JP2005261867A - Tubular artificial organ - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tubular artificial organ made of an knitted fabric of inelastic resin fiber such as polyester resin, usable as an artificial blood vessel with excellent durability, to be easily handled and easily organized even if the thickness of the tube is increased and the porosity is decreased, hardly generating leakage of liquid. <P>SOLUTION: The double-structured artificial organ with an external layer and an internal layer has (a) a layer A as the internal layer and a layer B as the external layer, or (b) the layer B as the internal layer and the layer A as the external layer, or (c) layers C as the external layer and the internal layer. The layers A, B and C are tubular fiber structures of knitted and/or woven synthetic resin fiber; the porosity and the thickness of the layer A are larger than those of the layer B, and the porosity and the thickness of the layer C are in a specific range. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a tubular prosthesis such as an artificial blood vessel, and is excellent in handleability and curability, particularly flexible, has a good attachment and suturability with a biological organ such as a biological blood vessel, and is easily blocked by forceps It is related to the prosthesis.

  As an artificial blood vessel having a double-pipe structure, Patent Document 1 discloses a stretchable and porous A layer composed of a fiber structure in which non-stretchable fibers are knitted, woven or non-woven, and stretchable and porous. A tubular body comprising a B layer made of a material having the above-mentioned structure, wherein the A layer and the B layer are arranged so as to have holes communicating from the outside to the inside of the tubular body wall. An artificial blood vessel tubular body is disclosed.

Patent Document 2 discloses a branched artificial blood vessel in which one or more side tubes are derived from an artificial blood vessel main tube by stitching, and the artificial blood vessel main tube, the one or more side tubes and the reinforcing tube are woven of thermoplastic resin fibers. A branched artificial blood vessel, which is a knitted tube and has a double structure in which a suture tube and a side tube of an artificial blood vessel main tube are overlapped with a reinforcing tube on the artificial blood vessel main tube, is disclosed.
In Patent Document 3, an object of the present invention is to provide an artificial blood vessel that is excellent in occlusion of a puncture hole at the time of needle puncture without impairing the surface characteristics, biocompatibility, and flexibility of a PTFE porous tube. As described above, the pipe wall has a multilayer structure composed of two or more layers of a tetrafluoroethylene resin porous body, and has a non-adhesive portion at the interface between at least two layers of the porous body layer. An artificial blood vessel characterized by the above is disclosed.

JP-A-4-146745 JP 2002-017758 A JP-A-6-343688

For tubular prostheses such as knitted fabric artificial blood vessels, if the thickness of the tube is small, the attachment to the biological blood vessel is poor, and it is difficult to handle the flow of fluids such as blood with forceps. It is done. In addition, liquid leakage from the needle hole after suturing is likely to occur. If you try to improve flexibility and organization by increasing the porosity (water permeability) while keeping the thickness of the tube small, the strength of the tube will decrease, the durability of long-term implantation will be inferior, and liquid leakage will occur. It is easy to cause a large amount of bleeding due to intraoperative operation, and may cause ceroma after implantation.
On the other hand, when the thickness of the tube is increased and the porosity is lowered, the tube becomes hard and lacks flexibility.
In addition, increasing the thickness of the tube and increasing the porosity improves handling and organization, but it tends to leak and is poor in strength. Pretreatment of the tube (pre-clotting) is preoperative. Therefore, it may be necessary to pay attention to fluid leakage during the operation.
The present invention is a polyester resin that can be used for artificial blood vessels that have excellent handling properties, good organization, hardly leak, and have excellent durability even when the tube thickness is increased and the porosity is reduced. The purpose of the present invention is to provide a tubular prosthesis made of a non-stretchable resin fiber knitted fabric.

  The present invention was completed by using a tubular product made of non-stretchable polyester resin fibers, examining the layer structure, examining the porosity and thickness of the tube, examining the processed fibers, and examining the coating. Is.

