WO2009118912A1 - Stent and stent graft - Google Patents

Stent and stent graft Download PDF

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Publication number
WO2009118912A1
WO2009118912A1 PCT/JP2008/056234 JP2008056234W WO2009118912A1 WO 2009118912 A1 WO2009118912 A1 WO 2009118912A1 JP 2008056234 W JP2008056234 W JP 2008056234W WO 2009118912 A1 WO2009118912 A1 WO 2009118912A1
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WO
WIPO (PCT)
Prior art keywords
stent
blood vessel
sheath
graft
annular
Prior art date
Application number
PCT/JP2008/056234
Other languages
French (fr)
Japanese (ja)
Inventor
良彦 横井
Original Assignee
グローブ株式会社
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 グローブ株式会社 filed Critical グローブ株式会社
Priority to PCT/JP2008/056234 priority Critical patent/WO2009118912A1/en
Priority to JP2010505135A priority patent/JPWO2009118912A1/en
Publication of WO2009118912A1 publication Critical patent/WO2009118912A1/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
    • A61F2/02—Prostheses implantable into the body
    • A61F2/04—Hollow or tubular parts of organs, e.g. bladders, tracheae, bronchi or bile ducts
    • A61F2/06—Blood vessels
    • A61F2/07—Stent-grafts
    • 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
    • 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
    • A61F2/89—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure the wire-like elements comprising two or more adjacent rings flexibly connected by separate members
    • 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
    • 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
    • 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
    • A61F2002/828—Means for connecting a plurality of stents allowing flexibility of the whole structure
    • 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
    • A61F2002/9155—Adjacent bands being connected to each other
    • A61F2002/91558—Adjacent bands being connected to each other connected peak to peak
    • 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
    • A61F2230/00—Geometry of prostheses classified in groups A61F2/00 - A61F2/26 or A61F2/82 or A61F9/00 or A61F11/00 or subgroups thereof
    • A61F2230/0002—Two-dimensional shapes, e.g. cross-sections
    • A61F2230/0028—Shapes in the form of latin or greek characters
    • A61F2230/0054—V-shaped

Definitions

  • the present invention relates to a stent and a stent graft used for treatment of an expandable lesion generated in a blood vessel.
  • the arterial system serving as the route is constantly exposed to high blood pressure. For this reason, due to arteriosclerosis, inflammation and the like, an expandable lesion is likely to occur particularly in the aorta region which is an elastic artery. This dilated lesion is a fatal disease that eventually fails due to blood pressure and causes major bleeding in the body.
  • a method of blocking blood pressure from the inside of a blood vessel to an aneurysm using a stent graft in which a tubular fixation device called a stent is covered with an artificial blood vessel material has recently been less burdened on patients. It is attracting attention.
  • FIG. 6 is a view showing a use state of a stent graft 900 according to a conventional example.
  • a conventionally used stent 910 has a substantially tubular shape whose diameter can be expanded and contracted, and includes a plurality of annular units 911 arranged in series with each other, and a connecting portion 913 that connects these annular units.
  • the annular unit 911 is a wire member bent in a repeating pattern having a predetermined width in the axial direction, and is formed in a ring shape.
  • the stent graft 900 is configured by covering the side surface of the stent 910 with the graft 920 (see, for example, Patent Document 1).
  • the stent graft 900 is used as follows. First, the stent graft 900 is reduced in diameter to a sheath-like member called a sheath 930 and is detachably accommodated. Next, the stent graft 900 is delivered to the affected part in the blood vessel by operating through an operating part (not shown) provided in the sheath 930. Subsequently, when the sheath 930 is detached, the stent graft 900 is expanded (ie, expanded in diameter), and the annular unit 911 is closely attached to the blood vessel wall with a predetermined width. Then, since the graft 920 covering the annular unit 911 blocks the blood pressure to the affected part (aneurysm), the expandable lesion can be treated. Japanese Patent Laid-Open No. 3-151983
  • the above-described stent 910 has the following problems.
  • the wire member partially released from the sheath 930 is urged by the blood flow in the downstream direction (the arrow direction in FIG. 6), and is large with respect to the blood vessel wall 500.
  • Contact is made at an angle ⁇ (see FIG. 6A).
  • the deployed stent graft 900 is distorted and cannot sufficiently adhere to the blood vessel wall 500 (see FIG. 6B).
  • the stent 910 is deformed by the influence of blood flow or the like, so that the installation position is shifted, or a gap is generated between the graft 920 and the blood vessel wall 500, and blood pressure is transferred to the affected area through this gap. May be applied. In such cases, dilated lesions cannot be fully treated.
  • the present invention has been made in view of such problems, and an object thereof is to provide a stent and a stent graft that can improve adhesion to a blood vessel wall.
  • the present inventors have found that the angle of the wire member with respect to the blood vessel wall can be reduced by extending a part of the wire member constituting the annular unit released from the sheath and leaving it in the sheath,
  • the present invention has been completed. Specifically, the present invention provides the following.
  • a substantially tubular stent having a freely expandable diameter A plurality of annular units formed in a ring shape with wire members bent in a repetitive pattern having a predetermined width in the axial direction and arranged in series with each other; A connecting portion for connecting the annular units to each other; At least one end of the annular unit is a stent having an extension part of a predetermined length that extends inward toward the other end side.
  • the stent is used as follows. First, after covering the side surface of the stent with a graft, the diameter is reduced to a sheath-like member called a sheath, and the stent is detachably accommodated. The sheath is then manipulated to deliver the stent graft to the affected area within the vessel. Subsequently, when the sheath begins to be detached, the annular unit disposed at one end is released from the sheath.
  • the extending portion provided in the annular unit extends inward to the other end side and remains in the sheath. Further, the annular unit connected to the released annular unit through the connecting portion also remains in the sheath. For this reason, since the wire member partially released from the sheath is supported by the connecting portion and the extending portion, an increase in the angle with respect to the blood vessel wall is suppressed even when urged in the downstream direction by the blood flow. .
  • the adhesion to the blood vessel wall can be improved.
  • the predetermined width may be appropriately set according to the curvature of the blood vessel at the site where the stent is placed, the strength of the wire member, and the like. That is, when the degree of curvature of the blood vessel wall is small, the larger the width of the repeated pattern, the wider the contact surface with the blood vessel wall, and the stent posture can be stabilized. On the other hand, when the degree of curvature of the blood vessel is large, the non-contact surface with the blood vessel wall can be reduced and the followability to the blood vessel shape can be improved as the width of the repeated pattern is smaller.
  • the predetermined length may be appropriately set according to the diameter of the blood vessel at the site where the stent is placed, the curved pattern, and the like.
  • the wire member partially released from the sheath is supported in a well-balanced manner by the connecting portion and the extending portion installed so that the point on the central axis becomes the center of gravity.
  • the “figure” may be a straight line or a polygon, in other words, the number of installation points of the connecting part and the extending part is not particularly limited.
  • the wire member partially released from the sheath can be more balanced at three or more points by the connecting portion and the extending portion installed so that the point on the central axis becomes the center of gravity. Supported. Thereby, the adhesiveness with respect to the blood vessel wall can be improved more.
  • the length L of the extending portion is set so as to satisfy Formula 1
  • the angle formed between the wire member supported by the extending portion and the blood vessel wall is , Not exceeding the maximum allowable angle ⁇ . Therefore, the adhesion to the blood vessel wall can be improved to a desired level.
  • the angle ⁇ may be appropriately set according to the stretchability (radial direction and axial direction) of the stent, the flexibility of the wire member, etc., but is preferably 30 ° from the inventors' experience.
  • Predetermined width refers to the width of the entire shape composed of arbitrary members.
  • the “predetermined width” may be appropriately set according to the flexibility of the extending portion, but is a width intentionally added exceeding the width that the linear wire member has.
  • a stent graft comprising the stent according to any one of (1) to (7) and a graft covering a side surface of the stent.
  • the extending portion provided in the annular unit extends inward to the other end side and remains in the sheath. Further, the annular unit connected to the released annular unit through the connecting portion also remains in the sheath. For this reason, since the wire member partially released from the sheath is supported by the connecting portion and the extending portion, an increase in the angle with respect to the blood vessel wall is suppressed even when urged in the downstream direction by the blood flow. . Thereby, since the stent graft after expansion
  • FIG. 1 is an overall perspective view of a stent graft according to an embodiment of the present invention. It is a side view of FIG. It is a bottom view of FIG. It is a figure which shows the state with which the stent graft which concerns on the said embodiment was mounted
  • FIG. 1 is an overall perspective view of a stent 20 according to an embodiment of the present invention.
  • 2 is a side view of FIG. 1
  • FIG. 3 is a bottom view of FIG.
  • the stent 20 is generally tubular as a whole, and its diameter r is expandable and contractable.
  • the stent 20 includes a plurality of annular units 21a to 21e arranged in series with each other, and connecting portions 22a to 22d that connect the annular units 21a to 21e adjacent to each other.
