the cover film 22b is not particularly limited, but a polymer material that is soluble in an organic solvent and has little toxicity is preferable. Examples of the polymer material used for the cover film 22b include non-biodegradable polymers and biodegradable polymers, and non-biodegradable polymers such as polyurethane or silicone resin are particularly preferable.
　円筒部２２の軸方向長さは、ステント２０の用途によって適宜決定されるが、たとえば１０～２００ｍｍとすることができる。また、円筒部２２の拡張時の外径も、ステント２０を留置する箇所などに応じて適宜決定されるが、たとえばφ２～２０ｍｍ程度とすることができる。なお、円筒部２２の縮径時（ステントデリバリーシステム１０に収容されている時）の外径は、拡径時（ステントデリバリーシステム１０から放出された時）の外径に対して、１／２～１／１０程度である。 The axial length of the cylindrical portion 22 is appropriately determined depending on the application of the stent 20, but may be, for example, 10 to 200 mm. Further, the outer diameter of the cylindrical portion 22 at the time of expansion is also appropriately determined according to the location where the stent 20 is placed, but can be, for example, about φ2 to 20 mm. Note that the outer diameter of the cylindrical portion 22 when the diameter is reduced (when accommodated in the stent delivery system 10) is 1/2 of the outer diameter when the diameter is expanded (when released from the stent delivery system 10). About 1/10.
　図２に示すように、円筒部２２の近位端に接続する柔軟部２４は、円筒部２２に比べて柔軟であり、軸方向からの力に対して円筒部２２より変形しやすい。柔軟部２４は、円筒部２２の近位端からのびる複数の線状部材２５を有している。線状部材２５の一方の端部である基端２５ａは、円筒部２２におけるフレーム部２２ａに接続しており、他方の端部である先端２５ｂは、基端２５ａから円筒部２２の外側方向に湾曲するように伸びている。 As shown in FIG. 2, the flexible portion 24 connected to the proximal end of the cylindrical portion 22 is more flexible than the cylindrical portion 22 and is more easily deformed than the cylindrical portion 22 with respect to a force from the axial direction. The flexible portion 24 has a plurality of linear members 25 extending from the proximal end of the cylindrical portion 22. The base end 25a, which is one end of the linear member 25, is connected to the frame portion 22a of the cylindrical portion 22, and the tip 25b, which is the other end, extends from the base end 25a toward the outside of the cylindrical portion 22. It extends to bend.
　図３等に示すように、ステント２０の近位端側の柔軟部２４は、ステント２０がステントデリバリーシステム１０に収容されている間は、線状部材２５の先端２５ｂが軸方向に伸ばされた状態で、アウターシース５０と接触部６６の辺部６６ｂとの間に収容されている。そして、図１（ｂ）に示すようにステントデリバリーシステム１０から放出されると、線状部材２５の先端２５ｂは、基端２５ａから円筒部２２の外側方向に湾曲するように弾性変形し、図２に示す状態となって体内に留置される。 As shown in FIG. 3 and the like, the flexible portion 24 on the proximal end side of the stent 20 is such that the distal end 25b of the linear member 25 is extended in the axial direction while the stent 20 is housed in the stent delivery system 10. In the state, it is accommodated between the outer sheath 50 and the side part 66 b of the contact part 66. 1 (b), when released from the stent delivery system 10, the distal end 25b of the linear member 25 is elastically deformed so as to bend from the proximal end 25a to the outer side of the cylindrical portion 22, It becomes in the state shown in 2 and is left in the body.
　図２に示すように、線状部材２５の先端２５ｂには、丸い先端保護部２６が連結されている。先端保護部２６は、２本の線状部材２５の先端２５ｂに連結されている。円筒部２２の近位端に接続する柔軟部２４は、円筒部２２の円周方向に沿って略等間隔に接続する、合計６本の線状部材２５を有しているが、線状部材２５の数は特に限定されない。 As shown in FIG. 2, a round tip protection portion 26 is connected to the tip 25 b of the linear member 25. The tip protector 26 is connected to the tips 25 b of the two linear members 25. The flexible portion 24 connected to the proximal end of the cylindrical portion 22 has a total of six linear members 25 connected at substantially equal intervals along the circumferential direction of the cylindrical portion 22. The number of 25 is not particularly limited.
