Dissecting Circle of Willis Arteries via Endoscopic Endonasal Techniques

Introduction: Endoscopic endonasal approaches for intracranial and intradural tumors have gained increasing attention. Previous limitations for removal have included the involvement of underlying cerebral vasculature. With increasing experience, resections of more challenging lesions are being attempted.

Methods: A retrospective review was performed analyzing endoscopic endonasal resections of anterior skull base intracranial tumors between July 2007 and December 2010 by a single team at a single institution. Lesions with involvement of cerebral vessels were defined, on MR imaging, as those in which arteries of the circle of Willis either directly abutted or passed through the tumor. Resection, stroke, and vascular injury rates were reviewed.

Results: Of 105 total cases, 27 met radiographic criteria for some circle of Willis involvement. Tumor types included meningioma, giant pituitary adenoma, and craniopharyngioma. Resection included dissection of the anterior cerebral, anterior communicating, posterior cerebral, posterior communicating, and basilar arteries. The rate of gross total resection was 20/27 (74.1%), stroke 1/27 (3.7%), and vascular injury 1/27 (3.7%).

Conclusion: Complex skull base intracranial tumors with intimate involvement of the cerebral vasculature can be resected with endoscopic endonasal techniques with acceptable rates of resection and morbidity. In the setting of vascular injury, immediate endovascular intervention may be needed. More experience will lead to improved resection and lowered morbidity rates.