1 From the Division of Plastic and Reconstructive Surgery and the Vascularized Composite Allotransplantation Laboratory, Center for Transplantation Sciences, Massachusetts General Hospital, Harvard Medical School; the Department of Plastic, Reconstructive, and Aesthetic Surgery, Hôpital Européen Georges Pompidou, Assistance Publique-Hôpitaux de Paris; and the Institute of Anatomy and Organogenesis, URDIA, EA4465, UFR Biomédicale des Saints-Pères, Faculté de Médecine Paris Descartes, Université de Paris.