Near-Total versus Gross-Total Resection of Large Vestibular Schwannomas: Facial Nerve Outcome

Introduction: Large vestibular schwannomas (VS) with brainstem compression are generally reserved for surgical resection. Surgical aggressiveness, however, must be balanced with the morbidity from inadvertent cranial nerve injury. The purpose of the present investigation is to evaluate the clinical presentation, management modality and patient outcomes following near-total resection versus those of gross-total resection of large VS.

Methods: Between January 2010 and March 2018, a retrospective chart review was completed to capture patients who had VS Hannover grades T4a (compression of brainstem) and T4b (compression of the brainstem accompanied by dislocation of the 4th ventricle). Primary data points that were collected included patients demographics, preoperative symptoms, tumor size, extent of resection (near-total or gross-total resection), and postoperative neurological outcome including facial nerve House–Brackman score.

Results: Thirty-six patients underwent surgery for treatment of large (Grade 4a and 4b) vestibular schwannomas by the senior author. Five patients presented with some degree of facial weakness prior to surgery and only 6 had serviceable hearing. Facial nerve integrity was preserved in 35 patients (97%) at the completion of the surgery. Twenty-seven patients underwent complete resection and nine had near-total (>98%) resection in an attempt to improve facial nerve function. Among patients with total resection, 74% (20/27) had grade I–II House–Brackman facial nerve function at follow-up while 100% (9/9) of the group with near-total resection had grade I–II facial nerve function. Risk of meningitis, CSF leak, and sinus thromboses was not statistically different in both groups. There was no stroke, no brainstem injury, or death. Mean follow-up was 36 months.

Conclusion: Near-total resection (>98%) seems to offer a benefit in terms of facial nerve functional outcome compared with total resection in surgical management of large vestibular schwannomas. This strategy obviates the need for upfront radiosurgery for residual tumors as opposed to subtotal resection. Longer term follow-up and larger series are needed to support this paradigm as a standard facial nerve preservation approach for large vestibular schwannomas.

No conflict of interest has been declared by the author(s).