  • the annular units 21a to 21e are formed of ring-shaped wire members, and the wire members are bent in a repeating pattern having a predetermined width H with respect to the axial direction AX.
  • This repetitive pattern is a zigzag pattern formed by bending the wire member at a substantially constant angle in the bent portions 211a to 211e positioned at a substantially constant interval.
  • Intervening portions 214a to 214e interposed between the bent portions 211a to 211e are not particularly limited, but are substantially linear in the present embodiment.
  • the width H may be appropriately set according to the degree of curvature of the blood vessel, the strength of the wire member, and the like at the site where the stent 20 is placed. That is, when the degree of curvature of the blood vessel wall is small, the larger the width H, the wider the contact surface with the blood vessel wall, and the posture of the stent 20 can be stabilized.
  • the width H when used for the treatment of an aortic aneurysm, the width H may be 7 mm or more and 25 mm or less.
  • the diameter r may be appropriately set according to the blood vessel diameter or the like at the site where the stent 20 is placed.
  • the diameter r in the natural state may usually be 50 mm or more and 60 mm or less.
  • the number of the bent portions 211a to 211e may be set as appropriate so that the bending angle of the central axis CT of the stent 20 can be precisely adjusted as will be described later.
  • the number of V-shaped structures (a structure in which one bent portion and two intervening portions sandwiching the bent portion) can be set to be alternately odd and even in the order of the annular units 21a to 21e. .
  • the number of V-shaped structures is preferably 7 or more and 12 or less.
  • the wire member is not particularly limited, and is usually used, stainless steel such as SUS316L, superelastic alloy such as Ti—Ni alloy, titanium, titanium alloy, tantalum, tantalum alloy, platinum, platinum alloy, tungsten, tungsten It may be composed of a metal such as an alloy.
  • cyclic units formed of these metals are biocompatible polymer materials such as polyurethane, polyvinyl pyrrolidone, and polyvinyl alcohol, and materials obtained by immobilizing physiologically active substances such as heparin and urokinase on this polymer material.
  • the surface may be coated with a material mixed with an antithrombotic component such as argatroban, shirazazole, or salvogrelate hydrochloride.
  • the manufacturing method of the annular units 21a to 21e is not particularly limited.
  • the annular units 21a to 21e can be formed into an annular shape as a whole by joining one or more portions of a linear wire member by a known method such as welding, brazing, or caulking. do it.
  • the annular unit 21a disposed at one end of the stent 20 has an extension 212 having a predetermined length L that extends inward toward the other end.
  • the extending portion 212 has a loop shape in which both ends of the linear wire member are connected to the bent portion 211a of the annular unit 21a. Further, the extending portion 212 has a predetermined width W toward the central axis CT of the stent 20. This width W may be set as appropriate according to the strength of the extending portion 212.
  • the shape of the extended portion 212 is not particularly limited to a loop shape, but is preferably a curved shape having no cusps or corners in order to prevent the extended portion 212 from sticking into the blood vessel wall.
  • the extension part 212 is comprised by the linear wire member in this embodiment, it is not limited to this, The plate-shaped member of the width W may be sufficient.
  • the installation position of the extending part 212 is not particularly limited, it is preferable to use the bent part 211a as in the present embodiment in that the annular unit 21a can be supported in a well-balanced manner as will be described later.
  • the material of the extension part 212 may be the same material as the annular unit described above.
  • the length L of the extending part 212 in this embodiment satisfies the following formula 2.
  • L ⁇ R ⁇ cos30 ° Formula 2 (In the formula, R is the blood vessel diameter at the site where the stent 20 is installed.)
  • the tip 215 of the extending part 212 is located between the annular unit 21c and the annular unit 21d.
  • the central axis CT of the 20 is bent most greatly between the annular unit 21c and the annular unit 21d, and the portion between the annular unit 21c and the annular unit 21d has the maximum degree of bending of the blood vessel during use. It will be installed in the site (usually the site where the aneurysm occurs). In other words, the extending portion 212 extends toward a portion where the degree of bending of the blood vessel is maximum.
  • the extending portion 212 is provided only in the annular unit 21a, but may be provided in the other annular units 21b to 21e, particularly the annular unit 21b adjacent to the annular unit 21a. Thereby, since the annular unit 21b is supported also by the extension part in addition to the graft 30 described later, an increase in the angle with respect to the blood vessel wall is further suppressed.
  • connection base point 221 that is the installation point of the connection part 22 a in the annular unit 21 a is located at an equal distance from the extension base point 213 that is the installation point of the extension part 212.
  • the graphic connecting the connection base point 221 and the extension base point 213 is an isosceles triangle whose center of gravity is on the central axis CT of the stent 20.
  • the connecting portions 22a to 22d are provided in the bent portions 211a to 211e so as to be substantially in line with the interposed portions 214a to 214e.
  • each of the connecting portions 22a to 22e is installed with one or more bent portions 211a to 211e (for example, one to four).
  • the angle formed by the axes of the adjacent annular units 21a to 21e is the angle between the connecting portions 22a to 22e, that is, the bending portion 211a. It increases in proportion to the number of up to 211e.
  • the connecting portion 22a has two bent portions 211a and 211b
  • the connecting portion 22b has two bent portions 211b and 211c
  • the connecting portion 22c has three bent portions 211c and 211d.
  • the connecting portion 22d is provided with two bent portions 211d and 211e, and the central axis CT of the stent 20 is bent at an angle corresponding to the number of the bent portions 211a to 211e.
  • all of the connecting portions 22a to 22d have substantially the same length, but the present invention is not limited to this.
  • the lengths of the connecting portions 22a to 22d may be appropriately set so that the central axis CT of the stent 20 bends at a desired angle.
  • the structure of the connecting portion is not particularly limited as long as it has a function of connecting the annular units 21a to 21e. That is, as in the present embodiment, it may be composed of a wire member joined to the annular units 21a to 21e, but may be composed of a graft 30 sewn to the annular units 21a to 21e described later. In this case, the graft 30 also acts as a connecting portion.
  • an X-ray opaque part and a medicine container may be provided at a desired position of the stent 20 as necessary.
  • it may be as conventionally well-known (for example, refer WO03 / 097155 pamphlet).
  • the stent 20 may be produced by a conventionally known method (see, for example, WO03 / 097155 pamphlet).
  • the graft 30 indicated by a broken line in FIGS. 1 to 3 is made of a conventionally known material, for example, a synthetic resin such as a polyethylene terephthalate fiber such as “Dacron (registered trademark)” or a film made of a fluororesin such as polytetrafluoroethylene. It's okay.
  • a synthetic resin such as a polyethylene terephthalate fiber such as “Dacron (registered trademark)” or a film made of a fluororesin such as polytetrafluoroethylene. It's okay.
  • the stent graft 10 is manufactured by inserting the stent 20 into the graft 30.
  • the diameter r of the stent 20 is reduced at a predetermined rate.
  • a stent with a natural diameter of 40 mm can be reduced to 30 mm and inserted into a 31 mm diameter graft.
  • FIG. 4 is a view showing a state in which the stent graft 10 is attached to the sheath 40.
  • the sheath 40 is composed of a flexible small-diameter tubular member, and the stent graft 10 is detachably inserted into the distal end portion (left side in FIG. 4) of the sheath 40.
  • the stent 20 is inserted so that the annular unit 21a is on the distal end side of the sheath 40, the diameter r is reduced, and the stent 20 is extended in the axial direction.
  • the sheath 40 is connected to an operation unit (not shown), and a dilator (not shown) capable of expanding the diameter is accommodated inside the sheath 40 on the proximal side of the stent graft 10.
  • a dilator capable of expanding the diameter
  • the procedure for installing and using such an operation unit and dilator may be as conventionally known (see, for example, JP-A-2006-130064).
  • a set including the sheath 40, the stent graft 10 detachably accommodated in the sheath 40, an operation unit, and the like is referred to as a delivery system 11.
  • the graft 30 between the annular units 21a to 21e is stored in a space between the connecting portions 22a to 22d. Thereby, when the stent graft 10 is deployed in the blood vessel, the stored graft 30 is released from the space and is in close contact with the blood vessel wall. Here, if the graft 30 is not stored in the space, the length of the graft 30 at the curved portion of the blood vessel is insufficient after deployment, so that the graft 30 may be separated from the blood vessel wall and not sufficiently adhered.
  • FIG. 5 is a diagram showing a use state of the stent graft 10. A method of using the stent graft 10 will be described with reference to FIG.
  • the delivery system 11 is moved into the blood vessel on the capillary vessel side from the annular unit 21a side and moved to the affected part by manipulating the external operation part.
  • the movement is performed while confirming the position of the stent graft 10 with an image from the stent X-ray imaging apparatus as necessary.
  • connection base point 221 is on the large bay side (outside of the curved part, the upper side in FIG. 5), and the extension base point 213 is on the small bay side (curved part).
  • the dilator is expanded in diameter in a state of being on the inner side of FIG.
  • the sheath around the dilator comes into close contact with the blood vessel wall, and the position of the stent 20 is fixed to the affected part.
