The Retroauricular Approach to the Facial Nerve Trunk

Background: Exposure of the common trunk of the facial nerve has traditionally been approached based on principles of parotidectomy, which is associated with high rates of facial nerve palsy and landmarks that may be unreliable. On the basis of experience gained with vascularized composite allotransplantation of the face, the authors propose a retroauricular approach that may be more time-effective and safe. Methods: In the proposed retroauricular facial nerve approach, an incision is made posterior to the ear in the retroauricular sulcus, and dissection proceeds anteriorly to the mastoid fascia to the base of the conchal bowl. The anteroinferior edge of the external auditory canal is followed as a reference structure to locate the facial nerve trunk (FNT), coursing between the stylomastoid foramen (posteromedially) and entering the parotid gland (anteriorly). Twelve unilateral FNT dissections were performed in 6 fresh human cadaver heads. Six dissections were performed for illustration and proof of concept using full facial transplant, conventional, and limited retroauricular exposures; 6 additional dissections were performed by trainees to assess reliability and replicability of technique. Results: The FNT was successfully identified in all 12 dissections. Trainees tended toward being more time efficient in exploring the anatomy when using the limited retroauricular technique than with the conventional approach, 7.8 +/- 0.78 minutes versus 13.0 +/- 3.3 minutes (P = 0.089). No intraoperative injury to any critical structure was noted with either technique. Conclusion: A retroauricular approach to the FNT based on liberating anterior tissues from the auditory canal provides expedient and aesthetic exposure of the FNT.