　線状部材２５は、弾性変形可能な材料で構成され、たとえば円筒部２２のフレーム部２２ａと同様の材料で構成される。線状部材２５の長さは、特に限定されないが、たとえば、１０～５０ｍｍの範囲で選択されることが好ましい。また、線状部材２５の線径は、フレーム部２２ａを構成するストラットの線径より細いことが好ましい。また、先端保護部２６は、線状部材２５と同様の材料としてもよく、Ｘ線不透過材料で構成してもよい。先端保護部２６をＸ線不透過材料で構成した場合、先端保護部２６は、Ｘ線マーカーとして機能する。 The linear member 25 is made of an elastically deformable material, for example, the same material as the frame portion 22a of the cylindrical portion 22. The length of the linear member 25 is not particularly limited, but is preferably selected in the range of 10 to 50 mm, for example. Moreover, it is preferable that the wire diameter of the linear member 25 is thinner than the wire diameter of the strut which comprises the flame | frame part 22a. The tip protection part 26 may be made of the same material as that of the linear member 25 or may be made of an X-ray opaque material. When the tip protector 26 is made of an X-ray opaque material, the tip protector 26 functions as an X-ray marker.
　円筒部２２の遠位端に接続する柔軟部２８は、円筒部２２の近位端に接続する柔軟部２４と、その接続位置および形状が対称であることを除き同様である。 The flexible part 28 connected to the distal end of the cylindrical part 22 is the same as the flexible part 24 connected to the proximal end of the cylindrical part 22 except that its connection position and shape are symmetrical.
　ステント２０の柔軟部２４、２８は、ステント２０が管腔臓器間をバイパスするように留置された際、径方向に広がることにより管腔臓器の内壁に接触する。柔軟部２４、２８は、その弾性力によりステント２０を支持することにより、ステント２０のマイグレーションを効果的に防止できる。また、柔軟部２４、２８は、ステント２０の留置時および留置後において、比較的硬質である円筒部２２の遠位端または近位端が体内管腔に強く接触することを防止する緩衝部として機能し、ステント２０が体内管腔を傷つける問題を防止できる。 When the stent 20 is placed so as to bypass between the luminal organs, the flexible portions 24 and 28 of the stent 20 come into contact with the inner wall of the luminal organ by spreading in the radial direction. The flexible parts 24 and 28 can effectively prevent migration of the stent 20 by supporting the stent 20 by its elastic force. In addition, the flexible portions 24 and 28 serve as buffer portions that prevent the distal end or proximal end of the relatively rigid cylindrical portion 22 from coming into strong contact with the body lumen during and after placement of the stent 20. It can function and prevent the problem that the stent 20 damages the body lumen.
　図２に示すステント２０の製造方法は、特に限定されないが、たとえばチューブ状若しくはパイプ状の母材を、ＹＡＧレーザー等で加工することによりフレーム部２２ａおよびその両端に接続する柔軟部２４、２８を一体に成形した後、フレーム部２２ａのみにカバー膜２２ｂを被覆することにより作製することができる。この場合、線状部材２５の湾曲形状は、加工後に癖付けすることにより形成される。なお、柔軟部２４、２８を構成する線状部材２５は、フレーム部２２ａとは別途形成されたのち、溶接等によりフレーム部２２ａの遠位端および近位端に固定されてもよい。 The manufacturing method of the stent 20 shown in FIG. 2 is not particularly limited. For example, by processing a tube-shaped or pipe-shaped base material with a YAG laser or the like, the frame portion 22a and the flexible portions 24, 28 connected to both ends thereof are formed. After being integrally molded, the cover film 22b can be covered only on the frame portion 22a. In this case, the curved shape of the linear member 25 is formed by brazing after processing. The linear members 25 constituting the flexible portions 24 and 28 may be formed separately from the frame portion 22a and then fixed to the distal end and the proximal end of the frame portion 22a by welding or the like.
　図３は、図１（ａ）に示す第１状態において、ステントデリバリーシステム１０に収容されたステント２０の周辺部分を示す部分拡大図である。なお、図３では、説明を容易にするために、アウターシース５０を透視している。図３に示すように、ステント２０の円筒部２２は、インナーシャフト６０の第２の部分６０ｂと、アウターシース５０との間に収容される。また、円筒部２２の遠位端に接続する柔軟部２８（遠位端柔軟部）も、円筒部２２と同様に、第２の部分６０ｂと、アウターシース５０との間に収容される。 FIG. 3 is a partially enlarged view showing a peripheral portion of the stent 20 accommodated in the stent delivery system 10 in the first state shown in FIG. In FIG. 3, the outer sheath 50 is seen through for easy explanation. As shown in FIG. 3, the cylindrical portion 22 of the stent 20 is accommodated between the second portion 60 b of the inner shaft 60 and the outer sheath 50. Further, the flexible portion 28 (distal end flexible portion) connected to the distal end of the cylindrical portion 22 is also accommodated between the second portion 60 b and the outer sheath 50, similarly to the cylindrical portion 22.
