JP2962606B2 - Medical prostheses - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a medical prosthesis for reinforcing tissues, preventing air leakage, and stopping hemostasis in thoracic surgery such as lung, trachea and bronchial anastomosis, and gastrointestinal surgery.

[0002]

2. Description of the Related Art For example, in respiratory surgery such as trachea and bronchial surgery, a strong force is applied to a sutured anastomosis, which may cause the tissue to be torn, air leaks, and bleeding.
Also, in the operation of a real organ such as a digestive organ, when the tissue is soft or the tissue is sutured under tension, the same problem as described above occurs.

For the purpose of solving such a problem, the present applicant has filed Japanese Patent Application No. 61-240922 (Japanese Patent Application Laid- Open No. 63-95).
No. 041) discloses a pledget made of a biodegradable and absorbable material that does not remain as a foreign body in the body after healing and that does not cause granulation, scarring, or fistula. The present invention relates to an improvement thereof. .

[0004]

In the above-mentioned applications, uniformity of the density, thickness, strength and elongation of the prosthesis is important in terms of ease of operation and functions such as reinforcement, air leakage and hemostasis. Requirements, and growth and form stabilization,
This is a particularly important requirement for eliminating stress and distortion applied to the application site. The present invention has solved such a problem.

[0005]

According to the present invention, a knitted fabric made of a biodegradable and absorbable material is reversed in the knitting direction, that is, the wale direction of the knitted fabric and the course direction are reversed. The present invention relates to the provision of a medical prosthetic material characterized by being laminated and needle-punched into a nonwoven fabric.

[0006]

According to the present invention, in a medical prosthesis material in which knitted fabrics knitted of biodegradable and absorbable materials are overlapped and needle-punched into a non-woven fabric, the knitting direction is changed so that the knitting directions are different. And the fabric in the wale direction are alternately stacked, that is, the fabrics with different knitting directions are sequentially stacked and integrated, regardless of the direction, the thickness, density, strength, and elongation are uniform throughout, A medical prosthesis material meeting the above-mentioned purpose can be obtained. That is, generally
When indicating the knitting direction of the knitted fabric, the formed stitch
(Loop) horizontal streak course and vertical streak wale
In the present invention, the knitted fabrics are
In the course of integration, such a course or wale
Instead of overlapping so that the directions of
Invert, for example, overlap and integrate
It is characterized by the fact that

[0007] However, when the same knitting direction is superimposed on each other, a direction is generated in the elongation, and it is possible to apply the method to a technique requiring such a function. A configuration of the present invention having no uniform elongation is desired. For example, when applied to pulmonary constriction or hemostasis of a liver stump, if the property is not isotropic, especially if it is not isotropic in elasticity, it may cause unnecessary stress or distortion to the lung or liver. Or create a dead space. Also, stress and distortion interfere with the normal functioning of the organs, and the dead space becomes the nest of infection. In this regard, the fact that the knitted fabric is made of the material means that the lamination of the different-direction knitted fabric and the elongation thereof are suppressed by the needle punch, but the elongation rate is uniform, and unlike the woven fabric, the molded product, etc. It is suitable because it has a moderate buffering effect on elongation at the time of application.

[0008] The biodegradable and absorbable material constituting the present invention is a filamentous polyglycolic acid, polylactic acid, a copolymer of glycolic acid and lactic acid, a synthetic polymer such as paradioxanone, caprolactone, or the like. Can be exemplified by natural materials such as collagen, chitin and the like. However, since these materials have different decomposition behaviors in a living body, those suitable for the purpose and use are appropriately selected and used. However, in particular, in terms of strength and hydrolysis rate, polyglycolic acid,
Copolymers of glycolic acid and lactic acid are preferred.

On the other hand, knitting of such a material may be performed by using various knitting machines to form an arbitrary structure such as flat knitting, rubber knitting, and vertical knitting. A flat knitted fabric knitted in a tubular shape is preferred. Incidentally, the knitted fabric knitted in a tubular shape in this manner becomes a double fabric as it is when flattened, and the laminating operation becomes easy.

