Surgical management of facial vascular anomalies: role of intraoperative seventh nerve monitoring

Abstract

Surgical management of facial hemangiomas, the most common childhood neoplasms and infiltrating facial vascular malformations, has the risk of injury to the facial nerve and remains controversial. The aim of this study was to analyze the use of the commercially available Neurosign 100® Nerve Monitor in those cases of facial vascular anomalies where resection was considered the appropriate treatment. On a prospective basis, six consecutive patients with deep (so-called infiltrating) vascular anomalies of the face (two hemangiomas, three lymphatic malformation, one lymphatico-venous malformation) were enrolled in this study. During surgical preparation, electromyographic (EMG) activity of the muscles innervated by the facial nerve was monitored. The variables collected included the patient’s sex, age at surgery, location of the lesion and depth, prior treatment, diagnostic workup, site of skin incision, operating time, operative and postoperative complications, and reconstructive outcome. All lesions were resected without major bleeding. Postoperatively, all patients showed regular, symmetrical function of the facial nerve. The mean operating time was 136.7 min (range 90 to 240 min). During the preparation using surgical instruments, EMG activity was noted both as a graphic signal showing facial nerve activity and as an acoustic signal. In all patients, the branches of the facial nerve were identified clinically by electrode stimulation at 30 Hz. Postoperatively, all patients had improvement of facial asymmetry and deformity; preoperative pain episodes and functional impairments resolved completely. Intraoperative facial nerve monitoring provides feedback regarding the location, extent, and ongoing functional status of the facial nerve in the surgical management of infiltrating benign lesions such as hemangiomas and vascular malformations. Besides an overall distinct indication for surgery, we recommend its use for prevention of iatrogenic facial nerve injury.