　これに対して、ステント２０の近位端に接続される柔軟部２４は、インナーシャフト６０の第１の部分６０ａの遠位端に配置された接触部６６の辺部６６ｂ（図３参照）とアウターシース５０との間に収容されている。図４は、図３に示すステント２０の収容部分を、ステント２０を非表示状態にして表したものであり、図４と図３とを比較することにより、柔軟部２４が、接触部６６の辺部６６ｂ（図３参照）とアウターシース５０との間に収容されることが理解できる。 On the other hand, the flexible part 24 connected to the proximal end of the stent 20 is connected to the side part 66b (see FIG. 3) of the contact part 66 disposed at the distal end of the first part 60a of the inner shaft 60. It is accommodated between the outer sheath 50. FIG. 4 shows the accommodation portion of the stent 20 shown in FIG. 3 with the stent 20 hidden. By comparing FIG. 4 and FIG. It can be understood that it is accommodated between the side portion 66b (see FIG. 3) and the outer sheath 50.
　図６は、接触部６６を構成する金属リングの外観図である。接触部６６は、軸方向に伸びる略多角柱状の外形状を有している。接触部６６の中央には、軸方向に貫通する貫通孔６６ｃが形成されている。図７に示すように、接触部６６の貫通孔６６ｃは、インナーシャフト６０の内管６２に挿通されている。 FIG. 6 is an external view of a metal ring constituting the contact portion 66. The contact part 66 has a substantially polygonal columnar outer shape extending in the axial direction. In the center of the contact portion 66, a through hole 66c penetrating in the axial direction is formed. As shown in FIG. 7, the through hole 66 c of the contact portion 66 is inserted through the inner tube 62 of the inner shaft 60.
　図７に示すように、接触部６６は、外管６４の遠位端から露出した内管６２における近位端の外周面に形成されるリング設置部６２ｂに取り付けられている。接触部６６の近位端側の端面は、外管６４の遠位端側の端面である外管遠位端面６４ｂに接触している。これにより、接触部６６がステント２０を押し出す力は、外管遠位端面６４ｂによって確実に受け止められる。 As shown in FIG. 7, the contact portion 66 is attached to a ring installation portion 62 b formed on the outer peripheral surface of the proximal end of the inner tube 62 exposed from the distal end of the outer tube 64. The end surface on the proximal end side of the contact portion 66 is in contact with the outer tube distal end surface 64 b that is the end surface on the distal end side of the outer tube 64. Thereby, the force which the contact part 66 pushes out the stent 20 is reliably received by the outer tube | pipe distal end surface 64b.
　図８（ａ）は、接触部６６の軸方向に垂直な断面を表している。図８（ａ）に示すように、接触部６６は、軸方向に垂直な断面において、外管６４（第１の部分６０ａ）の外径と略一致した外径を有する３つの頂部６６ａを有する。頂部６６ａの外表面は、軸方向から見て外管６４の外周面と略一致する円弧形状を有しており、３つの頂部６６ａは、周方向に等間隔（１２０°間隔）で配置されている。 FIG. 8A shows a cross section perpendicular to the axial direction of the contact portion 66. As shown in FIG. 8A, the contact portion 66 has three top portions 66a having an outer diameter substantially coincident with the outer diameter of the outer tube 64 (first portion 60a) in a cross section perpendicular to the axial direction. . The outer surface of the top portion 66a has an arc shape that substantially matches the outer peripheral surface of the outer tube 64 when viewed from the axial direction, and the three top portions 66a are arranged at equal intervals (120 ° intervals) in the circumferential direction. Yes.
