Veterinary Wound Healing Association 5th Congress, Hannover, Germany. May 10-12 2001
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| CULTURED SKIN GRAFTS Jagdeep Nanchahal, PhD, FRCS (Plast) Senior Lecturer in Plastic and Reconstructive Surgery Imperial College School of Medicine Charing Cross Hospital London W6 8RF More than 10,000 patients per year need admission to hospital for burns in England and Wales and many of these require skin grafting. The commonest technique for resurfacing full-thickness skin defects is with split-thickness autografts, which may be expanded 4-6 fold by meshing. Unfortunately, patients with extensive burns may have few donor sites and there is morbidity associated with the harvesting of skin grafts. Twenty five years ago the problem appeared close to solution with the description of a reliable technique for culturing large numbers of keratinocytes. The initial reports were encouraging, with expansions of up to 10,000-fold. The three week delay between taking the donor skin and producing large sheets of keratinocytes for grafting prompted the use of allogeneic keratinocytes. However, these cells survived for less than a week on full-thickness defects and were acting as sophisticated dressings. The absence of a dermal component predisposed to contactures and blistering. Cadaveric skin allografts give excellent results, with the dermis surviving and the epidermis may be later replaced with cultured autologous keratinocytes. Unfortunately, the demand of cadaver skin in the USA outstrips supply by 4-7 fold and there is a real risk of transmission of infection, including HIV. This has prompted the development of dermal substitutes, including: · AllodermTM (freeze dried human dermis) · DermagraftTM (cultured human fibroblasts and their products on a Vicryl mesh) · IntegraTM (collagen and glycosaminoglycan dermal layer overlain with Silastic sheet) All these require resurfacing with either split thickness autograft or cultured keratinocytes. ApligrafTM consists of a collagen and fibroblast dermis covered with cultured keratinocytes and has been used on chronic ulcers, where multiple applications are often necessary. Our experience in a similar model gave satisfactory results in clean, elective wounds in terms of correcting contour defects with little contracture or hypertrophic scarring. Furthermore, we were able to demonstrate long-term survival of allogeneic cells using a Y chromosome probe. However, when applied to burn wounds, all the cultured skin equivalents were lost, emphasising the need for a more resilient construct in this hostile environment. Return to index of Abstracts | About the VWHA |