Permanent facial palsy and recurrence rate after surgery for benign parotid tumors: pairwise and network meta-analysis of different parotid surgery techniques

Background: Parotid surgery for benign tumors has shifted from total parotidectomy (TP) toward less invasive procedures such as partial parotidectomy (PP) and extracapsular dissection (ECD). This study compared these techniques regarding tumor recurrence rate (TRR) and permanent facial palsy rate (FPR). Methods: A systematic review, pairwise and network meta-analysis were performed on studies reporting TRR and FPR for TP, PP, and ECD. Eligible publications were identified in PubMed, Web of Science, and Cochrane Library through 2024. Rates were analyzed using arcsine transformation and arcsine differences (ASD) with random- or fixed-effects models. Results: Of 1,249 detected publications, 23 studies with 4,674 adult patients were included. Mean follow-up was 66.0 ± 56.5 months. The average TRR was 2.9 ± 2.9%, and the average FPR was 3.0 ± 5.5%. Network meta-analysis showed no significant TRR difference for ECD (ASD: -0.00; 95% CI: -0.06-0.06) or TP (ASD: -0.07; 95% CI: -0.17-0.04) vs. PP in the random-effects model. For FPR, no significant differences were found between TP and PP or between ECD and PP. Only one study compared ECD with TP for FPR, preventing a meta-analysis. Conclusions: The findings suggest that, when feasible, ECD appears to offer recurrence risks similar to PP, while both may have slightly higher TRR than TP. Permanent facial palsy risk seems comparable between ECD and PP and may be lower for ECD/PP than for TP. The results should be interpreted with caution, as there is a lack of studies with long-term follow-up. Well-designed randomized surgical studies with long-term follow-up are needed.