Pectoral skin flap as a reliable and simple model for vascularized composite skin transplantation research

In this study, the authors explored the feasibility of transplanting a "pectoral skin flap" as an alternative model for composite skin allotransplantation research. Genetically inbred male Lewis rats (LEW; RT1l) (n = 13), weighing 250 to 300 gr, were used as recipients and Brown Norway rats (BN; RT1n) (n = 8) rats were used as donors. Five Brown Norway rats had bilateral and three had unilateral flap harvest with a total of 13 flap transplantations to Lewis rats. All flaps were transplanted to the groin regions of the recipients and microsurgical anastomoses with 10-0 nylon were performed between the axillary vessels of the flaps and the femoral vessels of the recipient animals. The mean operation time was 55 min, with an ischemia time of 25 min. All transplantations were successful immediately postoperatively. The recipient animals were treated with Cyclosporine A (16 mg/kg/day) from the day of the surgery for 1 week, and then discontinued. One flap developed infection at postoperative day 11 and one flap had partial (50 percent) necrosis. The early signs of rejection started 8 to 9 days after the cessation of the immunosuppressive treatment, and all flaps were acutely and uniformly rejected within 3 to 4 days. The feasibility of harvesting two flaps from one donor animal allowed saving donor animal lives and reducing donor-specific variables.