JPH05146500A - Polyvinyl alcohol based surgical suture yarn - Google Patents

Abstract

PURPOSE:To obtain the surgical suture yarn which is inexpensive and has excellent biocompatibility and handling property by forming polyvinyl alcohol(PVA) based fibers having respectively specific tensile strength, tensile breaking elongation, knot strength and single fiber fineness into braided yarn and thereby forming the surgical suture yarn. CONSTITUTION:The surgical suture yarn consisting of the PVA based fibers is formed by forming the PVA based fibers satisfying various specific conditions as the braided yarn. The tensile strength of the PVA based fibers is set at <=6g/d, the tensile breaking elongation at <=7% and the knot strength at <=3g/d, respectively. The single fiber fineness thereof is set at <10 denier. The braided yarn is constituted of sheath yarn consisting of, for example, 8 times number and core yarn consisting of half this number. As a result, the suture yarn which is inexpensive, has the excellent biocompatibility, is resilient to prevent the slip off of the suture yarn from each other even with slight ligature, and has the excellent handling property equiv. to the handling property of the suture yarn made of silk yarn is obtd.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surgical suture made of polyvinyl alcohol (hereinafter abbreviated as PVA) fiber.

It is difficult to quantify the quality of suture handling because it depends greatly on the subjectivity of the operator who uses it, but in general, the suture has a high knot holding power and is flexible, and It is said that the higher the strength, the better the handling property. Of the surgical sutures currently used in clinical practice, silk sutures are flexible and have excellent knot holding power, so when the operator ties them up, they tend to be tight, so-called handling characteristics are good. Most preferred because there is It is considered that the excellent knot holding power of the silk thread is due to the fact that the fiber surface of the silk thread is scaly and thus the frictional force between the fibers is high.

However, the suture made of silk thread is not only inexpensive, because it has a high price of silk thread, a large variation due to natural fiber, an unstable supply, and a poor biocompatibility. Therefore, there is a strong demand for a suture made of synthetic fiber which is excellent in uniformity, can be stably obtained, and is excellent in biocompatibility.

Further, since the silk suture has a tensile strength of only about 3 to 4 g / d, it has been difficult to apply it to a site where high tensile strength is required. For this reason, sutures made of polyester fibers or polypropylene fibers are made. However, since these fibers have a breaking elongation of 20% or more, the sutures are stretched at the time of tying and the handleability is poor. There was a problem.

Further, sutures made of high-strength polyethylene fibers or aramid fibers have been tried, but polyethylene fibers have a low frictional force between fibers and thus have a low knot holding power and a poor handling property. there were. Aramid fiber is inferior in biocompatibility and has a fatal defect when used as a suture.

In order to solve these drawbacks, the present inventors have proposed in Japanese Patent Application No. Hei 2-257998 a surgical suture having a high tensile strength and a high knot holding force, which is made of PVA fiber having good biocompatibility and high strength. Suggested a thread. This suture is applied to a site requiring high tensile strength such as large abdominal wall, large blood vessel, heart, transplant of artificial organ, tendon, ligament, bone marrow, periosteum, etc., but the results of further study by the present inventors Although this suture certainly has high tensile strength, it has been found that it has a high knot holding power due to its lack of flexibility, but it has a drawback of being poor in handling as compared with a silk suture.

[0007]

Although sutures made of various synthetic fibers have been tried as described above, they have not been put into practical use due to the above problems.
Therefore, the present invention is an inexpensive PV with excellent biocompatibility.
It is a technical object to provide a surgical suture made of an A-based fiber and having excellent handleability comparable to that of a silk suture.

[0008]

Means for Solving the Problems As a result of intensive studies for solving the above problems, the present inventors have found that a PVA-based fiber having a single yarn fineness of less than 10 denier is used as a fiber constituting a suture. The present invention has been achieved by discovering that a suture having a high knot holding power comparable to that of a silk suture and good handling properties can be obtained.

That is, the present invention has the following structures. Polyvinyl alcohol having a tensile strength of 6 g / d or more, a tensile elongation at break of 7% or less, a knot strength of 3 g / d or more, and a single yarn fineness of less than 10 denier made into a braided polyvinyl. Alcohol surgical suture.

The present invention will be described in detail below. The tensile strength of the PVA-based fiber for forming the PVA-based surgical suture of the present invention needs to be 6 g / d or more, preferably 8 g / d or more. When the tensile strength is lower than 6 g / d, the strength as a suture thread is lower than that of a silk suture thread, which is not suitable. Next, the single yarn fineness of the PVA-based fiber for forming the PVA-based surgical suture of the present invention is 1
It is very important that it is less than 0 denier.

That is, since the PVA fiber has the highest initial elastic modulus among general-purpose fibers, the rigidity of the fiber is high. Therefore, when the single yarn fineness is high, the formed suture thread also has high rigidity, and there is a problem of handling property that it is difficult to bind when tied. In order to solve this point, a method of lowering the initial elastic modulus of the fiber can be considered, but in this case, the breaking elongation is increased, which causes a new problem that the feeling of knotting becomes poor.

