Anatomy,techniques and outcomes of microsurgery via infratemporal epidural approach for dumbbell-shaped trigeminal schwannomas

LI Jun-qing; MA Xiao-er; XUE Jun-feng; YANG Kong-bin

doi:10.13798/j.issn.1009-153X.2024.11.003

Abstract：Objective To investigate the anatomy,techniques,and efficacy of microsurgery via infratemporal epidural approach for dumbbell-shaped trigeminal schwannomas.Methods Eight cadaveric head specimens were dissected using the infratemporal epidural approach to expose the Meckel's cave,cavernous sinus,and trigeminal nerve root,and relevant anatomical landmarks were measured.Additionally,a retrospective analysis was conducted on the clinical data of 15 patients with dumbbell-shaped trigeminal schwannoma who underwent resection through infratemporal epidural approach between 2010 and 2020,summarizing the surgical experience.Results Cadaveric dissection revealed that the infratemporal epidural approach provided excellent exposure of the trigeminal nerve root;the anteromedial triangle and supraorbital triangle had relatively small areas of(52.4±13.1)mm2 and(27.4±6.3)mm2,respectively.The postoperative MRI reexaminations of 15 patients with dumbbell-shaped trigeminal schwannomas showed that complete tumor resection was accomplished in 13 patients(87%),and subtotal resection was carried out in 2(13%).Of the 15 patients followed up for 6 months postoperatively,11 patients(73.3%)experienced symptom relief or stabilization,while 4 developed new neurological deficits.Postoperative complications occurred in 5 patients,all involving cranial nerve injury.Conclusions The infratemporal epidural approach offers certain advantages for resecting dumbbell-shaped trigeminal schwannomas but carries a relatively high risk of complications.Further optimization of surgical techniques is necessary to balance tumor resection and neural function preservation,thereby improving surgical outcomes.