Nerve Transfers for Facial Transplantation : a cadaveric study for motor and sensory restoration

BACKGROUND Restoration of facial animation and sensation are highly important for the outcome after facial allotransplantation. The identification of healthy nerves for neurotization, through recipient to donor nerve coaptation, is of particular importance for successful nerve regeneration within the allograft. However, due to the severity of the initial injury and resultant scar formation, a lack of healthy nerve stumps in the recipient is a commonly encountered problem. In this study, we evaluate the technical feasibility of performing nerve transfers in facial transplantation for both sensory and motor neurotization. METHODS Fifteen fresh cadaver heads were used in this study. The study was divided in two parts. First, the technical feasibility of nerve transfer from the cervical plexus (CP) to the mental nerve (MN) and the masseter nerve (MaN) to the buccal branches of the facial nerve (BBFN) was assessed. Next, we performed nerve transfers in simulated face transplants to describe the surgical technique focusing on sensory restoration of the midface and upper lip by neurotization of the infraorbital nerve (ION), sensory restoration of the lower lip by neurotization of the MN, and smile reanimation by neurotization of the BBFN. RESULTS In all specimens coaptation of at least one of branches of the CP to the mental nerve was possible as well as between the masseter nerve to the buccal branch of the facial nerve. In simulated face transplant procedures nerve transfers of the supraorbital nerve (SON) to the infraorbital nerve (ION), cervical plexus branches to the mental nerve, and masseter nerve to facial nerve are all technically possible. CONCLUSION Nerve transfers are a technically feasible option that could theoretically be used in face transplantation either as a primary nerve reconstruction when there are no available healthy nerves, or as a secondary procedure for enhancement of functional outcomes. The supraorbital nerve, branches of the cervical plexus an