  • the sheath 40 is pulled toward the proximal end side (external side)
  • the stent graft 10 is sequentially released from the sheath 40 from the distal end side.
  • FIG. 5A is a diagram illustrating an initial release state of the stent graft 10. Specifically, a part of the annular unit 21 a is released from the sheath 40. At this time, the extended portion 212 provided in the annular unit 21 a has the tip 215 remaining in the sheath 40 and is locked to the end of the sheath 40. For this reason, the annular unit 21a is urged toward the large bay side with the end portion of the sheath 40 as a fulcrum and the extended base point 213 as an action point.
  • the annular units 21a and 21b are sequentially released from the sheath 40 as shown in FIGS. 5 (b) and 5 (c).
  • the annular unit 21a has an enlarged diameter, but is urged toward the large bay side by the extending portion 212, as in FIG. For this reason, the raise of the angle (alpha) with respect to the blood vessel wall 500 of the wire member which comprises the annular unit 21a is suppressed.
  • the stent graft 10 can be installed in an affected part with the attitude
  • the angle ⁇ formed by the wire member supported by the extending portion 212 and the blood vessel wall 500 does not exceed 30 °. It becomes. Therefore, since the stent graft 10 is deployed without being greatly distorted, the adhesion to the blood vessel wall 500 can be improved to a desired level.

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Abstract

It is intended to provide a stent, i.e., an almost tubular stent (20) having an extensible diameter which comprises a plurality of circular units (21a) to (21e) that are each in the shape of a ring made of a wire member having a definite width (H) in the axial direction and being folded in a zigzag pattern and located in series to each other and connecting parts (22a) to (22d) connecting these circular units (21a) to (21e) to each other, wherein the adhesiveness to blood vessel wall thereof can be improved, and a stent graft. To achieve this object, the circular unit (21a) provided at one end has an extended part (212) having a definite length (L) which inward extends toward the other end.

Description

ステント及びステントグラフトStent and stent graft
　本発明は、血管に生じた拡張性病変の治療に使用されるステント及びステントグラフトに関する。 The present invention relates to a stent and a stent graft used for treatment of an expandable lesion generated in a blood vessel.
　人体の恒常性を保持するために血液の循環を保持する上で、その経路となる動脈系は常に高い血圧にさらされている。そのため、動脈硬化や炎症等に起因して、特に弾性動脈である大動脈領域においては、拡張性病変が発生しやすい。この拡張性病変は、最終的に血圧により破綻し、体内への大出血を引き起こす致命的な疾患である。 In maintaining blood circulation in order to maintain the homeostasis of the human body, the arterial system serving as the route is constantly exposed to high blood pressure. For this reason, due to arteriosclerosis, inflammation and the like, an expandable lesion is likely to occur particularly in the aorta region which is an elastic artery. This dilated lesion is a fatal disease that eventually fails due to blood pressure and causes major bleeding in the body.
　拡張性病変の治療方法として、近年、ステントと呼ばれる管状の固定器具を人工血管材料で被覆したステントグラフトを用い、血管内側から動脈瘤への血圧を遮断する方法が、患者に与える負担が小さいことから着目されている。 As a method for treating dilated lesions, a method of blocking blood pressure from the inside of a blood vessel to an aneurysm using a stent graft in which a tubular fixation device called a stent is covered with an artificial blood vessel material has recently been less burdened on patients. It is attracting attention.
　図６は、従来例に係るステントグラフト９００の使用状態を示す図である。
　従来使用されているステント９１０は、径が伸縮自在な略管状の形状であり、互いに直列に配置された複数の環状ユニット９１１と、これら環状ユニット同士を連結する連結部９１３と、を備える。環状ユニット９１１は、軸方向に関して所定幅を有する繰返しパターンで折曲されたワイヤ部材で、輪状に形成されている。このようなステント９１０がグラフト９２０で側面を被覆されることで、ステントグラフト９００が構成される（例えば、特許文献１参照）。 FIG. 6 is a view showing a use state of a stent graft 900 according to a conventional example.
A conventionally used stent 910 has a substantially tubular shape whose diameter can be expanded and contracted, and includes a plurality of annular units 911 arranged in series with each other, and a connecting portion 913 that connects these annular units. The annular unit 911 is a wire member bent in a repeating pattern having a predetermined width in the axial direction, and is formed in a ring shape. The stent graft 900 is configured by covering the side surface of the stent 910 with the graft 920 (see, for example, Patent Document 1).
　ステントグラフト９００は次のように使用される。
　まず、ステントグラフト９００を、シース９３０と呼ばれる鞘状部材に縮径して着脱可能に収容する。次に、シース９３０に設けられた図示しない操作部を介して操作することで、ステントグラフト９００を血管内の患部に送達する。続いて、シース９３０を脱離させると、ステントグラフト９００が展開（即ち、拡径）され、環状ユニット９１１が所定幅で血管壁に密着する。すると、環状ユニット９１１を覆うグラフト９２０が、患部（動脈瘤）への血圧を遮断するので、拡張性病変を治療できることとなる。
特開平３－１５１９８３号公報 The stent graft 900 is used as follows.
First, the stent graft 900 is reduced in diameter to a sheath-like member called a sheath 930 and is detachably accommodated. Next, the stent graft 900 is delivered to the affected part in the blood vessel by operating through an operating part (not shown) provided in the sheath 930. Subsequently, when the sheath 930 is detached, the stent graft 900 is expanded (ie, expanded in diameter), and the annular unit 911 is closely attached to the blood vessel wall with a predetermined width. Then, since the graft 920 covering the annular unit 911 blocks the blood pressure to the affected part (aneurysm), the expandable lesion can be treated.
Japanese Patent Laid-Open No. 3-151983
　しかしながら、前述したステント９１０には次のような問題があった。
　シース９３０がステントグラフト９００から脱離され始めると、シース９３０から部分的に解放されたワイヤ部材が、血流によって下流方向（図６における矢印方向）へと付勢され、血管壁５００に対して大きい角度βをなして接触する（図６（ａ）参照）。すると、展開後のステントグラフト９００は歪んで設置され、血管壁５００に対する密着性が充分に得られない（図６（ｂ）参照）。 However, the above-described stent 910 has the following problems.
When the sheath 930 begins to be detached from the stent graft 900, the wire member partially released from the sheath 930 is urged by the blood flow in the downstream direction (the arrow direction in FIG. 6), and is large with respect to the blood vessel wall 500. Contact is made at an angle β (see FIG. 6A). As a result, the deployed stent graft 900 is distorted and cannot sufficiently adhere to the blood vessel wall 500 (see FIG. 6B).
　このため、患部への設置後、血流等の影響でステント９１０が変形することで、設置位置がずれたり、グラフト９２０と血管壁５００との間に間隙が生じ、この間隙を通じて血圧が患部へと印加されたり、といった事態が起こる場合がある。このような場合、拡張性病変を充分に治療することはできない。 For this reason, after installation in the affected area, the stent 910 is deformed by the influence of blood flow or the like, so that the installation position is shifted, or a gap is generated between the graft 920 and the blood vessel wall 500, and blood pressure is transferred to the affected area through this gap. May be applied. In such cases, dilated lesions cannot be fully treated.
　本発明は、このような問題に鑑みてなされたものであり、血管壁に対する密着性を向上できるステント及びステントグラフトを提供することを目的とする。 The present invention has been made in view of such problems, and an object thereof is to provide a stent and a stent graft that can improve adhesion to a blood vessel wall.
　本発明者らは、シースから解放された環状ユニットを構成するワイヤ部材の一部を延出させ、シース内に残すように設計することで、ワイヤ部材の血管壁に対する角度を低減できることを見出し、本発明を完成するに至った。具体的には、本発明は以下のようなものを提供する。 The present inventors have found that the angle of the wire member with respect to the blood vessel wall can be reduced by extending a part of the wire member constituting the annular unit released from the sheath and leaving it in the sheath, The present invention has been completed. Specifically, the present invention provides the following.
　（１）　径が伸縮自在な略管状のステントであって、
　軸方向に関して所定幅を有する繰返しパターンで折曲されたワイヤ部材で輪状に形成され、互いに直列に配置された複数の環状ユニットと、
　前記環状ユニット同士を連結する連結部と、を備え、
　少なくとも一端に配置された前記環状ユニットは、他端側へと内方に延出する所定長さの延出部を有するステント。 (1) A substantially tubular stent having a freely expandable diameter,
A plurality of annular units formed in a ring shape with wire members bent in a repetitive pattern having a predetermined width in the axial direction and arranged in series with each other;
A connecting portion for connecting the annular units to each other;
At least one end of the annular unit is a stent having an extension part of a predetermined length that extends inward toward the other end side.
　（１）の発明によれば、ステントは以下のように使用される。
　まず、ステントの側面をグラフトで被覆した後、シースと呼ばれる鞘状部材に縮径して着脱可能に収容する。次に、シースを操作して、ステントグラフトを血管内の患部に送達する。続いて、シースを脱離させ始めると、一端に配置された環状ユニットがシースから解放される。 According to the invention of (1), the stent is used as follows.
First, after covering the side surface of the stent with a graft, the diameter is reduced to a sheath-like member called a sheath, and the stent is detachably accommodated. The sheath is then manipulated to deliver the stent graft to the affected area within the vessel. Subsequently, when the sheath begins to be detached, the annular unit disposed at one end is released from the sheath.
　ここで、環状ユニットに設けられた延出部は、他端側へと内方に延出してシース内に残る。また、解放された環状ユニットと連結部を介して連結された環状ユニットも、シース内に残る。このため、シースから部分的に解放されたワイヤ部材は、連結部及び延出部に支持されるので、血流によって下流方向へと付勢されても、血管壁に対する角度の上昇が抑制される。 Here, the extending portion provided in the annular unit extends inward to the other end side and remains in the sheath. Further, the annular unit connected to the released annular unit through the connecting portion also remains in the sheath. For this reason, since the wire member partially released from the sheath is supported by the connecting portion and the extending portion, an increase in the angle with respect to the blood vessel wall is suppressed even when urged in the downstream direction by the blood flow. .
　これにより、展開後のステントグラフトは血管壁に対して略平行に設置されるから、血管壁に対する密着性を向上できる。 Thereby, since the stent graft after deployment is installed substantially parallel to the blood vessel wall, the adhesion to the blood vessel wall can be improved.
　ここで、所定幅は、ステントが留置される部位における血管の湾曲度、ワイヤ部材の強度等に応じて、適宜設定されてよい。即ち、血管壁の湾曲度が小さい場合、繰返しパターンの幅が大きい程、血管壁との接触面が広がり、ステントの姿勢を安定化できる。一方、血管の湾曲度が大きい場合、繰返しパターンの幅が小さい程、血管壁との非接触面を少なくでき、血管形状への追従性を向上できる。 Here, the predetermined width may be appropriately set according to the curvature of the blood vessel at the site where the stent is placed, the strength of the wire member, and the like. That is, when the degree of curvature of the blood vessel wall is small, the larger the width of the repeated pattern, the wider the contact surface with the blood vessel wall, and the stent posture can be stabilized. On the other hand, when the degree of curvature of the blood vessel is large, the non-contact surface with the blood vessel wall can be reduced and the followability to the blood vessel shape can be improved as the width of the repeated pattern is smaller.
　また、所定長さは、ステントが留置される部位における血管の径、湾曲パターン等に応じて、適宜設定されてよい。 Further, the predetermined length may be appropriately set according to the diameter of the blood vessel at the site where the stent is placed, the curved pattern, and the like.
　（２）　前記連結部及び前記延出部は、前記環状ユニットにおける各々の設置点を結ぶ図形の重心が、前記ステントの中心軸上となるように配置されている（１）記載のステント。 (2) The stent according to (1), wherein the connecting portion and the extending portion are arranged so that the center of gravity of the figure connecting the respective installation points in the annular unit is on the central axis of the stent.
　（２）の発明によれば、シースから部分的に解放されたワイヤ部材は、中心軸上の点が重心となるように設置された連結部及び延出部によって、バランス良く支持される。これにより、ワイヤ部材の血管壁に対する角度の上昇がより抑制されるので、血管壁に対する密着性をより向上できる。 According to the invention of (2), the wire member partially released from the sheath is supported in a well-balanced manner by the connecting portion and the extending portion installed so that the point on the central axis becomes the center of gravity. Thereby, since the raise of the angle with respect to the blood vessel wall of a wire member is suppressed more, the adhesiveness with respect to the blood vessel wall can be improved more.
　なお、「図形」は、直線でも多角形でもよく、換言すれば、連結部及び延出部の設置点数は特に限定されない。 In addition, the “figure” may be a straight line or a polygon, in other words, the number of installation points of the connecting part and the extending part is not particularly limited.
　（３）　１つの前記環状ユニットに対して、前記連結部は２点に設けられている（２）記載のステント。 (3) The stent according to (2), wherein the connecting portion is provided at two points with respect to one annular unit.
　（３）の発明によれば、環状ユニット同士を２点で連結したので、環状ユニット同士の間における不測のねじれが抑制される。このため、予定通りの姿勢でステントグラフトを患部に設置できる。 According to the invention of (3), since the annular units are connected at two points, unexpected twisting between the annular units is suppressed. For this reason, a stent graft can be installed in an affected part with the posture as planned.
　また、この発明によれば、シースから部分的に解放されたワイヤ部材は、中心軸上の点が重心となるように設置された連結部及び延出部によって、３点以上で、よりバランス良く支持される。これにより、血管壁に対する密着性をより向上できる。 Further, according to the present invention, the wire member partially released from the sheath can be more balanced at three or more points by the connecting portion and the extending portion installed so that the point on the central axis becomes the center of gravity. Supported. Thereby, the adhesiveness with respect to the blood vessel wall can be improved more.
　（４）　前記所定長さは、以下の数式１を満たす（１）から（３）いずれか記載のステント。
　Ｌ≧Ｒ÷ｃｏｓΘ・・・数式１
（式中、Ｌは所定長さ、Ｒは前記ステントが設置される部位における血管直径、Θは前記ワイヤ部材と血管壁とがなす角度として許容される最大の角度である。） (4) The stent according to any one of (1) to (3), wherein the predetermined length satisfies the following formula 1.
L ≧ R ÷ cosΘ Formula 1
(In the formula, L is a predetermined length, R is a blood vessel diameter at a site where the stent is installed, and Θ is a maximum angle allowed as an angle formed by the wire member and the blood vessel wall.)
　（５）　Θは３０°である（４）記載のステント。 (5) The stent according to (4), wherein Θ is 30 °.
　（４）又は（５）の発明によれば、数式１を満たすように延出部の長さＬを設定したので、この延出部で支持されたワイヤ部材と、血管壁とがなす角度は、許容される最大の角度Θを上回らないものとなる。従って、血管壁に対する密着性を所望のレベルにまで向上できる。 According to the invention of (4) or (5), since the length L of the extending portion is set so as to satisfy Formula 1, the angle formed between the wire member supported by the extending portion and the blood vessel wall is , Not exceeding the maximum allowable angle Θ. Therefore, the adhesion to the blood vessel wall can be improved to a desired level.
　ここで、角度Θは、ステントの伸縮性（径方向及び軸方向）、ワイヤ部材の可撓性等に応じて適宜設定されてよいが、発明者の経験上、３０°であることが好ましい。 Here, the angle Θ may be appropriately set according to the stretchability (radial direction and axial direction) of the stent, the flexibility of the wire member, etc., but is preferably 30 ° from the inventors' experience.
　（６）　前記延出部は、前記ステントの中心軸に向かって所定の幅を有する（１）から（５）いずれか記載のステント。 (6) The stent according to any one of (1) to (5), wherein the extending portion has a predetermined width toward the central axis of the stent.
　（６）の発明によれば、一端に配置された環状ユニットがシースから解放される際、所定の幅の延出部がシース内に残る。このため、延出部のよじれが抑制されるので、予定通りの姿勢でステントグラフトを患部に設置できる可能性を向上できる。 According to the invention of (6), when the annular unit arranged at one end is released from the sheath, an extension portion having a predetermined width remains in the sheath. For this reason, since the kinking of the extension part is suppressed, the possibility that the stent graft can be placed on the affected part in a planned posture can be improved.
　「所定の幅」は、任意部材で構成された全体形状の幅を指す。なお、「所定の幅」は、延出部の可撓性に応じて適宜設定されてよいが、線状のワイヤ部材が有するような幅を超え、意図的に付加された幅である。 “Predetermined width” refers to the width of the entire shape composed of arbitrary members. The “predetermined width” may be appropriately set according to the flexibility of the extending portion, but is a width intentionally added exceeding the width that the linear wire member has.
　（７）　前記延出部は、ワイヤ部材の両端が前記環状ユニットに接続されたループ状である（６）記載のステント。 (7) The stent according to (6), wherein the extending portion has a loop shape in which both ends of a wire member are connected to the annular unit.
　（７）の発明によれば、ワイヤ部材の両端が環状ユニットに接続されているので、ワイヤ部材の端部が血管壁に刺さるといった事態を予防できる。 According to the invention of (7), since both ends of the wire member are connected to the annular unit, it is possible to prevent a situation in which the end of the wire member is stuck in the blood vessel wall.
　（８）　（１）から（７）いずれか記載のステントと、このステントの側面を被覆するグラフトと、を備えるステントグラフト。 (8) A stent graft comprising the stent according to any one of (1) to (7) and a graft covering a side surface of the stent.
　（８）の発明によれば、（１）から（７）の発明と同様の効果が得られる。 According to the invention of (8), the same effects as the inventions of (1) to (7) can be obtained.