　図８（ａ）に示すように、接触部６６は、３つの頂部６６ａの間を直線的に接続する３つの辺部６６ｂを有している。頂部６６ａの両端部と中心位置６０ｃとがなす角θ１は、辺部６６ｂの両端部と中心位置６０ｃとがなす角θ２より小さくなっており、ステントデリバリーシステム１０が第１状態であるとき、辺部６６ｂとアウターシース５０との隙間が大きく確保される。θ１／θ２の値は、たとえば、０．１～０．９とすることができる。なお、本明細書において、「直線的に接続する」の「直線的に」は、厳密な意味で辺部が直線状であることを意味するものではなく、本発明を逸脱しない範囲において、より具体的には、辺部とアウターシースとの間に形成される隙間にステントの柔軟部が容易に収容できる限りにおいて、辺部の一部または全部が折れ線状や曲線状であることを妨げない。 As shown in FIG. 8A, the contact portion 66 has three side portions 66b that linearly connect the three top portions 66a. An angle θ1 formed between both ends of the top 66a and the center position 60c is smaller than an angle θ2 formed between both ends of the side 66b and the center position 60c, and when the stent delivery system 10 is in the first state, A large gap is secured between the portion 66b and the outer sheath 50. The value of θ1 / θ2 can be set to 0.1 to 0.9, for example. In the present specification, “straightly connected” in “straightly connected” does not mean that the side portion is linear in a strict sense, and in a range not departing from the present invention. Specifically, as long as the flexible part of the stent can be easily accommodated in the gap formed between the side part and the outer sheath, it does not prevent part or all of the side part from being a polygonal line or a curved line. .
　接触部６６の複数の頂部６６ａは、中心位置６０ｃに対する配置が異なるが、互いに同じ形状を有する。また、複数の辺部６６ｂについても、頂部６６ａと同様に、中心位置６０ｃに対する配置が異なるが、互いに同じ形状を有する。ただし、複数の頂部６６ａまたは複数の辺部６６ｂは、互いに異なる形状を有していてもよい。 Although the arrangement | positioning with respect to the center position 60c differs, the some top part 66a of the contact part 66 has the mutually same shape. The plurality of side portions 66b also have the same shape as each other, although the arrangement with respect to the center position 60c is different, similarly to the top portion 66a. However, the plurality of top portions 66a or the plurality of side portions 66b may have different shapes.
　図３に示すようにステントデリバリーシステム１０内に収容されているステント２０において、円筒部２２の近位端に接続する柔軟部２４は、接触部６６における３つの辺部６６ｂとアウターシース５０との間に形成される隙間をそれぞれ通過して、近位端側に伸びている。ステントデリバリーシステム１０が第１の状態である場合、接触部６６の外側は、アウターシース５０に覆われるため、図２のように外側に向けて湾曲する癖付けが施されている線状部材２５であっても、線状部材２５を弾性変形により伸ばして辺部６６ｂに近づけ、その復元を外側からアウターシース５０で押さえつけることにより、好適に辺部６６ｂとアウターシース５０の間に収容される。 As shown in FIG. 3, in the stent 20 housed in the stent delivery system 10, the flexible portion 24 connected to the proximal end of the cylindrical portion 22 is formed by the three side portions 66 b of the contact portion 66 and the outer sheath 50. Each of the gaps formed between them extends through the proximal end side. When the stent delivery system 10 is in the first state, the outer side of the contact portion 66 is covered with the outer sheath 50, and therefore, the linear member 25 that is brazed to curve outward as shown in FIG. Even so, the linear member 25 is stretched by elastic deformation and brought close to the side portion 66b, and its restoration is pressed by the outer sheath 50 from the outside, so that it is suitably accommodated between the side portion 66b and the outer sheath 50.
　近位端側の柔軟部２４を構成する６本の線状部材２５は、各辺部６６ｂとアウターシース５０との隙間に、２本ずつ均等に収容されている。ただし、各辺部６６ｂとアウターシース５０との隙間に収容される線状部材２５の数は、互いに異なっていてもよい。 The six linear members 25 constituting the flexible portion 24 on the proximal end side are equally accommodated two by two in the gaps between the side portions 66b and the outer sheath 50. However, the number of the linear members 25 accommodated in the gaps between the side portions 66b and the outer sheath 50 may be different from each other.
