Intraoperative facial nerve monitoring on operative duration in parotidectomy: a systematic review and meta-analysis

Abstract Background Intraoperative facial nerve monitoring (IONM) can be used during parotidectomy. However, its effect on operative duration remains controversial. This systematic review and meta-analysis aimed to evaluate the association between IONM use and operative duration in parotidectomy. Methods A systematic search of MEDLINE, Embase, and the Cochrane Library was conducted for studies published up to January 2026. Studies reporting operative duration for parotidectomy performed with and without IONM were included. Data extraction and quality assessment were performed independently by reviewers. Random-effects meta-analyses were conducted to calculate mean differences (MDs) with corresponding 95% confidence intervals (CIs) for operative duration and tumor size. Subgroup, sensitivity, and publication bias analyses were also performed. Results Eight studies comprising 1677 patients were included. Overall, IONM use was associated with a statistically significant reduction in operative duration (MD, − 5.62 min; 95% CI, − 11.02 to − 0.23). In procedure-specific analyses, operative duration was significantly shorter with IONM in superficial parotidectomy (MD, − 9.09 min; 95% CI, − 17.49 to − 0.70), whereas no significant difference was observed in total parotidectomy. Pooled analyses showed no significant differences in tumor size between IONM and non-IONM groups in either the overall cohort or the superficial parotidectomy group. Conclusions IONM use is associated with a reduction in operative duration in parotidectomy overall and in superficial parotidectomy. These findings suggest a potential procedural efficiency benefit of IONM in selected parotidectomy cases.