JP2005304792A - Method of holding reduced diameter of stent, stent with reduced diameter being held, and method to increase it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method to easily hold a reduced diameter of a stent and easily increase it without requiring an outside sheath or special equipment and with a simple mechanism. <P>SOLUTION: This is to provide a method to hold the reduced diameter of the stent whose diameter is reduced using a wire rod. It is characterized by (1) the wire rod having a fold section A folded in two is wound once around the outer circumference of the stent with the reduced diameter, and a moving side of the wire rod of the main section wound around the outer circumference of the stent is folded in two and passed through the hoop of the fold section A; (2) the moving side of the wire rod passed through the fold section is folded in two to make a fold section B, the moving side of the wire rod having the fold section B folded in two is wound once around the outer circumference of the stent with the reduced diameter to the same direction as (1) mentioned above, and a moving side of the wire rod of the main section wound around the outer circumference of the stent is folded in two and passed through the hoop of the fold section B; and (2) mentioned above is repeated one or more times to hold the reduced diameter of the stent with the reduced diameter. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for maintaining a reduced diameter of a stent that is inserted and disposed in a tubular organ of a human body such as a blood vessel, a ureter, a bile duct, and a trachea, a stent having a reduced diameter using the reduced diameter holding method, and a stent thereof The present invention relates to a method for expanding a stent.

  In recent years, in order to treat human tubular organs such as blood vessels, ureters, bile ducts, and trachea, stents are inserted and placed through these catheters in affected areas. For example, a treatment method is known in which a covered stent is placed in a stenosis portion of a blood vessel to be expanded, or a covered stent is placed in a place where an aneurysm is formed to prevent rupture of the aneurysm.

  As a method for inserting a covered stent, a method is also employed in which a catheter is inserted percutaneously into a tubular organ such as a blood vessel, and the covered stent is pushed through the catheter into the tubular organ. Also, if the treatment site is difficult to insert by such a method, or if there are multiple treatment sites and the workability is poor with the method of inserting through a catheter, the body is surgically incised. A method of inserting a covered stent directly into an affected part of a tubular organ is employed.

  As described above, even when the covered stent is inserted directly into the affected part of the tubular organ, the covered stent needs to be held in a reduced diameter state in order to insert the covered stent through the cut end of the tubular organ. However, since the covered stent is expanded and fixed to the inner wall of the tubular organ when it is placed in the tubular organ, it needs to be constrained from the outside in order to keep it in a reduced diameter state.

  For this purpose, Patent Document 1 discloses a feeding device that temporarily restrains an expandable implant in a crushed state and feeds it to a deployment site so as to surround the expandable implant. Configured to connect the implant in a collapsed state while delivering the implant through a mammalian body lumen, and connecting the portions of the sheet to each other to maintain the implant in the collapsed state An apparatus comprising a member is disclosed.

  Patent Document 2 further includes a stent having a base side end and a distal end, and a line releasably coupled to the stent to hold the stent in a folded state. A medical device is disclosed that is arranged to be released so that the stent gradually expands in a direction from the proximal end to the distal end.

JP-T-2001-506902 JP 2000-503559 A

  An object of the present invention is to provide a reduced diameter holding method capable of easily holding a stent with a reduced diameter and further easily expanding with a simple mechanism without requiring an external sheath or special equipment.

The first of the present invention is a reduced diameter holding method for holding the reduced diameter of a stent that has been reduced in diameter using a wire,
(1) A wire having a bent portion A bent twice is wound around the outer periphery of a stent having a reduced diameter, and the main moving end side wire wound around the outer periphery of the stent is bent twice to bend the bent portion A. Through the ring of
(2) The bending end B is formed by bending the moving end side wire rod that has passed through the ring of the bending portion, and the bending end portion B having the bending portion B is formed as the moving end side wire rod with the wire rod of the above (1). One turn on the outer circumference of the stent reduced in diameter in the same winding direction, and the main end of the moving end side wire wound around the outer circumference of the stent is double-folded and passed through the loop of the bent portion B.
It is another object of the present invention to provide a method for maintaining a reduced diameter of a stent, characterized by maintaining the reduced diameter of a stent that has been reduced in diameter by repeating the above (2) at least once.
The method of maintaining the reduced diameter of the stent is as follows. (1) and (2) are performed once from the distal end or the vicinity of the distal end of the reduced diameter stent to the proximal end or the vicinity of the proximal end opposite to the distal end. The diameter reduction is preferably maintained by repeating the above or a plurality of times.
In the method for maintaining the reduced diameter of the stent, it is preferable that the holding interval near the tip or near the tip is narrow.
In the method of maintaining the reduced diameter of the stent, in (1) and (2) above, the intersection of the bent portion B and the wire portion that is double-folded on the moving end side wire rod wound around the outer periphery of the stent, It is preferable that it is linear with respect to the length direction of the stent.