The first of the present invention is a two-layered tubular prosthesis X having an outer layer and an inner layer,
(A) A two-layer structure having an A layer as an inner layer and a B layer as an outer layer, or (b) a two-layer structure having a B layer as an inner layer and an A layer as an outer layer,
A layer and B layer are tubular fiber structures by knitting and / or weaving synthetic resin fibers,
It is to provide a prosthesis characterized by the porosity and thickness of the A layer being greater than the porosity and thickness of the B layer.

A preferred embodiment of the prosthesis X of the present invention will be shown.
The prosthesis X of the present invention has (1) a two-layer structure (a) in which the inner layer has an inner diameter of 4 mm or more and less than 8 mm, and the inner layer is the A layer and the outer layer is the B layer.
(2) When the inner diameter of the inner layer is 8 mm or more, a two-layer structure (a) in which the inner layer is an A layer and the outer layer is a B layer, or a two-layer structure in which the inner layer is a B layer and the outer layer is an A layer (b ) Is preferable.
The prosthesis X of the present invention has (1) a two-layer structure (a) in which the inner layer has an inner diameter of 4 mm or more and less than 8 mm, and the inner layer is the A layer and the outer layer is the B layer.
(2) When the inner diameter of the inner layer is 8 mm or more, a two-layer structure (b) in which the B layer is the inner layer and the A layer is the outer layer is particularly preferable.
In the prosthesis X of the present invention, the difference in porosity between the A layer and the B layer is preferably ^{20 to} 6000 ml / (cm ² · min).
In the prosthesis X of the present invention, the difference in thickness between the A layer and the B layer is preferably 20 to 500 μm.
In the prosthesis X of the present invention, a part or all of the synthetic resin fibers of the A layer are preferably crimped fibers.
In the prosthesis X of the present invention, it is preferable that a part of the A layer and the B layer are combined and / or entangled.
In the prosthesis X of the present invention, the outer layer is preferably coated with gelatin.

The second of the present invention is a two-layered tubular prosthesis Y whose outer layer and inner layer are C layers,
C layer is a tubular fiber structure by knitting and / or weaving synthetic resin fibers,
An object of the present invention is to provide a prosthesis characterized in that the porosity of the C layer is 150 ml / (cm ² · min) or less and the thickness is 50 to 200 μm.

A preferred embodiment of the prosthesis Y of the present invention will be shown.
In the prosthesis Y of the present invention, it is preferable that a part or all of the synthetic resin fibers of the C layer are crimped fibers.
In the prosthesis Y of the present invention, it is preferable that a part of the outer layer and the inner layer C layers are joined and / or entangled.
In the prosthesis Y of the present invention, the outer layer is preferably coated with gelatin.

  The prosthesis X and the prosthesis Y of the present invention have an excellent maneuverability, good organization, less liquid leakage, and excellent durability even when the tube thickness is increased and the porosity is slightly reduced. It is an available tubular prosthesis such as a blood vessel.

The prosthesis X of the present invention is
(1) A layer having a large porosity and thickness is excellent in elongation, flexibility, and organization,
(2) The B layer having a small porosity and thickness is excellent in strength and has a property of being difficult to extend in the radial direction and the axial direction, so it has excellent shape retention, excellent hemostasis and antithrombotic properties, By using the A layer and the B layer for the outer layer and the inner layer, the defects of each layer can be complemented, and a prosthesis having excellent characteristics of each layer can be provided.
The prosthesis X of the present invention adopts a double tube structure combining these two layers, so that it has excellent suturability and can easily close the needle hole at the time of suturing, has good attachment with a living blood vessel, and is flexible. It is possible to provide a prosthesis that facilitates forceps operation.

In the prosthesis Y of the present invention, the C layer has a small porosity and thickness, excellent strength, and is difficult to extend in the radial and axial directions, so it has excellent shape retention, hemostasis and antithrombotic properties. It is an excellent layer.
Therefore, the prosthesis Y of the present invention is a prosthesis in which the C layer is doubled, has a large reduction in porosity, clinically less blood leakage, and improves safety. Further, since two thin ones are stacked, it does not become harder than necessary, and is excellent in needle passing, forceps operation, flexibility, and handleability.

