Frank W Reichenbacher, M S

Use of porcine skin in burn treatment Although skin has long been regarded as the best material to cover an area of skin loss, the type, how to obtain it in the form desired, and how to use it for maximum benefit, was not evident. Until 1951, when Silvetti described the use of bovine skin as a temporary dressing,’ heterologous skin, (that is, skin of a species different from that of the recipient) was applied with the idea of permanent “take”. This invariably resulted in rejection. In 1951, Silvetti suggested that the substitute skin be removed, and new skin applied at regular intervals. Homograft skin (skin from another human, usually cadaver) is now also applied a s a temporary dressing. This eliminates the rejection problem, but limited availability and cost of procurement of homograft skin restrict its use. In 1965, Bromberg, Song, and Mohn reported the use of pigskin as a temporary biologic dressing.2 Pigskin is similar to human skin and has a minimal immune response. It can be produced in quantity because bristles are easily removed and the skins are uniFrank W Reichenbacher, ME, is vice

president of the Burn Treatment Skin Bank, Phoenix, A r k He received his BS from the Massachusetts Institute of Technology, Cambridge, and an M S from Rensselaer PoEytechnic Institute, Troy, N Y .

652

form in size which facilitate processing. Pigskin is widely used in the initial treatment of partial-thickness burns. Second degree burns, such as scalds a t relatively low temperatures, will heal within five to six days under pigskin. Deeper,partial-thickness wounds require longer healing. Temporary skin coverage, such as porcine xenografts, decreases excessive loss of water, proteins, and other materials which weep from the burn surface, particularly during the granulating phase. It protects the wound from infection by reducing surface bacterial concentration. Pain is reduced when exposed nerve endings are covered. Mobility of the patient is increased and maintenance of joint and muscle function is facilitated. Temporary skin coverage aids in the debridement of dermal debris and reepithelialization appears to occur faster when the wound is protected by a biologic cover. Porcine xenografts decrease the healing time of second degree burns and can be used to insure optimal conditions for autografting, thus reducing the number of grafting procedures. And finally, when donor sites are limited, pigskin may provide a closed wound until autografting is possible. Pigskin is supplied prepacked in both viable and nonviable form. Viable skin is processed to prevent total cellular death; nonviable skin is radiation sterilized and, therefore, not

AORN Journal, March 1975, Vol 21, N o 4

alive. Viable skin is supplied in fresh and fresh-frozen form. Fresh skin, stored in a refrigerator a t 40 F (4C), has a useful life of about two weeks; fresh-frozen skin may be stored in a freezer for up to three months. If the temperature is less than -110 F (-73 C ) , the skin may be stored indefinitely. Nonviable skin also comes in two forms: frozen-irradiated, which can be stored in a freezer for up to six months or indefinitely at -110 F (-73 C) or lower; and freeze-dried (ie lyophilized) skin, which can be stored at room temperature for up to 24 months. The expiration date for each type is stamped on the individual packages. Porcine skin is available in an assortment of sizes: 3” x 12” rolls for medium size wounds; 3” x 48” rolls for large injuries; 8” x 18” wide strips for large surfaces, such as burns of the back; and 3” x 4” patches for coverage of ulcers and small injuries. Application of pigskin begins when a significant portion of eschar has separated. The pigskin, with its fine mesh backing removed and tailored to fit the burn, is placed on the wound, dermal side down. The skin will not adhere if placed upside down. The dermal side always faces the center of rolled skin; if the skin is unrolled, the surfaces can be distinguished by the fact that porcine skin tends to curl toward the dermal surface if held up at one end. An important objective when applying skin is to achieve adherence to the wound. V- and X-shaped slits cut into the xenograft help to conform i t to surface irregularities. Once the skin is applied, it is usually covered with a dressing, sometimes impregnated with a topical antibacterial agent. This dressing is held in place by a semi-elastic gauze or an elastic net dressing. In 654

some areas, no dressing is necessary. The dressing is removed daily from the pigskin. After blebs are debrided and nonadherent graft trimmed or removed, a fresh dressing is applied. At three- or four-day intervals, the adherent pigskin is removed and replaced with fresh skin after thorough cleansing of the wound. Hides are obtained from meat companies where the pigs are raised under sanitary confinement conditions. The pig used is a cross-breed of the Yorkshire, Hampshire, and Duroc. When slaughtered, the animals weigh about 220 pounds and a r e five to six months old. Most slaughterhouses scald pigs in hot water to remove their bristles. However, scalding ruins the skin for use as a biologic dressing. Our hide sources do not scald the animals. The hides are cut into three- or nine-inch wide strips. Excess fat is removed from the underside of the strips to furnish skin of relatively uniform thickness. Uniformity makes shaving and dermatoming easier. After defatting, strips are shaved with a straight razor and then scrubbed in a machine. The hide strips are dermatomed (a thin layer of skin is planed off the epidermal side), and the skin is then inspected, trimmed, and sorted into various sizes. Skin to be processed a s fresh, frozen, freeze-dried, and frozen-irradiated is separated and identified. Skin is rolled onto gauze backing in the packaging room. The skin is handled aseptically in sterile laminar flow fields,

Nores I. A N Silvetii, et al, ”Preliminary experimental studies of bovine embryo skin grafts,” Trunspluntution Bulletin, 4 (1957) 25. 2. B E Bromberg, I C Song, M P Mohn, ”The use. of pig skin as a temporary biologic dressing,” Plustic and Reconstructive Surgery, 36 (July 1965)

00-09.

AORN Journal, March 1975, Vol 21, No 4

Use of porcine skin in burn treatment.

Frank W Reichenbacher, M S Use of porcine skin in burn treatment Although skin has long been regarded as the best material to cover an area of skin l...
172KB Sizes 0 Downloads 0 Views