The second of the present invention is to provide a stent having a reduced diameter obtained by the first method for maintaining a reduced diameter of the present invention.
A third aspect of the present invention is to provide a stent having a reduced diameter which is further provided with a cover on the outer periphery of the stent having a reduced diameter.

4th of this invention is the expansion method of the 2nd diameter-retained stent of this invention,
A method for expanding a stent having a reduced diameter, wherein the stent having a reduced diameter is expanded by pulling an end portion or a vicinity of the end portion of a wire rod having a bent portion A that is bent twice. Is to provide.

The present invention does not require an external sheath or special equipment, and can easily reduce the diameter of the stent by a simple method.
By using the holding method of the present invention, the diameter reduction can be performed simply, reliably and efficiently.
The stent having a reduced diameter held by the holding method of the present invention can be easily expanded by pulling the moving end side wire.
By the holding method of the present invention, the wire rod on the moving end side that has passed through the bent portion comes to the inside of the wire rod on the stationary end side that is wound around the outer periphery of the stent. You can pull without receiving.

  When the reduced diameter retention stent of the present invention is used for an open-type operation, since a sheath is not necessary, (1) the diameter can be reduced and the burden on the operator or patient can be reduced, (2) excellent visibility, (3) It has effects such as preventing twisting, shifting, and damage of the graft when passing through the inside.

Embodiments of the present invention will be described below in detail with reference to the drawings. However, the present invention is not limited to these embodiments.
In the present invention, the drawings described below are examples of the present invention, and are not limited to the shapes described in the drawings. The drawings described below, the contents described below, and the contents described below are described below. The figures and the figures described below can be combined with the contents described below.

1 (a) to 1 (c) show a method for maintaining the reduced diameter of the stent 1 that has been reduced in diameter using the wire 2 having a double bent portion shown in FIG.
FIG. 1A is a schematic diagram in which a wire 2 having a bent portion 3 bent twice is wound around the outer circumference of a stent 1 having a reduced diameter. Each part of the wire wound around the outer periphery of the stent is a main part 4, a stationary end side wire 6, a moving end side wire 5, a bending part 3, and a bending part ring 7.
FIG. 1B shows a bent portion 10 formed by bending the moving end side wire 5 in a double manner at the main portion 4 of the wire wound around the outer periphery of the stent. The bent portion 10 of the moving end side wire is bent at the bent portion 3. FIG. The passage portion 12 is a wire rod that passes through the ring 7 of the bending portion 3 by bending the moving end side wire 5 in a double manner, and the tip portion is the bending portion 10.
FIG.1 (c) is a schematic diagram which lengthens the length of the passage part and makes it the passage part 12a by drawing the moving end side wire 5 of the passage part 12 of FIG.1 (b). In the passage part 12, the stationary end side wire is not drawn. The bent portion 10 of the passage portion 12a is further wound once in the same direction as the winding direction of the wire 2 in FIG. 1A, and the moving end side wire rod of the main portion of the passage portion 12a is double-folded to newly bend the bent portion. C was made, and the diameter of the bent portion C was reduced by passing the bent portion C through the ring of the bent portion 10 of the passage portion 12a, and further repeating FIG. 1 (b) and FIG. 1 (c) one or more times. The stent can be held in a reduced diameter.
The intersection 13 between the wire rod of the bent portion 3 and the stationary end side wire rod of the passage portion 12a in FIG. 1 (c) intersects the wire rod of the bent portion 3 and the static end side wire rod of the passage portion 12a in a state of being tied. ing.

