JPH06319755A - Connector for artificial blood vessel and manufacture thereof - Google Patents

Abstract

PURPOSE:To eliminate the lowering of anti-thrombus property of a connector by arranging a connection part with an artificial blood vessel as tubular non-porous body comprising a hollow body made of a synthetic resin, a central part thick on the side of the outer circumference and an anastomosis part with tubular porous vital vessel to enable the operation of transplanting and replacing of the artificial blood vessel handily and safely. CONSTITUTION:A connection part with an artificial blood vessel 4 is made up of a tubular non-porous body and is inserted into a lumen of a PTFE porous tube, for instance. to join the artificial blood vessel 4. The central part thick on the side of the outer circumference has a role to make a connecter resist compression to support the strength of the connection part 1 thin and requiring a shape holding property while maintaining the overall shape of the connector. Moreover, an anastomosis part 3 with a vital blood vessel is made up of a tubular porous body 4. This enables the employing of an anastomosis method using operation thread identical to the conventional artificial blood vessel 4 thereby achieving higher freedom for a slant anastomosis, end-side anastomosis and the like and moreover, an accurate anastomosis with lower thrombus property.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an artificial blood vessel connector (also referred to as a connection terminal or a joint) used for medical purposes, and more specifically, a connector capable of simply and safely connecting an artificial blood vessel. And a manufacturing method thereof.

[0002]

2. Description of the Related Art A porous material made of polytetrafluoroethylene resin (hereinafter abbreviated as PTFE) is a material having heat resistance, chemical resistance, weather resistance, nonflammability, and low friction. In addition to surface characteristics such as coefficient, water repellency / oil repellency, non-adhesiveness, etc., because it is porous, it has characteristics such as flexibility, fluid permeability, collection / filtration of fine particles, low dielectric constant / dielectric loss tangent, etc. Is added, and due to these unique characteristics, the application is expanding not only to the general industrial field but also to a wide range of fields such as the medical field and the clothing field. The PTFE porous body is used, for example, as a medical material such as an artificial blood vessel in addition to a filtration membrane, a diaphragm, and a sealing material.

Among the uses as an artificial blood vessel, the artificial blood vessel for dialysis shunt is a large field of application. An internal shunt is widely used as a blood access for hemodialysis in long-term dialysis patients. This is for cases where the anastomoses or punctures of autologous blood vessels have disappeared due to frequent reoperation of the shunt. . Artificial blood vessels for dialysis shunts are usually anastomosed in a bypass shape connecting arteries and veins in the forearm or brachial, and PTFE porous tubes having excellent flexibility and biocompatibility are generally used.

Although this PTFE porous tube is excellent in biocompatibility, it does not have the self-repairing property like a living blood vessel, and the hole of the puncture needle remains after the puncture needle is removed in the puncture performed every time during dialysis. . The repair of needle holes in PTFE porous tubes only relies on healing by the surrounding living tissue. However, at first, the needle hole can be repaired by surrounding living tissues, but the porous structure is gradually disturbed due to repeated puncture, and as a result, hemostasis is reduced and blood / plasma There has been a problem that hematoma or seroma occurs due to leakage, or the intima abnormally thickens during repeated blood leakage and blood coagulation due to puncture, resulting in aneurysm / vascular occlusion.

On the other hand, for example, an artificial blood vessel (elastic resin tube) made of a resin having elasticity such as silicone rubber or urethane resin has a needle hole that is easily closed after puncture and withdrawal, and has hemostatic properties. It is good. However, the elastic resin tube cannot be anastomosed because it has a low tear strength against surgical thread during anastomosis with a living blood vessel, and is particularly necessary for internal shunt application for transplantation into a narrow area such as the forearm and upper arm. There is a problem that it is not flexible and buckles easily.

In addition, since the artificial blood vessels that have been put into practical use and are made of a porous PTFE material, PET (polyethylene terephthalate) fabric, or the like are porous, part of the biological tissue around the artificial blood vessel enters through the holes, It has an effect of firmly adhering to form an adventitia-like tissue of a blood vessel, imparting a degree of hemostasis, or integrating an artificial blood vessel in a living body. On the other hand, since the elastic resin tube is non-porous, it has poor adhesiveness to the surroundings and does not have strength reinforcement by surrounding tissues. Further, although the elastic resin tube has a better local hemostatic property than the PTFE porous tube, the strength of the entire tube is severely deteriorated due to repeated puncture, and the risk of tube rupture is high. By making the elastic resin tube porous, it is possible to improve the adhesion with surrounding tissues, but the tube strength, tear strength, and buckling resistance are significantly reduced. It is difficult to use as a blood vessel.

As described above, the artificial blood vessel shunt becomes unusable sooner or later, and it is usually necessary to repeatedly perform replacement surgery of the artificial blood vessel for the dialysis shunt. In addition, dialysis patients to whom the shunt is applied often have complications, and when the thrombotic tendency is high, it is necessary to repeat the shunt operation in 1 to 2 years.