　本発明によれば、一端に配置された環状ユニットがシースから解放された際、環状ユニットに設けられた延出部は、他端側へと内方に延出してシース内に残る。また、解放された環状ユニットと連結部を介して連結された環状ユニットも、シース内に残る。このため、シースから部分的に解放されたワイヤ部材は、連結部及び延出部に支持されるので、血流によって下流方向へと付勢されても、血管壁に対する角度の上昇が抑制される。これにより、展開後のステントグラフトは血管壁に対して平行に設置されるから、血管壁に対する密着性を向上できる。 According to the present invention, when the annular unit disposed at one end is released from the sheath, the extending portion provided in the annular unit extends inward to the other end side and remains in the sheath. Further, the annular unit connected to the released annular unit through the connecting portion also remains in the sheath. For this reason, since the wire member partially released from the sheath is supported by the connecting portion and the extending portion, an increase in the angle with respect to the blood vessel wall is suppressed even when urged in the downstream direction by the blood flow. . Thereby, since the stent graft after expansion | deployment is installed in parallel with the blood vessel wall, the adhesiveness with respect to the blood vessel wall can be improved.
本発明の一実施形態に係るステントグラフトの全体斜視図である。1 is an overall perspective view of a stent graft according to an embodiment of the present invention. 図１の側面図である。It is a side view of FIG. 図１の底面図である。It is a bottom view of FIG. 前記実施形態に係るステントグラフトがシースに装着された状態を示す図である。It is a figure which shows the state with which the stent graft which concerns on the said embodiment was mounted | worn with the sheath. 前記実施形態に係るステントグラフトの使用状態を示す図である。It is a figure which shows the use condition of the stent graft which concerns on the said embodiment. 従来例に係るステントグラフトの使用状態を示す図である。It is a figure which shows the use condition of the stent graft which concerns on a prior art example.
符号の説明Explanation of symbols
　１０　ステントグラフト
　２０　ステント
　２１ａ～２１ｅ　環状ユニット
　２２ａ～２２ｄ　連結部
　３０　グラフト
　４０　シース
　２１１ａ～２２１ｅ　屈曲部
　２１２　延出部
　２１４ａ～２１４ｅ　介在部 DESCRIPTION OF SYMBOLS 10 Stent graft 20 Stent 21a-21e Annular unit 22a-22d Connection part 30 Graft 40 Sheath 211a-221e Bending part 212 Extension part 214a-214e Interposition part
発明を実施するための形態BEST MODE FOR CARRYING OUT THE INVENTION
　以下、本発明の一実施形態について、図面を参照しながら説明する。ただし、本発明は、以下の実施形態に限定されるものではない。 Hereinafter, an embodiment of the present invention will be described with reference to the drawings. However, the present invention is not limited to the following embodiments.
　図１は、本発明の一実施形態に係るステント２０の全体斜視図である。図２は図１の側面図であり、図３は図１の底面図である。 FIG. 1 is an overall perspective view of a stent 20 according to an embodiment of the present invention. 2 is a side view of FIG. 1, and FIG. 3 is a bottom view of FIG.
　＜ステント＞
　ステント２０は全体として略管状であり、その直径ｒが伸縮自在である。このステント２０は、互いに直列に配置された複数の環状ユニット２１ａ～２１ｅと、互いに隣接する環状ユニット２１ａ～２１ｅ同士を連結する連結部２２ａ～２２ｄと、を備える。 <Stent>
The stent 20 is generally tubular as a whole, and its diameter r is expandable and contractable. The stent 20 includes a plurality of annular units 21a to 21e arranged in series with each other, and connecting portions 22a to 22d that connect the annular units 21a to 21e adjacent to each other.
　〔環状ユニット〕
　環状ユニット２１ａ～２１ｅは、輪状のワイヤ部材で形成され、このワイヤ部材は、軸方向ＡＸに関して所定幅Ｈを有する繰返しパターンで折曲されている。この繰返しパターンは、略一定の間隔で位置する屈曲部２１１ａ～２１１ｅにおいて、略一定の角度でワイヤ部材が屈曲されて形成されたジグザグパターンである。 [Ring unit]
The annular units 21a to 21e are formed of ring-shaped wire members, and the wire members are bent in a repeating pattern having a predetermined width H with respect to the axial direction AX. This repetitive pattern is a zigzag pattern formed by bending the wire member at a substantially constant angle in the bent portions 211a to 211e positioned at a substantially constant interval.
　屈曲部２１１ａ～２１１ｅの各々の間に介在する介在部２１４ａ～２１４ｅは、特に限定されないが、本実施形態では略直線状である。 Intervening portions 214a to 214e interposed between the bent portions 211a to 211e are not particularly limited, but are substantially linear in the present embodiment.
　幅Ｈは、大きすぎると、血管壁に対するステント２０の追従性が悪化する一方、小さすぎると、ステント２０の径拡張力が不充分となる。このようなことを踏まえつつ、幅Ｈは、ステント２０が留置される部位における血管の湾曲度、ワイヤ部材の強度等に応じて、適宜設定されてよい。即ち、血管壁の湾曲度が小さい場合、幅Ｈが大きい程、血管壁との接触面が広がり、ステント２０の姿勢を安定化できる。一方、血管の湾曲度が大きい場合、幅Ｈが小さい程、血管壁との非接触面を少なくでき、血管形状への追従性を向上できる。大動脈瘤の治療に使用される場合、幅Ｈは、７ｍｍ以上２５ｍｍ以下であってよい。 If the width H is too large, the followability of the stent 20 to the blood vessel wall is deteriorated, whereas if it is too small, the diameter expansion force of the stent 20 is insufficient. With this in mind, the width H may be appropriately set according to the degree of curvature of the blood vessel, the strength of the wire member, and the like at the site where the stent 20 is placed. That is, when the degree of curvature of the blood vessel wall is small, the larger the width H, the wider the contact surface with the blood vessel wall, and the posture of the stent 20 can be stabilized. On the other hand, when the degree of curvature of the blood vessel is large, the smaller the width H, the smaller the non-contact surface with the blood vessel wall, and the followability to the blood vessel shape can be improved. When used for the treatment of an aortic aneurysm, the width H may be 7 mm or more and 25 mm or less.
　また、直径ｒは、ステント２０が留置される部位における血管径等に応じて適宜設定されてよい。大動脈瘤の治療に使用される場合、自然状態における直径ｒは、通常５０ｍｍ以上６０ｍｍ以下であってよい。 Further, the diameter r may be appropriately set according to the blood vessel diameter or the like at the site where the stent 20 is placed. When used for the treatment of an aortic aneurysm, the diameter r in the natural state may usually be 50 mm or more and 60 mm or less.
　屈曲部２１１ａ～２１１ｅの個数は、後述するようにステント２０の中心軸ＣＴの屈曲角度を精密に調整できるよう、適宜設定されてよい。例えば、Ｖ字構造（１個の屈曲部及びこの屈曲部を挟む２個の介在部をあわせた構造）の数は、環状ユニット２１ａ～２１ｅの順に、交互に奇数、偶数となるように設定できる。これにより、ステント２０が屈曲された際でも、隣接する環状ユニット２１ａ～２１ｅは、対向するＶ字構造同士が接触することがないので、重なり合うことができる。よって、血管の湾曲度が大きい部位にも対応できることとなる。なお、Ｖ字構造の数は、７個以上１２個以下であることが好ましい。 The number of the bent portions 211a to 211e may be set as appropriate so that the bending angle of the central axis CT of the stent 20 can be precisely adjusted as will be described later. For example, the number of V-shaped structures (a structure in which one bent portion and two intervening portions sandwiching the bent portion) can be set to be alternately odd and even in the order of the annular units 21a to 21e. . Thus, even when the stent 20 is bent, the adjacent annular units 21a to 21e can overlap each other because the opposing V-shaped structures do not contact each other. Therefore, it is possible to deal with a region where the degree of curvature of the blood vessel is large. The number of V-shaped structures is preferably 7 or more and 12 or less.
　ワイヤ部材としては、特に限定されず、通常使用されている、ＳＵＳ３１６Ｌ等のステンレス鋼、Ｔｉ－Ｎｉ合金等の超弾性合金、チタン、チタン合金、タンタル、タンタル合金、プラチナ、プラチナ合金、タングステン、タングステン合金等の金属で構成されていてよい。 The wire member is not particularly limited, and is usually used, stainless steel such as SUS316L, superelastic alloy such as Ti—Ni alloy, titanium, titanium alloy, tantalum, tantalum alloy, platinum, platinum alloy, tungsten, tungsten It may be composed of a metal such as an alloy.
　また、これら金属で形成された環状ユニットは、ポリウレタン、ポリビニルピロリドン、ポリビニルアルコール等の生体適合性高分子材料、この高分子材料にヘパリン、ウロキナーゼ等の生理活性物質が固定された材料、高分子材料にアルガトロバン、シラスタゾール、塩酸サルボグレラート等の抗血栓成分が混合された材料等で、表面が被覆されていてよい。 In addition, cyclic units formed of these metals are biocompatible polymer materials such as polyurethane, polyvinyl pyrrolidone, and polyvinyl alcohol, and materials obtained by immobilizing physiologically active substances such as heparin and urokinase on this polymer material. Further, the surface may be coated with a material mixed with an antithrombotic component such as argatroban, shirazazole, or salvogrelate hydrochloride.