[0010] The nonwoven fabric made by the needle punch may be formed so that the knitting directions are different, that is, the wale direction and the course direction of the knitted fabric are alternately arranged for each piece, or a plurality of the knitted fabrics are laminated. The knitted fabrics may be stacked and punched alternately, or a single or a plurality of pre-punched knitted fabrics may be stacked and punched again as described above. The needle punching method is a conventionally known means for producing a nonwoven fabric, whereby the laminated fabric is integrated, and the density, thickness, strength, and elongation are made uniform. The number of layers varies depending on the material used, the thickness of the yarn, and the knitting density, but is arbitrarily selected according to the application. Usually, in the intended use of the present invention, the density, thickness, tensile strength and tensile elongation at break are respectively 90 to 300 g / mm ² , 0.25 to 0.
60 mm, 300 to 1200 gf, preferably in the range of 20 to 50%. To achieve such a configuration, for example, a 30-35 denier 12 filament yarn is knitted flat so that the basis weight is 35 to 50 g / m ² . It is knitted into a tissue in a tubular shape, and two to four of them are stacked so that the knitting directions are different.

In preparing the nonwoven fabric, a knitted fabric assuming the final use size is prepared in advance, or the integrated nonwoven fabric is cut into an appropriate size, and if necessary, a needle is passed through the needle for passing a needle through it. Holes are provided to constitute an example of the prosthetic material of the present invention.

[0012] For such a prosthesis for suturing ,
Various treatment agents, for example, wax, silicone, beeswax, lubricating copolymers containing polyoxyethylene blocks and polyoxypropylene blocks, or , Fatty acids are stearic acid, palmitic acid, lauric acid, myristic acid, and esters are monoesters, diesters,
The sucrose fatty acid ester, which is a polyester, may be used alone or in a mixture, and then adhered by an arbitrary method such as dipping or coating to impart the above-mentioned function. The treatment may be performed at any stage such as a yarn stage, a knitted fabric stage, and a nonwoven fabric stage.

The prosthetic material of the present invention constituted as described above is used as a suturing cloth for preventing rupture of body tissue in a surgical operation, as a prosthetic material for reinforcing body tissue, or
Is used to be interposed between body tissues, for example, to prevent adhesion
It can be suitably used as a patch cloth such as a stop film . Hereinafter, the configuration will be described with an example.

[0014]

EXAMPLE In a solvent obtained by mixing trichlorophenol 7 in phenol 10 at a ratio of 7 and dissolving it in 190
After heating at 3 ° C. for 3 minutes, a polyglycolic acid chip having a viscosity (ηsp / c) of 1.5 as measured by cooling to 30 ° C. is melt-spun at 245 ° C. and stretched 1.8 times. 1
A 2-filament, 33 denier polyglycolic acid yarn was obtained. Using an 18 gauge circular knitting machine, this was 45 g / m ²
To obtain a tubular flat knitted fabric. After giving a light needle punch to the circular knitted fabric in the wale direction,
It was cut into a size of 22 × 22 cm. A plurality of nonwoven fabrics having such a configuration are prepared, and firstly, the knitting directions are different, that is, one in the wale direction and one in the course direction are stacked one by one, and needle-punched to form a 4PLY integrated nonwoven fabric. Obtained. In the same manner, three or four non-woven fabrics were stacked and needle-punched under the same conditions as above to obtain nonwoven fabrics of 6PLY and 8PLY.

[0015] The above components are further treated at 100 ° C and 18 ° C.
Hot press under the condition of 0 kg / cm ² for 10 minutes
It was of the prosthesis. Prosthesis of the present invention constructed as described above had the performance shown in Table 1. In the control section in Table 1, two nonwoven fabrics were superimposed so as to have the same knitting direction, and 4PLY was obtained. Further, the tensile strength and elongation in the table were set to a size of 4 × 50 mm for the sample, and this was measured using an Instron type tensile tester to obtain a distance between chucks of 2 mm.
0 mm, measured at a pulling speed of 100 mm / min.