[0008] In this shunt operation, an artificial blood vessel is anastomosed between the artery and vein of the forearm or the upper arm in a bypass shape. However, in the anastomosis of the blood vessel, when there is a step, a blood clot is likely to occur, and therefore the artificial blood vessel is as much as possible. It is a very complicated and time-consuming operation that requires a high degree of technical skill to sew several needles at intervals of several hundreds of μm so as to prevent blood leakage while maintaining the consistency of the blood vessels of the living body.

On the other hand, if it is impossible to completely repair an artificial blood vessel deteriorated by puncturing hundreds to thousands of times with only the healing power of the living body, an anastomosis that is extremely complicated and requires high technical skill. It is conceivable to change the surgery itself to a simple and highly reproducible method without relying on technical skills. If the vascular anastomosis between the living blood vessel and the artificial blood vessel can be omitted or simplified at the time of reoperation, the shunt operation itself is
Local anesthesia is enough, so even if surgery is done once a year,
The burden on the patient can be reduced.

Therefore, conventionally, as a method for simplifying blood vessel anastomosis, an anastomosis method using a laser or glue, a simple anastomosis method using a connecting device, etc. have been proposed. Compared with this, the anastomosis portion has a higher thrombotic property, and has not been widely put into practical use. For example, the anastomosis method using laser or glue has a weak connection force,
High risk of bleeding from the anastomotic surface. In the conventional anastomosis method using a connecting device, a step can be formed at two places, a living blood vessel and a device, and a device and an artificial blood vessel. In addition, since strength is generally required, the device must be made of a material with high thrombosis. , Blood clots are likely to occur. Also, to connect between arteries and veins of different diameters like a shunt,
The anastomotic part of either of the artificial blood vessels will be anastomosed with those having different diameters. Therefore, it has been attempted to cut the body blood vessel at an angle to match the diameter of the anastomosis portion with the artificial blood vessel, but with the conventional connection device, it was difficult to make an anastomosis to such a diagonally cut body vessel. .

[0011]

DISCLOSURE OF THE INVENTION An object of the present invention is to allow an artificial blood vessel to be transplanted and replaced easily and safely, and yet to have an antithrombotic property at an anastomosis portion with a living blood vessel or a connection portion with an artificial blood vessel. To provide a connecting device for an artificial blood vessel which does not decrease Another object of the present invention is to provide an artificial blood vessel connector which is particularly suitable for connecting the artificial blood vessel for dialysis shunt and the living blood vessel.

As a result of intensive studies to overcome the above-mentioned problems of the prior art, the inventor of the present invention uses a synthetic resin hollow body having a specific material and structure as a connecting tool to connect between a living blood vessel and an artificial blood vessel. It has been found that the above-mentioned object can be achieved by arranging the above. That is, a joint part of a non-porous body that can easily replace an artificial blood vessel that deteriorates due to puncture and a porous body anastomosis part that can be anastomosed with a conventional surgical thread with a living blood vessel of a different material are held together. , When a hollow body with a specific structure having a thick central portion with high compression resistance is used as a connecting tool, a new artificial blood vessel can be easily connected at the connecting portion without performing a blood vessel anastomosis during re-operation. However, it was found that the antithrombotic property at the anastomosis part and the connection part is not deteriorated.

Further, in the connector having such a specific structure, the end portion of the synthetic resin tubular porous body used as an artificial blood vessel is processed to form a thick portion and a non-porous body. It can be easily manufactured by forming the tip portion.
Furthermore, by forming a thick portion and a tip of a non-porous body at both ends of a relatively long tubular porous body made of a synthetic resin, by cutting at both ends of the porous body, ,
It is convenient for shunt surgery because it can obtain two connectors (connecting part of non-porous body / thickness part / anastomosis part of porous body) and one artificial blood vessel (intermediate tubular porous body). is there. The present invention is
It was completed based on these findings.

[0014]

Thus, according to the present invention, a synthetic resin hollow body is connected to an artificial blood vessel, which is a tubular non-porous body, the outer peripheral side has a thick central portion, and a tubular body. There is provided a connector for an artificial blood vessel, which has an anastomosis portion made of a porous body with a living blood vessel. Further, according to the present invention, at both ends of the tubular porous body made of synthetic resin, the outer peripheral side has a thick portion, and the tip portion made of the tubular nonporous body,
An artificial blood vessel connector characterized by being formed respectively is provided.

Furthermore, according to the present invention, a rigid cylindrical member is inserted into the inner cavity of at least one end of a synthetic resin tubular porous body, and the end is heated to a temperature not lower than the melting point of the synthetic resin. And a mold is pressed against the outer peripheral surface of the end portion to form a thick portion on the outer peripheral side and a distal end portion made of a tubular nonporous body, for producing an artificial blood vessel connector. A method is provided.

The present invention will be described in detail below. Examples of the synthetic resin forming the connector of the present invention include PTF.
Examples thereof include E, PET, polyurethane resin, silicone resin and the like. However, since the connection with the artificial blood vessel is inserted into the lumen of the artificial blood vessel and connected without suturing with a surgical thread, it is necessary to have a shape-retaining force that keeps the tube in a compressed state. Strong PT without means
FE and PET are preferred.