　図３に示すように、円筒部２２の近位端に接続する柔軟部２４が、辺部６６ｂとアウターシース５０との間に形成される隙間を通過することにより、接触部６６は、ステント２０における円筒部２２の近位端に対して、直接接触することができる。すなわち、図７に示す接触部６６の頂部６６ａは、アウターシース５０によって収縮状態に保たれているステント２０の円筒部２２の外径と略等しい外径を有する。このため、接触部６６の頂部６６ａ周辺における接触部遠位端面６６ｄは、ステントデリバリーシステム１０がステント２０を放出するとき、ステント２０の円筒部２２の近位端に接触し、円筒部２２に対して直接、ステント２０を遠位端側に押す力を作用させることができる。 As shown in FIG. 3, the flexible portion 24 connected to the proximal end of the cylindrical portion 22 passes through a gap formed between the side portion 66 b and the outer sheath 50, so that the contact portion 66 becomes free from the stent 20. Can directly contact the proximal end of the cylindrical portion 22. That is, the top portion 66 a of the contact portion 66 shown in FIG. 7 has an outer diameter that is substantially equal to the outer diameter of the cylindrical portion 22 of the stent 20 that is maintained in a contracted state by the outer sheath 50. For this reason, the contact portion distal end surface 66d around the top portion 66a of the contact portion 66 contacts the proximal end of the cylindrical portion 22 of the stent 20 when the stent delivery system 10 releases the stent 20, and the Thus, a force for pushing the stent 20 toward the distal end side can be directly applied.
　接触部６６を構成する金属リングの材質は、外管６４を構成する樹脂より硬質の金属または合金であれば特に限定されず、ステンレス、金、白金、タングステン等とすることができ、また、金、白金、タングステン等のＸ線不透過材料とすることにより、接触部６６がＸ線不透過マーカーとなるため好ましい。接触部６６は、角柱状または円柱状の材料を準備した後、これを機械加工することによって頂部６６ａ、辺部６６ｂおよび貫通孔６６ｃを形成したり、図６に示す形状の金属リングを鋳造したりすることにより作製できるが、接触部６６の作製方法は特に限定されない。 The material of the metal ring constituting the contact portion 66 is not particularly limited as long as it is a metal or alloy harder than the resin constituting the outer tube 64, and may be stainless steel, gold, platinum, tungsten, etc. It is preferable to use an X-ray opaque material such as platinum or tungsten because the contact portion 66 becomes an X-ray opaque marker. For the contact portion 66, after preparing a prismatic or columnar material, the top portion 66a, the side portion 66b and the through hole 66c are formed by machining the material, or a metal ring having the shape shown in FIG. 6 is cast. However, the manufacturing method of the contact portion 66 is not particularly limited.
　図７に示すように、接触部６６は、たとえば接着等により内管６２のリング設置部６２ｂに固定されるが、接触部６６の固定方法は特に限定されない。 As shown in FIG. 7, the contact portion 66 is fixed to the ring installation portion 62b of the inner tube 62 by, for example, adhesion, but the fixing method of the contact portion 66 is not particularly limited.
　上述したように、ステントデリバリーシステム１０では、ステント２０の円筒部２２を設置する第２の部分６０ｂの近位端側に配置される接触部６６が、複数の頂部６６ａと複数の辺部６６ｂとを有する。辺部６６ｂは頂部６６ａを直線的に接続しているため、辺部６６ｂとアウターシース５０との間に形成される隙間を、柔軟部２４が通過できる。これにより、接触部６６の頂部６６ａは、ステント２０を放出する際に、ステント２０の円筒部２２の近位端に直接接触して、ステント２０をアウターシース５０から押し出すことができる。この際、複数の頂部６６ａが円筒部２２を押すことにより、確実かつバランス良くステント２０を押すことができる。 As described above, in the stent delivery system 10, the contact portion 66 disposed on the proximal end side of the second portion 60b where the cylindrical portion 22 of the stent 20 is installed has the plurality of top portions 66a and the plurality of side portions 66b. Have Since the side part 66b connects the top part 66a linearly, the flexible part 24 can pass through a gap formed between the side part 66b and the outer sheath 50. Thereby, when releasing the stent 20, the top portion 66 a of the contact portion 66 can directly contact the proximal end of the cylindrical portion 22 of the stent 20 to push the stent 20 out of the outer sheath 50. At this time, the plurality of top portions 66a press the cylindrical portion 22, whereby the stent 20 can be pressed reliably and in a well-balanced manner.