  Since the prosthesis X and the prosthesis Y of the present invention are coated with gelatin only on the outer layer, the amount of gelatin coating on the entire prosthesis can be reduced, and the heat generated from gelatin can be reduced. Improves.

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, and the drawings described below and the contents described below can be combined.

The prosthesis X of the present invention will be described below.
The prosthesis X of the present invention is
(1) A layer having a large porosity and thickness is excellent in elongation, flexibility, and organization,
(2) The B layer having a small porosity and thickness is excellent in strength, has a property of being difficult to extend in the radial direction and the axial direction, and thus has excellent shape retention, excellent hemostasis and antithrombotic properties. By using the A layer and the B layer for the outer layer and the inner layer, the defects of each layer can be complemented, and a prosthesis having excellent characteristics of each layer can be provided.
The prosthesis X of the present invention adopts a double tube structure combining these two layers, so that it has excellent suturability and can easily close the needle hole at the time of suturing, has good attachment with a living blood vessel, and is flexible. It is possible to provide a prosthesis that facilitates forceps operation.

In the knitted and woven structure of synthetic resin fibers, if the radial extension is large, it may cause rupture and aneurysm formation, and the sutured tube may pull at both ends, which may cause the suture to tear or break. It is done. In addition, if the elongation in the major axis direction is large, the implanted tube may cause kinking and induce blockage.
Since the prosthesis X of the present invention has the property of being difficult to extend in the radial direction and the axial direction, and is excellent in maintaining the shape, the problem due to the extension in the radial direction as described above, and the axial direction It is possible to provide a prosthesis in which problems due to elongation are suppressed.

An example of the prosthesis X and the prosthesis Y of the present invention is shown in FIG. The prosthesis 1 has a two-layer structure of an outer layer 2 and an inner layer 3. The outer layer 2 is coated with gelatin.
Another example of the prosthesis X and the prosthesis Y of the present invention is shown in FIG. The prosthesis 4 is a prosthesis with a side tube having a main tube 5 and a side tube 8. The main tube 5 has a two-layer structure of an outer layer 6 and an inner layer 7. The side tube 8 has a two-layer structure of an outer layer 9 and an inner layer 10. The entire tube has a two-layer structure. The outer layer 6 and the outer layer 9 are coated with gelatin.

FIGS. 3 to 5 are schematic sectional views of a prosthesis having a double-pipe structure in which the prosthesis X of the present invention has an A layer as an inner layer and a B layer as an outer layer.
The prosthesis 11 of FIG. 3 has a two-layer structure of an inner layer 12 and an outer layer 13, and the inner layer and the outer layer can be separated.
In the prosthetic devices 21 and 31 of FIGS. 4 and 5, the inner layer and the outer layer are partially joined. In the prosthesis 21, the inner layer and the outer layer partially have a double woven structure, and are joined at that portion (24 and the like). In the prosthesis 31, the inner layer and the outer layer are partially bonded by a method such as adhesion or fusion (34, etc.).

6 to 8 are schematic views of cross sections of a prosthesis having a double-pipe structure in which the prosthesis X of the present invention has a B layer as an inner layer and an A layer as an outer layer.
The prosthesis 41 in FIG. 6 has a two-layer structure of an inner layer 42 and an outer layer 43, and the inner layer and the outer layer can be separated.
In the prosthetic devices 51 and 61 of FIGS. 7 and 8, the inner layer and the outer layer are partially joined. In the prosthesis 51, the inner layer and the outer layer partially have a double woven structure and are joined (54, etc.). In the prosthesis 61, the inner layer and the outer layer are partially joined by a method such as adhesion or fusion (64 or the like).
The partial bonding between the inner layer and the outer layer may be a known method such as bonding by fibers such as weaving, knitting, braiding, sewing and / or entanglement, bonding by adhesion, bonding by fusion, or a plurality of these. Can be combined.
It is preferable that the inner layer and the outer layer are partially combined to prevent fraying during cutting.
In the prosthesis shown in FIGS. 1-8, the outer layer is coated with gelatin.
1 to 8, layers A and B are tubular fiber structures formed by knitting and / or weaving synthetic resin fibers.

