Resection of Synthetic Petroclival Meningiomas in a 3D-Endoscopic Transtubular Anterior Transpetrosal Approach

Objective: Extradural anterior petrosectomies are commonly used in the resection of petroclival meningiomas, though the application of temporal retraction carries the risk of the venous complications. We investigate a less invasive 3D endoscopic anterior transpetrosal approach through a subtemporal keyhole craniotomy using a minimally invasive tubular retractor system. Study Design, Material, and Methods: Subtemporal keyhole craniotomies were performed on five preserved cadaveric heads (ten sides) previously injected with medium (three sides, 1.0-2.4 cm), large (four sides, 2.5-4.4 cm), or giant (three sides, >4.5 cm) synthetic petroclival meningiomas. A ViewSite brain access system of tubular retractors (Vycor Medical, Inc., Boca Raton, Florida, United States) was placed into the keyhole and secured to supply minimal temporal retraction. An extradural anterior petrosectomy was performed and the degree of resection was assessed using the Simpson grading scale. Results: This approach is most suitable for use on smaller, medium, and petroclival meningiomas. Gross-total resections (Simpson grades I and II) were achieved in all three medium petroclival meningiomas. Subtotal and partial resections (Simpson grades I and III) were each achieved in two large petroclival meningiomas, and partial resections (Simpson grade IV) were achieved in all three giant tumors. Conclusion: The application of 3D endoscopic transtubular anterior transpetrosal approaches in the treatment of medium petroclival meningiomas is both feasible and effective.