Operative Strategies for Aplastic Circle of Willis Arteries on CTA in Meningioma Surgery: A Case Report.

Background and importance: Meningiomas frequently involve critical neurovascular structures. Preoperative imaging with computed tomography angiography (CTA) can help understand the relationship of tumor with neurovascular structures. Although CTA was useful in preoperative planning and less invasive, we present a unique case in which it mistakenly represents a hypoplastic anterior cerebral artery as aplastic and thus displays poor sensitivity in the Circle of Willis.

Clinical presentation: A 66-year-old woman presented with new onset seizures and MRI demonstrated a sphenoid wing meningioma with tumor involvement of the internal carotid artery and right M1 artery. On preoperative CTA, a right A1 artery was not appreciated. However, a hypoplastic right A1 artery was identified during careful dissection guided by micro-Doppler and found to be encased within the tumor. All arteries were preserved, and a near-total resection was achieved with a small remnant of tumor at the supraclinoid internal carotid artery.

Conclusion: Although CTAs can be useful in understanding vascular anatomy and its association with tumors, they are not ideal for providing information about hypoplastic arterial segments. Seemingly aplastic arteries on CTA may very well be present, albeit hypoplastic. While we recognize the usefulness of a less invasive modality of CTA to help guide surgical strategy, we underscore recognizing this potential pitfall and recommend the use of the microvascular Doppler during careful dissection when working within tumor in the location of a seemingly aplastic artery.