As a result of investigations aimed at solving this problem, the present inventors have found that reducing the single yarn fineness is extremely useful for improving flexibility, and have reached the present invention. As a result, it was found that by setting the single yarn fineness to less than 10 denier, it is possible to impart appropriate flexibility as a suture. The single yarn fineness is preferably less than 8 denier, more preferably less than 6 denier, and even more preferably less than 4 denier.

P for forming the surgical suture of the present invention
The tensile breaking elongation of the VA fiber needs to be 7% or less. A tensile elongation at break of more than 7% is not suitable because the seam is displaced. The initial elastic modulus and knot strength of the PVA-based fibers forming the surgical suture of the present invention are not particularly limited, but are preferably 120 g / d or more and 4 g / d or more, respectively.

As a method for producing such a braid made of PVA type fiber, a known method can be adopted. For example, it can be manufactured as a braid composed of a sheath yarn composed of a multiple of 8 and a core yarn composed of about half of the sheath yarn.

The method for producing the PVA-based fiber for producing the PVA-based surgical suture of the present invention is not particularly limited, but the dry / wet spinning method or gel spinning method described in Japanese Patent Application No. 1-122030 can be used. It is manufactured according to the optimum conditions.

It can also be produced by a known wet spinning method, but in this case, it is preferable not to use boric acid or borate as an additive, and it is preferable that the so-called acetalization treatment is not carried out. It is preferable in terms of sex.
For example, an approximately 16% aqueous solution of PVA having a degree of polymerization of preferably 1500 or more, and preferably having a saponification degree of 99 mol% or more is contained at a temperature of 20 ° C. containing 350 g / l of sodium hydroxide from a spinneret having a pore diameter of 0.08 mmφ. Wet spinning in the coagulation bath, and the coagulated filaments obtained are subjected to treatments such as neutralization, moist heat, water washing, and drying according to a conventional method, and then drawn in a hot air bath set at 230 to 250 ° C. It can be manufactured.

[0017]

The surgical suture of the present invention has extremely excellent knot holding power and handleability because the PVA-based fiber, which is relatively inexpensive in yarn production and excellent in biocompatibility, is used as a constituent element, This is because the flexibility of the suture can be increased by setting the single yarn fineness to less than 10 denier. Furthermore, since PVA-based fibers have fine irregularities on the fiber surface in the direction perpendicular to the fiber axis, the frictional force between the fibers is high, and there is a concern that the sutures will slip through even if tied only once or twice. It is a surgical suture with extremely excellent knot holding power.

[0018]

EXAMPLES Next, the present invention will be specifically described by way of examples.

Example 1 1 of PVA having a degree of polymerization of 1700 and a degree of saponification of 99.9 mol%
A 6% by weight aqueous solution containing 350 g / l of sodium hydroxide from a spinneret having a hole diameter of 0.08 mm and a hole number of 40.
Wet spinning was carried out in a coagulation bath at 0 ° C. and taken up at a speed of 5 m / min. The obtained coagulated yarn was subjected to treatments such as neutralization, moist heat and washing with water, and then dried. During this period, three-fold spinning and drawing was performed. The dried yarn was further stretched 4 times in a hot air heating bath having an internal temperature set to 235 ° C., and PV of 100 d / 40 f was obtained.
A fiber bundle was obtained. This PVA fiber bundle has a tensile strength of 7 g / d
It had a tensile elongation at break of 6.5% and a knot strength of 5.0 g / d.

Furthermore, four PVA fiber bundles (400 d /
160 f) was used as a core thread and 8 pieces as a sheath thread to form a braid, and a suture thread having a diameter of about 0.6 mm was produced. This suture is very flexible and has a knot holding force of 4.3 g / d.
No slippage at the knot was observed.

Further, this suture was implanted under the dorsal skin of an experimental rat for 12 weeks and then taken out to measure its strength. The strength was 85% of the initial strength, which was extremely excellent. It retained its performance.

[0022]

Comparative Example 1 A suture was obtained by forming a braid with a commercially available high-strength polyethylene fiber in the same manner as in the example. This suture is
The flexibility was insufficient, and the knot holding force was measured. As a result, the knot portion began to slip when a stress of only 1.2 g / d was applied, and finally the knot was completely unwound.

[0023]

INDUSTRIAL APPLICABILITY The suture thread of the present invention is inexpensive, excellent in biocompatibility, and flexible, and there is no fear that the suture threads will slip out even when tied only once or twice, and the suture thread made of silk thread It has excellent handling properties comparable to.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Masatsugu Mochizuki, 23 Uji Kozakura, Uji City, Kyoto Prefecture Unitika Central Research Institute (72) Inventor Kunihiko Takagi 23, Uji Kozakura, Uji City Kyoto Prefecture Unitika Stock Company Central Research In-house

Claims (1)

[Claims] 1. A braid made of polyvinyl alcohol fiber having a tensile strength of 6 g / d or more, a tensile breaking elongation of 7% or less, a knot strength of 3 g / d or more, and a single yarn fineness of less than 10 denier. A polyvinyl alcohol surgical suture characterized by: