JPS63315048A - Preparation of artificial blood vessel - Google Patents

Abstract

PURPOSE:To obtain an artificial blood vessel excellent in fray resistance, an antithrombogenic property and an anatomic property, by a method wherein a spacer is inserted in tubular cloth and high pressure fluid treatment is applied to said cloth to interlace at least a part of feathers and/or loop like fibers with the fibers constituting the fundamental structure of the cloth. CONSTITUTION:This method is one for applying high pressure fluid treatment to tubular cloth having feathers and/or loop like fibers and the tubular cloth may be composed of either one of a knitted fabric, a fabric and a braided string and can be arbitrarily selected regardless of the kinds of structures. At least a part of fibers constituting the structure of the cloth consist of extremely fine fibers A having monofilament finess of 1.0 denier or less, pref., 05 denier or less and fibers B exceeding 1.0 denier, pref., 1.5 deniers and the skeletal of an artificial blood vessel is formed from said fibers. A spacer such as a cylindrical, rod like or plate like material is inserted in the tubular cloth and at least a part of the feathers and/or loop like fibers are interlaced with the fibers constituting the fundamental structure of the cloth by high pressure fluid treatment to make it possible to obtain the artificial blood vessel excellent in fray resistance, an antithrombogenic property and an anatomic property.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for producing an artificial blood vessel formed into a tube of fibers and having excellent fraying resistance, antithrombotic properties, and anastomotic properties.

(Prior Art) Conventional artificial blood vessels made of woven or knitted fabrics are woven or knitted fabrics made of polyester fibers, and in order to prevent blood leakage from the walls of the artificial blood vessels, they are made of very dense or tightly woven fabrics. Made of knitted fabric.

(Problems to be Solved by the Invention) Artificial blood vessels made of textiles in particular have poor needle passability during surgery and are extremely difficult to anastomose with biological blood vessels, placing an excessive burden on the operator. . In addition, since it is a simple structure consisting of only a simple woven structure, fraying occurs when passing a sewing needle through it or connecting it to a biological blood vessel, which tends to cause anastomosis failure.

In the worst case scenario, blood may leak and cause instant death, a fatal flaw.

Therefore, conventional measures taken to improve the fraying resistance and needle passability have been knitting using a very complicated warp knitting structure, as disclosed in, for example, Japanese Patent Application Laid-open No. 53-137599. For this reason, the knitting structure had to be complicated, so the fineness of the yarn used had to be made finer, and the knitting machine needed to be very special and highly precise.

The present inventors have arrived at the present invention as a result of intensive study on the above-mentioned problem, which is a fatal defect in artificial blood vessels.

(Means for solving problems) The present invention has the following configuration.

(1) A method of applying high-pressure fluid treatment to a tubular fabric having fluff and/or looped fibers, the method comprising inserting a spacer inside the tubular fabric and then applying high-pressure fluid treatment to treat the fluff and/or looped fibers. 1. A method for manufacturing an artificial blood vessel, comprising intertwining at least a portion of the looped fibers with fibers constituting basic tissue.

(2) The method for manufacturing an artificial blood vessel according to claim (1), wherein at least some of the fibers constituting the tissue of the tubular fabric are ultrafine fibers of 0.5 denier or less.

In the present invention, the tubular fabric may be any of knitted fabrics, woven fabrics, braided cords, etc., and can be arbitrarily selected regardless of the type of tissue. Also, the fiber may be one type of fiber, or two types of fiber may be used.
It is also possible to mix or pull fibers of more than seeds. Also, although it is acceptable to use one type of thread during the formation of the basic structure, it is more preferable to use two or more types of thread.

Further, the polymer used as the fiber may be of any type, such as polyester, polyamide, polytetrafluoroethylene, polyolefin, etc., but polyester is particularly preferred. When using multi-component fibers, the final polymer remaining is the above-mentioned polymer, but other combination components include polystyrene, polyethylene, water-soluble polyamide, alkaline aqueous solution-soluble polyester, water-soluble polyvinyl alcohol, etc., as appropriate. is possible.

