JPS62194854A - Biocompatible long-term biodegradable reticulated cloth - 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 The present invention relates to an implantable cloth for subcutaneous or overnight implantation to immobilize a wound and prevent the formation of unsightly scar tissue.

BACKGROUND OF THE INVENTION Implants in the form of meshes and the like have long been used in surgical treatments to strengthen local areas on the surgical side or in the vicinity of wounds. Such an implant is assimilated by the living tissue (skin or muscle tissue), thereby achieving strong adhesion of the damaged tissue.

However, implants consisting of meshes or mesh-containing composites not only require firm healing of the injured tissue, but also provide cosmetically clean healing without producing unduly unsightly scars. Previously, it was not recognized that it could be implanted into the skin or just under the skin, if necessary. In fact, it has heretofore been considered inappropriate to use mesh-type cloth for subcutaneous or intradermal implantation.

This is because the absorption and assimilation of the mesh by living tissues results in strong healing of the wound, but at the same time leaves behind excessively ugly scar tissue.

Purpose and Summary of the Invention The purpose of the present invention is to provide a working metal for fixing a distal opening during the power dissipation process;
Another object of the present invention is to provide a mesh-like cloth for overnight and subcutaneous implantation that is designed to minimize the formation of unsightly scar tissue.

To this end, the present invention provides a flexible, delicate, biocompatible and long-term biodegradable reticulated fabric comprising a first
The resistance of the fabric to expansion along the axis and the surface of the first
The reticulated fabric is breathless with a temporary biocompatible binder such that the ratio of the fabric's resistance to expansion along at least one other second axis that is not parallel to the axis is a known value. The present invention provides a reticulated fabric characterized in that the binder is of a property that it loses its rigidity shortly after coming into contact with body fluids rather than immediately.

The method of implanting the cloth subcutaneously or overnight to control the formation of scar tissue involves (a) determining the orientation of the wound to be healed relative to the surrounding skin tissue; and (b) determining the orientation of the wound to be healed relative to the surrounding skin tissue; (c) Align the axis of the cloth that is relatively easy to expand with the axis of relatively low stress within the skin, and align the axis of the cloth that is relatively easy to expand with the axis #MXt-inside the skin. a) implanting the iron blood directly under or into the skin so as to straddle the wound in such a manner that it supports the wound;
It consists of allowing the iron blood to promote wound healing and act as a channel to relieve stress through the wound.

DESCRIPTION OF THE EMBODIMENTS Referring to FIG.
A composite fabric is shown consisting of layers 1.2.3 inserted below. The first layer 1 of the composite fabric consists of tricot knitted and stretched fibers of a biodegradable polymer such as so-called "white" silk.

The more a tricot knitted fabric is stretched in one direction, the less it stretches in that direction and the more it stretches in a direction perpendicular to that direction. This fabric layer 1 is arranged so that its relatively less stretchable axis is located parallel to the wound line. This arrangement was found to avoid excessive scar tissue formation. The mechanism is thought to be as follows.

Scar tissue forms along the wound line or longitudinal axis of the wound because biological fibers align longitudinally along the wound and collect in fibrous bundles. Previous attempts to heal wounds without producing unsightly scar tissue have focused on resisting stress transverse to the wound line. However, the generation of ugly longitudinal fibrous tissue
Previous attempts have focused solely on resisting transverse stresses, which are thought to be due to longitudinal stresses acting through the skin parallel to the wound line, inhibiting the excessive production of longitudinal scar tissue. I can't. If the shrubbery can resist longitudinal stress,
It is believed that the stimulatory factors for longitudinal fibrosis that would otherwise be imparted to the scar tissue are minimized, thus
Scar reactions that produce longitudinal fibers and thicken the scar into key-like tissue are inhibited.

The fabric layer 1 of the invention is stretchable in a direction transverse to the wound line, thus allowing some stretch of the skin along that direction and thus stimulating the production of fibers in the transverse direction. Therefore,
The combined action of the fabric layer 1 is such that it promotes the production of a more uniform matrix consisting of skin fibers extending both longitudinally and transversely of the wound, rather than consisting primarily of skin fibers extending longitudinally of the wound. be.

The second component or layer 2 of the composite fabric is lightly crosslinked (@<crosslinked f
c) Consists of a foam gelatin layer. This gelatin layer was found to adsorb fibroplasts from the skin, thereby increasing the absorption and assimilation of the composite fabric into the skin fibers. Lightly cross-linked foam gelatin 2 (e.g. TM Pritish Pharmacopy's "Gelfoam") swells when exposed to body fluids and living tissues and presses against the underside of the skin, thereby allowing the composite fabric to penetrate into the skin. Further assists absorption and assimilation.

If this cloth is to be implanted subcutaneously, as shown in Figure 1, rather than into the skin, the gelatin bulge should be kept to a minimum. Gelatin is used as a binder to complement the composite fabric and to fix the yarns at their intersections to maintain a prestressed state.

