JPS61213047A - Use of living body decomposing and absorbing medical device and set therefor - 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 Industrial Application] The present invention relates to a method of using a medical device formed from a polymer having lactic acid and/or glycolic acid as a main constituent unit.

Furthermore, it relates to a set for direct use in implementing such a method.

[Conventional technology]

Biodegradable and absorbable materials are widely used as sutures, but in recent years, their application to other uses is also being considered. For example, Japanese Patent Publication No. 58-29105 discloses a felt hemostatic material, and Japanese Patent Application Laid-Open No. 59-97654 discloses a bone fixing device. Although some of the materials used in these materials are naturally derived, such as collagen, synthetic polymers are attracting attention because of their stable quality and ease of sterilization.

(Problems to be solved by the invention) Fibers and films made from biodegradable and absorbable materials are flexible, so there is no particular problem, but rigid ones such as bone fixing devices can change their shape freely. Metal products such as stainless steel, which have traditionally been used as bone fixation devices, can be deformed to some extent by applying strong force, so it is difficult to finely adjust the final shape. However, synthetic polymers cannot do this, so there is a problem that various shapes and sizes must be prepared depending on the condition of the part of the body where they will be used.Moreover, Even if a wide variety of shapes are available, it is impossible to perfectly fit each patient, which may cause problems in treatment.

(Means and effects for solving the problem) As a result of various studies on biodegradable and absorbable polymers, the present inventors have found that certain polymers exhibit high rigidity at room temperature and temperatures around body temperature6.
Nevertheless, we have discovered that it can be relatively easily deformed by just a little heating. The present invention has been made based on this knowledge.

In the present invention, a polymer having lactic acid and/or glycolic acid as a main structural unit is used as the polymer.

The polymer may be a homopolymer or a copolymer. Further, other components may be copolymerized in small amounts. These polymers are disclosed in Japanese Patent Publication No. 41-2784, Japanese Patent Publication No. 434192, and Japanese Patent Application Publication No. 48-4871.
It can be manufactured by a known method described in Publication No. 7 and the like.

The above-mentioned polymers have enough rigidity to be used for bone fixation at temperatures below 50°C, but at temperatures above 50°C they soften and become easily deformed. Changes can be made. The heating temperature should be 50°C or higher, but if it is too high, polymer deterioration becomes a problem and the risk of burns increases.
It is necessary that the temperature is 120°C or lower, preferably 60°C.
-100°C. The heat treatment may be carried out in air, but it can also be carried out in water or other liquid.

Generally, thermoplastic polymers do not soften unless heated to a temperature close to their melting point, but even though the above-mentioned polymer has a melting point above ℃, it does not soften at temperatures much lower than that. This is something that cannot be predicted.

As mentioned above, the present invention uses lactic acid and/or
Alternatively, a polymer whose main constituent unit is glycolic acid is selected, and when a rigid medical device made of such a polymer is fixed to a living body, the device is heated to 50 to 120°C to soften it and adjust its shape. This is a method of using a biodegradable and absorbable medical device, which is characterized by carrying out the following changes.

In order to carry out such a method, a means for heating the medical instrument, that is, a heating device is required, but it is preferable to use an electrical heating device because the temperature can be easily controlled.

〔Example〕

Example 1° D, L-5 cutide (cyclic condensate of D, L4 acids)
160 at a reduced pressure of 108 MHg in the presence of 0.03% by weight tin octylate and 0.01% by weight lauryl alcohol.
The molecular weight was 4500 by ring-opening polymerization.
A lactic acid polymer of G was synthesized. The obtained polymer was injection molded to have a width of 23 mm and a thickness of 0 mm. A plate with a length of EIIX of 103 was made. This plate-like material was rigid at room temperature and could be used for bone fixation, but when immersed in hot water at 60°C, it softened and could not be easily deformed by hand. Ta.

A part of the sample obtained above was aseptically implanted under the skin of the back of a rabbit (above the dorsal fascia), sacrificed 2 months after breeding, the implanted area was incised, and the condition of the sample was observed. did.

In addition, the surrounding tissue that was in contact with the sample was examined histopathologically. As a result, the surface of the sample became cloudy and decomposition had begun, but no findings such as inflammation or vascular hyperplasia were observed in the surrounding tissue.

Example 2゜Example 1. In the same manner as above, 80 parts by weight of D,L,-lactide and 20 parts by weight of glycolide (a cyclic condensate of glycolic acid) were reacted to obtain a lactic acid-glycolic acid copolymer. The obtained polymer was injection molded to have a width of 23 x thickness of 0.53.
A plate-like object with a length of 103 was made. This plate-like material was rigid at room temperature, but when heated to 70° C. in air, it could be easily deformed by hand.

Example 8 In the same manner as in Example 1, glycolide was reacted and colored under reduced pressure to obtain a glycolic acid polymer. The obtained polymer was injection molded to make a plate-like product having a width of 2 cm, a thickness of 0.53 cm, and a length of 10 cm. This plate-like material had rigidity at room temperature, but at 0°C
It could be easily deformed by immersing it in hot water.

〔Effect of the invention〕

According to the present invention, the shape of a biodegradable and absorbable medical device formed from a synthetic polymer can be easily adjusted or changed when used in a living body, so that it is possible to easily adjust or change the shape of a biodegradable and absorbable medical device formed from a synthetic polymer. There is no need to prepare. Moreover, since it can be adjusted to the optimal shape for the living body, it has the advantage of increasing the therapeutic effect.

Claims (5)

[Claims] (1) When fixing a rigid medical device made of a polymer whose main constituent units are lactic acid and/or glycolic acid to a living body, the device is heated to 50 to 120°C to soften it and adjust its shape. or a method of using a biodegradable and absorbable medical device. (2) The method according to claim 1, wherein the medical instrument is a bone fixation device. (3) A biodegradable and absorbable medical instrument set comprising a rigid medical instrument made of a polymer whose main constituent units are lactic acid and/or glycolic acid and a heating means. (4) The set according to claim 3, wherein the medical instrument is a bone fixation device. (5) The set according to claim 3 or 4, wherein the heating means includes temperature control means.