In the prosthesis X of the present invention,
(1) When the inner diameter of the inner layer is 4 mm or more and less than 8 mm, it is considered that the effect of promoting the healing of the inner surface is excellent by adopting a two-layer structure (a) in which the A layer is the inner layer and the B layer is the outer layer. And
(2) When the inner diameter of the inner layer is 8 mm or more, a two-layer structure (a) in which the inner layer is an A layer and the outer layer is a B layer, or a two-layer structure in which the inner layer is a B layer and the outer layer is an A layer (b ) Is considered to be excellent in handling properties,
In particular, when (2) the inner diameter of the inner layer is 8 mm or more, the two-layer structure (b) in which the inner layer is the B layer and the outer layer is the A layer has an excellent effect of quickly fixing and stabilizing the outer tissue. Conceivable.

As the synthetic resin fibers of the A layer and the B layer, fibers that have been crimped or fibers that have not been crimped can be used. As a combination, some of the fibers that have been crimped in both the A layer and the B layer are used. Or when using all, when using a part or all of the fiber which crimped only the A layer, the case where using a part or all of the fiber which crimped only the B layer can be mentioned.
By using a crimped fiber for at least one of the A layer and the B layer, the two layers are likely to be partially entangled, so that it is difficult to open the gap between the layers or between the layers.
In particular, by using a fiber in which part or all of the fibers of the A layer are crimped, when the A layer is used as an outer layer, it is excellent in texture, healing promotion, and handleability improvement, and when the A layer is used as an inner layer, it promotes healing. It is considered preferable and preferable.
The crimping process of the fiber can be performed by a known method.

The pipe of the two-layer structure of A layer or B layer, or A layer and B layer is partially or partially between the fibers of the A layer, between the fibers of the B layer, or between the A layer and the B layer using water or air. What was entangled as a whole can be used.
A layer in which a part of the A layer and the B layer are combined can be used.

The difference in porosity between the A layer and the B layer is preferably 20 to 6000 ml / (cm ² · min), more preferably 80 to 5000 ml / (cm ² · min), and more preferably 100 to 4500 ml / (cm ² · Min), particularly preferably in the range of 150 to 4000 ml / (cm ² · min), is preferable because of excellent healing promotion and handleability.
The difference between the thicknesses of the A layer and the B layer is preferably 20 to 500 μm, more preferably 80 to 450 μm, more preferably 100 to 420 μm, and particularly preferably 150 to 400 μm, because of excellent handleability.

  The thickness of the prosthesis X of the present invention is not particularly limited as long as there is no practical problem, but the A layer is preferably 70 to 800 μm, more preferably 100 μm to 750 μm, more preferably 150 μm to 700 μm, and particularly preferably 200 μm to 600 μm. Can be used. The B layer is preferably 50 to 300 μm, more preferably 50 μm to 200 μm, particularly preferably 50 μm to 180 μm.

The porosity of the prosthesis X of the present invention is not particularly limited as long as there is no practical problem, but the A layer is 25 to 6500 ml / (cm ² · min) or less, more preferably 100 to 6000 ml / (cm ² · min), Furthermore, 200-5000 ml / (cm < ² > * min) is preferable. The B layer is preferably 5 to 500 ml / (cm ² · min) or less, more preferably 5 to 400 ml / (cm ² · min), and further preferably 5 to 300 ml / (cm ² · min).

  The prosthesis Y of the present invention is a tubular prosthesis having a two-layer structure in which an outer layer and an inner layer are C layers, and an example of the prosthesis Y is shown in FIG. The prosthesis 101 has a two-layer structure of an outer layer 102 and an inner layer 103. The outer layer 102 is coated with gelatin. In FIG. 9, the C layer is a tubular fiber structure formed by knitting and / or weaving synthetic resin fibers.