The synthetic resin tubular porous body for producing the connector of the present invention, and the artificial blood vessel connected by the connector are PTFE porous tube and P
ET tubular fabrics are preferred. Since the PTFE porous tube and the PET tubular fabric have flexibility and flexibility and are excellent in biocompatibility, they are highly used as an artificial blood vessel, and the non-porous portion is It is hard and has excellent shape retention. Furthermore, in a medium diameter region such as a shunt, a PTFE porous tube having excellent antithrombogenicity is particularly preferable.

The PTFE porous tube can be manufactured, for example, by the method described in Japanese Patent Publication No. 42-13560. Specifically, first, a liquid lubricant is mixed with PTFE unsintered powder, and the mixture is molded into a tube shape by extrusion or the like. The liquid lubricant is removed from the molded product by heating evaporation or the like, or the liquid lubricant is not removed, and the molded product is stretched in at least one axial direction. Sintering temperature of 327 ° C with heat shrinkage prevention
When the structure which is heated and stretched as described above is sintered and fixed, a PTFE porous tube having improved strength can be obtained.

This PTFE porous tube has a fine fibrous structure composed of very fine fibers and nodules connected to each other by the fibers, and this fine fibrous structure forms a porous space. . The fiber diameter and length, the size of the nodule, and the number thereof can be changed depending on the conditions of stretching and sintering, and the pore diameter and porosity of the PTFE porous tube can be freely determined.

The PTFE porous tube used in the present invention is not limited to a specific production method as long as it has a porous space. For example, Japanese Patent Publication 60-37
A PTFE porous tube having an uneven structure on the outer surface, which is manufactured by the manufacturing method described in Japanese Patent No. 736, can be preferably used.

The connecting device of the present invention comprises one end (connecting portion) made of a tubular nonporous body, a thick central portion having a high compression resistance, and the other end (anastomosis portion) made of a tubular porous body. It is configured. A specific example of the connector will be described with reference to the drawings. As shown in FIG. 1, the connector of the present invention basically has a connecting part (1) for connecting to an artificial blood vessel, and a thick central part (2) having a role of retaining a shape against compression. ,
It is composed of three parts, an anastomosis part (3) for performing an anastomosis with a surgical thread similar to the anastomosis of an artificial blood vessel and a living blood vessel.

The connecting portion (1) with the artificial blood vessel is formed of a tubular nonporous body. This connection part (1) connects an artificial blood vessel, for example, by inserting it into the lumen of a PTFE porous tube. This connection can only be inserted into the lumen of a flexible artificial blood vessel unless it is sufficiently rigid and relatively rigid. Therefore, this connecting portion is made of a non-porous body. To firmly connect the artificial blood vessel and the connection part,
There are methods such as providing irregularities, protrusions, grooves, etc. for increasing frictional force on the outer surface of the connection portion, adhering with an adhesive, or reinforcing the insertion portion from the outside. According to the results, a method in which the outer diameter of the connecting portion (1) is slightly increased toward the tip, a method in which scale-like minute unevenness is provided on the outer surface of the connecting portion so as to increase the frictional force in the detaching direction, and then The method of tying a thread around the artificial blood vessel on the connecting portion by tying it up is highly effective.

Since the connecting portion (1) is inserted into the lumen of the artificial blood vessel, the inner diameter thereof tends to be slightly smaller than the inner diameter of the artificial blood vessel, and a step is likely to occur. In order to reduce this step difference that causes thrombus, it is preferable to make the connecting portion (1) thin. Further, in order to increase the frictional force of the connection surface, it is also effective to make the outer diameter slightly larger than the inner diameter of the artificial blood vessel to be connected. Further, as shown in FIG. 1, the shape of the connecting portion (1) is such that the outer diameter becomes slightly larger toward the tip, and the connecting portion (1) is tapered so that it becomes thinner toward the tip, so that there is little step difference. It has a smooth inner surface shape and good shape retention.

From the above, it is desirable that the connecting portion (1) be thin and have shape retention. And in order to reduce the step caused by the use of the connecting tool as much as possible,
The connecting part (1) is preferably integrally formed with the thick central part (2) and the anastomosis part (3). The length of the connection part (1) is usually 1 to 5 m from the viewpoint of ease of connection with an artificial blood vessel, reliability of connection, resistance to thrombosis, etc.
m, preferably about 1.5 to 3 mm.

The central portion (2) whose outer peripheral side is thick has a role of imparting compression resistance to the connecting tool, and the strength and shape retention of the connecting portion (1), which is desired to be thin and retain shape. It is a part that maintains the shape of the entire connector while supporting the sex. Further, the thick central portion (2) is connected to the connecting portion (1).
Is a place to be grasped and operated when inserted into the lumen of the artificial blood vessel, and is also a place to retain the shape against compression when the artificial blood vessel is bound with a thread. Further, the thick central part (2) forms a boundary with the anastomosis part (3), and a convex shape as shown in FIG. 1 is provided so that the position of the connecting tool can be easily distinguished during re-operation. Further, it is preferable to color with a blue dye or the like.

