Nerve Transfers for Facial Transplantation: A Cadaveric Study for Motor and Sensory Restoration

Background: Restoration of facial animation and sensation is highly important for the outcome after facial allotransplantation. The identification of healthy nerves for neurotization is of particular importance for successful nerve regeneration within the allograft. However, because of 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, the authors 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 into two parts. First, the technical feasibility of nerve transfer from the cervical plexus to the mental nerve and the masseter nerve to the buccal branches of the facial nerve was assessed. Next, the authors 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 infra-orbital nerve, sensory restoration of the lower lip by neurotization of the mental nerve, and smile reanimation by neurotization of the buccal branches of the facial nerve. Results: In all specimens, coaptation of at least one of the branches of the cervical plexus to the mental nerve and between the masseter nerve to the buccal branch of the facial nerve was possible. In simulated face transplant procedures, nerve transfers of the supraorbital nerve to the infraorbital nerve, cervical plexus branches to the mental nerve, and masseter nerve to facial nerve are all technically possible. Conclusions: 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.