Facial allotransplantation procurement using a transparotid approach: A new anatomical model

Abstract

Full face transplantation is a complex procedure and a detailed plan is needed. Coaptation of motor nerve branches at more distal sites instead of the level of the main trunk is highly desirable, but may be difficult to find, are thin, fragile and have limited length for safe and tension-free coaptation. In addition, nerve grafts may be necessary. In this study, the technical feasibility of facial allotransplantation procurement using a transparotid approach was investigated. Three mock cadaver dissections were performed, procuring full face transplants with en bloc facial nerve dissection. The facial nerve (main trunk, temporofacial/cervicofacial divisions, and individual facial branches) was elevated en bloc as part of the allograft, dissected out from the parotid completely, and left as loose attachments to the allograft specimen. Full face transplantation with en bloc facial nerve dissection was technically feasible, allowing for more proximal or distal nerve section, and to achieve the desired length and diameter for appropriate matching during nerve coaptation. This technique follows principles of targeted nerve reinnervation. It allows to select the level of facial nerve section to the temporofacial and cervicofacial divisions or final branches, with further adaptation to the remaining recipient's anatomic structures, and avoiding the need for nerve grafts; it also excludes the parotid gland (reduces bulk). Despite a small increase in the time required for dissection, this disadvantage may be compensated by an improved functional recovery.