Since the central portion (2) of the wall thickness is not inserted into the lumen of the artificial blood vessel, the thickness is not particularly limited. However, if it is too thick, the anastomosis operation becomes difficult and the body blood vessel is aligned. As the property is impaired,
The thickness can be appropriately determined. The central portion (2) of the wall thickness needs to be thick on the outer peripheral side, and the inner peripheral side of the connecting tool should be free from a step at this portion.
The thick portion of the central portion (2) may be integrally molded with the same material as the connecting portion (1) and the anastomosis portion (3), or a reinforcing ring made of a synthetic resin of another material may be arranged. do it,
They may be formed in close contact with each other. The thick central portion (2) is usually a non-porous body or a low-porosity porous body. The length of the central portion of the wall thickness is usually 0.5 to 3 from the viewpoint of imparting compression resistance, operability, distinguishability, antithrombotic property and the like.
It is about mm.

The anastomosis part (3) is a part for performing an anastomosis with a surgical thread similar to the conventional anastomosis between an artificial blood vessel and a living blood vessel. Therefore, the anastomosis part (3) is made of a tubular porous body similar to a conventional artificial blood vessel. This is a characteristic feature of the connector of the present invention which is greatly different from the conventional connecting device. The conventional connecting device has a difficulty in connecting to a living blood vessel and has a problem of thrombosis due to the generation of a step. However, with the connecting device of the present invention, an anastomosis similar to the suturing of an artificial blood vessel can be performed. Therefore, those problems can be solved.
The length of the anastomosis part (3) can be appropriately determined depending on the ease of anastomosis operation with a living blood vessel.

In the method for forming a shunt using the connecting device of the present invention, as shown in FIG. 2, first, the connecting device (5) is anastomosed (6) with a surgical thread to each living blood vessel bypassing the anastomosis portion (3). . Next, as shown in FIG. 3, an artificial blood vessel (4) made of a tubular porous body between the two connecting tools (5, 5).
, And insert the connecting portions (1) of the connecting device into the inner cavities of both ends of the artificial blood vessel. After the insertion, the thread (8) is tied around the outer circumference of the artificial blood vessel on the connecting portion so that the connecting tool and the artificial blood vessel do not come off. This completes the first shunt plastic surgery and performs dialysis using the artificial blood vessel between the connectors.

The puncture of the injection needle in dialysis is performed near the center of the transplanted shunt graft. In the present invention, the artificial blood vessel between the connecting tools corresponds to this portion,
When this artificial blood vessel deteriorates after two years or several years, as shown in FIGS. 4 and 5, re-operation for replacing the artificial blood vessel is performed. At this time, conventionally, the artificial blood vessel deteriorated by puncture was excised, and a new artificial blood vessel was anastomosed to the artificial blood vessel with a surgical thread. However, when the connector (5, 5) of the present invention is used, the artificial blood vessel (9 ) Can be easily fastened to the connection tool (5, 5) by wrapping a surgical thread around the outer circumference, so that the surgical thread (10) is cut and only the deteriorated artificial blood vessel (9) is removed and connected. Since the tools (5, 5) can be left anastomosed with the living blood vessel (7), the new artificial blood vessel (11) is already anastomosed with a new surgical thread (12) or the like. It is only necessary to perform a simple operation of attaching it to the connection part 13). In the connecting operation between the artificial blood vessel and the connecting device, the artificial blood vessel can be easily attached and detached and the safety is high. Therefore, compared with the conventional suturing operation, it is not only technically easy, but also the required time can be greatly shortened to a fraction.

When the connector of the present invention is used, two procedures are performed in the first transplant operation, that is, anastomosis with a living blood vessel and connection with an artificial blood vessel. Although it takes time, the time can be significantly shortened during re-operation. In addition, if the artificial blood vessel and the connecting device are connected in advance, even during the first surgery,
The transplant operation can be performed in the same time as when transplanting a conventional artificial blood vessel.

The connecting device of the present invention is similar to the conventional connecting device in that there is a connecting portion on both the artificial blood vessel side and the living blood vessel side, but on the living blood vessel side, an anastomosis using a surgical thread is performed. Therefore, the thrombosis is low. In addition, the connection part with the artificial blood vessel is a non-porous body, and its shape is thinned or the diameter is tapered toward the distal end to prevent a step from occurring to a minimum. it can. The central portion for imparting compression resistance and shape retention also has a wall thickness on the outer peripheral side, so that it is possible to prevent the occurrence of a step due to the connector.