In order to make the present invention more effective, it is preferable that at least some of the fibers constituting the tissue be ultrafine fibers having a single filament fineness of 1.0 denier or less.

By using ultrafine fibers, the three-dimensional confounding effect due to high-pressure flow, which will be described later, is enhanced, and a so-called LOW POralS artificial blood vessel is obtained which is extremely flexible and has low leakage.

Furthermore, by using ultrafine fibers, a large number of fine fiber gaps are formed, making it easier for cells and fibers to enter, resulting in extremely thin, uniform, and firm fibrin deposition.

However, on the other hand, there are problems such as strength deterioration of fibers in vivo, and in some cases absorption and disappearance (which is thought to be due to a certain hydrolysis effect in vivo), so the thinner the fiber, the better.

Therefore, in order to solve these characteristics and problems at the same time, we use ultrafine fibers (A) of 1.0 denier or less, more preferably 0.5 denier or less, and ultrafine fibers (A) of more than 1.0 denier, more preferably 1.5 denier. It is preferable that the skeleton of the artificial blood vessel is formed by fibers (B) exceeding . (B)
Fibers suppress deterioration in the body, while ultrafine fibers (A)
By using this, it is possible to improve fuzz and/or loop development, biocompatibility, flexibility, entanglement properties, and needle passability.

The fibers used in the present invention may be filament yarns or stable yarns, but filament yarns have the advantage of being able to be adjusted more freely in terms of the wall thickness of the artificial blood vessel.

Furthermore, if the artificial blood vessel has fluff and/or loops, it has good neointimal formation properties, and it is particularly preferable that the artificial blood vessel has fluff and/or loops of ultrafine fibers. In some cases, the outer wall may also have fluff and/or loops to enhance adhesion to the surrounding tissue, and the present invention can simultaneously achieve this purpose.

In addition, regarding the above-mentioned ultrafine fibers, in blood vessel formation,
Fibers that are already in the form of ultra-fine fibers may be used as they are, but by forming a tube using fibers that can be made ultra-fine by chemical or physical means, and then making them ultra-fine, the result is ultra-fine fibers. The tube may be formed of fibers. Ultrafine fibers can be obtained by using normal spinning methods with due care, but it is also possible to create ultrafine fibers by stretching undrawn yarn under specific conditions, as in the case of polyester. be.

On the other hand, fibers that can be made ultra-fine by post-processing include removing one component of multicomponent fibers or peeling them off, as shown in Japanese Patent Publication No. 48-22126, Japanese Patent Publication No. 53-22593, etc. It means a type of fiber that becomes thinner or ultra-fine. In the case of such fibers, even if the fiber is of normal thickness, it can be made extremely fine after processing, which may cause problems during processing, such as during weaving, knitting, stringing, and various thread processing methods before weaving or knitting. This is preferable because it can minimize thread breakage, fuzz generation, etc. when threading.

The most characteristic feature of the present invention is that high-pressure fluid treatment is applied to a tubular fabric such as an artificial blood vessel.

High-pressure fluid treatment is most commonly performed on sheet-like objects, but it is unthinkable to apply high-pressure fluid treatment to tube-like objects, especially artificial blood vessels. This is because if a tube-shaped object is folded flat and processed, the inner surfaces will intertwine and become integrated, and if high-pressure fluid is prevented from penetrating to prevent integration, there will be a large amount of water to escape. disappears.

This is because not only does entanglement not occur, but also the shape of the tube-like object cannot be maintained. Further, in order for the fibers to become intertwined, movement of the fibers is essential, and for this purpose, it is thought that the insert must be considerably smaller than the inner diameter of the tube-like object.

However, as a result of extensive studies, the present inventors have found that by inserting a spacer such as a cylindrical object, a rod-like object, or a plate-like object inside a tube-like object, the inner walls of the tube will not stick to each other during high-pressure fluid treatment, and If the object is twisted or
It has been unexpectedly discovered that the initial objective of the present invention can be achieved by taking care to prevent wrinkles.

