Osteocutaneus Hemiface Allotransplantation Model in Rats

Introduction:With the advancement of composite tissue allotransplantation (CTA), satisfactory reconstruction of extensive facial defects including bone and soft tissues became possible. The aim of this study is to extend the application of face transplantation model by incorporation of premaxilla and whole hemifacial structures. Material and method: Five allotransplantations were performed from 5 Lewis-Brown Norway (LBN)(RT1n+1) donors to 5 Lewis(RT11) recipients under Cyclosporin A monotherapy. Whole hemiface grafts; composed of nose, lower lip, upper lip, auricle, upper/lower eyelids, scalp and premaxilla; were dissected based on common carotid artery and external jugular vein. A heterotopic transplantation was performed to the inguinal region of the recipient rat. Common carotic artery and external jugular vein of the graft were anastomosed to the femoral artery and vein, respectively. Direct observation, computed tomographic scan, and microangiography were used for assessment of transplants. Results: All transplants survived indefinitely over 100 days. Microangiography showed preserved vascularization of the graft. At the first 3 days, an edema was observed which subsided following days. Total operation time of the recipient rat was around 90 minutes and the average ischemia time was 45 minutes. During the follow-up period no sign of rejection was observed in transplanted skin and mucosa. Tooth and hair growth was seen. Computerized tomography showed vital premaxillary bone segment. Conclusion: We have introduced a new hemiface allotransplantation model including whole hemifacial soft tissues as well as the premaxillary bone segment. In this allotransplantation model, longterm survival over 100 days was achieved. Composite osseomusculocutaneous hemiface allograft transplantation in clinical practice will provide several advantages over standard reconstructive surgery. It enables a single stage reconstruction of the whole hemiface. Our results are encouraging, and potential clinical opportunities will be rewarding for patients with complex facial deformities.