[Timing of facial nerve decompression for Bell's palsy: systematic review and Meta-analysis].

Objective: To compare the surgical effects of facial nerve decompression for bell's facial palsy at different times, and to provide reference for evaluating the best operation time of Bell's palsy. Methods: A systemic search of subject-related clinical studies published before December 2023 was conducted. Meta-analysis was performed with RevMan5.3 software for the literatures meeting the inclusion criteria to compare the efficacy of different surgical timing. Surgical outcome was defined as the effective by house-Brackmann grade Ⅰ-Ⅲ, and satisfactory recovery was defined by grade Ⅰ-Ⅱ. Results: A total of 10 literatures were included, including 498 cases. The overall quality of literatures was high, and no obvious publication bias was suggested. The effective rate of facial nerve decompression in general was 86.1%-100.0%, and the satisfactory recovery rate was 50.0%-80.5%. The effective rate of operation within 3 months (91.4%) was higher than that after 3 months (81.4%, OR=3.66, 95%CI: 1.53-8.73, P=0.003); The effective rate of operation within 6 months (90.3%) was higher than that after 6 months (69.0%, OR=4.34, 95%CI: 1.74-10.86, P=0.002). The satisfactory recovery rate of operation within 2 months (64.9%) was higher than that of operation group (37.9%, OR=2.54, 95%CI: 1.26-5.11, P=0.009). The satisfactory recovery rate of the operation group within 3 months (58.9%) was higher than that of the operation group after 3 months (15.4%, OR=7.14, 95%CI: 2.40-21.20, P<0.001). Conclusions: For Bell's palsy with complete facial paralysis, facial nerve decompression is an effective treatment option. The effective rate of operation within 3-6 months after onset is higher than that after 3-6 months. The satisfactory recovery rate of operation within 2-3 months after onset is higher than that after 2-3 months. This provides an important basis for the choice of the best operative time and the prediction of the surgical outcome for Bell's palsy.