Therefore, the gelatin does not immediately lose its adjuvant action when the composite fabric comes into contact with body fluids, allowing the surgeon to handle the composite fabric more easily. However, the gelatin should only be used to coat the yarns of the fabric layer, rather than forming a matrix sheet that completely embeds the fabric layer. The gelatin may be crosslinked or non-crosslinked, but if it is crosslinked, the crosslinking should be minimized. This is because it has been found that the presence of a significant amount of strong bridge weakens the scar after 2-3 weeks.

Unfortunately, because lightly crosslinked foam gelatin swells when in contact with body fluids, when an implant consisting only of a fabric layer and a gelatin binder is attempted to be inserted subcutaneously or overnight, the sheet or fabric tends to curl; Insert operations become difficult. In order to prevent this curl, in the present invention, a thin mat of lightly crosslinked (high crosslinking rate) gelatin is added as the third layer of the composite fabric shown in FIG. A laminate is constituted of a cloth layer 1 and a crosslinked gelatin layer 3.

Referring to FIG. 2, an embodiment is shown using a fabric layer 1 substantially similar to that described above, with the addition of a layer 2 of lightly crosslinked foam gelatin. However, in this embodiment, the first
The fabric layer 1 and the lightly crosslinked gelatin W are formed by a waterproof, relatively rigid transparent nylon sheath 6 without adding a thin layer 3 of lightly crosslinked gelatin to prevent curling as in the embodiment shown in the figure.
I2 is wrapped. In this example, the wound has suture 7
The implanted composite fabric is maintained in a dry planar configuration until the plastic sheath 6 is removed just before it is completely closed.

FIG. 5 shows the removal of the cylindrical plastic sheath 6 just before the wound 5 is completely sewn shut.

The fabric layer 1 is attached to the skin 4 by sutures 7,
The sheath 6 is not attached to the skin 4. When using a sheath,
The sheath is slightly longer than the required length of the fabric layer so that the wound 5 can be sutured except for one end thereof, and yet the sheath can surround substantially the entire fabric layer. Therefore, before the wound 5 is completely sutured, the sheath 6 protrudes from one end of the wound as shown in FIG. The surgeon can grasp the sheath 6 close to the edge 8 of the wound and pull it in the longitudinal direction of the wound to pull the sheath 6tl - out of the skin and fabric layer 1. Fabric layer 1 is left in or under the skin, but the entire edge of the fabric layer is removed if necessary to facilitate complete suturing of the wound with all of the fabric layer remaining in or subcutaneous. You can cut it out at 8.

The use of sheaths is advantageous in that it is possible to avoid the use of heavily cross-linked gelatin, which is removed from the body only very slowly over a long period of time by cellular activity.

When using a sheath as described above, the gelatin of the composite fabric tends to adhere to the sheath when bodily fluids enter from the end of the sheath during implantation, so a lubricant is interposed between the composite fabric and the sheath. It may be desirable to leave the

Such a lubricant can be any biocompatible oil, but vitamin E oil has been found to be suitable. Coating the composite fabric with an oil such as vitamin E has the additional advantage that the softening effect exerted on the binder (gelatin) by body fluids is delayed, at least until the surgeon has completed implantation.

Referring to FIG. 3, yet another embodiment of the invention is shown. In this embodiment, the fabric layer 1 is surrounded by a lightly crosslinked gelatin 2, which is further surrounded by a sheath 6. This composite fabric is adapted to be implanted subcutaneously, rather than subcutaneously. Thus, subcutaneous implantation is often preferable. This is because, in the case of subcutaneous implantation, a gap may occur between the cloth and the lower surface of the skin. Of course, subcutaneous implantation is preferred in localized areas, such as the eyelids, where there is insufficiently inferior skin to perform effective intraepidermal implantation.

FIG. 4 shows an embodiment of the invention specifically designed for use in intradermal implantation. In this example, the fabric layer is a tricot knitted cylinder? 3rd except that it is formed as
This is similar to the embodiment shown in the figure. The tricot knitted cylinder body 9 surrounds a core body made of lightly crosslinked foam gelatin 2,
The gelatin promotes fibroplast ingrowth and assists in compressing the tubular mesh (composite fabric) to the skin.

In this firing fAj, the gelatin actually acts to press the cloth against the skin. This embodiment also uses a sheath 6 for ease of handling.

One of the main considerations for the surgeon before using the fabric according to the invention is the direction of the prevailing stresses in the skin around the wound. If reduction of an existing scar is desired, the surgeon should be able to determine the principal stresses acting on the scar by examining the existing scar tissue according to the theory disclosed herein. . This is because the fact that the scar is thick and raised as a noodle-like collagen bundle is evidence that a predominant stress exists in a direction parallel to such a reptile-like tissue.

Therefore, a fabric should be selected that is relatively inelastic in the direction parallel to the predominant stress line compared to other axes within the region.

If the surgeon is unable to visually inspect the existing scar to determine the predominant stresses acting along the wound, he or she may be able to identify various This can be inferred from past experiences with patients' wounds.

In any case, the longitudinal force acting along the scar is one of the main stresses that must be suppressed to avoid scar embankment, and therefore the implantable fabric It must provide sufficient support along the axis of the scar.

Some company's fabrics, when made with non-expandable yarns, have 114 diagonal (along one axis) almost no expansibility along one axis. It has a relatively small expansibility, but exhibits a considerably large expansibility in a direction perpendicular to such an oblique axis.

