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Published on: February 11, 2019
Efficacy of Intraoperative Facial Nerve Monitoring in Parotidectomy: A Systematic Review and Meta-Analysis
Bryle Nicole Barrameda1, Anusha Gogulapati1, Katherine Guo1
1School of Medicine, University of California, Davis, Sacramento, California, USA.
Objective:
To assess the effectiveness of intraoperative facial nerve monitoring (FNM) in reducing immediate and permanent postoperative facial nerve weakness after primary parotidectomy.
Data Sources:
PubMed-NCBI database, January 1970 to May 2025.
Review Methods:
A systematic review and meta-analysis were performed in accordance with PRISMA guidelines. Eligible studies compared primary parotidectomy performed with versus without FNM and reported outcomes as House-Brackmann grade ≥2. Two reviewers independently extracted study characteristics and outcomes. Study quality was assessed with the Newcastle-Ottawa Scale. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated; random-effects models were used when heterogeneity (I²) exceeded 30%. Number needed to monitor (NNM) was calculated for significant endpoints.
Results:
Ten studies (n = 1047; 568 FNM, 479 control) met inclusion criteria. FNM was associated with nearly halved odds of immediate postoperative weakness (OR = 0.49; 95% CI, 0.35-0.67; P < .01; I² = 20.2%), corresponding to an NNM of 7. Permanent weakness was also associated with a significant reduction (OR = 0.49; 95% CI, 0.30-0.81; P < .01; I² = 12.9%), with an NNM of 11. Included studies were of moderate-to-high quality (NOS 6-8/9), though domain-level biases, particularly lack of blinding and incomplete confounder adjustment, were common. No significant publication bias was detected.
Conclusion:
Intraoperative FNM during primary parotidectomy was associated with reduced immediate and permanent postoperative dysfunction. These results, which extend beyond prior meta-analyses limited to immediate outcomes, support routine adoption of FNM as an adjunct to optimize nerve preservation and reduce morbidity.