FIG. 2 shows the stent 1 that has been reduced in diameter by performing the operations of FIGS. 1 (a), 1 (b), and 1 (c) a plurality of times using the wire 2 for the stent 1 that has been reduced in diameter. It is a schematic diagram which shows a part. In FIG. 2, each part of the stent 11 whose diameter is reduced using the wire 2 is the proximal end side 15, and the distal end side is not shown in FIG. 2.
The bending end of the wire rod in which the bending portion of the moving end side wire rod is wound once is created by bending the moving end side wire rod of the main portion of the wire rod wound around the stent twice. By arranging the portions 14a, 14b, and 14c that pass through in a straight line in the length direction of the stent, the moving-end-side wire rods in the portions 14a, 14b, and 14c that pass through the loop of the bent portion of the wire rod in the length direction of the stent. And can be provided in a straight line. The moving end side wire provided in a straight line has a low resistance when the stent is expanded, and can be easily expanded.
Moreover, since the moving end side wire 5 is provided under the stationary end side wire 6, the end of the moving end can be easily pulled when the stent is expanded even in a bent state.

4 (a) to 4 (c) show a method for maintaining the reduced diameter of the stent 1 that has been reduced in diameter using the wire 2 having a double bent portion shown in FIG.
FIG. 4A is a schematic diagram in which the wire 2 having the bent portion 3 bent twice is wound around the outer periphery of the stent 1 having a reduced diameter. Each part of the wire wound around the outer periphery of the stent is a main part 4, a stationary end side wire 6, a moving end side wire 5, a bending part 3, and a bending part ring 7.
FIG. 4 (b) shows the main part 4 of the wire wound around the outer periphery of the stent. Under the stationary end side wire 6, the bent portion 3 of the wire 2 is passed, and then the moving end side wire 5 is folded twice. FIG. 6 is a schematic diagram in which a bent portion 10 is created and the bent portion 10 is passed through a ring 7 of the bent portion 3. The passing portion 16 is a portion that passes through the ring 7 of the bending portion 3 of the moving end side wire 5, and the tip portion is the bending portion 10.
FIG. 4C is a schematic diagram in which the length of the passage portion 16 is increased to be the passage portion 16a by pulling the moving end side wire 5 of the passage portion 16 of FIG. 4B. The bending portion 10 of the passage portion 16a is further wound once in the same direction as the winding direction of the wire 2 in FIG. 4A, and the moving end side wire rod of the main portion of the passage portion 16a is double-folded to newly bend the bending portion. And passing through the loop of the bent portion 10 of the passage portion 16a, and further repeating FIG. 4 (b) and FIG. 4 (c) one or more times to hold the reduced diameter stent. be able to.
The intersection 13a between the wire rod of the bending portion 3 and the stationary end side wire rod of the passage portion 16a in FIG. 4C intersects the wire rod of the bending portion 3 and the static end side wire rod of the passage portion 16a in a crossed state. ing.

FIG. 5 shows a stent 17 in which a reduced diameter is maintained by performing the operations of FIG. 4A, FIG. 4B, and FIG. It is a schematic diagram which shows a part of. In FIG. 2, each portion of the stent 17 whose diameter is reduced using the wire 2 is a proximal side 19, and the distal side is not shown in FIG. 2.
The bending end of the wire rod in which the bending portion of the moving end side wire rod is wound once is created by bending the moving end side wire rod of the main portion of the wire rod wound around the stent twice. By arranging the portions 18a, 18b, and 18c to be passed through in a straight line in the length direction of the stent, the moving-end-side wire is passed through the portions 18a, 18b, and 18c in the length direction of the stent through the loop of the bent portion of the wire. And can be provided in a straight line. The moving end side wire provided in a straight line has a low resistance when the stent is expanded, and can be easily expanded.
Moreover, since the moving end side wire 5 is provided under the stationary end side wire 6, the end of the moving end can be easily pulled when the stent is expanded even in a bent state.

  In the present invention, the reduced diameter of the reduced diameter stent can be maintained by combining the knots shown in FIGS. 1B and 4B.