These five different resistances to swelling can be exploited, for example, when the scar extends obliquely to the folds of the skin. It is known that scars that extend parallel to the skin folds are easy to heal, and scars that extend perpendicular to the skin folds are difficult to heal. For this reason, support for the skin is required in the direction perpendicular to the skin folds, and in the case of oblique scars, the fully uninflated axis of the implant should be aligned with the direction of the wound line, and the It has been found to be preferable to extend the relatively less distension axis of the skin transversely to the folds of the skin. Preferably, the expansion axis of the fabric is aligned parallel to the folds of the skin.

The fabrics of the present invention can be designed separately for subcutaneous and intradermal implants. Both cloths are made from mesh weave cloth. The size of the mesh is determined according to the mesh pattern of collagen bundles in the deep layers of the skin. This reticular pattern can be seen when skin grafts are harvested from the donor's local area. The local filament pattern of the graft donor is similar to that of a coarse bridal veil (tulle).

Another factor that determines the thread thickness and stitch size of the fabric is that the fabric must allow rapid ingrowth of fibrous tissue to adequately anchor it to the skin. That's true. The thread must be thick enough to withstand the tension of the tissue without breaking, but not so thin that it will dig into the tissue when subjected to tension. The bulk of the implant should not be so thick as to cause an excessive foreign body reaction.

The composite fabric of the present invention provides an aid for managing stress within the scar and its surrounding tissue and inducing the formation of a balanced collagen matrix around the scar that is similar to that of normal tissue. It was designed as such. In normal tissue, the matrix of collagen bundles extends in different directions, but the scar composition is formed as a result of the production of collagen bundles in a single direction. "Long-term bioaccessibility" means 1 to 5.
This means that it has the property of being decomposed by living organisms within a year.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of the fabric of the invention implanted under the skin transverse to the longitudinal axis of the wound; FIG. 2 is similar to FIG. 1 of the fabric of the invention in the sheathed version; FIG. 3 is a cross-sectional view showing another type of fabric of the invention inserted into a sheath and implanted into the skin; FIG. 4 is a cross-sectional view showing yet another type of book inserted into a sheath. FIG. 5 is a sectional view showing the cloth of the invention being implanted into the Koshin, and FIG. 5 is a perspective view showing the sheathed cloth of FIG. 4 being inserted into the Koshin along the wound. 1: Fabric layer 2: Binder 3: Thin gelatin layer 6: Transparent nylon sheath □ - Name of agent: Motohiro Kurauchi 1.
Hiroshi Kazama )+-′

Claims (1)

Claims: 1) A soft, delicate, biocompatible, long-term biodegradable reticulated fabric comprising: a resistance of the fabric to expansion along a first axis of the fabric surface; The reticulated fabric is bound by a temporary biocompatible binder such that the ratio of the fabric's resistance to expansion along at least one other second axis that is not parallel to the first axis is a known value. Reticulated fabric fixed under stress, characterized in that the binder is of a nature that loses its rigidity shortly after coming into contact with body fluids, rather than immediately. 2) A reticulated fabric according to claim 1 made of "white" silk yarn with a diameter of 0.009 mm to 0.2 mm. 3) The reticulated fabric according to claim 1 or 2, which is formed as tulle having stitches with a width of 0.01 mm to 5 mm. 4) The reticulated fabric according to claim 1 or 2, which is tricot knitted with stitches having a width of 0.01 mm to 5 mm. 5) The binder is made by lightly coating the fabric with dried gelatin or collagen.
The reticulated cloth according to any one of items 1 to 4. 6) The reticulated fabric according to claim 5, wherein the binder is lightly crosslinked. 7) The binder is coated on only one side of the fabric as a sufficiently cross-linked gelatin layer to prevent the fabric from curling when implanted subcutaneously in a patient. The reticulated fabric according to item 5 or 6. 8) the fabric is laminated as two fabric layers, the binder is dried gelatin or collagen, and when the fabric is implanted into the skin, expansion of the binder causes each fabric layer to bind to the skin; Claim 8, wherein the binder is interposed between the two fabric layers so that the binder adsorbs fibroblasts from the skin through each fabric layer.
Reticulated cloth as described in section. 9) The reticulated fabric according to claim 8, wherein the two fabric layers are formed by flattening a single cylindrical fabric. 10) The fabric and binder combination is coated with oil to delay the softening effect exerted on the binder by body fluids at least until the surgeon has completed implantation of the fabric. The reticulated fabric according to any of Item 9. 11) The reticulated fabric according to claim 10, wherein the oil is pure vitamin E. 12) the fabric is inserted into a sheath adapted to be partially implanted with the fabric; the sheath has a sheath sufficient to prevent curling, buckling or curling of the fabric; Claims: 1. A fabric that is rigid and is adapted to prevent contact between body fluids and at least a majority of the fabric, and to allow removal from around the fabric by a surgeon just prior to completing wound closure. The reticulated cloth according to any one of items 1 to 11. 13) The reticulated fabric of claim 12, wherein said sheath is made of rigid transparent nylon.