JPH0471549A - Cushioning material for surgery - Google Patents

Abstract

PURPOSE:To change a soft cushioning material with low repulsion elasticity into a fine shape and covering it in close contact without damaging tissues by forming a draw porous fluororesin sheet made of polytetra fluoroethylene and having specific porosity and thickness. CONSTITUTION:Polytetra fluoroethylene is preferably used for fluororesin. A cushioning material made of a draw porous fluororesin sheet is formed with one sheet or a laminated body of multiple sheets, and the sheets are integrally stuck by heat fusion or an adhesive for the laminated body. The porosity of the laminated body is set to 75-95%, and its thickness is set to 0.1-1.0mm. The porosity is set to 75-95%, preferably 80-90%. When the porosity is less than 75%, the shape following property and the flexibility at the end section are insufficient. When it exceeds 95%, operability is deteriorated. The average fine hole diameter of the cushioning material is set to 0.1-10mum, preferably 0.2-3.0mum. The thickness is set to 0.1-1-mm, preferably 0.3-0.7mm. When the thickness is less than 0.1mm, the cushioning property is poor. When it exceeds 1mm, operability is deteriorated.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a cushioning material used in surgical operations, particularly head surgeries.

(Prior art and its problems) In craniotomy in neurosurgery, laparotomy in cardiac surgery, thoracic surgery, and abdominal surgery, in order to prevent the surgical jig from compressing and touching tissues other than the necessary areas,
Buffer material is used.

As such cushioning materials, woven fabrics or nonwoven fabrics made of hydrophilic materials such as cotton, collagen, and polyvinyl alcohol have conventionally been used.

However, cushioning materials made of such hydrophilic materials (1) absorb or adsorb body fluids such as blood generated during surgery and become stained with the body fluids, making it difficult to visually identify the tissue and the cushioning material; (2) Absorption of body fluids may change the properties of the cushioning material, causing it to swell or contract; (3) linters are likely to be generated, becoming a source of contamination; and (4) ease of use may be affected due to poor slippage. (5) If the treatment lasts for a long time, the buffer material may adhere to the tissue due to coagulation of blood absorbed into the buffer material or deposition of fibrin, and if this material is forcibly removed, new wounds may occur. This included various problems such as those that occurred.

(Problem of the Invention) An object of the present invention is to provide a new cushioning material that solves all of the above-mentioned problems found in conventional cushioning materials.

(Unavailable Means for Solving the Problems) The present inventors have conducted extensive research to solve the above problems, and as a result, have completed the present invention.

That is, according to the present invention, there is provided a surgical cushioning material made of a stretched porous fluororesin sheet having a porosity of 75 to 95% and a thickness of 0.1 to 1.0 mm.

The fluororesin used as the raw material for the cushioning material of the present invention is generally known to have no sensitization to living organisms and to have antithrombotic properties, and is used as an artificial tissue material such as artificial blood vessels, blood access, and cardiac abdominal patches. ing. The inventors
It was discovered that this fluororesin has advantageous properties as a material for cushioning materials in surgical operations, and it was made into a sheet with a specific porosity and thickness by stretching it into a porous material. It was discovered that all the drawbacks of cushioning materials made from this material have been solved, and that they are extremely excellent as cushioning materials for surgical operations. The present invention was completed based on such knowledge.

The method of producing stretched porous sheets from fluororesin is well known, for example, as described in Japanese Patent Publication No. 51-1
It is detailed in Japanese Patent Publication No. 8991, Japanese Patent Publication No. 56-45773, Japanese Patent Publication No. 56-17216, etc., and the pore diameter, porosity and thickness can be arbitrarily changed depending on the manufacturing conditions. Examples of the fluororesin include polytetrafluoroethylene (PTFE), tetrafluoroethylene/hexafluoropropylene copolymer, polyvinylidene fluoride, and the like. In the present invention, the use of PTFE is preferred.

The cushioning material made of the stretched porous fluororesin sheet of the present invention is composed of two sheets or a laminate of a plurality of sheets. In the case of a laminate, the sheets are bonded together by heat sealing or adhesive.

In this case, the porosity of the laminate is defined as 75 to 95%, and the thickness as 0.1 (0.0 mm).

In the cushioning material of the present invention, the porosity is 75 to 95%.

Preferably it is 80-90%. If the porosity is less than 75%, shape followability and edge flexibility will be insufficient, making the material unsuitable for use as a cushioning material. On the other hand, when it exceeds 95%, operability (handling) deteriorates.

The average pore diameter of the buffer material is 0.1 to 10 tones, preferably 0.2 to 3.0 tones.

In the cushioning material of the present invention, the thickness is 0.1 to 11I1
ml, preferably 0.3 to 0.7+++ m. 0.
If the thickness is less than 1 mm, the cushioning properties will be poor;
If the thickness exceeds , the operability will deteriorate.

(Effects of the Invention) The cushioning material of the present invention is flexible and has extremely low impact resilience;
It can be deformed to follow minute shapes, and it can cover the target tissue in a soft and tight manner without damaging it.Moreover, its compressive modulus is extremely low, making it an excellent energy absorber. Furthermore, even if the edge of the sheet hits tissue, the possibility of damaging the tissue is extremely low. Furthermore, since it is water repellent and does not absorb or adsorb body fluids, the properties and color of the sheet will not change even during long-term treatment. Therefore, the cushioning material of the present invention does not lose its energy absorbing effect (buffering effect) even during long-term treatment, and its visibility is not impaired. Furthermore, even if body fluids solidify during long-term treatment, the cushioning material of the present invention has non-adhesive properties, so that when the cushioning material is removed from the tissue, there will be no adhesion between the material and the tissue. No fresh wounds will be caused.

