JP2011206096A - Suture reinforcing material for medical use - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a suture reinforcing material for medical use formed of bioabsorbable polymeric nonwoven fabric which has no direction with respect to the elongation of the material or the strength necessary for cutting.SOLUTION: Pieces of knitting fabric which is made from bioabsorbable fibers are layered so that the knitting directions may make an angle of 45°, i.e. the direction of wales and the direction of courses of knitting fabric may make an angle of 45° for every piece or they may make an angle of 45° when several pieces are layered and are punched to form nonwoven fabric. By this method, the suture reinforcing material for medical use which has no direction with respect to the elongation or the strength necessary for cutting can be formed.

Description

The present invention relates to a suture suture material for medical purposes for the purpose of reinforcing a tissue, preventing air leakage, and hemostasis in thoracic surgery, digestive surgery and the like, which is performed under an endoscope.

For example, in the operation of respiratory system tissue such as the lung, a strong force may be applied to the sutured anastomosis, which may damage the tissue, causing air leakage, bleeding, and the like. Also, in the operation of a real organ such as a digestive organ, the same problem as described above occurs when a fragile biological tissue is sutured with tension.

In order to solve such a problem, the present applicant does not remain as a foreign substance in the body after healing in Japanese Patent Application Laid-Open No. 63-95041 (Patent Document 1) and Japanese Patent Application Laid-Open No. 5-76586 (Patent Document 2). Further, a suture reinforcement material made of a biodegradable and absorbable material that does not cause granulation, scarring or fistula is disclosed.

2. Description of the Related Art In recent years, endoscopic surgery with less burden on patients is frequently performed in surgery in the thoracic surgery region and abdominal surgery region. In endoscopic surgery, several tubes called ports are inserted into the body and surgery is performed using a dedicated surgical tool. In the case of conventional thoracotomy and laparotomy, it is possible to operate under a wide field of view while looking at the operative field, and it is particularly problematic even if the medical device such as the suture reinforcement used has directionality. It never happened. However, when performing an operation under an endoscope, the visual field is limited to the monitor screen of the endoscope. Further, since the medical device is operated while looking at the monitor in a very narrow space, if the suture reinforcement or the like has a direction, the operation becomes very difficult. Therefore, it is desirable that the medical device such as a suture reinforcing material is a uniform material having no directionality in the strength and elongation.

In particular, since the suture reinforcement is to be cut together with the organ, it is not preferable that there is a strong direction necessary for cutting with the blade, and if the elongation is different, the material is stretched only in a specific direction by the blade. This is not preferable.

JP-A-63-95041 Japanese Patent Laid-Open No. 5-76586

The present invention provides a medical suture reinforcement material made of a bioabsorbable polymer nonwoven fabric that does not have the strong directionality necessary for the elongation and cutting of the material.

In the present invention, the knitted fabric knitted with the biodegradable absorbent material is laminated so that the knitting direction, that is, the wale direction of the knitted fabric and the course direction are at an angle of 45 degrees, and the nonwoven fabric is formed by needle punching. The present invention relates to the provision of a medical prosthetic material characterized in that

The present invention provides a medical prosthetic material in which knitted fabrics knitted with a biodegradable absorbent material are overlapped and made into a non-woven fabric by needle punching, so that the knitting directions overlap at an angle of 45 degrees. Directional fabrics and wale direction fabrics are alternately stacked and integrated, so that, regardless of the direction, the thickness, density, strength, and elongation are uniform throughout, and medical prosthetics that meet the above objectives Is obtained. That is, when expressing the knitting direction of a knitted fabric that is generally knitted, a horizontal line of a formed stitch (loop) is called a course, and a vertical line is called a wale. When superimposing and integrating, the courses or wale directions are not overlapped so that they coincide with each other, but they are superimposed and integrated so that the directions are at an angle of 45 degrees. is there.

If the same knitting direction is overlapped, directionality will occur in the stretch, and it is possible to apply it to a technique that requires such properties, but in general it causes stress and distortion. A configuration of the present invention that has no uniform elongation is desired. For example, when applied to pulmonary stitches or hemostasis of stumps of the liver, if the properties are not isotropic, especially in terms of stretchability, unnecessary stress and strain will be applied to the lungs and liver. There is a possibility of causing it or creating a dead space. Stress and distortion interfere with the normal functioning of the organ, and the dead space becomes the nest of infection.

In particular, in recent years, laparoscopes have been used in abdominal surgery, and thoracoscopes have been used in thoracic surgery, and endoscopic surgery using an endoscope without opening or thoracotomy has increased. ing. In endoscopic surgery, an automatic suturing device is used for tissue excision and suturing. In such an endoscopic surgical technique, when the suture reinforcement material or the like has directionality, it is extremely difficult to confirm the directionality of the material while looking at the monitor with a narrow visual field. Therefore, it can be seen that the cutability and elongation of the suture reinforcing material are substantially equal in all directions.

In this respect, the knitted fabric is laminated at an angle of 45 degrees as the material, and the elongation rate is uniform although the elongation is suppressed by the needle punch. It is suitable because it sometimes has an appropriate buffering action against elongation.

The biodegradable absorbable material constituting the present invention is a synthetic polymer such as fiberized polyglycolic acid, polylactic acid, a copolymer of glycolic acid and lactic acid, paradioxanone, caprolactone, that is, aliphatic polyester. Although these can be exemplified, since these have different decomposition behaviors in vivo, those suitable for the purpose and application can be appropriately selected and used. However, particularly in terms of strength and hydrolysis rate, polyglycolic acid or glycolic acid-lactic acid copolymer is preferred, including that it can be controlled by the processing conditions after the nonwoven fabric is produced.

