2025 Proffered Presentations
S262: SURGICAL MANAGEMENT OF 65 FACIAL NERVE SCHWANNOMAS AIMING FOR IMPROVEMENT OF FACIAL FUNCTION
Ken Matsushima, MD, PhD; Michihiro Kohno, MD, PhD; Nobuyuki Nakajima, MD, PhD; Norio Ichimasu, MD, PhD; Kiyoaki Tsukahara, MD, PhD; Taro Inagaki, MD, PhD; Tokyo Medical University
Objective: The conventional surgical treatment of facial nerve schwannoma, total resection and facial nerve reconstruction, can provide long-term tumor control with unfavorable facial nerve function (House-Brackmann grade 3 or worse). Since 2005, we have utilized facial nerve preservation surgery (subtotal tumor removal and/or bony decompression) in selected patients, such as one with no or mild preoperative facial nerve palsy and sufficient intraoperative facial nerve electromyograms, for postoperative functional improvement and maintenance of good facial nerve function. This study reports our experiences of the microsurgical treatment of facial nerve schwannomas during these 19 years.
Methods: Consecutive 65 patients with sporadic facial nerve schwannomas (mean age: 42.1 years old) underwent microsurgical resection by the senior author (M.K.) under detailed neuromonitoring including facial nerve monitoring. Their clinical information, tumor location, and intraoperative findings were retrospectively evaluated, focusing on pre- and postoperative facial nerve function.
Results: The facial nerve palsy was identified in 89% of the patients without treatment history. Tumors were classified based on their main location into 5 types; cerebellopontine angle type (29%), intrameatal type (17%), middle fossa type (6%), tympanic type (24%), and mastoid type (25%). The retrosigmoid approach was mainly selected for the cerebellopontine angle type, the middle fossa approach for the intrameatal, middle fossa, and tympanic types, and the retrolabyrinthine approach for the mastoid type. Among 67 surgeries for 61 patients with more than 1-year follow-up, facial nerve preservation surgery was utilized in 47 cases, and facial nerve reconstruction (with total removal) surgery was selected in 20. Mean House-Brackmann grade was improved in both groups; from 3.5 to 3.1 in nerve preservation surgery and 4.6 to 4.0 in nerve reconstruction surgery. During the follow-up period (mean 90 months), 7 patients with nerve preservation surgery required additional surgical treatment.
Conclusion: By utilizing different surgical strategies based on preoperative facial nerve function and intraoperative neuromonitoring, the improvement of facial function was achieved in many of our patients. More clinical experience including radiosurgery is required to achieve both maintenance of better facial nerve function and longer tumor control.
