Useful Method for Intraoperative Monitoring of Facial Nerve in a Scarred Bed.

Facial nerve is the main cranial nerve for the innervation of facial expression muscles. Main trunk of facial nerve passes approximately 1 to 2 cm deep to tragal pointer. In some patients, where a patient has multiple operations, fibrosis due to previous operations may change the natural anatomy and direction of the branches of facial nerve. A 22-year-old male patient had 2 operations for mandibular reconstruction after gunshot wound. During the second operation, there was a possible injury to the marginal mandibular nerve and a nerve stimulator was used intraoperatively to monitor the nerve at the tragal pointer because the excitability of the distal segments remains intact for 24 to 48 hours after nerve injuries. Thus, using a nerve stimulator at the operational site may lead to false-positive muscle movements in case of injuries. Using the nerve stimulator to stimulate the main trunk at the tragal point may help to distinguish the presence of possible injuries. A reliable method for intraoperative facial nerve monitoring in a scarred operational site was introduced in this letter.