When connecting an artery and a vein in a shunt operation in a bypass manner, the vein is usually thinner than the artery. Further, the shunt is not an end-to-end anastomosis that originally connects the end of the living blood vessel and the end of the artificial blood vessel, but an end side anastomosis that connects the end of the artificial blood vessel to the side surface of the living blood vessel is often performed. In this end-side anastomosis, the end portion of the artificial blood vessel is obliquely cut so that the blood flow smoothly flows, and the anastomoses are performed so as to distribute or join the blood flow obliquely from the side surface of the living blood vessel. Since this oblique angle varies depending on the condition of the living blood vessel of the patient, the method of operation, and the operator, the end of the artificial blood vessel is cut obliquely during the operation. With traditional connection devices,
Even if there was no correspondence for this oblique anastomosis, there was a limit to adjustment. On the other hand, in the connector of the present invention, the anastomosis part (3) made of a tubular porous body is preliminarily long, so that the shape of the anastomosis end is cut and adjusted freely as in the case of the artificial blood vessel. It is possible to

The connector of the present invention comprises a single connecting part (1) made of a tubular nonporous body, a central part (2) having a thick outer peripheral side, and an anastomosis part (3) made of a tubular porous body. Although it can be provided as a unit of, as an actual product form, at both ends of the tubular porous body made of synthetic resin, a portion with a thick outer peripheral side and a tip made of a tubular non-porous body, respectively, Those having a formed structure are preferable.

A concrete example thereof is shown in FIG. As shown in FIG. 6, at both ends (14, 14) of the tubular porous body (15),
A connecting portion (tip portion) made of a tubular non-porous body and a thick portion on the outer peripheral side are provided. This connecting tool is, so to speak, an artificial blood vessel with a connecting tool, and when used, as shown in FIG. 7, it is cut at two or more places at any part of the tubular porous body (1
8, 18) and both ends are used as two connectors (17, 17), and the intermediate part is used as an artificial blood vessel (16) made of a tubular porous body. When the length of the tubular porous body in the middle portion is short, it is possible to obtain only two connecting tools by cutting at one place in the middle portion.

It can be said that the connector having this structure is suitable for manufacturing the connector. That is, it is sufficient to form a thick part at both ends of the tubular porous body and an anastomosis part made of a non-porous body at the tip, and as a method therefor, a rigid body, for example, stainless steel, is formed at the end of the tubular porous body. With the columnar object made of a round bar inserted, this end is heated to a temperature equal to or higher than the melting point of the synthetic resin forming the tubular porous body, and a mold having a desired shape is pressed around the end of the cylindrical resin to form a tubular shape. It is possible to form a thick portion having a high compression resistance at the end of the porous body and a tubular non-porous body at the tip.

More specifically, as shown in FIG. 8, the end of the tubular porous body (16) is covered with a stainless round bar (19) which is widened from the middle, and a metallic mold (2
Cover with 0, 21). At this time, the portion forming the connecting portion (1) at the tip and the thick central portion (2) needs strength, and in order to make it non-porous or to reduce the porosity, the stainless steel is shrunk in advance. Cover with a round bar. For this purpose, for example, a PTFE porous body tube having an uneven structure on the outer surface, which is manufactured by the manufacturing method described in Japanese Patent Publication No. 60-37736, is suitable because it easily shrinks.

By using a stainless round bar which is widened from the middle as shown in FIG. 8, the shape of the connecting portion (1) made of the tubular non-porous body is thin and tapered toward the tip. Can be expanded. Of course, in addition to such a shape, as long as the connecting portion (1) made of a tubular non-porous body is thinned, a step is not generated as much as possible when connected to an artificial blood vessel. , Can be preferably used.

The mold is shaped so as to form a thickened portion on the outer peripheral side, and normally two tubular molds (2
0, 21) are used in combination. That is, one female mold (20) was provided with a tubular step, and when the male mold (21) was inserted into it, a convex thick portion was formed. The thing is illustrated.

In the state shown in FIG. 9, when the end portion of the tubular porous body is heated to a temperature equal to or higher than the melting point of the synthetic resin forming the tubular porous body, the tip portion becomes non-porous and has a thick wall. The portion also becomes a non-porous material or a porous material having a significantly low porosity.

By this manufacturing method, a hollow molded article having a connecting portion (1) made of a tubular nonporous body, a central portion (2) having a thick outer peripheral side, and an anastomosis portion (3) made of a tubular porous body is obtained. Obtained as a seamless integrally molded product. Such a hollow molded article has a structure in which a highly dangerous step that disturbs the blood flow and becomes a starting point of thrombus formation cannot be formed on the inner surface, and is extremely advantageous as a connector for an artificial blood vessel. However, since the integrally molded product is advantageous only in the inner peripheral surface that comes into contact with the blood flow, for example, for a thick part for imparting compressive strength, a synthetic resin ring or the like is arranged on the outer peripheral surface of the hollow molded body. You may form it. Also in the manufacturing method of the present invention, it is possible to arrange a reinforcing ring at the end of the tubular porous body (16) and heat bond it when the connecting portion (1) is molded. For example, PTFE or FEP can be added to a PTFE porous tube.
A non-porous ring of (tetrafluoroethylene-hexafluoroethylene copolymer) is previously arranged on the outer periphery,
It is possible to perform simultaneous bonding at the time of heat molding.

In the heating step, the end of the tubular porous body, the stainless round bar, and the mold are heated above the melting point of the synthetic resin forming the tubular porous body. At that time, as shown in FIG. Mold by pressing the mold. By performing this operation on both ends of the tubular porous body, it is possible to obtain a product having a structure in which a connecting tool is formed on both ends of an artificial blood vessel made of the tubular porous body. As described above, this product can be cut into two or more arbitrary places to obtain two connectors and an artificial blood vessel.

