JP2009160079A - Biological duct stent - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a biological duct stent whose stretch in a tube axial direction is suppressed and restorability after deformation and deformation resistance are improved. <P>SOLUTION: The biological duct stent is configured in the cylindrical body 1 of net-like tissue by the knitting, braid-like textile or tube knitting of bioabsorbable fibers 3, and a plurality of reinforcing beams 2 extending along the axial direction of the cylindrical body 1 are distributed and disposed in the circumferential direction of the cylindrical body 1. The reinforcing beams 2 are configured of the bioabsorbable fibers 3, and connected to the cylindrical body 1 at the intersection position 4 or optional position of the knitting configuring the cylindrical body 1. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a biological duct stent used for expanding a constricted biological duct or protecting a damaged duct such as an aneurysm. The term “biological duct” as used herein refers to a tubular tissue in a living body, and specifically includes blood vessels, trachea, digestive tract, ureter, fallopian tube, bile duct and the like.

Conventionally, various types of biological ducts have already been proposed (see, for example, Patent Document 1).
JP 2002-200196 A

In Patent Document 1, the entire stent is formed as a cylindrical body of a knitted tissue with a bioabsorbable fiber in order to ensure insertion into a tortuous living body passage and a living body operation after mounting.
However, a stent composed of a tubular body of such a stitched tissue tends to be deformed (reduced diameter) due to the tensile force in the cylinder axis direction, but tends to have a lack of resilience, and the desired position of the biological duct In some cases, the operation to insert and place in an accurate and proper state may be delayed or difficult, and the deformability to external force is good, but depending on the application location, the resistance to deformation may be insufficient or after elastic deformation In some cases, there is a case where the restoring force is insufficient, and there is a concern that a desired function cannot be exhibited.

  The present invention has been proposed to overcome the above-mentioned concerns, and has an object to provide a biological duct stent that suppresses elongation in the cylinder axis direction and has improved restorability after deformation and deformation resistance. Yes.

In order to achieve the above object, the present invention provides a biological duct stent constructed of a knitted body of a bioabsorbable fiber, a braided woven fabric, or a tubular braided knitted fabric in a tubular structure of a stitch-like structure, Reinforcing bars extending along the axial direction are distributed and arranged in a plurality in the circumferential direction of the cylindrical body.
According to this configuration, the expansion of the cylinder in the cylinder axis direction is suppressed by the reinforcing bar. In addition, since the reinforcing bars are distributed and arranged in a plurality in the circumferential direction of the cylindrical body, it is possible to extend to some extent in the cylinder axis direction between the reinforcing bars and the reinforcing bars so that the cylindrical body is inserted into the biological duct. The diameter can be reduced to ensure smooth insertion. Further, the external force acting on the cylindrical body is reinforced by the reinforcing bar and extends in the axial direction, so that it is not crushed, and the resilience and deformation resistance after deformation of this type of cylindrical body can be improved. . Moreover, since the stitch-like structure of the cylindrical body is joined in the axial direction by the reinforcing bar, the cylindrical body can be cut at an arbitrary position in the cylindrical axis direction.

The reinforcing bar is preferably made of a bioabsorbable fiber. In this case, the cylindrical body and the reinforcing bar are preferably the same bioabsorbable fiber, but may be different.
The cylindrical body and the reinforcing bar are preferably made of monofilament yarn.
Further, the reinforcing bar may be arranged at any of the circumferentially equal position or the unequal position of the cylindrical body. In the case where the reinforcing bars are arranged at equal positions in the circumferential direction of the cylindrical body, the deformation resistance against external force and the restoring property after deformation can be averaged at each position in the circumferential direction. In addition, when reinforcing bars are arranged at unequal positions in the circumferential direction of the cylinder, parts where the interval between reinforcing bars is narrow can be used according to the direction in which strong external force acts, and parts where the action of external force is weak Can be used in correspondence with a portion where the interval between the reinforcing bars is widened. In short, when it is necessary to narrow or widen the arrangement intervals of the reinforcing bars only at specific positions in the circumferential direction than at other positions, the reinforcing bars may be unevenly arranged to meet such requirements. desirable.

Further, it is desirable that the reinforcing bar is coupled to the cylindrical body at an intersection position or an arbitrary position of a stitch constituting the cylindrical body.
In addition, the reinforcing bars may be arranged to be bonded along the axial direction on the inner surface side or the outer surface side of the cylindrical body, or may be inserted along the axial direction by inserting in a zigzag manner on the inner and outer surfaces of the cylindrical body. Good.

  ADVANTAGE OF THE INVENTION According to this invention, the biological duct stent which suppressed the expansion | extension to a cylinder axis direction and improved the restoring property after a deformation | transformation and deformation resistance can be provided.