The prosthesis Y of the present invention will be described below.
The prosthesis Y of the present invention is a tubular prosthesis having a two-layer structure in which an outer layer and an inner layer are C layers,
C layer is a tubular fiber structure by knitting and / or weaving synthetic resin fibers,
The porosity of the C layer is 150 ml / (cm ² · min) or less, preferably 130 ml / (cm ² · min) or less, more preferably 100 ml / (cm ² · min) or less, particularly preferably 80 ml / (cm ² Min) or less, and a thickness of 50 to 200 μm, preferably 80 to 200 μm, more preferably 100 to 180 μm, and particularly preferably 120 to 180 μm.
In the prosthesis Y of the present invention, the C layer has a small porosity and thickness, excellent strength, and is difficult to extend in the radial and axial directions, so it has excellent shape retention, hemostasis and antithrombotic properties. Is excellent. Therefore, the prosthesis Y with the C layer doubled has a large reduction in porosity, clinically less blood leakage, and safety is improved. Further, since two thin ones are stacked, it does not become harder than necessary, and is excellent in needle passing, forceps operation, flexibility, and handleability.

The outer layer of the prosthesis Y of the present invention is preferably coated with gelatin.
As the synthetic resin fiber of the C layer, a crimped fiber or a non-crimped fiber can be used.
By using a crimped fiber for at least one of the C layers used for the outer layer and the inner layer, the two layers are likely to be partially entangled, so that it becomes difficult to open the gap between the layers and the gap between the layers.
In particular, it is preferable to use a fiber in which some or all of the fibers are crimped in the outer layer, which is considered to be excellent in promoting healing and improving handleability.
The crimping process of the fiber can be performed by a known method.
One in which a part of the outer C layer and the inner C layer are combined can be used.

A layer, B layer and C layer are
A tubular fiber structure by knitting and / or weaving synthetic resin fibers;
A knitted fabric, a woven fabric, a braided fabric, or the like, or a combination thereof can be used, and a twill weave, a plain weave, or a knitted fabric can be used, and a velor structure or a texture may be partially included.

A layer, B layer, and C layer are not crimped, or have a crimped portion between a non-crimped portion and a non-crimped portion, and the end is crimped What is not a part (it may have a part which is not crimped except an edge part) etc. can be used preferably.
As the A layer and the B layer, those that can be crimped to the same shape, those that can be crimped to the same state, those that are not crimped, and the like can be used.

  As the crimping process, a method of processing the surface of a tube of a woven or knitted fabric such as a plain weave of thermoplastic resin fibers into an uneven shape can be used. For example, the method described in U.S. Pat. No. 3,337,673, that is, a plain woven tube of thermoplastic resin fibers is fitted on a round bar surface, and threads are wound spirally from the top of the tube at equal intervals, and the tube is directly pivoted. A method of forming a wrinkle by compressing and shrinking in the direction, heating and heat setting. The method described in Japanese Patent Application Laid-Open No. 1-155860, that is, a plain-woven tube of thermoplastic resin fibers is fitted into a screw rod whose surface is sufficiently polished, and an appropriate yarn is wound around the screw groove, and the state is left as it is. For example, a method of heat-setting and heat-setting may be preferably used.

As the synthetic resin used for the synthetic resin fibers constituting the A layer, the B layer, and the C layer, a thermoplastic synthetic resin can be used. Polyolefin such as polyethylene, polypropylene, ethylene-α-olefin copolymer, polyamide, polyurethane And polyesters such as polyethylene terephthalate, polybutylene terephthalate, polycyclohexane terephthalate, polyethylene-2,6-naphthalate, and fluororesins such as fluorinated polyolefins such as tetrafluoroethylene (PTFE) and ETFE. More preferably, fluorine resin such as PTFE and ETFE, which is chemically stable and has high durability and little tissue reaction, chemically stable and has high durability, little tissue reaction, and excellent mechanical properties such as tensile strength Polyesters such as polyethylene terephthalate are preferred. Particularly preferred is a polyester such as polyethylene terephthalate having a glass transition temperature of 60 ° C. or higher because the strength of the polyester resin may be reduced by body temperature.
The synthetic resin used for the synthetic resin fiber is non-stretchable, and a resin having a characteristic that does not have great elasticity can be used.

  As the synthetic resin fiber, a spinnable, circular, elliptical, U-shaped, hollow, ribbon-like, cross-sectional shape such as a different diameter that is not circular or elliptical, and a spinnable thread can be used. Preferably 0.01 to 5 denier, more preferably 0.1 to 3 denier, more preferably 0.2 to 2 denier, particularly preferably 0.3 to 1 denier monofilaments, preferably several to several hundreds. More preferably 10 to 700 yarns, particularly preferably 10 to 100 yarns twisted or bundled yarns can be used.

  The prosthesis X, prosthesis Y, each layer (A layer, B layer, C layer), synthetic resin fiber, synthetic resin, etc. of the present invention are not coated with a biological component such as heparin, collagen, gelatin, etc. Further, those coated with an antithrombotic material such as heparin, collagen, acetylsalicylic acid, and gelatin can be used.

  The tensile strength of the prosthesis X and the prosthesis Y of the present invention is not particularly limited as long as there is no practical problem, but preferably 5 kg or more, more preferably 7 kg to 30 kg, particularly preferably 8 kg to 25 kg. be able to.

The outer diameter of the prosthesis X and the prosthesis Y of the present invention is not particularly limited as long as there is no practical problem, but it is 4 mm or more, preferably 4.5 mm or more, more preferably 5 mm or more, particularly preferably 6 mm or more to 60 mm or less. Preferably, it is 55 mm or less, more preferably 50 mm or less, particularly preferably 45 mm or less.
The length of the prosthesis X and the prosthesis Y of the present invention is not particularly limited as long as there is no practical problem, but it is 2 cm or more, preferably 2.5 to 50 cm, more preferably 3 to 40 cm, particularly preferably 4 to 30 cm. Can be used.

  The artificial organ X and the artificial organ Y of the present invention can be used for tubular structures such as artificial blood vessels, artificial esophagus, and artificial trachea.

The evaluation method of characteristics is shown.
(1) Porosity: 120 mmHg of water is allowed to flow through the tubular material at 37 ° C., and the porosity is calculated from the weight of the outflowed water, the surface area of the tubular material, and the time.
The measurement of the porosity of the A layer, the B layer, and the C layer is performed with an uncoated material such as gelatin.
(2) Tensile strength: The tensile strength is measured at a temperature of 23 ° C., a tensile speed of 10 mm / min, and the sample is 1 cm in the radial direction (width) and 2 cm in the axial direction (length). The tensile strength is an average value of 5 measurement samples.
For example, in the case of a plain woven fabric of synthetic resin fibers, the tensile strength in the weft direction is measured.

[Example 1]
The thermoplastic resin fiber used was a twist of a plurality of 0.7 denier monofilaments made of polyethylene terephthalate.
(1) A plain woven fabric and an inner diameter of 10 mm using 150 denier thermoplastic resin fibers (429) as weft yarn (length direction) as B layer (inner layer) and 100 denier thermoplastic fiber as warp yarn (circumferential direction) The tube was made. The obtained plain woven fabric and tubular product had a tensile strength of 18.0 kg, a wall thickness of 150 μm, and a porosity of 50 ml / (cm ² · min).
(2) As the weft yarn (length direction) as the A layer (outer layer), thermoplastic resin fibers (508 fibers), 100 denier and 400 denier fibers are used alternately, and the warp yarn (circumferential direction) is 100. Using a denier thermoplastic fiber, a plain woven fabric and a tubular product having an inner diameter of about 10 mm, which is slightly larger than the B layer, were prepared. The obtained plain-woven cloth and tubular product had a tensile strength of 9.5 kg, a wall thickness of 450 μm, and a porosity of 4000 ml / (cm ² · min).

(3) The tubular product obtained in (1) above is covered with the tubular product obtained in (2) above, and an artificial blood vessel E having a two-layer structure consisting of an A layer (outer layer) and a B layer (inner layer) having an inner diameter of 10 mm is provided. Produced.

[Comparative Example 1]
The thermoplastic resin fiber used was a twist of a plurality of 0.7 denier monofilaments made of polyethylene terephthalate. An artificial blood vessel F having a single-layer structure having an inner diameter of 10 mm was prepared using 150 denier thermoplastic resin fibers (429) as weft (length direction) and 100 denier thermoplastic resin fibers as warp (circumferential direction).

The artificial blood vessel E and the artificial blood vessel F were each transplanted with the abdominal aorta of a hybrid adult dog.
First, one end of the artificial blood vessel E and the artificial blood vessel F was anastomosed to the central side of the biological blood vessel. As compared with the artificial blood vessel F, the artificial blood vessel E was better than the artificial blood vessel F, and the suture property was improved. Thereafter, the pre-clotting process was performed by opening and closing the clamp once. Subsequently, the blood flow was blocked by clamping to an intermediate portion between the artificial blood vessel E and the artificial blood vessel F. At this time, the artificial blood vessel E was easier to clamp than the artificial blood vessel F, and neither bleeding from the peripheral portion of the clamp nor bleeding from the central suture portion was observed in both the artificial blood vessel E and the artificial blood vessel F. Subsequently, the peripheral sides of the artificial blood vessel E and the artificial blood vessel F were sutured to resume blood flow. In both the artificial blood vessel E and the artificial blood vessel F, bleeding from the artificial blood vessel including the peripheral anastomosis portion did not occur.

[Example 2]
The thermoplastic resin fiber used was a twist of a plurality of 0.7 denier monofilaments made of polyethylene terephthalate.
(1) A plain woven fabric and an inner diameter of 10 mm using 150 denier thermoplastic resin fibers (429) as weft yarn (length direction) as B layer (inner layer) and 100 denier thermoplastic fiber as warp yarn (circumferential direction) The tube was made. The obtained plain woven fabric and tubular product had a tensile strength of 18.0 kg, a wall thickness of 150 μm, and a porosity of 50 ml / (cm ² · min).
(2) As the weft yarn (length direction) as the A layer (outer layer), thermoplastic resin fibers (508 fibers), 100 denier and 400 denier fibers are used alternately, and the warp yarn (circumferential direction) is 100. Using a denier thermoplastic fiber, a plain woven fabric and a tubular product having an inner diameter of about 10 mm, which is slightly larger than the B layer, were prepared. The obtained plain-woven cloth and tubular product had a tensile strength of 9.5 kg, a wall thickness of 450 μm, and a porosity of 4000 ml / (cm ² · min).
Furthermore, this tubular product was coated with gelatin, and its porosity was measured. The porosity was 0.2 ml / (cm ² · min).

(3) The tubular product obtained in (1) above is covered with the tubular product obtained in (2) above to produce a two-layer artificial blood vessel composed of an A layer (outer layer) and a B layer (inner layer) having an inner diameter of 10 mm. did.
Even if this artificial blood vessel was bent or a forceps operation was performed, there was no problem in use.

[Example 3]
The thermoplastic resin fiber used was a twist of a plurality of 0.7 denier monofilaments made of polyethylene terephthalate.
(1) A plain weave cloth and an inner diameter of 10 mm using 150 denier thermoplastic resin fibers (429) as the weft (length direction) as the C layer (inner layer) and 100 denier thermoplastic resin fibers as the warp (circumferential direction) The tube was made. The obtained plain woven fabric and tubular product had a tensile strength of 18.0 kg, a wall thickness of 150 μm, and a porosity of 70 ml / (cm ² · min).