The artificial blood vessel connector of the present invention exhibits very excellent characteristics as a shunt application in an artificial dialysis patient in the following points. The anastomosis part with the living blood vessel is formed from a tubular porous body, and since the anastomosis method using the surgical thread similar to the conventional artificial blood vessel can be adopted, there is a high degree of freedom for diagonal anastomosis, end side anastomosis, etc. In addition, a reliable anastomosis with low thrombosis can be performed. It is easy to remove an artificial blood vessel that has deteriorated due to repeated punctures during dialysis and to reconnect a new artificial blood vessel. Further, since the artificial blood vessel has high reproducibility, it is possible to estimate the replacement time, and it is possible to manage the systematically.

From the above, both the complexity of re-operation and the risk of side effects such as vascular occlusion, aneurysm formation, and infection during the dialysis period can be greatly reduced as compared with the prior art. Further, according to the production method of the present invention, it is possible to obtain the product of the present invention as a seamless integrally molded product, and when used as a connector between a living blood vessel and an artificial blood vessel, cause a thrombus. It is possible to reduce the difference in level. In addition, in the case of a product in which both ends of a synthetic resin tubular porous body are formed with a thick portion on the outer peripheral side and a tubular non-porous tip, they are free during surgery. The higher the
There is little waste such as cutting margins at the end of anastomosis, and it is advantageous in terms of cost and management as compared with the case where individual connecting devices are produced.

[0044]

EXAMPLES The present invention will be specifically described below with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

The methods for measuring the physical properties are as follows. In any of the tests, the test was performed in a state where at least one connecting portion between the connecting device of the examples and comparative examples and the artificial blood vessel made of the tubular porous body was included as the test site. <Leakage pressure> The water pressure when water comes out from the outer wall of the artificial blood vessel for the first time when the water pressure is gradually applied from the inside of the artificial blood vessel. <Tensile strength> The maximum tensile strength value when a PTFE porous tube having a length of 25 cm is chucked at both ends with a chuck interval of 10 mm and pulled at a speed of 50 mm / min by a tensile tester. <Patent rate> The ratio of the number of artificial blood vessels in which blood flow was observed at the time after transplanting the artificial blood vessels to animals and keeping them alive for a certain period of time to the total number of transplanted artificial blood vessels. <Thrombus thickness> An artificial blood vessel was transplanted to an animal, and after being kept alive for a certain period of time, the artificial blood vessel was fixed with formalin, dried at a critical point, and then, with a scanning electron microscope, the inner surface of the cross section cut in the longitudinal direction was examined. The average value of the measured thrombus layer. <Inner thickness> Same as above, which is an average value of the measured thickness of the inner membrane formed on the inner surface of the artificial blood vessel of the sample.

[Example 1] With respect to 100 parts by weight of PTFE fine powder (F104 manufactured by Daikin Industries, Ltd.),
20 parts by weight of a liquid lubricant (SS Drysol manufactured by Esso Co., Ltd.) was mixed as an auxiliary agent and molded into a tube by a ram extruder, and then the liquid lubricant was dried at 50 ° C. for 1 week. This extruded tube was stretched by 500% while being heated in an electric furnace under the conditions of a furnace temperature of 350 ° C. and a residence time in the furnace of 120 seconds, and then a 2 mmφ stainless steel rod was inserted into the inner cavity and fixed at both ends. Heat treatment at ℃ for 10 minutes,
A PTFE porous tube having a porosity of 75%, an average fiber length of 30 μm, an inner diameter of 2 mmφ and an outer diameter of 3 mmφ (thickness 0.5 mm) was obtained.

Then, the PTFE porous tube obtained above was covered on a stainless steel round bar as shown in FIG. 8, and the length 3 mm behind the skirt with the expanded diameter was twisted in the circumferential direction to a length of about 1 /. Compressed to 3. Next, a mold made of stainless steel having the shape shown in FIG. 8 was covered, and the mold was pushed down while the jig was heated for 10 minutes on a hot plate heated to 700 ° C. to mold the mold. Similarly, the other end of the PTFE porous tube was treated, and as a result, from a tubular nonporous body having a length of 2 mm, an outer diameter of 2.5 mm and a thickness of 0 to 0.3 mm taper from the end. A tip, length of 1 mm,
An artificial blood vessel with a connector made of a PTFE porous tube having a thick portion having a thickness of 1 mm and an inner diameter of 2 mm at both ends was obtained.

[Example 2] A heat treatment after stretching was performed at 950 ° C.
Stay in a glass tube with an inner diameter of 35 mmφ heated to 60
A porous PTFE tube was prepared in the same manner as in Example 1 except that the outer surface was provided with an uneven structure having a recess depth of 50% of the film thickness and a distance between projections of 300 μm. Processed into a length of 2 mm, an outer diameter of 2.5 mm, and a thickness of 0 mm to 0.3 mm from the end of the tubular non-porous tip end portion, a length of 1 mm, a thickness of 1 mm, an inner diameter of An artificial blood vessel with a connector made of a PTFE porous tube having a 2 mm thick portion at both ends was obtained.