[0016]

[Table 1]

[Evaluation of Degradability] The 4PLY suture prosthetic material of the present invention was immersed in a physiological saline solution at 37 ° C., and the strength reduction due to hydrolysis was measured. The results are shown in Table 2, where after 7 days, the strong decrease began,
Although the strength decreased to about 20% of the initial strength on the 14th day, this function does not hinder practical use at all.

[0018]

[Table 2]

[Evaluation of Reinforcement Efficacy] Four adult dogs, each weighing 7 to 15 kg as experimental animals, were intramuscularly injected at a dose of 0.4 cc / kg each of Ketalal and Ceractal, and subjected to general anesthesia. The cervical trachea of such an adult dog was cut between the 7th and 8th tracheal cartilages, and the sterilized 6PLY prosthetic material of the present invention was applied to both sides of the central and distal ends.
End-to-end anastomosis with thread. At this time, two samples were used for the membrane-like portion and 10 samples were used for the tracheal cartilage portion so as to obtain a full thickness suture.
After transplantation, the animals were sacrificed at 2, 4, 12, and 52 weeks, respectively, and the degradation and absorption of the sample, the loosening of the suture at the anastomotic site, and the degree of dropping into the trachea were observed. As a result, no tissue rupture was observed in each case, and the postoperative course was also good. Further, the prosthetic material was covered with living tissue in the second week, cells and capillaries entered and expanded in the fourth week, and were completely decomposed and absorbed in the twelfth week. At 52 weeks, the end-to-end anastomosis was completely healed without any foreign body reaction.

[Evaluation of Hemostatic Efficacy] Four white rabbits weighing 2.5 to 3.5 kg as test animals were intravenously injected with 0.5 cc / kg of Nembutal, subjected to general anesthesia, and opened to abdomen. A bleeding site having a depth of about 1 cm was formed on both left and right surfaces with a scalpel. The complement binding material of the present invention 8PLY fixed to such sites, compressing and fixed about 3 minutes,
The state of blood absorption and the hemostatic effect were observed. The state in which blood was absorbed by the sample was confirmed by the discoloration of the prosthetic material to reddish brown. Regarding the hemostatic effect, when the wound surface was observed after compression fixation for about 3 minutes, bleeding from the wound surface had stopped.

[Evaluation of Air Leak Prevention Efficacy] After general anesthesia was performed using a mongrel dog weighing 10 kg, a defect (1 cm × 1 cm) was made at three places on the lung surface with an electric scalpel, and the prosthetic material of the present invention 8PLY was used. Cover 4 corners with 4-0 V
It was fixed with cryl yarn. The inside of the thoracic cavity was filled with sterile physiological saline, the lungs were inflated by applying a positive pressure from the respiratory tract, and the state of air leakage from the sample at the operation site was observed. As a result, it was confirmed that there was no air leakage from the lungs.

[0022]

As described above, the present invention has an unprecedented function due to the uniform density, thickness, strength, and elongation, and can be suitably used as a prosthetic material in a surgical operation. In particular, when the emphysematous change in the lungs is strong in the elderly and it is difficult to stop air leakage by the conventional pulmonary suturing method, or when the application of such a prosthetic material can reduce the pulmonary squamous site, Appropriately applied to places and means that can reduce postoperative complications, and if it is considered that the operation will be easy in a short time, and also to sutures of soft tissue parts It is also useful in its effect.

──────────────────────────────────────────────────続 き Continued on the front page Examiner Naoko Tsukanaka (58) Field surveyed (Int.Cl. ⁶ , DB name) A61L 17/00

Claims (1)

(57) [Claims] 1. A medical prosthesis characterized in that knitted fabric knitted with a biodegradable and absorbable material is laminated so that its wale direction and course direction are opposite to each other, and this is made into a nonwoven fabric by needle punching. Wood.