　ステントデリバリーシステム１０は、ステント２０の近位端側の柔軟部２４を、インナーシャフト６０における第１部分６０ａの遠位端部に配置される接触部６６の辺部６６ｂとアウターシース５０との間に形成される隙間に収容できる。柔軟部２４に含まれる線状部材２５は、図３に示すように軸方向に沿って伸ばされた状態で収容されていてもよいが、線状部材２５は、湾曲しているか、または折りたたまれた状態で、辺部６６ｂとアウターシース５０との間に収容されていてもよい。また、線状部材２５の先端２５ｂは、接触部６６より近位端側に位置していてもよく、この場合、外管６４の遠位端部に、線状部材２５や先端保護部２６を収容する溝や切り欠きなどが形成されていてもよい。 In the stent delivery system 10, the flexible portion 24 on the proximal end side of the stent 20 is disposed between the side portion 66 b of the contact portion 66 disposed at the distal end portion of the first portion 60 a of the inner shaft 60 and the outer sheath 50. It can be accommodated in the gap formed in. The linear member 25 included in the flexible portion 24 may be accommodated in a state of being stretched along the axial direction as shown in FIG. 3, but the linear member 25 is curved or folded. In this state, it may be accommodated between the side portion 66b and the outer sheath 50. Further, the tip 25b of the linear member 25 may be positioned closer to the proximal end side than the contact portion 66. In this case, the linear member 25 and the tip protector 26 are provided at the distal end of the outer tube 64. A groove or a notch to be accommodated may be formed.
　図７に示すような接触部６６は、単純な形状を有しているため、成形や機械加工によって容易に製造することができ、また、寸法精度も良好である。なお、図８（ａ）に示すように、接触部６６における頂部６６ａと辺部６６ｂとは直接接続されているが、接触部６６の形状はこれに限定されない。たとえば、接触部６６における頂部６６ａと辺部６６ｂとの間に、他のＲ形状、面取り形状または溝形状などが形成されていてもよい。 Since the contact portion 66 as shown in FIG. 7 has a simple shape, it can be easily manufactured by molding or machining, and has good dimensional accuracy. In addition, as shown to Fig.8 (a), although the top part 66a and the side part 66b in the contact part 66 are directly connected, the shape of the contact part 66 is not limited to this. For example, another R shape, chamfering shape, or groove shape may be formed between the top portion 66a and the side portion 66b of the contact portion 66.
　ステントデリバリーシステム１０では、ステント２０の放出動作の際に、円筒部２２が近位端側へ向かう力を受けた場合であっても、円筒部２２の近位端側端面が、接触部６６の遠位端側端面に適切に押し当てられ、円筒部２２は第２の部分６０ｂに留まることができる。したがって、ステントデリバリーシステム１０では、柔軟部２４を押しつぶすことなく、ステント２０の放出動作を円滑に行うことができる。また、図７に示すように、接触部６６を外管６４の外管遠位端面６４ｂに接触させて配置することにより、ステント２０の放出動作において、円筒部２２からの力を、接触部６６および外管６４が安定して受け止めることができる。このため、ステントデリバリーシステム１０は、ステント２０の放出動作を円滑に行うことが可能である。また、ステントデリバリーシステム１０に、ステント２０を設置する際に、辺部６６ｂとアウターシース５０との隙間に柔軟部２４を収容する作業は、良好な作業性で行うことができる。 In the stent delivery system 10, even when the cylindrical portion 22 receives a force toward the proximal end side during the releasing operation of the stent 20, the proximal end side end surface of the cylindrical portion 22 has the contact portion 66. Appropriately pressed against the distal end face, the cylindrical portion 22 can remain in the second portion 60b. Therefore, in the stent delivery system 10, the releasing operation of the stent 20 can be performed smoothly without crushing the flexible portion 24. Further, as shown in FIG. 7, by placing the contact portion 66 in contact with the outer tube distal end surface 64 b of the outer tube 64, the force from the cylindrical portion 22 is applied to the contact portion 66 in the releasing operation of the stent 20. And the outer tube 64 can be received stably. For this reason, the stent delivery system 10 can smoothly perform the releasing operation of the stent 20. Moreover, when installing the stent 20 in the stent delivery system 10, the operation | work which accommodates the flexible part 24 in the clearance gap between the side part 66b and the outer sheath 50 can be performed by favorable workability | operativity.
　以上、実施形態を示しつつ本発明の特徴を説明したが、本発明はこれらの実施形態に示される具体的態様に限定されるものではなく、様々な他の実施形態を含むことは言うまでもない。たとえば、ステントデリバリーシステム１０では、図４に示すように、接触部６６が金属リングで構成されているが、接触部６６としてはこれに限定されず、接触部は樹脂製のリングを用いて構成してもよく、外管６４などの第１の部分６０ａに含まれる部材の遠位端を加工して接触部を構成してもよい。 As described above, the features of the present invention have been described while showing the embodiments. However, the present invention is not limited to the specific modes shown in these embodiments, and it goes without saying that various other embodiments are included. For example, in the stent delivery system 10, as shown in FIG. 4, the contact portion 66 is configured by a metal ring. However, the contact portion 66 is not limited to this, and the contact portion is configured by using a resin ring. Alternatively, the contact portion may be formed by processing the distal end of a member included in the first portion 60a such as the outer tube 64.