(Example) Next, the present invention will be explained in more detail with reference to Examples.

Example 1 30% naphtha was added as an extrusion aid to 1kg of unfired polytetrafluoroethylene resin fine powder.
The mixture was kept at 40°C for 24 hours to fully disperse the naphtha in the resin, then compacted, extruded using a ram extruder, and rolled repeatedly between a pair of metal rolls to a thickness of 150 mm. Obtain a long sheet of.

Next, this long sheet was dried at 200°C to remove naphtha, and then stretched 300% in the longitudinal direction and 200% in the short axis direction to form a stretched porous PTF with a thickness of 120R1 and a porosity of 85%.
It was made into an E-sheet. Eight of these sheets were stacked one on top of the other in the bias direction, sandwiched between two polished stainless steel plates, and then pressed using a hot platen press heated to 360°C at a pressure of 0.2 kg/cm. ffl for 20 minutes, then rapidly cooled to room temperature to a thickness of 800 pa (0.8
m+a), multilayered porous PTF with a porosity of 75%
Sample A of E sheet was obtained.

This sample A was further heated by 200 mm in each of the major axis direction and minor axis direction.
Sample B with a thickness of 700.4 (0.7 mm) and a porosity of 90%.
I got it.

When the samples A and B were observed with an electron microscope,
The cross section had a completely uniform structure, and it was confirmed that the eight laminated sheets were completely integrated.

Example 2 400ml of mineral spirit was added as a processing aid to 1 kg of unfired polytetrafluoroethylene resin fine powder, mixed well, and held at 40°C for 24 hours to blend the resin and the aid well. Ta. This was rolled repeatedly between metal rolls to form a sheet. After drying this sheet-like material at 200°C to remove the auxiliary agent, it was stretched 300% only in the major axis direction, and then heat-treated at 380°C for 30 minutes to obtain a sample C with a thickness of 250 degrees and a porosity of 80%. I got it.

Example 3 Thickness 120. created in Example 1. , A polyurethane adhesive was dotted onto a stretched porous PTFE sheet with a porosity of 85% at a coating amount of Log/rd, and four sheets were stacked together.
A laminate sample D having a thickness of 500 μs was obtained by processing at 150° C. for 1 hour.

Comparative Example 1 Ten stretched porous PTFE sheets with a thickness of 120 mm and a porosity of 85% prepared in Example 1 were stacked one by one in the bias direction, and sandwiched between stainless steel plates. Press with a hot plate press at a pressure of 10k.
Sample E is obtained after heat treatment at a treatment temperature of 360° C. for 20 minutes and cooling to room temperature. This sample E had a thickness of 500 mm and a porosity of 70%.

Each sample A to E obtained in the above Examples 1 to 3 and Comparative Example 1
Regarding commercially available hydrophilic cotton cushioning materials and collagen-based cushioning materials, their shape followability, edge flexibility, visibility, and shape retention were investigated as follows, and the results are shown in Table 1.

(1) Shape followability (formability) A jig with a total weight of 200 g is prepared by winding a stainless steel round wire with a wire diameter of 1 mmφ around a stainless steel round bar with an outer diameter of 12 mm without any gaps.

Separately, on a smooth glass plate about 7H thick, 20x50m
Multiple pieces of samples cut to size of m are approximately 1m thick.
Overlap to about m. The jig is gently placed approximately in the center of the stacked samples and left at room temperature for 5 minutes. After 5 minutes, remove the jig and observe the surface of the sample. Next, the top sample was taken out, held at both ends, and stretched slowly and gently to observe the surface condition and evaluate it using the following criteria.

(Judgment criteria) Excellent: The shape of the jig remains clearly on the surface, and when it is enlarged, the shape of the jig completely disappears.

Good: The shape of the jig remains almost on the surface, and when it is enlarged, most of the shape of the jig disappears.

Acceptable: Does the jig have a very slight shape?

Something that doesn't exist at all.

(2) End flexibility Commercially available fresh silk tofu 50mm x 50+am x
A piece cut to a size of 30 mm is prepared on a smooth glass plate.

On the other hand, cut the sample sheet into a size of 10 mm x 50 mm. The cut sample is lightly sandwiched between flat plastic plates with a width of 20nv+, a length of 100°C, and a thickness of 1.5H, with the tip protruding approximately 511II11 so as not to bend. Place this tip gently and at right angles to the surface of the aforementioned tone and press. It is acceptable if the tip of the sample is bent and does not enter the tone, and it is unacceptable if the tip is not bent and the tip does not enter the tone.

(3) Visibility The sample is cut into a size of 10 mm x 50 mm, placed in a 90 mm diameter petri dish containing fresh cow or pig blood, and left covered for about 1 hour. When the sample is taken out of the petri dish, it is considered acceptable if the sample adsorbs or absorbs blood and is stained with blood, or it is acceptable if the sample does not absorb or adsorb blood and is not stained.

(4) Improve shape retention and visibility! Observe the morphology of the sample. It is considered good if the form after the test has hardly changed from before the test, and it is judged bad if the form has changed.

Table 1 As can be seen from the results shown in Table 1, the products of the present invention (samples A to D) are significantly superior to conventional products as cushioning materials for surgical operations.

Claims (3)

[Claims] (1) Porosity: 75-95%, thickness: 0.1-1.0m
A surgical cushioning material made of a stretched porous fluororesin sheet of m. (2) The cushioning material according to claim 1, wherein the fluororesin sheet is composed of a plurality of laminates. (3) The cushioning material according to claim 1 or 2, wherein the fluororesin is made of polytetrafluoroethylene.