Hypervascular vestibular schwannomas

Area of Science:

• Neurosurgery
• Oncology
• Radiology

Background:

• Vestibular schwannoma (VS) is typically hypovascular, allowing for safe resection.
• Hypervascular VS, though uncommon, presents significant surgical challenges due to excessive bleeding.
• Understanding the distinct characteristics of hypervascular VS is crucial for effective management.

Purpose of the Study:

• To clarify the clinical characteristics of hypervascular VS.
• To evaluate the management strategies for hypervascular VS.
• To compare hypervascular VS with nonhypervascular VS.

Main Methods:

• Retrospective review of surgical reports and videos from 78 patients with unilateral VS.
• Comparison of clinical characteristics, radiological findings, and management between hypervascular (5 cases) and nonhypervascular (73 cases) VS.
• Analysis of MRI and angiographic findings for hypervascular VS.

Main Results:

• Hypervascular VS occurred in younger patients (29 vs. 52 years) and was larger and solid on MRI, with prominent draining veins.
• Angiography revealed extensive tumor vessels, tumor stains, and vertebrobasilar artery supply in hypervascular VS.
• A multi-stage surgical approach, involving initial partial resection, significantly reduced vascularity and bleeding, enabling successful total or near-total resection without major morbidity.

Conclusions:

• Hypervascular VS is characterized by early onset, solid nature, larger size, and distinct vascularity on imaging.
• MRI can suggest hypervascular VS by identifying multiple flow voids on the tumor surface.
• A staged surgical strategy is recommended for hypervascular VS to mitigate intraoperative bleeding and facilitate complete resection.