　また、接触部６６の形状は、図６および図８（ａ）に示すような３つの頂部６６ａと３つの辺部６６ｂを有するもののみに限定されず、接触部は、三角柱状以外の角柱状の外形状を有していてもよい。図８（ｂ）は、第１変形例に係る接触部１６６の軸方向に垂直な断面を示している。接触部１６６は、２つの頂部１６６ａと２つの辺部１６６ｂとを有している。図８（ｃ）は、第２変形例に係る接触部２６６の軸方向に垂直な断面を示している。接触部２６６は、４つの頂部２６６ａと４つの辺部２６６ｂとを有している。接触部６６の代わりに、第１または第２変形例に係る接触部１６６、２６６を用いたステントデリバリーシステムも、図１～図７に示すステントデリバリーシステム１０と同様の効果を奏する。 Further, the shape of the contact portion 66 is not limited to the shape having three top portions 66a and three side portions 66b as shown in FIGS. 6 and 8A, and the contact portion has a prismatic shape other than the triangular prism shape. It may have the outer shape. FIG. 8B shows a cross section perpendicular to the axial direction of the contact portion 166 according to the first modification. The contact portion 166 has two top portions 166a and two side portions 166b. FIG. 8C shows a cross section perpendicular to the axial direction of the contact portion 266 according to the second modification. The contact portion 266 has four top portions 266a and four side portions 266b. The stent delivery system using the contact portions 166 and 266 according to the first or second modification instead of the contact portion 66 also has the same effect as the stent delivery system 10 shown in FIGS.
　図８（ｄ）は、第３変形例に係る接触部３６６の軸方向に垂直な断面を示している。接触部３６６は、６つの頂部３６６ａと６つの辺部３６６ｂとを有している。また、接触部３６６の頂部３６６ａは、隣接する２つの辺部３６６ｂの接続点となっている。このような接触部３６６を、接触部６６の代わりにステントデリバリーシステム１０に適用することも可能である。 FIG. 8D shows a cross section perpendicular to the axial direction of the contact portion 366 according to the third modification. The contact portion 366 has six top portions 366a and six side portions 366b. The top portion 366a of the contact portion 366 is a connection point between two adjacent side portions 366b. Such a contact portion 366 can be applied to the stent delivery system 10 instead of the contact portion 66.
　１０…ステントデリバリーシステム
　２０…ステント
　２２…円筒部
　２２ａ…フレーム部
　２２ｂ…カバー膜
　２４、２８…柔軟部
　２５…線状部材
　２５ａ…基端
　２５ｂ…先端
　２６…先端保護部
　３０…操作部
　３１…ハウジング
　３３…操作レバー
　４０…最外管
　５０…アウターシース
　５２…編組体
　６０…インナーシャフト
　６０ａ…第１の部分
　６０ｂ…第２の部分
　６０ｃ…中心位置
　６２…内管
　６２ａ…ガイドワイヤルーメン
　６２ｂ…リング設置部
　６４…外管
　６４ｂ…外管遠位端面
　６６…接触部
　６６ａ…頂部
　６６ｂ…辺部
　６６ｃ…貫通孔
　６６ｄ…接触部遠位端面
　θ１、θ２…角
　８０…先端チップ DESCRIPTION OF SYMBOLS 10 ... Stent delivery system 20 ... Stent 22 ... Cylindrical part 22a ... Frame part 22b ... Cover membrane 24, 28 ... Flexible part 25 ... Linear member 25a ... Base end 25b ... Tip 26 ... Tip protection part 30 ... Operation part 31 ... Housing 33 ... Control lever 40 ... Outermost tube 50 ... Outer sheath 52 ... Braided body 60 ... Inner shaft 60a ... First part 60b ... Second part 60c ... Center position 62 ... Inner pipe 62a ... Guide wire lumen 62b ... Ring installation Portion 64 ... Outer tube 64b ... Outer tube distal end surface 66 ... Contact portion 66a ... Top portion 66b ... Side portion 66c ... Through hole 66d ... Contact portion distal end surface [theta] 1, [theta] 2 ... Angle 80 ... Tip

Claims (4)

  1. 　第１の外径を有する第１の部分と、前記第１の部分の遠位端に接続しており前記第１の外径より小さい第２の外径を有する第２の部分と、を有するインナーシャフトと、
    　前記第１の部分および前記第２の部分に挿通されており、前記第２の部分を覆う第１の状態から、前記第２の部分を遠位端から露出させる第２の状態へ、前記インナーシャフトに対して軸方向に相対移動可能なアウターシースと、
    　前記第２の部分と前記アウターシースとの間に収容される円筒部と、前記円筒部の近位端に接続しており前記軸方向からの力に対して前記円筒部より変形しやすい柔軟部と、を有するステントと、を有しており、
    　前記インナーシャフトは、前記第１の部分と前記第２の部分との境界位置に、前記ステントに接触する接触部を有し、
    　前記接触部は、前記軸方向に垂直な断面において、前記第１の外径以上の外径を有する複数の頂部と、複数の前記頂部の間を直線的に接続する複数の辺部と、を有することを特徴とするステントデリバリーシステム。     A first portion having a first outer diameter; and a second portion connected to a distal end of the first portion and having a second outer diameter that is smaller than the first outer diameter. An inner shaft,