[Embodiment 3] Instead of compressing 3 mm behind the skirt portion with the expanded diameter into about 1/3 of the length while twisting in the circumferential direction, an inner diameter of 2.5 mm, an outer diameter of 3 mm, and a length of 1 mm are used. 2 mm in length in the same manner as in Example 1 except that the FEP non-porous tube was previously coated on the portion.
With an outer diameter of 2.5 mm and a thickness of 0 to 0.3 mm from the end, which is a tip made of a tubular nonporous body, a length of 1 m.
m, a thickness of 1 mm, and an inner diameter of 2 mm to obtain an artificial blood vessel with a connector made of a PTFE porous body having a thick portion including a FEP coating layer at both ends.

Comparative Example 1 Comparative Example 1 was prepared by using the PTFE porous tubes at both ends, which had not been processed, in both the connector and the artificial blood vessel in Example 2.

[Comparative Example 2] Inner diameter 2 mm, outer diameter 2.5 mm
The PTFE non-porous tube of No. 2 was used as a connector, and the unprocessed PTFE porous tubes at both ends of Example 2 were used as artificial blood vessels.

[Comparative Example 3] In Example 3, the same FEP non-porous tube as in Example 3 was heat-bonded at a position 2 mm from the end of the PTFE porous tube without forming the connecting portions at both ends. Except for the above, the same procedure as in Example 3 was performed.

<Structural Evaluation> Examples 1 to 3 and Comparative Examples 1 to 1
The leak pressure and the tensile strength of the artificial blood vessel obtained in 3 were measured in a state where the connector was connected to the tubular porous body (artificial blood vessel). That is, as for the artificial blood vessel with a connecting tool, the connecting tool portions at both ends were cut and used as two connecting tools and one artificial blood vessel. As the connecting tool, a connecting portion made of a tubular non-porous body was inserted into the lumen of the artificial blood vessel, and a 6-0 polypropylene surgical thread was tied around it for two rounds. In the case of Comparative Example 1, since it cannot be fixed by this method, 12 simple locations were sewn with the same thread and sutured.

[0054] As a result, for the leakage water pressure, Examples 1 and 3 and Comparative Example 3, 0.5 kg / cm ^2, Example 2 and Comparative Example 2, and 0.3 kg / cm ^2, the tubular porous body It was the same as its own value, and the sealing property of the connection part was good. In Comparative Examples 1 and 3, water leaked from the connection portion, and the water leak pressure was lower than the value of the tubular porous body itself. Regarding the tensile strength, Examples 1-3 show a high value of 2.0-2.5 kgf as compared with 0.8-1.2 kgf of the comparative example, and there is no problem such as omission during transplantation and after transplantation. It was considered.

<Evaluation of Transplantation> Examples 1 to 3 and Comparative Examples 1 to 1
Each of the 3 artificial blood vessels was transplanted into the carotid artery of a rabbit weighing 13 to 15 kg. The total length of the connector is 5m
m, and with the same method as the structural evaluation, with the connecting tool connected to the tubular porous body (artificial blood vessel) in advance, the implantation length 3c
Then, 12 simple stenosis was performed and sutured. After transplanting, one hour after transplanting and after slaughter, the transplanted artificial blood vessel is taken out, the patency rate is investigated, and after fixation with formalin, critical point drying is performed, and thrombus formation on the inner surface of the artificial blood vessel is performed with a scanning electron microscope. The condition and the thrombus thickness were observed and measured.

Similarly, 4 weeks after the transplantation, a wound was opened, only the tubular porous body (artificial blood vessel) was removed, and a new artificial blood vessel was connected to the sample confirmed to be patent. Four weeks after the reoperation, the animals were sacrificed, and the patency rate was investigated, and the state of thrombus formation on the inner surface of the artificial blood vessel and the intimal pressure were observed and measured by a scanning electron microscope. The operation time excluding the anesthesia time and the wound closure time was 1.2 hours in Examples 1 to 3 and 1.5 hours in Comparative Example 1.3 at the time of initial transplantation, but there was no difference, but Example 1 was more effective in hemostasis. The time required was small, so it was a little shorter. Also,
In Comparative Example 2, the time was 0.8 hours, which was short because there was no sewn-up stitch.

However, in Comparative Example 2, half of them were already occluded one hour after the transplantation, and a red blood clot was formed at the step between the connector and the artificial blood vessel in the patent sample by observation of the inner surface. Four
The patency rate decreased to 17% after a week, and there was no patency after the reoperation, and a satisfactory patency was not obtained. In Comparative Example 3 as well, a patency rate of 67% was found 1 hour after transplantation, and a patency rate decreased to 33% after 4 weeks. On the inner surface observation, a red thrombus was formed between the connecting part of the connecting device and the artificial blood vessel, which was considered to be the cause of the blockage.