In the present invention, based on the above-mentioned technique and concept, it is necessary to intertwine at least a portion of the fluff and/or loop-like fibers with the fibers constituting the basic structure. By adopting such a configuration, it is possible to obtain an artificial blood vessel with excellent resistance to fraying, antithrombotic properties, and anastomotic properties.

In particular, regarding fraying resistance, in the past, the sutured parts of living blood vessels and artificial blood vessels were easily frayed during or after suturing, resulting in blood leakage and, in the worst case, instant death, which was a fatal flaw. The artificial blood vessel obtained according to the present invention has significantly improved resistance to fraying.

The method of manufacturing the artificial blood vessel according to the present invention is a method that uses high-pressure flow, and it is particularly preferable to form fuzz and/or loops on the fabric before injecting the high-pressure flow. Typical methods for forming fluff and/or loops include methods used when forming the basic structure, such as pile or cut pile woven and knitted fabrics.
It may be a satin texture or the like, or it may be a loop due to a yarn length difference developed by applying heat treatment or chemical treatment, or a yarn length difference resulting from a combination of textures that have been given, for example, a shrinkage difference. In addition, typical methods include raising treatment after weaving or knitting, such as a method using a raising machine, a method using a shirring machine, and a method of rubbing with sandpaper in some cases, but the present invention is not limited to these methods. The important point is that the fuzz and/or loops are formed before being sprayed with a high-pressure stream, rather than being sprayed with a high-pressure stream. In some cases, it may be better to treat the inner wall surface and outer wall surface to form fuzz/loop.

Although various methods for the entanglement treatment using a high-pressure flow can be considered, a method using a liquid is more efficient, and among them, a method using a water jet flow is the most preferable from the viewpoint of safety and economy. That is, there is a method in which a water jet punch of 5 to 200 ka/aK is used to spray water from a small hole onto a surface having fluff and/or loops (in some cases, both surfaces may have fluff and/or loops) and/or the back surface thereof. good. If the spray pressure is too low, the fibers will not get tangled, but if the spray pressure is too high, the fibers will be cut, which is not good. Within this range, it is determined as appropriate depending on the strength of the fibers, the fineness of the fibers, the thickness of the bundle, the flexibility of the artificial blood vessel, etc.

In addition, high-pressure flow treatment can be carried out by injecting high-pressure flow from a nozzle with many small holes that can be sprayed toward the artificial blood vessel from a part larger than the thickness of the artificial blood vessel. This may also be done by injecting high-pressure flow from a number of small holes located parallel to the folded structure. In this case, insert a spacer such as a cylindrical net, plastic, metal, glass, or in some cases a foam material that may or may not pass water through the tube, a plate-like material, or a certain type of material. By performing high pressure fluid treatment,
It is easy to dispose of the smudges that occur when the inner walls of the tube stick together, and in some cases, it can be used as a method for controlling the diameter of the tube.

Further, it is preferable that the water jet punch be oscillated from side to side or cyclically so as not to match the period of the basic tissue. Thereby, punch lines and moire phenomena can be reduced.

Furthermore, if the tube-shaped article is turned over and subjected to high-pressure flow treatment, the fraying resistance can be further improved, but this is not always necessary.

In addition, in the production of artificial blood vessels, it is necessary to form a fabric into a tube, and the method for forming a tube is to form the fabric into a tube, then cut it, and then form it into a tube-shaped object by sewing, gluing, fusing, or other means. However, when forming the basic tissue, it is more preferable to form it into a tube shape because there is no seam. In the former case, that is, when first forming a sheet-like object and then forming a tube-like object, the above-mentioned napping treatment etc. may be carried out at the sheet-like stage or after forming the tube-like object. Of course.

(Example) Next, the present invention will be explained more clearly with reference to Examples.
The validity of the present invention and the scope of rights are not limited or restricted thereby.

Example 1 The warp yarn and the weft yarn (back yarn) were made of polyethylene terephthalate 50 denier 24 filament temporarily twisted yarn, and the weft surface yarn was made of polymer array composite fiber with 78 parts of island component polyethylene terephthalate and 22 parts of sea component polystyrene. Using 245 denier 40 filament yarn with 36 fibers and 36 pieces, weave it into a tube with a so-called double weft weave to form a tube with an inner diameter of 19 mmφ and a length of 100 cm.The tube was washed with hot water, then dried and made with polystyrene using perchlorethylene. Next, a napping treatment agent was applied to this tube, and then the tube was napped using a napping machine.