FIG. 6 shows a reduced diameter holding stent in which a single wire is used and FIG. 1 (a), FIG. 1 (b) and FIG. A schematic diagram of an example is shown. The stent 21 having the reduced diameter is reduced in diameter and held by the wire 23 from the distal end side 22b to the proximal end side 22a of the stent 22. The wire 23 has one end from the wire end to the bent portion 28 as the moving end side wire 24, the other wire as the stationary end side wire 25, the end 24a of the moving end side wire, and the end of the static end side wire. 25a.
Intersections 27a, 27b, 27c, 27d, 27e, and 27f between the bent portion of the wire and the stationary end side wire intersect the bent portion and the stationary end side wire in a hooked state. The intersecting portions 27a, 27b, 27c, 27d, 27e, and 27f are preferably provided linearly in the length direction of the stent. Providing the intersecting portion in a straight line is preferable because the moving end side wire becomes straight and the resistance of pulling the end of the moving end side wire becomes small. The intervals between the intersecting portions are almost equally spaced from the distal end side to the proximal end side of the stent.
FIG. 7 is a schematic diagram in which a part of the distal end side of the stent is expanded by pulling the end portion 24a of the moving end side wire rod in the direction of the arrow 29. FIG.
By pulling the end portion 24a of the moving end side wire material in the direction of the arrow 29, the intersecting portion 27f of the wire material on the distal end side of the stent can be first unwound, and further, the stent is expanded from the distal end side by unraveling the intersecting portion 27e. I can do it. Furthermore, the stent can be expanded from the distal end side by unraveling the wires in the order of the intersecting portions 27d, 27c, 27b, and 27a.
The stent is an expanded portion 30a, a portion 30b where the stent starts to expand, and a reduced diameter portion 30c.

FIG. 8 shows a reduced diameter holding stent in which a single wire is used and FIG. 1 (a), FIG. 1 (b) and FIG. The schematic diagram of another example is shown. The stent 31 having the reduced diameter is reduced in diameter and held by the wire 33 from the distal end side 32b to the proximal end side 32a of the stent 32. The wire 33 has one end from the wire end to the bent portion 38 as the moving end side wire 34, the other wire as the stationary end side wire 35, the end 34a of the moving end side wire, and the end of the static end side wire. 35a.
Intersections 37a, 37b, 37c, 37d, 37e, 37f, and 38g between the bent portion of the wire and the stationary end side wire intersect the bent portion and the stationary end side wire in a hooked state.
The intervals between the crossing portions are connected at substantially equal intervals from the dense portion on the distal end side of the stent to the proximal end side in the other portions.
By providing a dense portion on the distal end side of the stent, the interval between the intersecting portions is improved in preventing the unraveling of the intersecting portion 37g on the distal end side and the bent portion 38 of the wire rod.
By pulling the end 34a of the moving end side wire 34 in the direction of arrow 39, the stent can be expanded in the same manner as in FIG. The intersecting portions 37a, 37b, 37c, 37d, 37e, 37f, and 38g are preferably provided linearly in the length direction of the stent. Providing the intersecting portion in a straight line is preferable because the moving end side wire becomes straight and the resistance of pulling the end of the moving end side wire becomes small.

FIG. 9 shows a reduction of the diameter of the stent held by reducing the diameter of the stent by repeating FIG. 1 (a), FIG. 1 (b) and FIG. 1 shows a schematic diagram of an example of a diameter-retaining stent. The stent 41 having the reduced diameter is reduced in diameter and held by the wire 43 from the distal end side 42b to the proximal end side 42a of the stent 42. The wire 43 has one end from the wire end to the bent portion 48 as the moving end side wire 44, the other wire as the stationary end side wire 45, the end 44a of the moving end side wire, and the end of the static end side wire. 45a.
Intersections 47a, 47b, 47c, 47d, 47e, 47f, and 47g between the bent portion of the wire and the stationary end side wire intersect the bent portion and the stationary end side wire in a hooked state. The intersecting portions 47a, 47b, 47c, 47d, 47e, 47f, and 47g are preferably provided linearly in the stent length direction. Providing the intersecting portion in a straight line is preferable because the moving end side wire becomes straight and the resistance of pulling the end of the moving end side wire becomes small. The intervals between the intersecting portions are almost equally spaced from the distal end side to the proximal end side of the stent.
A new wire 46 is passed through the loop of the bent portion 48 of the wire. By passing the wire 46 through the ring of the bent portion 48, it is possible to prevent the intersecting portion 47g from being unwound.
The wire 46 is provided below the stationary end side wire 45.
When the stent 42 is expanded, the wire rod 46 is pulled out in the direction of the arrow 49b, and then the end 44a of the moving end side wire rod is pulled in the direction of the arrow 49a, so that the stent 42 can be expanded sequentially from the distal end side of the stent.

