Comparative Surgical Outcomes of Schwannomas and Meningiomas in the Cerebellopontine Angle Using the Retrosigmoid Approach

Abstract

Background: Cerebellopontine angle (CPA) tumors, predominantly Schwannomas and Meningiomas, pose significant surgical challenges due to their proximity to cranial nerves and critical neurovascular structures. While the retrosigmoid approach is commonly employed for CPA tumor excision, tissue-based differences in surgical outcomes have not been extensively studied.

Objective: To evaluate histopathology-specific differences in tumor characteristics, extent of resection, and postoperative cranial nerve outcomes following retrosigmoid surgery for CPA tumors.

Methods: The study was a retrospective observational study involving 102 patients who were retrosigmoid resected CPA tumor between 2021 and 2024 in the Department of Neurosurgery, Lady Reading Hospital Peshawar, KPK, Pakistan. Demographics of the patients, the tumor nature, extent of resection, and postoperative complications were taken into consideration. The comparison of Schwannomas and Meningiomas was carried out by means of Chi-square and Fisher tests. The statistical significance was set at p = 0.05.

Results: Of the cohort, 65 patients were found to have Schwannomas and 37 had Meningiomas. The total resection among Schwannomas and Meningiomas was gross in 89.2 and 100 percent respectively. There were no major differences in consistency or vascularity of the tumor. Facial nerve weakness was found in 20.0% of Schwannomas and in 5.4% of Meningiomas (p = 0.011) and loss of gag reflex in 18.5% of Schwannomas and none in Meningiomas (p < 0.001).

Conclusion: For patients with similar tumor characteristics and surgical resection, Schwannomas are linked with greater risks of postoperative cranial nerve deficits, in comparison to Meningiomas. These results demonstrate the significance of histopathology-specialized risk evaluation and intraoperative measures to save cranial nerve functions.