Skin grafting

Skin graftingReconstructive or plastic surgery of the skin is often necessary to improve appearance and function over certain areas. About the face and neck and other exposed areas it is often used to correct unsightly and embarrassing deformities. About important joints which are otherwise nor­mal, plastic surgery can be useful in relieving surface contractures which limit motion. After large avulsions, burns, and ulcerations, this operative method will prevent such deformities and contractures.

Skin grafting simply means the transfer of skin from one area of the body to another. It is performed to provide the recipient site with a relatively normal pliable and elastic skin cov­ering, after injury through all its layers has re­sulted in, or would obviously result in, scar- tissue covering which has less desirable charac­teristics.

Split-Thickness Grafts. Skin grafting may be done by either of two basic methods. Split­thickness grafts are those of approximately one- half the thickness of the skin. The outer half is transferred from the donor site to the recipient site. (Full-thickness grafts entail the transfer of the entire skin thickness.)

Split-thickness grafts may be performed only after the recipient area has healed to the stage where granulation tissue is present, but before it turns to scar tissue. The transferred outer layer of skin forms a “seed” for the regenera­tion of normal thickness skin over the area. The new graft takes blood supply from the granu­lation tissue which makes up its base. Split- thickness grafts are performed by several tech­niques.

In the pinch-graft method, small circles of the outer layer of skin are removed from the donor site and placed over the granulating area of the recipient site.

In the full-cover technique, a sheet of the outer half of skin is cut from the donor site to be patterned to the size and shape of the re­cipient site, and it is then sutured in place at its new location. Special instruments are used to take the skin from the donor site.

With the postage-stamp method, a sheet of tissue is similarly taken from the donor area and then cut into smaller squares which are placed over the recipient defect. This has the advantage of covering a large recipient area from a much smaller donor area.

Split-thickness donor sites are selected at unexposed areas of the body with considera­tion of the quality of the skin and the ease of maintaining sterility and dressings. The thighs and hips are commonly selected areas. In skin reconstruction by plastic surgery of great mag­nitude, often several donor sites are needed. These areas heal readily. The remaining deeper half of the skin gives rise to replacement of the outer half, so the end result is a regeneration of normal skin. Upon first healing the area is reddened or darker than normal, but in a few months it becomes normal in appearance.

Full-Thickness Grafts. Full-thickness skin grafts may also be done by several methods.

Free full-thickness grafts are sometimes prac­tical, but for the most part they demand that the blood supply remain intact at one end of the graft so that it remains living tissue until it assumes a full blood supply at the new site.

The sliding graft is done by taking a full thickness of skin adjacent to the defect and ro­tating its free borders over the defect where it is sutured in place. The denuded area is then closed with sutures. This type of plastic pro­cedure is useful in many areas where the skin is loose, as over the thighs and trunk. It de­mands only one stage of operation.

A flap of full-thickness skin is cut and ele­vated from its bed. The underlying bare area is sutured closed. The part with the skin defect is placed under the flap, where it is sutured in place. After healing has progressed to the point where the flap has assumed a new blood sup­ply from the new region, the second part of the operation (Stage II) may be done; namely, cutting the flap free from the donor site with trimming and closing of the incised edges. This type of graft is useful for transfer of skin from the trunk to an extremity. It is commonly em­ployed to cover hand and arm defects, using the abdomen or thigh as the donor area, and from one leg to the other.

An example of the pedicle graft: the donor site is in the near vicinity of the defective recipient site. Two parallel in­cisions are made and the skin between them elevated. The bared base is closed with sutures. The two freed edges of skin are inverted and sutured to each other, making a tube of skin, or pedicle. At the second stage, an area of skin the size and shape of the defect is cut at one end of the pedicle. The pedicle is rotated to place this over the recipient defect, where it is sutured in place. The newly denuded area is closed. When the blood supply of the trans­ferred skin has established itself, the pedicle may be cut free at both ends as the third stage. The pedicle graft is commonly used for defects about the face where accurate cosmetic plastic im­provement is important. It may also be used between extremities and other areas.

Each type of skin grafting has advantages over the others. The surgeon’s choice of plastic procedure to be employed for the transplant of skin depends on several factors. Of major con­cern are the type of defect, the particular skin characteristics of both the donor and the re­cipient sites, the time required to complete the entire process, the importance of good skin cos­metics and “functionability,” the risks involved, the likelihood of an effective “take” of the transplanted skin, and the general condition of the patient. The donor site must also be awarded great consideration. In procedures of more than one stage, the entire course must be carefully calculated from the start.

FASCIAL GRAFTS

Fascia, the strong tissue investment lying be­neath the fatty layer over most of the body, serves as a donor structure in some reconstruc­tion procedures. Fascial transplants are usually obtained from the thigh region, and used in free grafts. The transferred tissue may be used in various types of hernia repair on the abdomen, replacement of destroyed tendons and ligaments, and fascial defects in other areas. In some cases, the fascial graft is cut in strips to be used as suture material for hernia repairs. Reconstruc­tion of the abdominal wall is frequently done by fascia transplants from the near vicinity, by slid­ing type of grafts similar to the sliding skin graft or by everting flaps of fascia to reinforce adjacent weakened areas or by fold­ing the fascia over on itself for strength. Fascia grafts find their greatest usefulness in the plastic reconstruction of areas where there is pressure or tension on the tissues.

OTHER TISSUE GRAFTS

Some other tissues in the body are also used as grafts in the surgical reconstruction of de­stroyed or defective parts. Bone grafts are fre­quently necessary and usually meet with excel­lent results. Cartilage grafts are occasionally employed in the plastic revision of the nose and ears, with the rib cartilages as the donor site. Occasionally segments of blood vessels which can safely be sacrificed are transplanted to re­place injured vital vessels. And on occasion nerve segments can be grafted.

 

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