Outcomes in Vestibular Schwannoma Surgery: insights from our last 100 cases

Abstract

Vestibular schwannoma (VS) is a benign tumor that varies in size and presentation. Surgery is the preferred treatment for large or symptomatic VS. Facial nerve (FN) preservation is a priority because of its impact on well-being. Despite advances in surgical technics and experience, 6% to 20% of patients still experience poor facial function post-surgery. Balancing FN preservation with tumor resection is challenging because residual tumors > 0.6 cm³ may grow further. Our center has refined its approach to prioritize FN function. This retrospective study evaluated outcomes of our last 100 consecutive cases of VS resection and outlines our current therapeutic indications. We included the last 100 consecutive cases of VS undergoing surgery from January 2022 to December 2023. Exclusion criteria included neurofibromatosis type 2-related schwannomatosis, recurrent VS surgery and radiosurgery, or pre-operative FN palsy. The mean tumor volume was 8.8 ± 0.6 cm³, corresponding to 1 case of KOOS grade 2, 19 cases of KOOS grade 3, and 80 cases of KOOS grade 4. Overall, 85 patients underwent surgery with a retrosigmoid approach; 33 cases exhibited a complex FN course that was challenging during tumor removal. Resection quality was assessed as gross total resection in 17 patients (no tumor remaining, not visible on MRI), near total resection in 22 (few tumor remaining, not visible on MRI), subtotal resection in 52 (residual tumor ≤ 0.5 cm³ on MRI), and partial resection in 9 (residual tumor ≥ 0.6 cm³ on MRI). In total, 94 patients had good FN function (grade I or II) immediately after surgery and 98 patients at last follow-up. Our experience with the last 100 consecutive VS surgeries highlights our revised policy to prioritize FN function, despite some minor residual tumor remaining of which only a few grow and will be treated by radiosurgery.

Keywords: Cerebellopontine angle tumors; Facial nerve; Hearing preservation; Neurosurgery; Retrosigmoid approach; Subtotal resection.