  FIG. 10 is a schematic diagram showing a part of a stent 61 with a reduced diameter, with a cover, provided with a cover 62 on the outer periphery of the stent wire that has been reduced in diameter using the wire shown in FIG. . The cover is made of thin transparent polyethylene.

  The stent having a reduced diameter according to the present invention can be prevented from being unwound at the intersection of wire rods by providing a cover on a part or all of the outer periphery thereof.

  In the method for expanding a stent having a reduced diameter according to the present invention, the end of the wire used for maintaining the reduced diameter of the stent can be sequentially expanded from the distal end side of the stent.

Any stent can be used as long as the stent can be reduced in diameter.
As a stent, a cylindrical structure made of a zigzag wire, a knitted fabric of one or a plurality of wires, a woven fabric or a braid, or a cylindrical structure obtained by combining a plurality of these, a metal cylindrical structure is a laser. A cylindrical structure processed by processing or the like can be used.
The stent is preferably a self-expanding stent.

Examples of the material of the wire rod and metal cylindrical structure used for the stent include stainless steel, tantalum, titanium, platinum, gold, tungsten, Ni-Ti, Cu-Al-Ni, Cu-Zn-Al, etc. A metal wire such as a shape memory alloy can be used. It is also possible to use a metal surface that is coated with gold, platinum or the like by means such as plating.
As a material for the wire rod and metal cylindrical structure used for the stent, a shape memory alloy to which a shape memory effect by heat treatment or superelasticity is imparted can be preferably used.
Although the thickness of the wire used for a stent is not specifically limited, For example, in the case of a blood vessel stent etc., 0.08-1 mm is preferable.
Although the thickness of the metal cylindrical structure used for the stent is not particularly limited, for example, in the case of a blood vessel stent or the like, 0.08 to 1 mm is preferable.

The stent can be provided with a cylindrical cover on the outer surface, the inner surface, or both the outer surface and the inner surface of the stent.
The cylindrical cover can be provided on the outer periphery, inner periphery, or both sides of the outer periphery and the inner periphery, preferably on the outer periphery, the inner periphery, or the entire surface on both sides of the outer periphery and the inner periphery.
The cylindrical cover can follow the reduced diameter shape and the expanded shape of the stent, and is preferably a soft tube, woven fabric, knitted fabric, or the like.

The cylindrical cover is formed by forming a thermoplastic resin into a cylindrical shape by extrusion molding, blow molding, or the like, a knitted fabric of thermoplastic resin fibers formed into a cylindrical shape, or a thermoplastic resin nonwoven fabric formed into a cylindrical shape. A cylindrical resin sheet, a porous resin sheet, or the like can be used. Furthermore, as the knitted fabric, known knitted fabrics and woven fabrics such as plain weave and twill weave can be used.
In addition, a cylindrical cover with a crease such as crimping can be used.
The tubular cover is preferably a seamless tubular structure.
A well-known artificial blood vessel etc. can be used for a cylindrical cover.

  The cylindrical cover is particularly excellent in strength, porosity, and productivity because the knitted fabric of thermoplastic resin fibers formed in a cylindrical shape and the plain weave fabric of thermoplastic resin fibers formed in a cylindrical shape are excellent. Is preferable.

  The cylindrical cover can be connected to part or all of the stent. Examples of the method of connecting the cylindrical cover to the stent include a method of sewing, a method of using an adhesive, and a method of fusing with a thermoplastic resin.