On the other hand, the material may be knitted using various knitting machines and knitted into an arbitrary structure such as flat knitting, rubber knitting, and warp knitting. A flat knitted fabric that is knitted in a straight line is preferred. In addition, if the knitted fabric knitted in this way is flattened, it becomes a double fabric as it is, and the laminating work becomes easy.

In addition, this non-woven fabric by needle punching is performed so that the knitting direction is at an angle of 45 degrees, that is, the waling direction and the course direction of the knitted fabric are at an angle of 45 degrees for each piece, or plural In a state where the sheets are stacked, the layers are stacked and punched so as to have an angle of 45 degrees, or one or a plurality of knitted fabrics punched in advance are stacked and punched again as described above. This needle punch 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 stacked 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 breaking elongation are 90 to 300 g / mm2, 0.25 to 0.60 mm, 300 to 1200 gf, and 20 to 50%, respectively. In order to obtain such a configuration, for example, a 12-filament yarn of 30 to 35 denier is knitted into a flat knitted structure so as to have a basis weight of 35 to 50 g / m2, and this is knitted. Two to four sheets are stacked so that the directions are different, and needle punching is performed with emphasis on softness in order to avoid irritation to the application site, especially during application.

When making a nonwoven fabric, prepare a knitted fabric that assumes the final use size in advance, or cut the integrated nonwoven fabric into an appropriate size, and if necessary, provide a through hole for passing a needle through it, An example of this invention prosthetic material is comprised.

In addition, for such prostheses for suturing, various treatment agents such as wax, silicon, beeswax, polyoxyethylene block and polyoxypropylene are used to improve the passage of the suture needle and suture during suturing. Or a sucrose fatty acid ester in which the fatty acid is steric acid, palmitic acid, lauric acid, myristic acid, and the ester is a monoester, diester, or polyester, or Can be mixed and attached by any method such as dipping or coating to impart the above functions. Such 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 suture reinforcing cloth to prevent tearing of the body tissue in a surgical operation, and as a prosthetic material for body tissue reinforcement, or interposed between body tissues. For example, it can be suitably used as an application cloth such as an adhesion prevention film. The configuration will be described below with an example.

Cutting method for measurement sample (straight cut) Cutting method for measurement sample (oblique cut)

(Example)
Dissolved in phenol 10 in a solvent mixed with trichlorophenol 7 and heated at 190 ° C. for 3 minutes, then cooled to 30 ° C. and measured for viscosity (ηsp / c) of 1. The polyglycolic acid chip No. 5 was melt-spun at 245 ° C. and drawn 1.8 times to obtain a 12-filament, 33-denier polyglycolic acid yarn. This was knitted using an 18 gauge circular knitting machine with a basis weight of 45 g / m ² to obtain a cylindrical circular knitted fabric. The circular knitted fabric was lightly needle punched in the wale direction and then cut into a size of 22 × 22 cm. A plurality of non-woven fabrics having such a configuration were prepared. First, each one was stacked so that the knitting direction was an angle of 45 degrees, and needle punching was performed to obtain a 4PLY integrated non-woven fabric. The obtained nonwoven fabric was further hot-pressed under conditions of 100 ° C. and 180 kg / cm 2 for 10 minutes to obtain a prosthetic material of the present invention.

(Comparative example)
A circular knitted fabric made of polyglycolic acid yarn was obtained by the same method as in the example. The circular knitted fabric was lightly needle-punched in the wale direction and then cut into a size of 22 × 22 cm. A plurality of non-woven fabrics having such a structure are prepared. First, the non-woven fabrics in which the knitting directions are different, that is, the ones in the wale direction and the course direction are stacked one by one and needle punched to integrate 4PLY. Obtained. The obtained non-woven fabric was further hot-pressed for 10 minutes under the conditions of 100 ° C. and 180 kg / cm 2 to obtain a comparative example.

(Evaluation)
The nonwoven fabrics created in the examples and comparative examples were cut into a size of 4 × 50 mm as shown in FIGS. 1 and 2, respectively, and used as measurement samples. Here, FIG. 1 is expressed as an orthogonal cut, and FIG. 2 is expressed as an oblique cut.
The tensile strength is measured when the measurement sample is measured with an Instron type tensile tester at a distance between chucks of 20 mm and a pulling speed of 100 mm / min.

(result)
Table 1 shows the measurement results of the maximum tensile stress.

In the comparative example, the tensile strength differed by about 40% depending on the cutting method of the measurement sample, whereas in the example, there was only a difference of about 5%. Therefore, by superposing the needles so that the knitting direction is at an angle of 45 degrees and performing needle punching, it was possible to produce a nonwoven fabric with less strong directionality, which is the object of the present invention.

The present invention provides a biodegradable and absorbable nonwoven fabric for medical use that does not have a strong difference depending on the direction of pulling.

Claims (3)

A medical prosthetic material, characterized in that a knitted fabric knitted with a biodegradable absorbable polymer is laminated so that the wale direction and the course direction are at an angle of 45 degrees, and this is needle punched into a nonwoven fabric . The medical prosthetic material according to claim 1, wherein the biodegradable absorbable polymer is an aliphatic polyester. The medical prosthetic material according to claim 1, wherein the biodegradable absorbable polymer is polyglycolic acid or a polyglycolic acid-lactic acid copolymer.

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