JPS63122459A - Mesh for breast wall - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to the provision of a mesh for use in repairing defects in the chest wall during surgery.

(Prior art) Currently, the reinforcing material for chest wall repair that is widely used in clinical practice is Marlex Mesh (C, R
.

(manufactured by Bard, Inc., trade name).

However, although these conventional devices are strong enough to perform their functions, they are not absorbable by the body, so even after the chest wall is reconstructed, living tissue invades and remains in the body as a foreign object, causing considerable tissue reactions. It has its drawbacks. It is also known to inhibit chest wall growth after chest wall reconstruction when applied to growing children.

(Problems to be Solved by the Invention) The present invention provides a chest wall mesh that is biodegradable and absorbable, has excellent biocompatibility, and
Since it does not remain in the body for a long time after fulfilling its function, it does not cause a foreign body reaction, and it has an unparalleled excellent effect especially when applied to growing children.

(Means for Solving the Problem) However, its structure is characterized by the fact that it is composed of a fabric that is knitted and woven in a porous manner using bioabsorbable synthetic polymer fibers. It is characterized in that it is made of biodegradable and absorbable polymers such as polyglycolic acid or polylactic acid, or a copolymer thereof.

(Function) Examples of surgical treatments in the thoracic surgery field to which the mesh of the present invention is suitably applied include the following.

In other words, chest wall abnormalities include rib and sternum abnormalities, pectus excavatum, pigeon chest, and chest wall hernia, which are congenital.

Or these acquired injuries, or those that cause serious damage to the chest wall due to a traffic accident or work-related accident. This is called a fluctuating thorax, which causes serious respiratory and circulation disorders due to the lack of support from the thorax, as well as inflammation of the chest wall and tumors of the chest wall.In the case of such inflammation, appropriate chemotherapy can be performed, but in cases that are difficult to treat, auxiliary cartilage is needed. It is necessary to perform excision or fistula resection, and radiation therapy may also be performed in the case of tumors, but surgical resection is considered the best treatment for most localized chest wall tumors; In all cases, surgical intervention is required.

The mesh used for this purpose does not require any high mechanical strength compared to the bone fixation devices used in the orthopedic field, and it is meaningful just to allow tissue to enter and serve as a stepping stone until the resected chest wall is reconstructed. Therefore, it is possible to use as desired, ranging from polyglycolic acid which is decomposed and absorbed in 2 to 3 months to poly-L-lactic acid which is decomposed and absorbed in 18 to 24 months.

In addition, it is applied by sewing a mesh cut to the size of the defect from the thoracic cavity side, and after the material has been removed, it is gradually absorbed into the body and remains in the body as a foreign material for a long time. It is extremely ideal for use in children because it does not stay in place and does not hinder the growth of the chest.

Hereinafter, its configuration, application effects, etc. will be explained by giving examples.

[Production Example 11 Viscosity (ηs
24 polyglycolic acid chips with a p/c) of 1.5
It was melt spun at 5°C and drawn to obtain a 120 denier yarn with 6 filaments. Combine 4 of these yarns to make an S twist of 507/
After applying M, heat treatment was performed at 105° C. for 3 hours. This about 4
A 14-gauge tricot knit using 80 denier polyglycolic acid was used to make a chest wall mesh with a knitting density of 288 g/rn'.

The chest wall mesh thus obtained has a moderate waist,
It received excellent evaluations as shown below.

[In vivo degradability evaluation 1 The mesh constructed as described above was cut into a size of 1 cm x 5 cm, and implanted under the skin of a domestic rabbit for 1 week, 2 weeks,
After 2 months, the layer was removed, and the decomposition and absorption rate of the material and tissue reaction were evaluated in comparison with a commercially available Marex mesh (soft) made of polypropylene.

Regarding the tissue reaction, although capillary invasion was observed in the Marex mesh after 2 weeks, it was hardly observed in one case, indicating that there was little inflammatory reaction. After two months, the mesh in this case had melted and disappeared.

In addition, as shown in Table 1, the 1-strength retention rate maintained sufficient strength to meet the initial and postoperative needs, but then rapidly decreased due to decomposition.

In contrast, the conventional product maintained a consistently low strength.

Table 1 (Unit = Kgf) [Practical Evaluation] The ribs on the right chest wall of an adult mongrel dog were cut, and the mesh constructed as described above was sewn from the inside of the chest cavity.

In order to observe the condition of the sutured area, the experimental dogs were sacrificed at 3 weeks, 1 month, 2 months, and 3 months after the operation, and the condition of the suture area was observed. By the third week, tissue had already entered and the chest wall that had been removed was being rebuilt. A month later, the shape of the eye of the mesh can still be seen, but the strength of the mesh itself was close to zero.

Two months later, the battlements had been rebuilt in near-perfect condition. There was little tissue reaction to the surrounding tissue during the decomposition process, and after three months, the mesh had been decomposed and absorbed, and the shape of the mesh was no longer recognizable.

[Production Example 2] Poly-L-lactic acid with a molecular weight of 1,410,000 was heated at 230°C.
The yarn was melt-spun and drawn (6 filaments) to obtain a 120-denier yarn. Four of these yarns were twisted, S-twisted at 50↑/M, and then heat treated at 105° C. for 3 hours.

Using this approximately 480 denier poly-L-lactic acid system,
A mesh for battlements was obtained with a gauge tricot knitting and a knitting density of 200 g/rr/.

This was evaluated as 1 in the same way as the above in vitro degradability evaluation
It was cut to a size of cm x 5 cm and implanted subcutaneously in a domestic rabbit, and after 1 month, 6 months, 12 months, and 24 months, the layer was removed and the decomposition and absorption rate of the material and tissue reaction were observed.

As a result, some angiogenesis was observed after 1 month, but thereafter there was very little inflammatory reaction and the affinity was good.

In addition, its strong retention rate is 5.5Kgf, 4.8KgF, 3.3 after 1 month, 6 months, and 12 months.
Kgf, 1. IKgf.

However, after 24 months, it became O and was decomposed and absorbed into one body, and the shape of the mesh was completely unknown.

(Effects of the Invention) As described above, the present invention has excellent features not found in the prior art, and can be very suitably applied to prosthesis of a chest wall resection.

Although polyglycolic acid and poly-monolactic acid are described as nine examples, meshes made of copolymers of both are also possible.
Degradability can be controlled by controlling these compositions, degree of polymerization, heat treatment conditions, etc.

Further, the weaving structure is not particularly limited, but it is preferable for the density to be in the range of 200 to 300 g/g for the purpose of application.
If this is less than 200g/m", there is a strong shortage,
It is not suitable because it has no waist, and on the other hand, if it exceeds 300g/m, it becomes too hard and irritates the affected area when applied, which is undesirable.Also, the woven structure is a tricot that does not cause fraying at the cut ends. Knitting is particularly preferred, and interlacing knitting and weaving of polyglygolic acid, poly-L-lactic acid, or a copolymer of both is of course also possible.

As described above, the present invention is an excellent chest wall mesh that has never existed before.

Claims (1)

[Claims] 1. A chest wall mesh comprising a knitted or woven fabric made of biodegradable and absorbable polymer material. 2. The chest wall mesh according to claim 1, wherein the biodegradable and absorbable polymer is polyglycolic acid or polylactic acid. 3. The chest wall mesh according to claim 1, wherein the biodegradable and absorbable polymer is a copolymer of polyglycolic acid and polylactic acid.