JPS6077764A - Artificial blood vessel - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to an artificial blood vessel with excellent anastomotic properties, antithrombotic properties, and shape retention properties.

(Prior art) The main characteristics required for an artificial blood vessel are that it is non-toxic to living organisms, 1. It goes without saying that there is no deterioration in the living body due to high-intensity fatigue, and in addition, (1) it has excellent antithrombotic properties. That's what I'm doing.

(2) Excellent anastomosis with biological blood vessels.

(3) Excellent shape retention.

Examples include. In the present invention, antithrombotic properties mean that vascular endothelial cells (new blood vessel walls) are formed immediately after M transfer.

Conventional artificial blood vessels are woven or knitted fabrics made of polyester fibers with single filament fineness of normal thickness.In addition, they are made of extremely high-density polyester fibers to prevent blood leakage from the walls of the artificial blood vessels and to maintain their shape. It is made of woven and knitted fabric filled with.

As a result, despite the use of softening methods such as crimping, the material remains extremely stiff, resulting in extremely poor 41m transmissibility during surgical sutures, and the hardening of living blood vessels due to arteriosclerosis. In such cases, this can be a major cause of anastomosis failure between the biological blood vessel and the artificial blood vessel, leading to risks such as massive bleeding. Moreover, in order to improve anastomotic properties, ffl1.
Q: If the material is made coarse, blood leakage cannot be prevented.

This was an even more important problem especially when anticoagulants were administered.

Furthermore, a serious problem with conventional artificial blood vessels is that the formation of vascular endothelial cells is slow and non-uniform. In other words, since it is a woven fabric made of thick fibers and tightly packed, there is no scaffold for the formation of vascular endothelial cells, and even if cells once adhere, they are easily washed away by the blood flow, which results in uniform endothelial cells. This causes important problems such as not only no blood clots are formed, but also the blood clots that flow out can occlude narrow blood vessels on the distal side.

As a means only for providing a scaffold for vascular endothelial cell formation, Japanese Patent Publication No. 117287-11728 and No. 52-946
99, No. 51-113094, and No. 53-137599, methods of forming loops on the surface of knitted fabrics are disclosed. However, since all of these are made of fibers of normal thickness, they are insufficiently effective for scaffold formation, and they also have other properties required for artificial blood vessels, such as needle passability and anastomotic properties. It has not been possible to obtain an artificial blood vessel that is fully satisfactory in terms of the characteristics required to facilitate the process, shape retention, extreme blood leakage, and no staining on living organisms.

In particular, if emphasis is placed on prevention of blood leakage and shape retention, problems will arise with anastomosis and needle passability; It was impossible to satisfy all the factors that were not included.

(Objective of the present invention) The present invention aims to improve the drawbacks of the conventional artificial blood vessels, and the purpose is to form vascular endothelial cells (new blood vessel walls) extremely early and uniformly, resulting in low blood leakage. The present invention relates to an unprecedented high-performance artificial blood vessel that has excellent shape retention properties, such as virtually no flattening or bending during or after surgery, is flexible, and has excellent anastomotic properties with living blood vessels.

(Configuration of the present invention) That is, the present invention.

(1) A woven or knitted fabric consisting of a multi-layer structure, which has at least a portion of ultra-fine fibers (A) of 0.5 denier or less on the inner and/or outer walls, and whose ground yarn is mainly 1.0 denier or less. An artificial blood vessel characterized by being made of fibers (B) of one denier or more.

(2) An artificial blood vessel further comprising the formation of piloere on the inner and/or outer walls of the artificial blood vessel.

(3) An artificial blood vessel further characterized in that a bulky textured thread is used as the ground thread.

(4) An artificial blood vessel further characterized in that the ultrafine fibers (A) and the fibers (B) are formed from any one of polyester, polyamide, polyolefin, and polytetrafluoroethylene.

(5) It also relates to an artificial blood vessel characterized by a water permeability of 2000 ml/min or less.

The most characteristic feature of the present invention is that ultra-fine fibers (A) are used, and the weave and knit structure is devised to make more effective use of the ultra-fine fibers through a multiple weave and knit structure. .

By using ultra-fine fibers (A>), the tube does not become hard even when the weaving density is increased, making it flexible, with excellent needle passability, and surprisingly, vascular endothelial cells (new blood vessel walls) are formed quickly and uniformly. The latter effect cannot be fully explained, but since the state of fibrin deposition is thought to have a very important meaning in the formation of vascular endothelial cells, superpolar 11I fibers (A> As a result, a large number of fine fiber gaps are formed.

It is not inconceivable that this is because fibrin deposition is extremely thin, uniform, and strong because cells and fibers can easily enter. In addition, by using ultrafine fibers (A) not only on the inner wall but also on the outer wall of the blood vessel, it blends well with the surrounding tissue of the blood vessel and has the effect of improving adhesion of the surrounding tissue, but it is not necessarily necessary for the outer wall. There are cases.

