JP2001252279A - Indwelling auxiliary implement for artificial blood vessel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an indwelling auxiliary implement capable of preventing an occurrence of a collapse or a bending nature in the case of transplanting an artificial blood vessel in a loop state and improving operability. SOLUTION: When the artificial blood vessel is transplanted in the loop state, the indwelling auxiliary implement of a tubular state having a collapse drag of 100 to 1,755 gf is inserted into the blood vessel. Thus, the operability is improved. Further, closure of the blood vessel due to a kink can be prevented as well.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an indwelling device to be inserted into an artificial blood vessel when the artificial blood vessel is implanted in a loop.

[0002]

2. Description of the Related Art When an artificial blood vessel is transplanted as a blood access for hemodialysis to a patient with renal failure, the artificial blood vessel is often transplanted in a loop shape in consideration of a wide puncture range and hemodynamics. In general, in consideration of healing after transplantation when transplanting in the form of a loop in this way, a method of partially incising only an anastomotic blood vessel portion and a portion forming a loop and indwelling subcutaneously through each incision wound is known. Used. However, the artificial blood vessel is originally a tube, which is easily crushed by bending. In addition, when the artificial blood vessel is placed subcutaneously through each incision, it tends to be broken and easily crushed.

[0003] If an artificial blood vessel is torn when implanted, there is a problem in that the blood vessel collapses at this location, and blood does not flow and the thrombus is blocked. In addition, when such collapse occurs, it is necessary to re-place the artificial blood vessel and sometimes to expand or increase the incision in the skin, which not only imposes a burden on patients and transplanters, but also causes troubles such as infection. Also increased.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and provides an indwelling assisting device for preventing the occurrence of crushing, bending habit and crushing when implanting an artificial blood vessel in a loop shape. It is.

[0005]

The above objects can be attained by the following inventions. (1) A tubular indwelling aid which is used by being inserted into an artificial blood vessel and has a crushing resistance of 100 to 1755 gf. (2) The indwelling assistant according to (1), which has a connector to a syringe at one end of the tubular indwelling assistant.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is intended to easily and surely prevent the above-mentioned crushing and bending habits during the placement of an artificial blood vessel.
This is a flexible tube-shaped auxiliary tool that is temporarily inserted into the inner surface of the artificial blood vessel during indwelling, and is pressed against crushing from the inside. Furthermore, it is preferable that the present auxiliary tool has a smooth outer surface so that the artificial blood vessel can be easily removed after placement without damaging the artificial blood vessel. It is also possible to provide a circumferential groove or a spiral groove on the surface which has been subjected to edging to reduce slip resistance, or to perform crimping.

Since the auxiliary device of the present invention has a tubular shape, providing a connector to a syringe at one end has an advantage that an artificial blood vessel or a living blood vessel can be easily washed during a transplantation operation.

[0008] Further, as described above, the tube-shaped one has an advantage that the washing can be easily performed. However, from the viewpoint of prevention of crushing, it is possible to use an auxiliary tool made of a flexible sponge-shaped round bar. Can exert the same effect as that of the tubular auxiliary tool. Generally, a tubular shape means a tube having a hollow shape, but in this specification, a sponge-like round bar is particularly regarded as one form of a tubular shape. In the case of such a sponge-like round bar, it is preferable to provide a thin coating film of Teflon or nylon in consideration of the slidability in the artificial blood vessel.

The product of the present invention has a tube-like shape and is flexible enough to have resistance to crushing and operability. As an index to satisfy these properties (resistance and flexibility), FDA guidelines (Guidance for the preparation of Researc
h and Marketing Applications for Vascular Graft Pr
The hardness of the artificial blood vessel described in osthese 11.1.6. Crush resistance) was adopted. The hardness of the artificial blood vessel can be determined by measuring a repulsive force (hereinafter, referred to as a crushing force) when the tube is crushed for a predetermined distance (25% of the inner diameter).

The indwelling assistant of the present invention has a crushing resistance of 100 to 175.
5 gf is preferred, and 100-1750 gf is more preferred. Such a crushing resistance can be imparted to the indwelling assistant by adjusting the wall thickness of the tube.

The indwelling aid of the present invention is preferably circular in order to be inserted into the lumen of an artificial blood vessel, and has an outer diameter less than the inner diameter of the artificial blood vessel to be used. Specifically, in consideration of resistance to crushing and ease of removal, for example, 6 mmφ
(Φ represents an inner diameter of 6 mm. The same applies to the following.) For an artificial blood vessel, an outer diameter of 4.5 to 5.5 mm, and for a 7 mm φ artificial blood vessel, 5.5 to 6.5 m
It is desirable to use an indwelling aid having an outer diameter of 7 to 7.5 mm for an artificial blood vessel representing m and 8 mmφ.

Further, since it is used in the medical field, it must be a material that has low toxicity to the human body and can be sterilized. As a material to be used, a thermoplastic elastomer such as vinyl chloride, polyurethane, or polypropylene, or a synthetic rubber such as silicone can be used.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The indwelling device of the present invention needs to have the hardness necessary for imparting a bending habit at the time of indwelling an artificial blood vessel and the flexibility to facilitate pulling out. For the index indicating hardness and flexibility, refer to the Guidance for the pr
eparation of Research and Marketing Applications f
or Vascular Graft Prosthese 11.1.6 Crush resistan
Based on the crushing resistance described in ce, it was determined by the measurement method of the same guideline.