(2) A two-layered artificial blood vessel was produced by covering the tubular product obtained in (1) twice.
This prosthesis had a porosity of 40 ml / (cm ² · min), a thickness of 300 μm, good needle-through and bendability, had appropriate elasticity, and was easy to handle.

1 is a perspective view showing one embodiment of a prosthesis. FIG. It is a perspective view which shows one Embodiment of the prosthesis with a side tube. 1 is a schematic cross-sectional view showing an embodiment of a prosthesis X. FIG. 1 is a schematic cross-sectional view showing an embodiment of a prosthesis X. FIG. 1 is a schematic cross-sectional view showing an embodiment of a prosthesis X. FIG. 1 is a schematic cross-sectional view showing an embodiment of a prosthesis X. FIG. 1 is a schematic cross-sectional view showing an embodiment of a prosthesis X. FIG. 1 is a schematic cross-sectional view showing an embodiment of a prosthesis X. FIG. 3 is a schematic cross-sectional view showing an embodiment of a prosthesis Y. FIG.

Explanation of symbols

1, 4, 11, 21, 31, 41, 51, 61: prosthesis X,
2, 6, 9: outer layers of the prosthesis,
3, 7, 10: inner layer of the prosthesis,
12, 22, 32, 42, 52, 62: A layer of prosthesis X,
13, 23, 33, 343, 53, 63: B layer of prosthesis X,
24, 34, 54, 64: coupling part,
101: Prosthesis Y,
102: Outer layer of prosthesis Y 103: Inner layer of prosthesis Y

Claims (8)

A two-layer tubular prosthesis having an outer layer and an inner layer;
(A) A two-layer structure having an A layer as an inner layer and a B layer as an outer layer, or (b) a two-layer structure having a B layer as an inner layer and an A layer as an outer layer,
A layer and B layer are tubular fiber structures by knitting and / or weaving synthetic resin fibers,
A prosthesis characterized by the porosity and thickness of the A layer being greater than the porosity and thickness of the B layer. A two-layer tubular prosthesis having an outer layer and an inner layer;
(1) When the inner diameter of the inner layer is 4 mm or more and less than 8 mm, a two-layer structure (a) in which the inner layer is an A layer and the outer layer is a B layer,
(2) When the inner diameter of the inner layer is 8 mm or more, a two-layer structure (a) in which the inner layer is an A layer and the outer layer is a B layer, or a two-layer structure in which the inner layer is a B layer and the outer layer is an A layer (b )age,
A layer and B layer are tubular fiber structures by knitting and / or weaving synthetic resin fibers,
A prosthesis characterized by the porosity and thickness of the A layer being greater than the porosity and thickness of the B layer. A two-layer tubular prosthesis having an outer layer and an inner layer;
(1) When the inner diameter of the inner layer is 4 mm or more and less than 8 mm, a two-layer structure (a) in which the inner layer is an A layer and the outer layer is a B layer,
(2) When the inner layer has an inner diameter of 8 mm or more, a two-layer structure (b) in which the inner layer is B layer and the outer layer is A layer,
A layer and B layer are tubular fiber structures by knitting and / or weaving synthetic resin fibers,
A prosthesis characterized by the porosity and thickness of the A layer being greater than the porosity and thickness of the B layer.   The prosthesis according to any one of claims 1 to 3, wherein a part or all of the synthetic resin fibers of the A layer are crimped fibers. The difference in porosity between the A layer and the B layer is 20 to 6000 ml / (cm ² · min),
The prosthesis according to any one of claims 1 to 4, wherein a difference in thickness between the A layer and the B layer is 20 to 500 µm.   The prosthesis according to any one of claims 1 to 5, wherein a part of the A layer and the B layer are combined. A tubular prosthesis having a two-layer structure in which an outer layer and an inner layer are C layers;
C layer is a tubular fiber structure by knitting and / or weaving synthetic resin fibers,
A prosthesis, wherein the porosity of the C layer is 150 ml / (cm ² · min) or less and the thickness is 50 to 200 μm. The artificial blood vessel according to claim 1, wherein the outer layer is coated with gelatin.

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