Endoscopic Endonasal Surgery for Cholesteatomas of the Posterior Cranial Fossa and Parasellar Region

Background: Endoscopic endonasal surgery (EES) offers a direct ventral corridor to the skull base, potentially enabling maximal resection of extensive cholesteatomas (epidermoid cysts) in the posterior cranial fossa and parasellar region. However, outcomes and complications specific to this approach require detailed analysis. Methods: A retrospective review was conducted on 34 patients who underwent EES for cholesteatomas of the posterior fossa and parasellar region at a single high-volume center (2011-2025). Surgical approaches were tailored to the lesion's extent. Extent of resection (near-total >95%, subtotal 90-95%), complications, and neurological outcomes were analyzed. Results: Near-total resection was achieved in 65% of cases and subtotal in 35%. The most frequent complications were postoperative cerebrospinal fluid (CSF) leakage (23.5%) and meningitis (23.5%; 33.3% in patients with intradural extension). Rates were significantly higher than for other skull base tumors. Only visual symptoms showed consistent postoperative improvement. New or worsened cranial nerve deficits occurred in 12% of cases. The rates of CSF leakage and meningitis were 25% and 33%, respectively. Arrested hydrocephalus requiring shunting developed in 14.7% of patients. Conclusion: EES provides a valid alternative for the surgical management of posterior fossa and parasellar cholesteatomas, allowing for a high degree of resection. However, it is associated with a notably higher risk of CSF leakage and meningitis compared to EES for other pathologies, attributable to the lesion's adhesive and inflammatory characteristics. Furthermore, significant recovery of preoperative neurological deficits (except visual) is uncommon. These findings underscore that such complex procedures should be performed in specialized centers with extensive expertise in endoscopic skull base surgery and multidisciplinary perioperative care.