The material of the cylindrical cover is polyolefin such as polyethylene, polypropylene, ethylene / α-olefin copolymer, polyamide, polyurethane, polyethylene terephthalate, polybutylene terephthalate, polycyclohexane terephthalate, polyester such as polyethylene-2,6-naphthalate, poly Fluorine resins such as fluorinated ethylene and polyfluorinated propylene, thermoplastic resins such as silicone, polylactic acid, polyglycolic acid, and polyurethane, and resin fibers thereof can be used.
In particular, the material of the cylindrical cover is preferably a chemically stable and highly durable polyester resin such as polyethylene terephthalate, a fluororesin such as polyfluorinated ethylene or polyfluorinated propylene, and these resin fibers. be able to.

  As the resin fiber, a spinnable, circular, elliptical, U-shaped, hollow, ribbon-like, cross-sectional shape with a different diameter other than circular or elliptical, and a thickness capable of spinning can be used. .01 to 5 denier, further 0.1 to 3 denier, especially more than 0.8 to 3 denier monofilament number to several hundred, further 10 to 700, especially 10 to 100 twisted yarn or bundle Can be used.

The porosity of the cylindrical cover can be used without particular limitation as long as it does not impair the use of the stent, but is 0 to 3000 [ml / (cm ² · min · 120 mmHg), 37 ° C.]. preferable.
The wall thickness of the cylindrical cover can be used without particular limitation as long as it does not impair the use of the stent, but is preferably 30 to 2000 μm.
The cylindrical cover may be fixed to the stent at one or more portions.

  The cylindrical cover, the resin fibers that make up the cylindrical cover, and the wire and metal tubular structures that make up the stent are coated with a biocompatible material such as heparin, collagen, acetylsalicylic acid, and gelatin. Can be used.

The wire may be any wire that does not impair the characteristics of the present invention, and the material, shape, thickness, and the like can be appropriately selected and used.
As a material used for the wire, synthetic resin such as the above-described cylindrical cover, resin fiber constituting the cylindrical cover, wire constituting the stent, metal, or the like can be used.

Any wire can be used as long as it does not impair the characteristics of the present invention. For example, the wire, tube, belt, plate, or the like can be used.
As the wire, monofilaments, multifilaments and / or resin fibers, etc., and these woven fabrics, knitted fabrics, braided fabrics, and bundles of a plurality of these can be used.

Examples of the wire material include polyolefins such as polyethylene, polypropylene, ethylene / α-olefin copolymer, polyamide, polyurethane, polyethylene terephthalate, polybutylene terephthalate, polycyclohexane terephthalate, polyester such as polyethylene-2,6-naphthalate, and polyfluoride. Fluorine resins such as fluorinated ethylene and polyfluorinated propylene, thermoplastic resins such as silicone, polylactic acid, polyglycolic acid, and polyurethane, thermosetting resins, and these resin fibers can be used.
In particular, the material of the wire is preferably chemically stable and highly durable, with little tissue reaction, polyester such as polyethylene terephthalate, fluororesin such as polyfluorinated ethylene or polyfluorinated propylene, and these resin fibers. it can.

By further providing a cover on the outer circumference of the stent having a reduced diameter, it is possible to prevent the wire from being unwound, and it can be easily inserted into a sheath or the like, which is preferable for reducing the frictional force.
As the cover, a cover that covers a part or all of the outer periphery of the stent, such as a cylindrical shape or a bag shape, can be used.
The cover preferably has a small thickness, and preferably has a thickness of 1000 μm or less, more preferably 600 μm or less, more preferably 100 μm or less, and particularly preferably 50 μm or less. preferable.
In particular, the cover is made of polyolefin such as polyethylene, polypropylene, ethylene / α-olefin copolymer, polyamide, polyurethane, polyethylene terephthalate, polybutylene terephthalate, polycyclohexane terephthalate, polyester such as polyethylene-2,6-naphthalate, and polyfluoride. Fluorine resins such as fluorinated ethylene and polyfluorinated propylene, and thermoplastic resins such as silicone, polylactic acid, polyglycolic acid, and polyurethane can be used.
In particular, the cover is preferably made of a polyolefin such as polyethylene, polypropylene, or ethylene / α-olefin copolymer because it has high flexibility in bending, smoothness on the surface, and high safety to living bodies.
Any cover such as transparent or opaque can be used, but a transparent cover is particularly preferable because of its excellent visibility.

