Clinical Trials of a Biosynthetic Temporary Skin Replacement, Dermagraft-Transitional Covering, Compared with Cryopreserved Human Cadaver Skin for Temporary Coverage of Excised Burn Wounds
Human cadaver allograft skin (HCAS) is widely used for covering excised burn wounds when limited available skin donor sites or the overall patient condition does not permit immediate grafting with autologous skin. However, recurring problems are associated with HCAS including limited supply, variable quality, ultimate immune rejection, and the potential for bacterial and viral disease transmission. These problems speak for the need for development of a dependable substitute for HCAS. We evaluated the ability of a biosynthetic analogue of human skin to temporarily close excised burn wounds in humans. Dermagraft-TC (Advanced Tissue Sciences, Inc.) (DG-TC) is composed of human neonatal fibroblasts cultured on a synthetic dressing (Biobrane; Dow Hickam, Inc.) that consists of nylon mesh fabric covered with a thin layer of silicone rubber membrane, which provides an epidermal "barrier." The material is stored frozen and thawed immediately before use. DG-TC is semitransparent, thus facilitating continuous observation of the underlying wound surface. Burn wounds in 10 patients (mean age 33.5 years, mean burn size 39.9% total body surface area) were surgically excised. Two variants of the DG-TC skin analogs were tested: a material that was cryopreserved to maintain fibroblast viability (DG-TC Red) and a material that was frozen without efforts to maintain fibroblast viability (DG-TC Blue). A control site on each patient received cryopreserved HCAS. Each study site was approximately 1% total body surface area. When clinically indicated, patients were returned to the operating room where the skin replacements were removed, the wound bed was evaluated and prepared for grafting, and the wounds were closed with meshed split-thickness autograft skin. The results showed that adherence to the wound and subsequent autograft "take" were excellent with both DG-TC variants and were at least equivalent to HCAS. No evidence of immune rejection of DG-TC was seen, whereas in four patients evidence of epidermal sloughing/rejection was noted in the HCAS control sites, which limited persistence of those grafts on the wound. Further clinical trials with this skin analogue are in progress.