On the other hand, Examples 1 to 3 and Comparative Example 1
Then, 100% patency rate 1 hour after transplantation and 4 week patency rate 8
The patency rate was 3 to 100%, and the patency rate at 4 weeks after reoperation was 67 to 83%, which was a high patency rate. On the inner surface observation, a vascular endothelial cell layer covered with a thin white thrombus after 1 hour and 4 weeks after re-implantation that already extends beyond the connectors on both ends and extends into the artificial blood vessel,
It was well organized.

Regarding the re-operation time, in Examples 1 to 3, the connection tool was clearly discriminated when the wound was opened, and it was possible to replace it in 30 minutes. However, in Comparative Example 1, the boundary of the connecting portion was not clear, and the same constriction suture was required as in the first operation, and the operation time was 2 hours. In Example 3, a thick intimal tissue was formed in the connector and the artificial blood vessel portion, which firmly adhered to each other and was extremely difficult to remove, and required a reoperation time of 2 hours 30 minutes.

Table 1 shows the results of the structures, compression insertability evaluations, and transplantation evaluations of each of the above Examples and Comparative Examples. As described above, only the examples have both the simplicity and the certainty of the surgery, and the superiority of the present invention has been proved.

[0061]

[Table 1]

[0062]

EFFECTS OF THE INVENTION According to the artificial blood vessel connector of the present invention, it is possible to realize transplantation of an artificial blood vessel that is much simpler and safer than in the past, and the complexity of re-operation and the period for performing dialysis. Both the risk of side effects such as vascular occlusion, aneurysm formation, and infection can be significantly reduced. Therefore, the artificial blood vessel connector of the present invention is very effective as a connector for an artificial blood vessel for a dialysis shunt, and the production method of the present invention is very effective for obtaining the connector.

[Brief description of drawings]

FIG. 1 is a schematic view showing an example of an artificial blood vessel connector of the present invention. It shows a state in which the left portion above the front surface of the connector is cut off, and the hatched portion shows the cut cross section.

FIG. 2 is a schematic diagram showing an intermediate stage when connecting an artificial blood vessel using the connector of the present invention.

FIG. 3 is a schematic diagram showing a final form when an artificial blood vessel is connected to a living blood vessel using the connecting device of the present invention. The anastomotic part and the connecting part at the left end show a state in which the upper part of the front face is cut off, and the hatched part shows the cut cross section. In addition, the parts of the connection tool are painted with a dotted pattern.

FIG. 4 is a schematic diagram showing how to remove a deteriorated artificial blood vessel when performing a reconnection operation of the artificial blood vessel using the connector of the present invention.

FIG. 5 is a schematic diagram showing how to attach a new artificial blood vessel when performing a reconnection operation of the artificial blood vessel using the connecting device of the present invention.

FIG. 6 is a schematic view showing one mode of the connector of the present invention (artificial blood vessel with connector).

FIG. 7 is a schematic diagram showing an example of how to use the connector shown in FIG.

FIG. 8 is a cross-sectional view showing an intermediate stage of the method for manufacturing a connector according to the present invention. The part painted with a dotted pattern represents the mold, and the shaded part represents the tubular porous body.

FIG. 9 is a cross-sectional view showing the final stage of the method for manufacturing a connector according to the present invention. The part painted with a dot pattern represents the mold, and the end part of the artificial blood vessel formed by the shaded part.

[Explanation of symbols]

 1 connection part of connection tool (connection part with artificial blood vessel) 2 thick central part of connection tool 3 anastomosis part of connection tool (anastomosis part with biological blood vessel) 4 tubular porous body (artificial blood vessel) 5 connection tool 6 Anastomosis site between connecting tool and living blood vessel 7 Living blood vessel 8 Surgical thread tied to the outer circumference of artificial blood vessel on the connecting portion 9 Artificial blood vessel cut out and removed from the connecting tool 10 Surgical thread removed by cutting 11 New artificial blood vessel 12 New Surgical thread for tying and stopping the artificial blood vessel 13 The connecting tool that is initially connected 14 The portion that serves as the connecting portion and the central portion of the wall thickness of the connecting tool 15 Tubular porous body portion 16 Tubular porous body (artificial blood vessel) 17 Connecting tool 18 cut surface 19 metal round bar 20 mold 1 21 mold 2 22 molded part of the connector of the present invention

Claims (3)

[Claims] 1. A synthetic resin hollow body, which is connected to an artificial blood vessel that is a tubular non-porous body, a central portion that is thick on the outer peripheral side, and an anastomosis portion with a living blood vessel that is a tubular porous body. An artificial blood vessel connector characterized by having. 2. At both ends of a tubular porous body made of synthetic resin,
An artificial blood vessel connector characterized in that a thicker portion on the outer peripheral side and a tip portion made of a tubular non-porous body are formed respectively. 3. A tubular body made of a rigid body is inserted into the lumen of at least one end of a tubular porous body made of a synthetic resin, and the end is heated to a temperature equal to or higher than the melting point of the synthetic resin. A method for manufacturing an artificial blood vessel connecting device, characterized in that a mold is pressed against the outer peripheral surface of the end portion to form a thick portion on the outer peripheral side and a tip portion made of a tubular nonporous body.