The ultrafine fiber (A) of the present invention refers to an ultrafine fiber of 0.5 denier or less, preferably 0.2 denier or less,
For blood vessel formation, fibers that are already in the form of ultra-fine fibers may be used as they are, but tubes are formed using fibers that can be made ultra-fine by chemical or physical means, and then ultra-fine. As a result, a tube may be formed of ultrafine fibers. Ultra-fine fibers can be obtained by using normal spinning methods with due care, but it is also possible to make ultra-fine fibers by stretching undrawn yarn under specific conditions, as in the case of polyester. It is.

On the other hand, examples of fibers that can be made ultra-fine by post-processing include Japanese Patent Publication No. 48-22126. It means a type of fiber that is fibrillated or ultra-fine by removing or exfoliating one component of a multicomponent fiber, as seen in Japanese Patent Publication No. 53-22593. In the case of such fibers, when processing into tubes, even if the fiber thickness is normal, it can be made ultra-fine after processing, so there are problems in processing, such as during weaving and production, and when various thread processing methods are used before weaving or knitting. This is preferable because it can minimize thread breakage, fuzz generation, etc. when threading.

The polymers used as fibers are polyester, polyamide, and polytetrafluoroethylene.

It does not matter what type it is, such as polyolefin.

Particularly preferred is polyester. When using multicomponent fibers, the final polymer remaining is the above polymer, but other combined components include polystyrene, polyethylene,
It is possible to appropriately combine water-soluble polyamide, alkaline aqueous solution-soluble polyester, water-soluble polyvinyl alcohol, and the like.

The combination of such polymers is determined on a case-by-case basis, taking into consideration thread-spinning properties, processability, etc.

Further, the ultrafine fiber (A) may be a so-called filament yarn or a staple yarn, but filament yarn is often preferable from the viewpoint of fluff removal. on the other hand,
The fiber (B) is preferably a multifilament yarn or stable yarn of 1.3 denier or more, preferably 1.3 denier or more, than 1.0 denier or more obtained by a normal spinning method, and monofilament yarn is preferable in some cases. However, multifilament yarns are often preferred, and it is more preferable to use textured yarns that have been subjected to a bulky process such as temporary twisting, as this can further improve needle passability and flexibility.

Woven and knitted fabrics having multiple textures as referred to in the present invention include, for example, double weft texture, double warp texture, double warp texture, texture with three or more layers in each side, texture with three or more layers in warp, weft pile texture, warp pile texture, etc. Specific examples include fabrics made from fabrics made from fabrics, applied fabrics, cut pile fabrics, and combinations of these fabrics.

Further, in the case of a knitted fabric, it can be easily formed using a knitted structure or the like that can have a structure similar to that of a woven fabric.

In addition, the yarn used in the multilayer structure is that the fibers that make up the two-layer structure include ultrafine fibers (A) and/or ultrafine fibers (A).
The fibers (B) and the fibers (B) are aligned or mixed together, and the fibers (B) and/or the ultra-fine fibers (
A) and fiber (B) are aligned or mixed. In the present invention, the inner wall and/or outer wall of the artificial blood vessel is composed of surface tissue.

The outer wall and/or the so-called intermediate wall between the inner and outer walls are constituted by the soil structure. The threads that make up the ground weave are called base threads, core threads, core threads, etc., and the ground weave is sometimes called back weave. By selecting these multiple tissues and thread usage, ultrafine fibers (A) of 0.5 deniers or less, which have excellent endothelial cell forming properties, can be actively formed on the inner and/or outer walls of the blood vessels, and the fibers can be By actively forming (B) on the outer wall and/or the so-called intermediate wall between the inner and outer walls, it has become possible to simultaneously enhance shape retention. Also internal and/or external walls.

And/or the moderate presence of ultrafine fibers (A) and fibers (B) in the so-called intermediate portion between the inner wall and the outer wall makes it possible to simultaneously impart needle-passability and flexibility. Therefore, by appropriately selecting the weaving/knitting structure and thread usage, the endothelial cell forming property of the artificial blood vessel and its compatibility with the living body can be improved, and at the same time, the needle i1! It has become possible to impart transmissibility, flexibility, and shape retention, and it has become possible to create artificial blood vessels according to the site and purpose of use.

As a means of making a tube, it is made into a woven or knitted fabric and then cut.
Although it is possible to form a tube-shaped object by sewing, gluing, or fusing, it is more preferable to form a tube-like object without seams when forming a woven or knitted fabric.

In order to make the present invention even more effective, it is preferable to form raised pili of ultrafine fibers (A) on the inner and/or outer walls of blood vessels. However, the napped fibers may coexist with fibers (B) limited to only ultrafine fibers (A>), and it is not necessary that all of the ultrafine fibers (A) be napped.

Furthermore, the term "napped" as used in the present invention refers to something in which loops and/or fluff are present, and means for creating napped means means for creating loops during weaving or knitting.