Hereinafter, embodiments of the biological duct stent of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic perspective view showing an embodiment of a biological duct stent according to the present invention, FIG. 2 is a side view, and FIG. 3 is an end view. In FIG. is there.
The tubular body 1 is composed of a knitted fabric, braided woven fabric, or tubular knitted fabric of the bioabsorbable fiber 3, and has a knitted structure as a whole.
1 and 2, the reinforcing bars 2 extend along the axial direction of the cylindrical body 1, and as shown in FIG. 3, a plurality of reinforcing bars 2 are arranged in the circumferential direction of the cylindrical body 1 (4 in FIG. 3). The book case is distributed as an example).

  The bioabsorbable fiber 3 includes polyglycolide, lactide (D, L, DL form), polycaprolactone, glycolide lactide (D, L, DL form) copolymer, glycolide ε-caprolactone copolymer, lactide (D , L, DL form) -ε-caprolactone copolymer, poly (p-dioxanone), glycolide lactide (D, L, DL form) —ε-caprolactone lactide (D, L, DL form) One type is used in the form of monofilament yarn, multifilament yarn, twisted yarn, braided cord, etc., but is preferably used in the form of monofilament yarn.

  The diameter of the fiber 3 is about 0.01 to 1.5 mm, and an appropriate fiber diameter and type are selected depending on the type and diameter of the biological duct to be used. For example, for a tracheal stent having a diameter of 20 mm, a monofilament yarn having a diameter of 0.05 mm to 0.7 mm is preferable. The reinforcing bar 2 has a fiber diameter of about 0.01 mm to 1.5 mm, preferably a monofilament yarn of 0.05 mm to 0.7 mm. Further, the number of ridges (the number in the circumferential direction of the intersection of the yarns intersecting at the end of the cylindrical body 1) is about 6 to 30, and preferably 10 to 20 for a tracheal stent having a diameter of 20 mm. The number of eyes per cylinder 1 is in the range of 30 to 900, and the length of the cylinder 1 in the cylinder axis direction is in the range of 10 mm to 150 mm. It is not constrained by.

  The cross section of the fiber 3 may be any of a circle, an ellipse, and other irregular shapes (for example, a star shape). Further, the surface of the fiber 3 may be hydrophilized by plasma discharge, electron beam treatment, corona discharge, ultraviolet irradiation, ozone treatment, or the like. Further, the fiber 3 may be applied or impregnated with a radiopaque material (for example, barium sulfate, gold chip, platinum chip, etc.) or a drug (for example, an antiplatelet agent, an antithrombotic agent, or a smooth muscle growth inhibitor). It may be coated with a natural polymer such as collagen or gelatin, or a synthetic polymer such as polyvinyl alcohol or polyethylene glycol.

  The cylindrical body 1 has a plurality of (for example, eight or twelve) yarn feeders around any form of the fiber 3, for example, an outer diameter silicone rubber tube (not shown) desired as a monofilament yarn. It is manufactured into a braided woven fabric using a braided machine having a knitting, or is knitted into a cylindrical stitch-like structure by a circular knitting machine (not shown). After the knitting, the filament yarn (fiber 3) is joined and fixed at the intersection point 4 of the stitches. This joining is performed by application of a solvent, or by welding, fusion, adhesion with an adhesive, or the like. Further, after the cylinder 1 is manufactured, heat setting is performed. The heat setting condition is about 30 minutes to 24 hours at a temperature between the glass transition point and the melting point of the polymer used. The yarn ends (ends of the fibers 3) at both ends of the cylindrical body 1 are joined together by welding, fusing, bonding with an adhesive, or the like. This joining position is an intersection of intersecting yarns (fibers 3).

Reinforcing bars 2 extend along the axial direction of the cylindrical body 1 with respect to the cylindrical body 1 and are distributed and arranged in a plurality in the circumferential direction of the cylindrical body 1.
The reinforcing bar 2 is preferably composed of a bioabsorbable fiber 3. In this case, the cylindrical body 1 and the reinforcing bar 2 are preferably the same bioabsorbable fiber 3, but may be different within the range of the materials described above.
Further, the reinforcing bar 2 may be arranged at any of the circumferentially equalized position or the unequal position of the cylindrical body 1. In the case where the reinforcing bars 2 are arranged at equal positions in the circumferential direction of the cylindrical body 1 as shown in FIG. 3, the deformation resistance against external force and the restoring property after deformation can be averaged at each position in the circumferential direction. Further, when the reinforcing bars 2 are arranged at unequal positions in the circumferential direction of the cylindrical body 1, the portions where the reinforcing bars 2 are arranged can be used in accordance with the direction in which a strong external force acts. It is possible to use a portion where the reinforcing bars 2 are widened corresponding to a weak portion. In short, when it is necessary to narrow or widen the arrangement interval of the reinforcing bars 2 only at a specific position in the circumferential direction of the cylindrical body 1 compared to other positions, the reinforcing bars 2 are not suitable to meet such requirements. It is desirable to arrange them equally.

