Clinical outcomes of resecting scarpa's ganglion during vestibular schwannoma surgery

Vestibular schwannomas are slow-growing tumors arising from the Schwann cells of the vestibular nerve. Scarpa’s ganglion, the vestibular nerve ganglion, is located within the internal auditory meatus. Surgical treatment of vestibular schwannomas carries the potential of resecting Scarpa’s ganglion along with the tumor. No prior studies have evaluated outcomes based on the presence of Scarpa’s ganglion within tumor specimens. The neurosurgery patient records were queried for patients who underwent surgical resection of vestibular schwannomas at the University of Missouri Healthcare between January 1, 2008 and December 31, 2018. Inclusion criteria consisted of minimum age of 18, imaging demonstrating an eighth nerve tumor, surgical resection thereof, and a final pathological diagnosis of WHO grade I schwannoma. Data were collected retrospectively. The histological slides of the tumors were reviewed, and the presence or absence of the ganglion was noted. Outcomes analyzed included postoperative dizziness, hearing, and facial nerve function. Fifty-two patients met inclusion criteria. Ten (19%) resected tumors contained portions of the ganglion. No difference in risk of resection of ganglion occurred based on the surgical approach (p = 0.2454). Mean follow-up duration was 24.6 months ± 26.2 standard deviation. No differences in postoperative hearing or dizziness (p = 0.8483 and p = 0.3190 respectively) were present if Scarpa’s ganglion was resected. House-Brackmann classification of facial nerve function at last follow-up was similar (p = 0.9190). Resection of Scarpa’s ganglion with vestibular schwannomas does not increase risk of post-operative dizziness, facial nerve weakness, or hearing loss.