    From the first state that is inserted through the first part and the second part and covers the second part, to the second state that exposes the second part from the distal end, the inner part An outer sheath that can move relative to the shaft in the axial direction;
    A cylindrical portion accommodated between the second portion and the outer sheath, and a flexible portion that is connected to the proximal end of the cylindrical portion and is more easily deformed than the cylindrical portion with respect to a force from the axial direction. And a stent having
    The inner shaft has a contact portion that contacts the stent at a boundary position between the first portion and the second portion;
    In the cross section perpendicular to the axial direction, the contact portion includes a plurality of top portions having an outer diameter equal to or larger than the first outer diameter, and a plurality of side portions linearly connecting the plurality of top portions. A stent delivery system comprising:
  2. 　前記軸方向に垂直な断面において、前記頂部の両端部と前記インナーシャフトの中心位置とがなす角θ１は、前記辺部の両端部と前記中心位置とがなす角θ２より小さいことを特徴とする請求項１に記載のステントデリバリーシステム。 In a cross section perpendicular to the axial direction, an angle θ1 formed by both ends of the top portion and the center position of the inner shaft is smaller than an angle θ2 formed by both ends of the side portion and the center position. The stent delivery system according to claim 1.
  3. 　前記インナーシャフトは、前記第１の外径を有する樹脂製の外管と、前記第２の外径を有しており、前記外管を挿通し、前記外管の遠位端から露出する遠位端が前記第２の部分を構成する内管と、を有する請求項１又は請求項２に記載のステントデリバリーシステム。 The inner shaft has a resin outer tube having the first outer diameter and the second outer diameter, and is inserted through the outer tube and is exposed from a distal end of the outer tube. The stent delivery system according to claim 1 or 2, wherein a distal end has an inner tube constituting the second portion.
  4. 　前記接触部は、金属リングで構成されていることを特徴とする請求項１から請求項３までのいずれかに記載のステントデリバリーシステム。 The stent delivery system according to any one of claims 1 to 3, wherein the contact portion is formed of a metal ring.
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JP2015513931A (en) * 2012-03-16 2015-05-18 マイクロベンション インコーポレイテッド Stent and stent delivery device
WO2015141399A1 (en) * 2014-03-17 2015-09-24 テルモ株式会社 Indwelling object delivery system
US20170135830A1 (en) * 2015-11-12 2017-05-18 The Provost, Fellows, Foundation Scholars, & the Other Members of Board, of The College of the Holy Implantable biocompatible expander suitable for treatment of constrictions of body lumen
JP2017176666A (en) * 2016-03-31 2017-10-05 日本ゼオン株式会社 Stent delivery system

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008508947A (en) * 2004-08-06 2008-03-27 ボストン サイエンティフィック リミテッド Medical instrument transport system
JP2015513931A (en) * 2012-03-16 2015-05-18 マイクロベンション インコーポレイテッド Stent and stent delivery device
WO2015141399A1 (en) * 2014-03-17 2015-09-24 テルモ株式会社 Indwelling object delivery system
US20170135830A1 (en) * 2015-11-12 2017-05-18 The Provost, Fellows, Foundation Scholars, & the Other Members of Board, of The College of the Holy Implantable biocompatible expander suitable for treatment of constrictions of body lumen
JP2017176666A (en) * 2016-03-31 2017-10-05 日本ゼオン株式会社 Stent delivery system

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