The diameter of the obtained tube was 8.5 mmφ. Next, after inserting a polyester film (spacer) with a width of 24 mm and a thickness of 0.12 mm into the tube, the discharge hole diameter was 0.25 mmφ, the discharge hole interval was 2.5 mm, and the pressure cuff was 0.
Water jet punching was performed under ko/- conditions.

The basic structure of the obtained artificial blood vessel was a double-layer structure, but it was observed that a large number of ultrafine fibers were mainly entangled between single fibers, between weaves, and between fiber bundles. The fraying resistance of the artificial blood vessel and the one before the water jet was examined. The fraying resistance was determined by cutting the artificial blood vessel at an angle of 45 degrees to the axis with scissors, passing a suture through the 2 mm stump, and measuring the fraying strength using a tensile test piece. As a result, the weight of the artificial blood vessel without water jet punch was 0.1 kg, while the weight of the artificial blood vessel was 1.7 kg. There was also fluff and roux 1 on both the inner and outer walls of the tube.

Example 2 When the artificial blood vessel obtained in Example 1 was turned over and water-jet punched again under the same conditions, the fluff and/or loops and fiber bundles of the ultrafine fibers were found to be more intricately intertwined than in Example 1. was observed.

Example 3 Using polyester fibers of 50 denier 18 filament and 50 denier 72 filament, the diameter was 20 in half weave using a 2 needle type, 30G double lash knitting machine.
A mmφ tube was formed, washed with boiling water, dried, and then subjected to a nap treatment. When observing the condition after raising, it was found that more fine fibers were raised than thick fibers, forming fuzz and loops. Furthermore, after inserting a 16 mmφ stainless steel rod (spacer) into the tube, a discharge port of 0°3 mmφ, a discharge hole interval of 2.5 mm, and a pressure cuff of 5 k (]
/(Water jet punching was performed under the conditions of d.

When the obtained artificial blood vessel was observed, it was found that the fine fineness was entangled with the thick fibers, and the fineness was found to be intertwined between the fibers, between the stitches, and between the fiber bundles. Although relatively rare, it was also observed that large fineness was intertwined with fineness. It was also observed that the fibers were present in the form of fluff or loops, and that some fibers of the fluff or loops penetrated between or within the fiber bundles and reached the inner wall of the tube. When we investigated the fraying properties of this artificial blood vessel, we found that it not only had improved fraying resistance compared to those that were not treated with water jet punching, but also had very few floating threads falling off at the stump.

In particular, the fraying resistance from the end of the stitch was very improved.

(Effect of the invention) The effects of the present invention are enumerated as follows.

(1) Dramatically improved resistance to abrasion, antithrombotic properties, and anastomotic properties.

(2) Fuzz and/or loops can be easily formed on both sides at the same time.

(3) Since it is a means for post-processing, the basic structure can be made simple or complex depending on the purpose at any time.

(4) Remove loose hair and floating hair caused by brushing treatment, etc.
It can be virtually eliminated by washing or reentangling.

As mentioned above, we have solved all of the problems that were impossible with conventional technology, and manufactured an artificial blood vessel that is extremely flexible, has excellent needle passability and abrasion resistance, and has excellent neointimal formation. I was able to find a way.

Claims (2)

[Claims] (1) A method of subjecting a tubular fabric having fluff and/or looped fibers to high-pressure fluid treatment, in which a spacer is inserted inside the tubular fabric, and then high-pressure fluid treatment is applied to the fluff and/or looped fibers. 1. A method for manufacturing an artificial blood vessel, comprising intertwining at least a portion of the looped fibers with fibers constituting basic tissue. (2) The method for manufacturing an artificial blood vessel according to claim (1), wherein at least some of the fibers constituting the tissue of the tubular fabric are ultrafine fibers of 0.5 denier or less.