Single-stage endoscopic endonasal approach for the complete removal of trigeminal schwannomas occupying both the middle and posterior fossae.

To introduce a purely endoscopic endonasal trans-Meckel's cave approach or a transclival approach for trigeminal schwannomas (TSs) involving both the middle and posterior fossae. This retrospective study reviewed the medical records and intraoperative videos of 8 patients with TSs occupying both the middle and posterior fossae who underwent an endoscopic endonasal approach (EEA) between January 2017 and October 2019. All 8 patients received total resection under a single-stage EEA. Six patients underwent endoscopic endonasal resection via a purely trans-Meckel's cave approach, and 2 patients underwent endoscopic endonasal resection via a trans-Meckel's cave approach combined with a transclival approach. There was no surgical-related hemorrhage or mortality and no cerebrospinal fluid leakage. All headache symptoms completely improved postoperatively (n = 3 patients). All cranial nerve (CN) symptoms (CN IX and CN VI) improved postoperatively. The most common preoperative symptom was facial numbness (n = 5 patients); 2 of these 5 patients showed a partial improvement, 1 patient experienced worsening, and 2 patients remained unchanged at the last follow-up. Four patients developed postoperative complications, including CN VI palsy (n = 2), dry eye (n = 2), mastication weakness (n = 1), and facial numbness (n = 2). All complications except for dry eye were relieved at the last follow-up, but the patients with dry eye did not develop corneal keratopathy. The endoscopic endonasal trans-Meckel's cave and transclival approaches provide adequate exposure and improve the rate of total resection for TSs occupying both the middle and posterior fossae with minimal invasion. It may be possible to use these approaches as a safe alternative to conventional surgical approaches.