　環状ユニット２１ａ～２１ｅの製造方法としては、特に限定されず、例えば、線状のワイヤ部材の１箇所以上を、溶接、ロウ止め、かしめ等の公知の手法で接合することで、全体として環状とすればよい。 The manufacturing method of the annular units 21a to 21e is not particularly limited. For example, the annular units 21a to 21e can be formed into an annular shape as a whole by joining one or more portions of a linear wire member by a known method such as welding, brazing, or caulking. do it.
　［延出部］
　ステント２０の一端に配置された環状ユニット２１ａは、他端側へと内方に延出する所定長さＬの延出部２１２を有する。この延出部２１２は、線状のワイヤ部材の両端が環状ユニット２１ａの屈曲部２１１ａに接続されたループ状である。また、延出部２１２は、ステント２０の中心軸ＣＴに向かって所定の幅Ｗを有する。この幅Ｗは、延出部２１２の強度に応じて、適宜設定されてよい。 [Extension part]
The annular unit 21a disposed at one end of the stent 20 has an extension 212 having a predetermined length L that extends inward toward the other end. The extending portion 212 has a loop shape in which both ends of the linear wire member are connected to the bent portion 211a of the annular unit 21a. Further, the extending portion 212 has a predetermined width W toward the central axis CT of the stent 20. This width W may be set as appropriate according to the strength of the extending portion 212.
　延出部２１２の形状としては、特にループ状には限定されないが、延出部２１２が血管壁に刺さることを予防するため、尖部や角部のない曲線形状であることが好ましい。また、延出部２１２は、本実施形態では、線状のワイヤ部材で構成されているが、これに限定されず、幅Ｗの板状部材であってよい。 The shape of the extended portion 212 is not particularly limited to a loop shape, but is preferably a curved shape having no cusps or corners in order to prevent the extended portion 212 from sticking into the blood vessel wall. Moreover, although the extension part 212 is comprised by the linear wire member in this embodiment, it is not limited to this, The plate-shaped member of the width W may be sufficient.
　延出部２１２の設置位置としては、特に限定されないが、後述するようにバランス良く環状ユニット２１ａを支持できる点で、本実施形態のように屈曲部２１１ａとすることが好ましい。また、延出部２１２の素材は、前述した環状ユニットと同様の素材であってよい。 Although the installation position of the extending part 212 is not particularly limited, it is preferable to use the bent part 211a as in the present embodiment in that the annular unit 21a can be supported in a well-balanced manner as will be described later. Moreover, the material of the extension part 212 may be the same material as the annular unit described above.
　本実施形態における延出部２１２の長さＬは、以下の数式２を満たす。
　Ｌ≧Ｒ÷ｃｏｓ３０°・・・数式２
（式中、Ｒはステント２０が設置される部位における血管直径である。） The length L of the extending part 212 in this embodiment satisfies the following formula 2.
L ≧ R ÷ cos30 ° Formula 2
(In the formula, R is the blood vessel diameter at the site where the stent 20 is installed.)
　延出部２１２の先端２１５は、環状ユニット２１ｃと環状ユニット２１ｄとの間に位置する。後述するように、２０の中心軸ＣＴは、環状ユニット２１ｃと環状ユニット２１ｄとの間で最も大きく屈曲し、使用時には環状ユニット２１ｃと環状ユニット２１ｄとの間の部分が、血管の屈曲度が最大の部位（通常、動脈瘤の発生部位）に設置されることとなる。即ち、延出部２１２は、血管の屈曲度が最大の部位に向けて延出することになる。 The tip 215 of the extending part 212 is located between the annular unit 21c and the annular unit 21d. As will be described later, the central axis CT of the 20 is bent most greatly between the annular unit 21c and the annular unit 21d, and the portion between the annular unit 21c and the annular unit 21d has the maximum degree of bending of the blood vessel during use. It will be installed in the site (usually the site where the aneurysm occurs). In other words, the extending portion 212 extends toward a portion where the degree of bending of the blood vessel is maximum.
　なお、本実施形態においては、延出部２１２が環状ユニット２１ａにのみ設けられているが、他の環状ユニット２１ｂ～２１ｅ、とりわけ環状ユニット２１ａに隣接する環状ユニット２１ｂにも設けられていてよい。これにより、環状ユニット２１ｂは、後述するグラフト３０に加え、延出部によっても支持されるので、血管壁に対する角度の上昇がより抑制される。 In the present embodiment, the extending portion 212 is provided only in the annular unit 21a, but may be provided in the other annular units 21b to 21e, particularly the annular unit 21b adjacent to the annular unit 21a. Thereby, since the annular unit 21b is supported also by the extension part in addition to the graft 30 described later, an increase in the angle with respect to the blood vessel wall is further suppressed.
　〔連結部〕
　連結部２２ａ～２２ｄは、ワイヤ部材で構成された直線状であり、環状ユニット２１ａ～２１ｅの各々の間に２つずつ設けられている。環状ユニット２１ａにおける連結部２２ａの設置点である連結基点２２１は、延出部２１２の設置点である延出基点２１３から互いに等しい距離に位置する。これにより、連結基点２２１及び延出基点２１３を結ぶ図形は、重心がステント２０の中心軸ＣＴ上にある二等辺三角形となる。 (Connecting part)
The connecting portions 22a to 22d are linear formed of wire members, and two are provided between each of the annular units 21a to 21e. The connection base point 221 that is the installation point of the connection part 22 a in the annular unit 21 a is located at an equal distance from the extension base point 213 that is the installation point of the extension part 212. As a result, the graphic connecting the connection base point 221 and the extension base point 213 is an isosceles triangle whose center of gravity is on the central axis CT of the stent 20.
　連結部２２ａ～２２ｄは、本実施形態においては、介在部２１４ａ～２１４ｅと略一直線状となるように、屈曲部２１１ａ～２１１ｅに設けられている。ここで、これら連結部２２ａ～２２ｅの各々は、屈曲部２１１ａ～２１１ｅの１個以上（例えば、１個～４個）をあけて設置される。 In the present embodiment, the connecting portions 22a to 22d are provided in the bent portions 211a to 211e so as to be substantially in line with the interposed portions 214a to 214e. Here, each of the connecting portions 22a to 22e is installed with one or more bent portions 211a to 211e (for example, one to four).
　この点についてより詳しく説明すると、隣接する環状ユニット２１ａ～２１ｅの軸同士がなす角度（即ち、ステント２０の軸の屈曲角度）は、連結部２２ａ～２２ｅの各々が挟む角度、即ち、屈曲部２１１ａ～２１１ｅの数に比例して大きくなる。本実施形態では、具体的には、連結部２２ａは２個の屈曲部２１１ａ、２１１ｂを、連結部２２ｂは２個の屈曲部２１１ｂ、２１１ｃを、連結部２２ｃは３個の屈曲部２１１ｃ、２１１ｄを、連結部２２ｄは２個の屈曲部２１１ｄ、２１１ｅをあけて設置されており、それぞれの屈曲部２１１ａ～２１１ｅの数に応じた角度でステント２０の中心軸ＣＴは屈曲することとなる。 This point will be described in more detail. The angle formed by the axes of the adjacent annular units 21a to 21e (that is, the bending angle of the shaft of the stent 20) is the angle between the connecting portions 22a to 22e, that is, the bending portion 211a. It increases in proportion to the number of up to 211e. Specifically, in the present embodiment, the connecting portion 22a has two bent portions 211a and 211b, the connecting portion 22b has two bent portions 211b and 211c, and the connecting portion 22c has three bent portions 211c and 211d. The connecting portion 22d is provided with two bent portions 211d and 211e, and the central axis CT of the stent 20 is bent at an angle corresponding to the number of the bent portions 211a to 211e.
　また、連結部２２ａ～２２ｄは、本実施形態では、すべて略等しい長さであるが、これに限定されない。連結部２２ａ～２２ｄの長さは、ステント２０の中心軸ＣＴが所望の角度で屈曲するように適宜設定されてよい。 Further, in the present embodiment, all of the connecting portions 22a to 22d have substantially the same length, but the present invention is not limited to this. The lengths of the connecting portions 22a to 22d may be appropriately set so that the central axis CT of the stent 20 bends at a desired angle.
　なお、連結部は、環状ユニット２１ａ～２１ｅ同士を連結する機能を有している限りにおいて、その構造は特に限定されない。即ち、本実施形態のように、環状ユニット２１ａ～２１ｅに接合されたワイヤ部材で構成されていてもよいが、後述する環状ユニット２１ａ～２１ｅに縫いとめられたグラフト３０で構成されてもよい。この場合、グラフト３０は連結部としても作用することになる。 The structure of the connecting portion is not particularly limited as long as it has a function of connecting the annular units 21a to 21e. That is, as in the present embodiment, it may be composed of a wire member joined to the annular units 21a to 21e, but may be composed of a graft 30 sewn to the annular units 21a to 21e described later. In this case, the graft 30 also acts as a connecting portion.