Further, the reinforcing bar 2 is formed by applying a solvent to the cylindrical body 1 at an intersection position 4 or an arbitrary position of the knitted structure of the fibers 3 constituting the cylindrical body 1 or by bonding, fusing, an adhesive, or the like. It is desirable that they are combined.
Further, the reinforcing bar 2 is disposed by being bonded along the axial direction on the inner surface side or outer surface side of the cylindrical body 1 or is disposed along the axial direction by being inserted into the inner and outer surfaces of the cylindrical body 1 in a zigzag manner. It only has to be.
In the embodiment of the present invention, the cylindrical body 1 is formed by cutting a polystyrene tube into a certain length, and standing 14 pins on the circumferences of both ends thereof. At that time, one end side pin is the other end side pin. 1 monofilament yarn made of lactide (D, L, L body) -ε-caprolactone copolymer (75:25) having a diameter of 0.5 mm is placed on the one end side. Hang around the first pin and wind it around the tube in a spiral, then fold it back with the other end pin, return to one end side again, fold it over the second pin and wind it, The yarn is passed through the bottom and knitted and knitted. This is repeated until the last pin, returning to the position of the first pin and joining the yarn ends to form the cylinder 1 having a diameter of 24 mm, a length of 40 mm, and 14 threads. Produced. After the production, the circumference of the cylinder 1 using four monofilament yarns made of lactide (D, L, L form) -ε-caprolactone copolymer (75:25) having a diameter of 0.5 mm as reinforcing bars 2. The four reinforcing bars 2 are arranged along the axial direction at four equal positions in the direction. At this time, the reinforcing bars 2 are passed in a zigzag shape (alternately) inside and outside the mesh structure of the fiber 3 constituting the cylindrical body 1. After the solvent (dioxane) is applied to the whole and air-dried to bond and bond the intersection position 4 of the fibers 3 and the intersection of the fibers 3 and the reinforcing bar 2, it is 105 ° C. under vacuum. Heated for 3 hours and heat set in a cylindrical shape.

The embodiment of the present invention has the above-described configuration, and the function and effect will be described next.
The present invention is a biological duct stent constructed of a knitted fabric, a braided woven fabric, or a tubular knitted fabric of a bioabsorbable fiber 3 in a tubular body 1 having a knitted structure, and is along the axial direction of the tubular body 1. Since the reinforcing bars 2 extending in this manner are distributed and arranged in a plurality in the circumferential direction of the cylindrical body 1, the expansion of the cylindrical body 1 in the cylinder axis direction is suppressed by the reinforcing bars 2. In addition, since the reinforcing bars 2 are distributed and arranged in a plurality in the circumferential direction of the cylindrical body 1, a certain amount of extension can be made in the cylindrical axis direction between the reinforcing bars 2 and the reinforcing bars 2, so that the biological conduit It is possible to ensure that the cylindrical body 1 is reduced in diameter and inserted smoothly. Furthermore, since the external force acting on the cylindrical body 1 is reinforced by the reinforcing bar 2, it is not stretched in the axial direction and is not crushed, thereby improving the resilience and deformation resistance of the seed cylindrical body 1 after deformation. can do. Moreover, since the stitch-like structure of the cylindrical body 1 is joined in the axial direction by the reinforcing bar 2, the cylindrical body 1 can be used by being cut at an arbitrary position in the cylindrical axis direction.

  The configuration and operational effects of the embodiment of the biological duct stent according to the present invention are as described above, but the present invention is not limited to this embodiment and can be implemented with various modifications. For example, the number of reinforcing bars 2 is selected from an appropriate number of 2 or more according to the application, use conditions, and the like. The reinforcing bars 2 may be inserted randomly or partially depending on the application.

1 is a schematic perspective view of an embodiment of a biological duct stent according to the present invention. 1 is a schematic side view of an embodiment of a biological duct stent according to the present invention. 1 is a schematic end view of an embodiment of a biological duct stent according to the present invention.

Explanation of symbols

1 Cylinder 2 Reinforcing bar 3 Bioabsorbable fiber 4 Intersection position

Claims (6)

  A biological duct stent constructed of a knitted body of a bioabsorbable fiber, a braided woven fabric, or a tubular braided knitted fabric and having a stitch-like structure, and a reinforcing bar extending along the axial direction of the tubular body. A biological duct stent characterized by being distributed and arranged in a plurality in the circumferential direction of the body.   The biological duct stent according to claim 1, wherein the reinforcing bar is made of a bioabsorbable fiber.   The living body stent according to claim 1 or 2, wherein the cylindrical body and the reinforcing bar are made of monofilament yarn.   The living duct stent according to any one of claims 1 to 3, wherein the reinforcing bar is disposed at a circumferentially equal position or an unequal position of the cylindrical body.   The biological duct stent according to any one of claims 1 to 4, wherein the reinforcing bar is coupled to the cylindrical body at an intersecting position of stitches constituting the cylindrical body or at an arbitrary position. .   The reinforcing bars are arranged to be bonded along the axial direction on the inner surface side or the outer surface side of the cylindrical body, or are arranged along the axial direction by inserting in a zigzag manner on the inner and outer surfaces of the cylindrical body. The biological duct stent according to any one of claims 1 to 4.

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