Paramedian supracerebellar transtentorial approach for Yaşargil T2 tentorial incisura meningiomas.

Abstract

OBJECTIVE: Tentorial incisura meningiomas, particularly those arising from the middle incisural region (Yaşargil T2), are surgically challenging because of their deep location and compression of critical neurovascular structures. These lesions typically have supratentorial or infratentorial extension but can also extend across both compartments. Although approach selection is often guided by the dominant compartment of tumor extension, for lesions with supratentorial-dominant extension, the optimal approach remains controversial, and a standardized strategy has not been established. Authors of this study evaluated the feasibility and outcomes of the paramedian supracerebellar transtentorial (PST) approach for Yaşargil T2 tentorial incisura meningiomas with a supratentorial-dominant or combined extension. METHODS: The authors retrospectively reviewed data from consecutive patients with radiographic and intraoperative findings consistent with a Yaşargil T2 tentorial incisura lesion treated via the PST approach from September 2005 through December 2025. Patients were placed in a semisitting position whenever feasible and in a semilateral position when semisitting was contraindicated. Collected data included demographics, tumor extension patterns, extent of resection on postoperative MRI, neurological outcomes, histopathology, rate of recurrence, and follow-up. RESULTS: Six patients, 1 male and 5 female, with an overall mean age of 43 years, underwent resection via the PST approach. Four lesions had predominantly supratentorial extension, and 2 had combined supra- and infratentorial growth, with no cases of isolated infratentorial extension. Five patients had been placed in the semisitting position and 1 in a semilateral position because of a cardiac contraindication to the semisitting position. No new permanent neurological deficits were observed. Postoperative MRI showed Simpson grade I resection in all 6 patients. The mean follow-up was 8.6 years. Histopathological analysis revealed 3 WHO grade 1 meningiomas, 1 WHO grade 2 meningioma (clear cell), and 2 solitary fibrous tumors (meningioma mimics). These diagnoses were evaluated according to the 2021 WHO classification. CONCLUSIONS: In this consecutive series, the PST approach was a viable single-corridor strategy for Yaşargil T2 tentorial incisura lesions, including supratentorial-dominant tumors, achieving Simpson grade I resection with no permanent neurological deficits. By providing early devascularization at the tentorial attachment and a gravity-assisted, retractorless working corridor with favorable deep venous visualization, the PST approach challenges compartment dominance as the primary determinant of approach selection.