　その他、ステント２０の所望の位置に、必要に応じて、Ｘ線不透過部や薬剤収容部を設けてもよい。これらの設置要領については、従来公知の通りでよい（例えば、ＷＯ０３／０９７１５５号パンフレット参照）。また、ステント２０の作製方法も、従来公知の方法でよい（例えば、ＷＯ０３／０９７１５５号パンフレット参照）。 In addition, an X-ray opaque part and a medicine container may be provided at a desired position of the stent 20 as necessary. About these installation points, it may be as conventionally well-known (for example, refer WO03 / 097155 pamphlet). The stent 20 may be produced by a conventionally known method (see, for example, WO03 / 097155 pamphlet).
　＜グラフト＞
　図１～３において破線で示されるグラフト３０は、従来公知の材料、例えば、「ダクロン（登録商標）」等のポリエチレンテレフタレート繊維、ポリテトラフルオロエチレン等のフッソ樹脂製のフィルムといった合成樹脂で形成されてよい。 <Graft>
The graft 30 indicated by a broken line in FIGS. 1 to 3 is made of a conventionally known material, for example, a synthetic resin such as a polyethylene terephthalate fiber such as “Dacron (registered trademark)” or a film made of a fluororesin such as polytetrafluoroethylene. It's okay.
　グラフト３０内にステント２０を挿入することで、ステントグラフト１０が作製される。ここで、図４には示していないが、ステント２０の直径ｒは、所定の割合で縮小されることとなる。例えば、自然状態における直径ｒが４０ｍｍのステントを３０ｍｍに縮径し、これを直径３１ｍｍのグラフト内に挿入できる。 The stent graft 10 is manufactured by inserting the stent 20 into the graft 30. Here, although not shown in FIG. 4, the diameter r of the stent 20 is reduced at a predetermined rate. For example, a stent with a natural diameter of 40 mm can be reduced to 30 mm and inserted into a 31 mm diameter graft.
　＜シース＞
　図４は、ステントグラフト１０がシース４０に装着された状態を示す図である。
　シース４０は柔軟な小径のチューブ状部材で構成され、このシース４０の先端部分（図４における左側）にステントグラフト１０が着脱可能に挿入される。このとき、ステント２０は、環状ユニット２１ａがシース４０の先端側となるように挿入されており、直径ｒが縮小され、軸方向に伸長されている。 <Sheath>
FIG. 4 is a view showing a state in which the stent graft 10 is attached to the sheath 40.
The sheath 40 is composed of a flexible small-diameter tubular member, and the stent graft 10 is detachably inserted into the distal end portion (left side in FIG. 4) of the sheath 40. At this time, the stent 20 is inserted so that the annular unit 21a is on the distal end side of the sheath 40, the diameter r is reduced, and the stent 20 is extended in the axial direction.
　シース４０には図示しない操作部に接続されるとともに、シース４０の内部には、ステントグラフト１０よりも基端側に、図示しない拡径可能なダイレータが収容されている。これにより、外部で操作部を操作してシースを血管内で移動させ、所定位置でダイレータを拡径することで、シースが血管壁に密着する。このような操作部及びダイレータの設置及び使用の要領は、従来公知の通りでよい（例えば、特開２００６－１３００６４号公報参照）。ここで、シース４０、このシース４０に着脱可能に収容されたステントグラフト１０、操作部等を備えるセットを、デリバリーシステム１１とする。 The sheath 40 is connected to an operation unit (not shown), and a dilator (not shown) capable of expanding the diameter is accommodated inside the sheath 40 on the proximal side of the stent graft 10. As a result, the sheath is brought into close contact with the blood vessel wall by operating the operating portion externally to move the sheath within the blood vessel and expanding the diameter of the dilator at a predetermined position. The procedure for installing and using such an operation unit and dilator may be as conventionally known (see, for example, JP-A-2006-130064). Here, a set including the sheath 40, the stent graft 10 detachably accommodated in the sheath 40, an operation unit, and the like is referred to as a delivery system 11.
　環状ユニット２１ａ～２１ｅ間のグラフト３０は、連結部２２ａ～２２ｄの間の空間に格納されている。これにより、血管内でステントグラフト１０が展開された際、格納されたグラフト３０が空間から解放され、血管壁に密着する。ここで、グラフト３０が空間に格納されていないと、展開後、血管の湾曲部位におけるグラフト３０の長さが不足するため、グラフト３０が血管壁から離間し、充分に密着できないおそれがある。 The graft 30 between the annular units 21a to 21e is stored in a space between the connecting portions 22a to 22d. Thereby, when the stent graft 10 is deployed in the blood vessel, the stored graft 30 is released from the space and is in close contact with the blood vessel wall. Here, if the graft 30 is not stored in the space, the length of the graft 30 at the curved portion of the blood vessel is insufficient after deployment, so that the graft 30 may be separated from the blood vessel wall and not sufficiently adhered.
　＜使用方法＞
　図５は、ステントグラフト１０の使用状態を示す図である。この図５を参照しながら、ステントグラフト１０の使用方法を説明する。 <How to use>
FIG. 5 is a diagram showing a use state of the stent graft 10. A method of using the stent graft 10 will be described with reference to FIG.
　まず、デリバリーシステム１１を環状ユニット２１ａ側から毛細血管側の血管内に侵入させ、外部の操作部を操ることで、患部へと移動させる。移動は、必要に応じて、ステントＸ線撮像装置からの画像で、ステントグラフト１０の位置を確認しながら行う。 First, the delivery system 11 is moved into the blood vessel on the capillary vessel side from the annular unit 21a side and moved to the affected part by manipulating the external operation part. The movement is performed while confirming the position of the stent graft 10 with an image from the stent X-ray imaging apparatus as necessary.
　続いて、ステントグラフト１０を患部（例えば、動脈瘤の発生部位）が到達すると、連結基点２２１が大湾側（湾曲部の外側、図５における上側）、延出基点２１３が小湾側（湾曲部の内側、図５における下側）になる状態で、ダイレータを拡径させる。すると、ダイレータ周囲のシースが血管壁に密着し、ステント２０の位置が患部に固定される。この状態で、シース４０を基端側（外部側）へと引っ張ると、ステントグラフト１０は先端側からシース４０から順次解放される。 Subsequently, when the affected part (for example, an aneurysm generation site) reaches the stent graft 10, the connection base point 221 is on the large bay side (outside of the curved part, the upper side in FIG. 5), and the extension base point 213 is on the small bay side (curved part). The dilator is expanded in diameter in a state of being on the inner side of FIG. Then, the sheath around the dilator comes into close contact with the blood vessel wall, and the position of the stent 20 is fixed to the affected part. In this state, when the sheath 40 is pulled toward the proximal end side (external side), the stent graft 10 is sequentially released from the sheath 40 from the distal end side.
　図５（ａ）は、ステントグラフト１０の初期解放状態を示す図であり、具体的には、環状ユニット２１ａの一部がシース４０から解放されている。このとき、環状ユニット２１ａに設けられた延出部２１２は、先端２１５がシース４０内に残り、シース４０の端部に係止される。このため、シース４０の端部を支点、延出基点２１３を作用点として、環状ユニット２１ａが大湾側に付勢されている。 FIG. 5A is a diagram illustrating an initial release state of the stent graft 10. Specifically, a part of the annular unit 21 a is released from the sheath 40. At this time, the extended portion 212 provided in the annular unit 21 a has the tip 215 remaining in the sheath 40 and is locked to the end of the sheath 40. For this reason, the annular unit 21a is urged toward the large bay side with the end portion of the sheath 40 as a fulcrum and the extended base point 213 as an action point.
　次に、シース４０を外部側へと更に引っ張ると、図５（ｂ）、（ｃ）に示されるように、環状ユニット２１ａ、２１ｂが、順次、シース４０から解放される。このとき、環状ユニット２１ａは、拡径しているが、図５（ａ）と同様に、延出部２１２によって大湾側に付勢される。このため、環状ユニット２１ａを構成するワイヤ部材の血管壁５００に対する角度αの上昇が抑制されている。 Next, when the sheath 40 is further pulled outward, the annular units 21a and 21b are sequentially released from the sheath 40 as shown in FIGS. 5 (b) and 5 (c). At this time, the annular unit 21a has an enlarged diameter, but is urged toward the large bay side by the extending portion 212, as in FIG. For this reason, the raise of the angle (alpha) with respect to the blood vessel wall 500 of the wire member which comprises the annular unit 21a is suppressed.
　やがて、シース４０をステントグラフト１０から完全に脱離すると、図５（ｄ）に示されるように、ステントグラフト１０は歪むことなく完全に展開し、血管壁５００に密着する。これにより、動脈瘤への血流は、グラフト３０で阻害されることになる。 Eventually, when the sheath 40 is completely detached from the stent graft 10, as shown in FIG. 5 (d), the stent graft 10 is completely deployed without being distorted and is in close contact with the blood vessel wall 500. As a result, blood flow to the aneurysm is inhibited by the graft 30.
