Hypoglossal-Facial Nerve Anastomosis: A Meta-Analytic Study

Abstract

Objectives: A meta-analysis was conducted on the outcome of facial nerve function after hypoglossal-facial nerve anastomosis in humans. The roles of the timing of and the underlying cause for surgery, the type of the repair, and previous facial nerve function in the final result were analyzed. Methods: Articles were identified by means of a PubMed search using the key words “facial-hypoglossal anastomosis,” which yielded 109 articles. The data were pooled from existing literature written in English or French. Twenty-three articles were included in the study after we excluded those that were technical reports, those describing anastomosis to cranial nerves other than the hypoglossal, and those that were experimental animal studies. Articles that reported facial nerve function after surgery and timing of repair were included. Facial nerve function had to be reported according to the House-Brackmann scale. If there was more than 1 article by the same author(s), only the most recent article and those that did not overlap and that matched the above criteria were accepted. The main parameter of interest was the rate of functional recovery of the facial nerve after anastomosis. This parameter was compared among all groups with Pearson's X2 test in the SPSS program for Windows. Statistical significance was set at a p level of less than .05. Results: Analysis of the reports indicates that early repair, before 12 months, provides a better outcome. The severity of facial nerve paralysis does not have a negative effect on prognosis. Gunshot wounds and facial neuroma are the worst conditions for favorable facial nerve recovery after anastomosis. Transection of the hypoglossal nerve inevitably results in ipsilateral tongue paralysis and atrophy. Modification of the anastomosis technique seems to resolve this problem. Nevertheless, the effect of modified techniques on facial reanimation is still unclear, because the facial nerve function results were lacking in these reports. Conclusions: Hypoglossal-facial nerve anastomosis is an effective and reliable technique that gives consistent and satisfying results.