For example, pile woven and knitted fabrics, their strength and pile method, processing after forming woven fabrics, such as raising with a napping machine, methods using a yarning machine, and depending on the case, the huffing method using sand vapor, etc. Although these are representative means, the present invention is not limited to these means. In addition, the pilafing state can be adjusted depending on the purpose, but an unexpected effect of the present invention is that because ultra-fine fibers are used, there is relatively little change in performance even if the pilfering state varies to some extent, and it shows stable performance. That's true. On the other hand, determining the fiber density when forming an artificial blood vessel is an extremely important issue, and the requirements vary depending on the situation, making it difficult, but the practical rule is to look at the water permeability as a reference. It's convenient. The water permeability referred to here refers to the amount of water (ml) that passes per minute per 1 cm of fabric under a pressure of 120 mm and 11 g. In the present invention, this value is 2000 m I/min or less, preferably 10100 O/min or less, or preferably 5 (lo
It is more effective in the case of artificial blood vessels with low water permeability of ml/min or less.

However, it will take (M is just a guideline and should not necessarily be taken as this, but actually 3000ml/
Even those with a water permeability of about 5,000 ml/min or 5,000 ml/min exhibit superior properties in terms of vascular endothelial cell formation and anastomotic properties compared to conventional products. However, the overall effect is especially pronounced under low water permeability. Generally speaking, under such low water permeability, the formation of endothelial cells is extremely difficult.However, when ultrafine fibers are used as in the present invention, this formation becomes easier, probably because the fibers and cells fit well. The artificial blood vessel of the invention can sufficiently achieve its purpose without crimping, so crimping is not necessary, but it may be effective in cases where greater flexibility and higher shape retention are required. be.

(Effects of the present invention) The present invention has been described in detail above, and although the artificial blood vessel of the present invention using ultrafine fibers has extremely low blood leakage, it is highly flexible, and also has excellent anastomosis (1j). Not only is it improved, but because it is an ultra-fine fiber, the number of scaffolds suitable for biological cell attachment increases significantly, increasing compatibility with the fiber, exhibiting excellent antithrombotic properties, and extremely inhibiting the formation of endothelial cells. The process was carried out quickly and successfully, resulting in an unprecedented artificial blood vessel.

Next, the present invention will be explained in more detail with reference to examples, but the present invention is not limited to these examples.

Example 1 A 50 denier 24 filament temporarily twisted polyethylene terephthalate yarn was used for the warp yarn and the weft ground yarn (back yarn), and the island component polyethylene terephthalate 78 was used for the weft surface yarn, which was a composite fiber defined in Japanese Patent Publication No. 48-22126. 22 parts of sea-component polystyrene, 245 fibers from 36 islands
Made of denier 40 filament, weaved into a tube with a so-called warp and warp double weave structure, inner diameter 11mφ, length]
Form a tube marked with 00, wash it with hot water, and then
Polystyrene was removed with 7&perchlorethylene. Next, this tube was fluffed using a fluffing machine. This tube was washed with hot water, dried, turned over, and then sterilized with ethylene oxide 1 gas and transplanted into the acquired thoracic descending aorta. The water permeability of this fabric was 295 ml/min.

When transplanting to the large aorta, suturing with living blood vessels was extremely easy and successful.

In particular, it had good needle passability and was soft, so it had excellent suturing and anastomosis properties. I did not perform preclonoting just before transplanting because the water permeability was low.

Almost no blood return was observed. However, blood seeped all over the cloth, turning it red. After that, the results of observing the resected sample of the 1st artificial blood vessel showed that on the 2nd day, the red color immediately after transplantation faded to pale red, and on the 200th day, the 7ξ incorporation of blood had decreased and the formation of neointima was remarkable. Recognize what is happening.

After 2 months, granulation-like swelling was observed, which indicates that neointimal formation is active in a non-dense manner. Approximately 3
By month 1, the newly formed inner wall of the blood vessel was almost complete and had become a glossy grayish white color.

This result shows that the healing is remarkable compared to conventional artificial blood vessels.Patent applicant: Toshi Co., Ltd.

Claims (5)

[Claims] (1) A mm product consisting of a multi-layer structure, which has at least a portion of ultra-fine fibers (A) of 0.5 denier or less on the inner and/or outer walls, and the ground yarn constituting the ground structure is mainly 1.0 denier. An artificial blood vessel characterized by being made of fibers (B) of one denier or more. (2) The artificial blood vessel according to claim (1), characterized in that the inner wall and/or the outer wall have piloere formed. (3) The artificial blood vessel according to claim (1) or (2), wherein a bulky textured yarn is used as the base yarn. (4) The ultrafine fibers (A) and/or the fibers (B) are made of any one of polyester, polyamide, polyolefin, and polytetrafluoroethylene. The artificial blood vessel described in (3). (5) The artificial blood vessel according to claims (1) to (4), wherein the i3 water rate is 2000 ml/n or less.