Effect analysis of hypoglossal-facial neurorrhaphy using a predegenerated sural nerve autograft for peripheral facial paralysis

Objective To evaluate the treatment effects of hypoglossal-facial 'side’-to-side neurorrhaphy using a predegenerated sural nerve autograft for facial paralysis following tumor resection in cerebellopontine angle (CPA) area. Methods We followed up 48 patients who developed facial paralysis as a result of CPA tumor removal and underwent hypoglossal-facial 'side’-to-side neurorrhaphy using a predegenerated sural nerve autograft between June 2013 to February 2016 at Neurosurgery Department of Beijing Tiantian Hospital, Capital Medical University. Eight other patients who served as controls did not receive any repair treatment. Patients in both groups received rehabilitation exercises and their static and dynamic facial images were collected. Electrophysiological tests of the facial nerve were conducted including electromyography, motor nerve conduction and F wave. The patients' facial nerve functions were assessed according to House-Brackmann grading scale(H-B scale). The follow-up lasted 2-36 months with an average of (12.1±13.4) months. Results In the surgical treatment group, 24/48 patients were found postoperatively to have significant facial function improvement on H-B scale, 21/48 patients to have improvement, and 3/48 remained unchanged. In the control group, 1/8 patient was found to have significant facial function improvement on H-B scale, 2/8 had improvement and 5/8 remained unchanged associated with marked atrophy of paralyzed facial muscles. Significant difference was identified in the facial function improvement on H-B scale between the surgical treatment and control groups (P<0.01). The improvement of facial nerve function was most evident if the surgical repair treatment was performed within the 6 months after the onset of facial paralysis. Conclusions Hypoglossal-facial 'side’-to-side neurorrhaphy may effectively treat facial paralysis resulting from CPA tumor resection. Better recovery of facial nerve function could be achieved when the surgical treatment is performed within the 6 months after the onset of the facial paralysis. Key words: Central nervous system neoplasms; Cerebellopontine angle; Facial paralysis; Transplantation, autologous; 'Side’-to-side neurorrhaphy