JP3366946B2 - Surgical suture - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a surgical suture used for suturing a surgical site in a surgical operation.

Conventional technology and its problems Conventional surgical sutures are made of fiber materials such as natural fibers such as silk and synthetic fibers such as polyamide, polyester, polypropylene, etc. Especially, monofilament yarns of these materials are excellent in tissue passing property. It is widely used from the standpoint of not damaging the skin and causing no inflammation.

However, the monofilament yarn is inferior in ligation and stability of the knot, and the knot is easily loosened after the operation, which causes various postoperative troubles. This tendency is particularly likely to occur when polypropylene having a high Young's modulus is used. In Japanese Utility Model Publication No. 53-52309, it is pointed out that the above-mentioned defect is caused by the circular cross section of the monofilament yarn, and as a means for eliminating this defect, the monofilament having an irregular cross section having a plurality of irregularities. A suture consisting of a thread is described.

However, the monofilament yarn having such a cross-sectional shape is inevitably insufficient in strength stability such that the structure has a complicated structure and the strength of each part of the yarn is uniform, and a portion having weak strength is partially generated during operation and There is a concern that post-operative troubles will occur and that bacteria will easily propagate.

DISCLOSURE OF THE INVENTION An object of the present invention is to provide a suture made of a monofilament thread which is excellent in stability of ligatures and knots, excellent in strength stability and low in bacterial contamination.

Means for Solving the Problems The present invention is a surgical suture characterized by comprising a monofilament yarn whose cross-sectional shape perpendicular to the longitudinal direction is an ellipse having an ellipticity of 5 to 20% represented by the following formula.

A: major axis of ellipse (mm) B: minor axis of ellipse (mm).

According to the study by the present inventor, the suture thread of the present invention, which has an elliptical cross-section in the direction perpendicular to the longitudinal direction of the monofilament thread and has an ellipticity defined by the above equation of 5 to 20% in a specific range, It was found that when the sutures are sewn together, the contact area at the knot becomes large and the friction coefficient becomes large at the same time, making it difficult for the knots to loosen or unravel, resulting in remarkable ligation and knot stability. Was done. That is, with the conventional monofilament thread which is a perfect circle, it was still easy to loosen or untwist even after the knot was made 2-3 times after the operation, but with the suture of the present invention, the untying knot can be formed by the first knot. The second knot secures it 2
A very stable knot is formed with a single ligation. In fact, when observing the knot by the suture of the present invention with a magnified photograph in comparison with a conventional suture having a perfect circular cross section, the latter knot is rounded and raised, whereas the knot by the former is a flat triangle. It is shaped like a rice ball, and it can be seen that the contact area between the yarns is large. In addition, the left and right thread ends become close to a straight line through the knot, facilitating thread handling during surgery, and not damaging the surrounding tissue or giving irritation when both thread ends are removed after surgery. . Moreover, the suture of the present invention not only has the characteristics of a monofilament thread that is excellent in tissue passage, does not damage the skin and is less likely to cause inflammation, and does not have a complicated uneven shape, so that the strength of each part can be easily increased. It has the advantages that it can be made uniform and has excellent strength stability, and that there is little risk of bacteria and the like breeding.

Furthermore, according to the research conducted by the present inventor, the suture of the present invention is excellent in ligation stability as described above, and therefore its elongation, especially when the knot is broken, is higher than that of a conventional suture having a perfect circular cross section. It was found that it could be great. That is, if a conventional suture having a perfect circular cross-section has a large elongation at the time of breaking the knot, the disadvantages of loosening and unwinding the knot are further promoted.
Therefore, the value has its own limit,
It was difficult to make it larger than 10%. However, if the elongation at break of the knot is low, the elongation of the yarn itself is insufficient, and there is a problem that the yarn is likely to break at the time of the knot or after the knot. On the other hand, according to the present invention, the elongation of the thread at the time of breaking the knot can be increased to 10% or more, so that the operation can be easily performed without cutting the thread during the operation, and the thread is cut after the operation. There is no fear. The large growth means
It means that the Young's modulus is low, and it is difficult for the package to curl. The knot is tightened as the nodule feels like it is eating. Moreover, the knot becomes tighter due to the return of the stretched yarn. The elongation at break of the knot portion is preferably 30% because if the elongation is too large, the yarn will be too elongated and the knot will not be tightened. Particularly preferred elongation at break of knot is 12
-25%. In this specification, the elongation at the knot fracture is
A surgical knot is made according to the tensile strength test method of "Plastic suture standard" (December 18, 1970, Ministry of Health and Welfare Notification No. 444), and then both ends of the sample are loaded through the knot using a tensile tester. It is expressed as a percentage of the elongation of the yarn when the yarn is cut and the yarn is cut (the following formula).

C: original length of thread D: length of thread at the time of cutting The suture of the present invention is characterized in that the ellipticity of the ellipticity is 5 to 20% as a cross-sectional shape, but its preferable ellipticity is
10-15%. When the ellipticity is less than 5%, the effect of being close to a true circle and being an ellipse is not sufficiently expressed, and when it exceeds 20%, it becomes too flat and the tissue is easily damaged, and it is difficult to pass through the needle hole when the needle is attached. is there.

The suture of the present invention may be composed of various fiber-forming polymers. For example, natural fibers such as silk and synthetic fibers such as polyamide, polyester and polypropylene are used. Among these, those made of polypropylene had a high Young's modulus and thus had a strong tendency to loosen or untwisted after the operation.However, according to the present invention, polypropylene is advantageous as a material without such a problem. Can be used for In particular, polypropylene having an isotactic structure can be preferably used.

A preferred embodiment of the suture of the present invention includes a suture in which a lubricant is uniformly mixed in the monofilament yarn constituting the suture. In the conventional sutures having a perfect circular cross section, the knot portion is easily loosened or unraveled, so that a lubricant that promotes the tendency is not mixed with the monofilament yarn. It is known that the surface of the suture is coated with a lubricant, but naturally there is a problem that the surface is slippery and the stability of the knot is poor, and the durability of the lubricant is poor and adhesion unevenness occurs. However, the suture of the present invention has an elliptical cross section having a specific ellipticity, and based on that, friction resistance can be increased and loosening and unraveling of the knot can be reliably prevented. Therefore, a lubricant is kneaded in the polymer as necessary. There is an advantage that it can be compounded and mixed to increase the lubricity of the thread and facilitate the formation of the knot during the operation. Moreover, since the lubricant is kneaded into the polymer, it has the advantage of being durable over time and being homogeneous.

Lubricants used for the above purpose in the present invention include fatty acid calcium such as calcium stearate, fatty acid amide such as stearic acid amide, organopolysiloxane,
Examples thereof include polyethylene, which can be safely used for living bodies. Of these, calcium stearate is particularly preferable. When kneading, the blending amount is preferably about 0.05-0.5% by weight with respect to the polymer. Various methods can be applied to knead the lubricant into the polymer. For example, a powdered lubricant may be mixed with the melted polymer to form a chip with a pelletizer. The lubricant is preferably kneaded and blended with the polymer, but it does not prevent application by coating or the like.

The surgical suture of the present invention is spun using a nozzle having a predetermined elliptical cross-sectional diameter, and spinning conditions such as an air gap when it is easily retroactively deformed using a circular nozzle.
It can be easily produced by an appropriate method such as spinning while changing the cooling temperature and the length of the cooling zone.

Since the surgical suture of the present invention has the above-mentioned effects, it can be widely used as a suture in various operations, and is particularly preferably used for blood vessel suturing and cardiac surgery.

Example MFI 3.7 (230 ° C., 10 minutes) isotactic polypropylene was spun under the following conditions to obtain a suture for vascular suture of the present invention of No. 8-0 size having an ellipticity of 7.8%. The performance is shown in Table 1.

Spinning temperature 235 ℃, nozzle diameter 0.35mmφ, discharge speed 2.60m
/ Min, air gap 5mm, cooling temperature 40 ~ 45 ℃, winding speed 14m /
The fiber was spun for 5 minutes and stretched 5.5 times at a stretching temperature of 150 ° C. The obtained suture had an ellipticity of 7.8%. Table 1 also shows the performance of the commercial products manufactured by N company.

After forming the knot, knot stability was evaluated by applying friction to the knot under a load of 60 g for 5 minutes and observing the state of loosening (looseness), and judging according to the following criteria.

○ No loosening △ Loose a little × Loose The present invention does not loosen. The strength also shows a relatively high value. Moreover, when this was actually provided to a plurality of doctors and the evaluation was requested, it was easy to tie it, and it was highly evaluated that it was difficult to untie.

In addition, in the above, the strength and elongation were measured at the time of cutting and measured according to the JIS measurement method. The knot strength and the elongation are the results measured according to the above-mentioned "plastic suture standard".

─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Kazuo Otsuki 2-13-4 Yushima, Bunkyo-ku, Tokyo Matsuda Medical Industry Co., Ltd. (72) Inventor Takusei Saito 38 Nishibabashita, Aono-cho, Ayabe-shi, Kyoto ―1 Gunze Co., Ltd. Kyoto Research Laboratory (72) Inventor Koji Nishitani 38-1 Nishibabashita, Aonomachi, Ayabe City, Kyoto Prefecture -1 Gunze Co., Ltd. Kyoto Research Laboratory (56) References JP-A-61-85947 (JP, A) ) JP-A-59-40861 (JP, A) JP-A-61-76163 (JP, A) Sekikai 58-68869 (JP, U) JP-B 45-2332 (JP, B1) JP-B 53- 14649 (JP, B1) (58) Fields surveyed (Int.Cl. ⁷ , DB name) A61L 17 D01F 6 D02G 3

Claims (4)

(57) [Claims] 1. A monofilament yarn whose cross-sectional shape perpendicular to the longitudinal direction is an ellipse having an ellipticity in the range of 5 to 20% represented by the following formula, and having an elongation at break of at least 10%. A surgical suture, characterized in that Ellipticity (%) = [(AB) / A] × 100 A: Elliptical major axis (mm) B: Elliptical minor axis (mm) 2. A monofilament yarn whose cross-sectional shape perpendicular to the longitudinal direction is an ellipse having an ellipticity in the range of 5 to 20% represented by the following formula, and a lubricant is incorporated in the monofilament yarn. A surgical suture characterized by: Ellipticity (%) = [(AB) / A] × 100 A: Elliptical major axis (mm) B: Elliptical minor axis (mm) 3. The surgical suture according to claim 1, wherein the monofilament thread contains a lubricant. 4. The surgical suture according to claim 1, wherein the polymer constituting the monofilament thread is polypropylene.