A New Composite Facial and Scalp Transplantation Model in Rats

Abstract

There are limited sources of autogenous tissue available for reconstruction of severe facial and scalp deformities caused by extensive tumor ablation, burns, or trauma. Allografts from cadaveric sources may serve as a reconstructive alternative. However, technical and immunological aspects of harvesting and transplanting face and scalp flaps limit the routine use of such procedures. For evaluation of the feasibility of composite-tissue reconstruction, an experimental model of composite face/scalp flap transplantation in rats was designed. Technical aspects of the model, survival rates, and the complications encountered during development of the model are presented. A total of 64 animals, in three experimental groups, were studied. In group I, the anatomical study group (n = 6), the anatomical features of the face and scalp region in rats were explored. Groups II and III were the transplantation groups. Isograft transplantations were performed between identical Lewis rats (RT11 to RT11), and allografts were transplanted, across major histocompatibility complex barriers, between Lewis-Brown Norway rats (RT1l/n) and Lewis rats (RT11). In group II (the control group, n = 8), transplantation of nonvascularized composite face/scalp isografts and allografts was performed. In group III (the transplantation group, n = 50), vascularized face/scalp isografts (n = 36) and allografts (n = 14) were transplanted. Complications included partial or total flap necrosis, death attributable to food aspiration, and poor general condition. To prevent acute and chronic allograft rejection, cyclosporine A (16 mg/kg per day) therapy was initiated 24 hours after transplantation; the dose was tapered to 2 mg/kg per day within 4 weeks and was maintained at that level thereafter. Long-term survival (>170 days) was achieved, without any signs of rejection, with low-dose (2 mg/kg per day) cyclosporine A therapy. This is the first report documenting successful composite face/scalp flap transplantation in the rat model.

Chimerism and bone marrow based therapies in transplantation

“…We have described for the first time a full-face allotransplantation model in the rat. 105 This model is a challenging surgical technique and carries complications; nevertheless, it proves the feasibility of performing such a complex procedure. For full-face allograft transplantation in the rat model, the main vascular structures of the head and neck were used bilaterally on carotid arteries, and jugular veins in the recipient, and so the perioperative mortality rates were higher as a result of brain ischemia and vascular problems.…”

Swine Hemi-Facial Composite Tissue Allotransplantation: A Model to Study Immune Rejection

“…In patients lacking their own "autologous" tissue for reconstruction, this surgical procedure enables reconstruction with tissue structurally similar to their own. 1 Presented at the 23th Annual Meeting of American Society for Reconstructive Microsurgery, Jan. [12][13][14][15]2008, Los Angeles, CA. 2 To whom correspondence and reprint requests should be addressed at Department of Plastic and Reconstructive Surgery, Chang Gung Memorial Hospital-Kaohsiung Medical Center, 123 Ta-Pei Road, Niao-Sung Hsiang, Kaohsiung 833, Taiwan.…”

Tongue Transplantation

“…Freedom from immunosuppression can only be achieved by inducing mixed chimerism and allograft tolerance. Her work suggests that the inclusion of donor allograft containing lymphoid and vascularized bone marrow may be the key to developing and maintaining donorspecific chimerism [21,28,29]. The previously described full face, double jaw, and tongue transplant included vascularized bone marrow within the mandible and may offer additional insight into the development of donor tolerance [24].…”