A method for using the indwelling aid and a method for implanting an artificial blood vessel according to the present invention will be described below with reference to FIG. Normally, when an artificial blood vessel is implanted in a roof shape as a flat access, only the skin near the anastomosis is incised to expose the blood vessel to be anastomosed.
(Figure 1.A). After the central or peripheral anastomosis, a part of the skin to be the roof ゜ is incised, the kraft is placed under the roof in a subcutaneous manner using a special tunneler or the like through the incision, and the kraft is transported to the other anastomosis. Therefore, after one end is anastomosed with a natural blood vessel, the product of the present invention is inserted into the artificial blood vessel from the other end (Fig. 1.B, C), and placed under the skin to prevent collapse.
(Figure 1.D), when the artificial blood vessel was pulled out to the opposite anastomosis,
Extract the product of the present invention (Fig. 1.E). This allows the graft to be implanted subcutaneously in a loop so as not to collapse (Fig. 1.F). Further, when washing the inside of the artificial blood vessel or the living blood vessel during the above operation, using the present invention in the form of a tube provided with a connector to the syringe at one end, using so that the connector portion comes out of the artificial blood vessel,
The cleaning operation can be facilitated by connecting a syringe containing a cleaning solution to this part (Fig. 1.E-2).

(Example 1) The correlation between the crushing resistance of the present indwelling device, the function of holding an artificial blood vessel against crushing, and the ease of pulling out of the artificial blood vessel was examined. First, prepare the indwelling aids shown in Table 1, and use these Guidance for the preparatio
n of Research and Marketing Applications for Vascu
lar Graft Prosthese Measured based on 11.1.6 Crush resistance. Next, a substitute dialysis artificial blood vessel having a 6 mmφ puncture resistance was prepared based on Japanese Patent Application Laid-Open No. 8-332218. Next, while bending the artificial blood vessel, it was confirmed at what radius a kink occurred. As a result, the artificial blood vessel collapsed at a radius of 4 mm.

Next, in order to confirm the function of holding the artificial blood vessel against crushing, it was examined whether or not the above-mentioned indwelling assistant was collapsed to the naked eye when bent to a radius of 4 mm after being inserted into the trial artificial blood vessel. As a result of the investigation, it was found that the use of an indwelling aid having a crushing resistance of 65 gf caused crushing to the naked eye, which required a crushing resistance of at least 100 gf (the results are shown in Table 1).

The ease of withdrawal was examined by pulling the other end of the indwelling auxiliary tool in this state to determine if it could be withdrawn without resistance. As a result of the examination, it was possible to easily pull out the indwelling aid with a crushing resistance of 65 to 996 gf without resistance, and to easily pull out the indwelling aid with 1755 gf although there was some resistance. Also, with the 1814 gf indwelling aid, when pulling out,
There was strong resistance and the inner surface was damaged (the results are shown in Table 1). From the above examination results, the indwelling device of the present invention
Physical properties of 100-1755 gf were required.

[Table 1]

(Example 2) An inner diameter of vinyl chloride of 3.
5mmφ, 5.1mmφ outer diameter, 400mm in length made a tubular indwelling aid (crush resistance 465gf) with a smooth outer surface, E
OG gas was sterilized. Using the product of the present invention, the artificial blood vessel described below was transplanted into the thigh of a mongrel dog in a roof ゜ shape (femoral arteriovenous shunt), and the operability was confirmed.

1. In the case of artificial blood vessels without lumen retention ePTFE is generally used as an artificial blood vessel for flat access
Artificial blood vessels are used. Although this artificial blood vessel is very soft and easy to perform an anastomosis operation, on the other hand, the lumen retention is low, and the roof may be crushed by the skin or an unreasonable roof {a roof with a radius} may be produced when the roof is produced. However, by using the product of the present invention, it is possible to detain without these troughs,
Further, after the placement, the removal was easy, and the artificial blood vessel could be placed reliably and easily in the shape of the roof.

2. In the case of an artificial blood vessel having a wall thickness and having a lumen retention property, the operability was confirmed using a dialysis substitute artificial blood vessel having a 6 mmφ puncture resistance and produced based on JP-A-8-332218. Was done. This prototype is an artificial blood vessel with a wall thickness and a lumen retention property. The artificial blood vessel of this type is broken when the loop radius is smaller than a certain radius or by the operation at the time of transplantation. Crushability is reduced. However, by holding the lumen from the inside using the product of the present invention, the occurrence of these breaks and habits was prevented, and the tube could be securely placed in a loop. In addition, it could be easily removed and the operability was good.

[0021]

According to the present invention, when the artificial blood vessel is implanted in a loop, the use of the indwelling aid of the present invention can prevent the occurrence of a crushing or bending habit and can reliably indwell the loop. In addition, the operability of the artificial blood vessel at the time of transplantation can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a method of using the indwelling assistant of the present invention and a method of transplanting an artificial blood vessel.

[Explanation of symbols]

 1; entire artificial blood vessel placement site (mainly arm or thigh) 2; artificial blood vessel anastomotic vein 3; artificial blood vessel anastomotic artery 4; subcutaneous pocket for loop preparation 5; artificial blood vessel 6; placement aid 7; ; Connector for syringe connection

Claims (2)

[Claims] Claims: 1. A tubular indwelling aid which is used by being inserted into an artificial blood vessel and has a crushing resistance of 100 to 1755 gf. 2. The indwelling assistant according to claim 1, wherein a connector to a syringe is provided at one end of the tubular indwelling assistant.