Tag: peritorcular

J Neurosurg 143:1449–1457, 2025

This clinical and anatomical study defines the structural composition of the torcular Herophili and its implications for resection of peritorcular meningiomas, presenting histological evidence of a delaminable collagenous plane between venous endothelium and dural fibrous layers. The authors propose a four-type classification of tumor invasion based on endothelial integrity to guide operative strategy and preserve venous flow.

Clinical outcomes from 14 patients treated between 1997 and 2018 are reported, demonstrating feasibility of gross-total resection for type I–II tumors via layer-by-layer dissection with venous wall reinforcement, while types III–IV require preservation of collateral drainage and tailored reconstructive or adjunctive approaches.

• Torcular Anatomy: The torcular wall consists of two main compartments—an inner venous structure lined by endothelium and supported by elastic and smooth muscle fibers, and an outer fibrous dural layer, separated by a collagenous cleavage plane that enables surgical delamination.

• Meningioma Classification: Peritorcular meningiomas are classified into four types based on anatomical invasion: Type I (dural involvement only), Type II (dural involvement with sinus compression/displacement), Type III (endothelial layer disrupted, tumor penetrates lumen), and Type IV (complete sinus occlusion).

• Surgical Technique: For Type I and II tumors, gross-total resection is feasible by dissecting the tumor away from the inner venous wall at the cleavage plane, preserving venous integrity and flow; in Types III and IV, focus shifts to preserving venous collaterals due to disrupted or occluded flow.

• Preoperative Planning: Detailed imaging and identification of venous collaterals are critical for operative planning, especially when sinus flow is compromised or occluded.

• Outcomes: Gross-total resection was achieved in all patients with Type I and II tumors, with lower recurrence rates; subtotal resection and higher recurrence were associated with Types III and IV and higher-grade meningiomas.

• Complications and Mortality: No surgical mortality was reported; complications included wound infections and, rarely, recurrence or death related to aggressive tumor biology rather than surgery itself.

• Role of Radiotherapy: Radiation therapy was reserved for high-grade, residual, or recurrent tumors, particularly when total resection was not possible or in cases of sinus wall involvement.

• Clinical Significance: Preservation of the torcular venous wall and flow is paramount for favorable outcomes; anatomical understanding of the torcula enables safer, more effective resections and reduces recurrence in benign cases.