The stent having a reduced diameter according to the present invention can be used by being inserted into a sheath or a catheter.
A sheath can be provided inside the stent having a reduced diameter according to the present invention.

  The stent, cylindrical cover, cover, and wire are made of X-ray-impermeable material at appropriate locations, for example, at both ends of the stent, cover or cylindrical cover, at the static end, at the moving end, or at the bent portion of the wire. It may be worn. As the X-ray opaque material, for example, gold, platinum, iridium, tantalum, tungsten, silver, or an alloy containing them is preferably used. The radiopaque material can be fixed to the stent by means of soldering, brazing, welding, adhesion, caulking, or the like.

  The present invention relates to a method for maintaining a reduced diameter of a stent that is inserted and disposed in a tubular organ of a human body such as a blood vessel, a ureter, a bile duct, and a trachea, and a reduced diameter held by using the reduced diameter holding method. It is a stent.

It is a schematic diagram which shows an example of the knot of the wire of the diameter-reduction holding method of this invention. It is a schematic diagram which shows a part of stent which diameter-retained using the wire. It is a schematic diagram of the wire folded in half and having a bending part. It is a schematic diagram which shows an example of the knot of the wire of the diameter-reduction holding method of this invention. It is a schematic diagram which shows one Example of the stent by which diameter reduction was hold | maintained using the wire. It is a perspective view which shows one Embodiment of the stent diameter-retained by the diameter-reduction holding method of this invention. It is a schematic diagram which shows an example of the expansion state of the stent by which diameter reduction was hold | maintained. It is a schematic diagram which shows one Example of the stent by which diameter reduction was hold | maintained using the wire. It is a schematic diagram which shows one Example of the stent by which diameter reduction was hold | maintained using the wire. It is a schematic diagram which shows a part of stent which was diameter-retained by the wire with a cover.

Explanation of symbols

1, 22, 32, 42: stent,
2.23, 33, 43: Wire,
3, 10, 28, 38, 48: bending portion of wire,
4: The main part of the wire wound around the outer periphery of the stent,
5, 24, 34, 44: Moving end side wire,
6, 25, 35, 45: Static end side wire,
7: Ring of bent part of wire,
11, 17, 21, 31, 41: stents with a reduced diameter,
12, 16: Passing portion of the bent portion of the moving end side wire,
14a, 14b, 14c, 18a, 18b, 18c: intersection,
61: Reduced diameter retained stent with cover,
62: Cover.

Claims (4)

It is a reduced diameter holding method for holding the reduced diameter of a stent that has been reduced in diameter using a wire,
(1) A wire having a bent portion A bent twice is wound around the outer circumference of a stent having a reduced diameter, and the main moving end side wire wound around the outer periphery of the stent is bent twice to bend the bent portion A. Through the ring of
(2) The bending end B is formed by bending the moving end side wire rod that has passed through the ring of the bending portion, and the bending end portion B having the bending portion B is formed as the moving end side wire rod with the wire rod of the above (1). One turn on the outer circumference of the stent reduced in diameter in the same winding direction, the double end of the main moving end side wire wound around the outer circumference of the stent is bent and passed through the ring of the bent portion B.
Furthermore, the reduced diameter holding method of the stent characterized by holding the reduced diameter of the stent which has been reduced in diameter by repeating the above (2) at least once.   2. A stent having a reduced diameter, wherein the stent is reduced in diameter by the method for maintaining a reduced diameter of a stent according to claim 1.   The stent having a reduced diameter according to claim 2, wherein a cover is further provided on an outer periphery of the stent having a reduced diameter. A method for expanding a stent having a reduced diameter according to claim 2,
A method for expanding a stent having a reduced diameter, wherein the stent having a reduced diameter is expanded by pulling an end portion or a vicinity of the end portion of a wire rod having a bent portion A that is bent twice. .

Images