　＜効果＞
　本実施形態に係るステントグラフト１０によれば、以下のような作用効果が得られる。 <Effect>
According to the stent graft 10 according to the present embodiment, the following effects can be obtained.
　（１）一端に配置された環状ユニット２１ａがシース４０から解放された際、環状ユニット２１ａに設けられた延出部２１２は、他端側へと内方に延出してシース４０内に残る。また、環状ユニット２１ａと連結部２２ａを介して連結された環状ユニット２１ｂも、シース内に残る。このため、シース４０から部分的に解放されたワイヤ部材は、連結部２２ａ及び延出部２１２に支持されるので、血流によって下流方向（図５における矢印方向）へと付勢されても、血管壁５００に対する角度αの上昇が抑制される（図６におけるβと比較されたい）。これにより、展開後のステントグラフト１０は血管壁５００に対して平行に設置されるから、血管壁５００に対する密着性を向上できる。 (1) When the annular unit 21a disposed at one end is released from the sheath 40, the extending portion 212 provided in the annular unit 21a extends inward to the other end side and remains in the sheath 40. Further, the annular unit 21b connected to the annular unit 21a via the connecting portion 22a also remains in the sheath. For this reason, since the wire member partially released from the sheath 40 is supported by the connecting portion 22a and the extending portion 212, even if it is urged by the blood flow in the downstream direction (the arrow direction in FIG. 5), An increase in the angle α with respect to the blood vessel wall 500 is suppressed (compare β in FIG. 6). Thereby, since the stent graft 10 after deployment is installed in parallel to the blood vessel wall 500, adhesion to the blood vessel wall 500 can be improved.
　（２）シース４０から部分的に解放されたワイヤ部材は、中心軸ＣＴ上の点が重心となるように設置された連結部２２ａ及び延出部２１２によって、バランス良く支持される。これにより、ワイヤ部材の血管壁５００に対する角度の上昇がより抑制されるので、血管壁５００に対する密着性をより向上できる。 (2) The wire member partially released from the sheath 40 is supported in a balanced manner by the connecting portion 22a and the extending portion 212 installed so that the point on the central axis CT becomes the center of gravity. Thereby, since the raise of the angle with respect to the blood vessel wall 500 of a wire member is suppressed more, the adhesiveness with respect to the blood vessel wall 500 can be improved more.
　（３）隣接する環状ユニット２１ａ～２１ｅ同士を２点で連結したので、環状ユニット２１ａ～２１ｅ同士の間における不測のねじれが抑制される。このため、予定通りの姿勢でステントグラフト１０を患部に設置できる。
　また、シース４０から部分的に解放されたワイヤ部材は、中心軸ＣＴ上の点が重心となるように設置された連結部２２ａ及び延出部２１２によって、よりバランス良く３点支持される。これにより、血管壁５００に対する密着性をより向上できる。 (3) Since the adjacent annular units 21a to 21e are connected at two points, unexpected twisting between the annular units 21a to 21e is suppressed. For this reason, the stent graft 10 can be installed in an affected part with the attitude | position as planned.
Further, the wire member partially released from the sheath 40 is supported at three points with a better balance by the connecting portion 22a and the extending portion 212 installed so that the point on the central axis CT becomes the center of gravity. Thereby, the adhesiveness with respect to the blood vessel wall 500 can be improved more.
　（４）数式２を満たすように延出部２１２の長さＬを設定したので、この延出部２１２で支持されたワイヤ部材と、血管壁５００とがなす角度αは３０°を上回らないものとなる。従って、ステントグラフト１０が大きく歪むことなく展開されるため、血管壁５００に対する密着性を所望のレベルにまで向上できる。 (4) Since the length L of the extending portion 212 is set so as to satisfy Formula 2, the angle α formed by the wire member supported by the extending portion 212 and the blood vessel wall 500 does not exceed 30 °. It becomes. Therefore, since the stent graft 10 is deployed without being greatly distorted, the adhesion to the blood vessel wall 500 can be improved to a desired level.
　（５）一端に配置された環状ユニット２１ａがシース４０から解放される際、所定の幅Ｗの延出部２１２がシース４０内に残る。このため、延出部２１２のよじれが抑制されるので、予定通りの姿勢でステントグラフト１０を患部に設置できる可能性を向上できる。 (5) When the annular unit 21 a disposed at one end is released from the sheath 40, the extending portion 212 having a predetermined width W remains in the sheath 40. For this reason, since the kinking of the extension part 212 is suppressed, the possibility that the stent graft 10 can be placed on the affected part in a predetermined posture can be improved.
　（６）延出部２１２を構成するワイヤ部材の両端が環状ユニット２１ａに接続されているので、ワイヤ部材の端部が血管壁５００に刺さるといった事態を予防できる。 (6) Since both ends of the wire member constituting the extending portion 212 are connected to the annular unit 21a, a situation in which the end portion of the wire member is stuck in the blood vessel wall 500 can be prevented.

Claims (8)

  1. 　径が伸縮自在な略管状のステントであって、
    　軸方向に関して所定幅を有する繰返しパターンで折曲されたワイヤ部材で輪状に形成され、互いに直列に配置された複数の環状ユニットと、
    　前記環状ユニット同士を連結する連結部と、を備え、
    　少なくとも一端に配置された前記環状ユニットは、他端側へと内方に延出する所定長さの延出部を有するステント。     It is a substantially tubular stent whose diameter can be expanded and contracted,
    A plurality of annular units formed in a ring shape with wire members bent in a repetitive pattern having a predetermined width in the axial direction and arranged in series with each other;
    A connecting portion for connecting the annular units to each other;
    At least one end of the annular unit is a stent having an extension part of a predetermined length that extends inward toward the other end side.
  2. 　前記連結部及び前記延出部は、前記環状ユニットにおける各々の設置点を結ぶ図形の重心が、前記ステントの中心軸上となるように配置されている請求項１記載のステント。 The stent according to claim 1, wherein the connecting portion and the extending portion are arranged such that the center of gravity of the figure connecting the installation points in the annular unit is on the central axis of the stent.
  3. 　１つの前記環状ユニットに対して、前記連結部は２点に設けられている請求項２記載のステント。 The stent according to claim 2, wherein the connecting portion is provided at two points with respect to one annular unit.
  4. 　前記所定長さは、以下の数式１を満たす請求項１から３いずれか記載のステント。
    　Ｌ≧Ｒ÷ｃｏｓΘ・・・数式１
    （式中、Ｌは所定長さ、Ｒは前記ステントが設置される部位における血管直径、Θは前記ワイヤ部材と血管壁とがなす角度として許容される最大の角度である。）     The stent according to any one of claims 1 to 3, wherein the predetermined length satisfies Formula 1 below.
    L ≧ R ÷ cosΘ Formula 1
    (In the formula, L is a predetermined length, R is a blood vessel diameter at a site where the stent is installed, and Θ is a maximum angle allowed as an angle formed by the wire member and the blood vessel wall.)
  5. 　Θは３０°である請求項４記載のステント。 The stent according to claim 4, wherein Θ is 30 °.
  6. 　前記延出部は、前記ステントの中心軸に向かって所定の幅を有する請求項１から５いずれか記載のステント。 The stent according to any one of claims 1 to 5, wherein the extending portion has a predetermined width toward a central axis of the stent.
  7. 　前記延出部は、ワイヤ部材の両端が前記環状ユニットに接続されたループ状である請求項６記載のステント。 The stent according to claim 6, wherein the extending portion has a loop shape in which both ends of a wire member are connected to the annular unit.
  8. 　請求項１から７いずれか記載のステントと、このステントの側面を被覆するグラフトと、を備えるステントグラフト。 A stent graft comprising the stent according to any one of claims 1 to 7 and a graft covering a side surface of the stent.
PCT/JP2008/056234 2008-03-28 2008-03-28 Stent and stent graft WO2009118912A1 (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103598929A (en) * 2013-11-28 2014-02-26 先健科技(深圳)有限公司 Thoracic aorta covered stent

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH1099447A (en) * 1996-06-13 1998-04-21 Nitinol Devices & Components Inc Stent
WO2002038085A1 (en) * 2000-11-13 2002-05-16 Kensey Kenneth R Device and method for reducing blood pressure
JP2008099995A (en) * 2006-10-20 2008-05-01 Guroobu Kk Stent and stent graft

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH1099447A (en) * 1996-06-13 1998-04-21 Nitinol Devices & Components Inc Stent
WO2002038085A1 (en) * 2000-11-13 2002-05-16 Kensey Kenneth R Device and method for reducing blood pressure
JP2008099995A (en) * 2006-10-20 2008-05-01 Guroobu Kk Stent and stent graft

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103598929A (en) * 2013-11-28 2014-02-26 先健科技(深圳)有限公司 Thoracic aorta covered stent
EP3075352A1 (en) * 2013-11-28 2016-10-05 Lifetech Scientific (Shenzhen) Co., Ltd. Thoracic aortic covered stent
EP3075352A4 (en) * 2013-11-28 2017-05-03 Lifetech Scientific (Shenzhen) Co., Ltd. Thoracic aortic covered stent

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