Endonasal endoscopic surgical approach for treating trigeminal schwannomas: A systematic review and meta-analysis

Trigeminal schwannomas (TSs) are the second most common type of intracranial schwannoma. Surgical approaches are chosen depending on the type of tumor extension. The middle fossa extradural approach, infratemporal extradural approach, transmaxillary approach, transmandibular approach, and transcervical approach have been used. However, these approaches are associated with a variety of complications including other cranial nerve dysfunction. Recently, with the wide application of endoscopic technology, the endoscopic endonasal approach (EEA) seems to be an alternative skull base surgical approach for skull base pathology.

The objective of the present study is to evaluate the safety and efficacy EEA approach for TSs.

We searched Medline, Embase, and Web of Science databases following PRISMA guidelines. We used single proportion analysis with 95% confidence intervals (CI) under a random-effects model, I2 to assess heterogeneity, and Baujat and sensitivity analysis to address high heterogeneity. Eligible studies included those with ≥4 patients treated with the endoscopic endonasal approach for trigeminal schwannomas.

Of the 2550 initially identified studies, 9 were selected, involving 195 patients, with a median follow-up of 36 months. The combined analysis showed a 29% (CI: 11%-49%) partial resection rate, while a pooled analysis for complete resection demonstrated an 84% rate (CI: 68%-99%). Preservation of cranial nerves reached a 99% rate (CI: 96%-100%) with a 100% preservation of facial function rate (CI: 97%-100%) and a 5% complications rate (CI: 0%-13%).

Based on these findings, our meta-analysis identified that the endonasal endoscopic approach for the treatment of trigeminal schwannomas presents a low rate of complications, favorable results regarding the preservation of facial function and cranial nerves, and, a high rate of effectiveness, demonstrated by the results of complete resection.