The Utility of Facial Nerve Monitoring for Parotid Surgery

Abstract

Objective: To assess the utility of facial nerve monitoring in preventing transient and permanent facial paralysis in patients undergoing parotid surgery. Method: PubMed, MEDLINE, and Cochrane Trial Registry through December 2011 were searched and combined with manual review of relevant article bibliographies. All studies were assessed by 3 reviewers. Systematic review and random-effects meta-analysis were performed of studies comparing the incidence of facial nerve injury in monitored and unmonitored parotid surgery. Results: Five studies met inclusion criteria and had data suitable for pooling (374 patients). Overall, monitoring provided no benefit in reduction of facial paralysis with an odds ratio (OR) of 0.754 (0.488, 1.165; P = .203). In addition, sensitivity analysis revealed that neither transient nor permanent facial paralysis is significantly reduced with the use of monitoring. Analysis of publication bias revealed a nonsignificant Egger’s regression intercept; however, a single imputed value representing a “missing” study was found to the left of the calculated OR. Addition of this imputed value in no way altered the significance of our findings. Conclusion: Facial nerve monitoring does not significantly reduce the incidence of transient or permanent facial paralysis in parotid surgery. While few “high-level evidence” studies were available for review, our results were not affected by publication bias. Nerve integrity monitoring should not be considered the standard of care for parotid surgery.