Retrosigmoid Intradural Suprameatal-Inframeatal Approach for Complete Surgical Removal of a Giant Recurrent Vestibular Schwannoma with Severe Petrous Bone Involvement: Technical Case Report.

BACKGROUND: Surgical removal of giant vestibular schwannomas with severe petrous bone involvement remains challenging due to the high risk of complications. The retrosigmoid intradural suprameatal-inframeatal approach (RISIA) allows for safe exposure extending from Meckel's cave to the petrous internal carotid artery (ICA).

CASE DESCRIPTION: A 27-year-old man presented with recurrence of a giant vestibular schwannoma (4.5 cm) invading Meckel's cave and the left petrous ICA. Symptoms included complete left facial palsy and hearing loss due to tumor invasion and previous operations, as well as left-sided trigeminal hypesthesia, abducens nerve palsy, and lower cranial nerve dysfunction due to tumor compression. The patient also exhibited severe discoordination and ataxia. The tumor was completely resected via the RISIA, which involved drilling of the suprameatal and inframeatal portions of the petrous bone. No approach-related complications were observed. Full recovery of cranial nerve functions (with the exception of those related to the facial and cochlear nerves) and balance were observed postoperatively.

CONCLUSIONS: The RISIA allows for safe and effective surgical access during complete tumor resection, even when severe involvement of Meckel's cave and the petrous ICA are observed. The present report is the first to demonstrate the usefulness of this approach in patients with recurrent giant vestibular schwannoma.