ABSTRACT
Endovascular methods have expanded the way we evaluate, follow, and ultimately treat vascular pathology. Whether in conjunction with open surgical procedures or in isolation, neurointerventional tools have enabled previously untreatable conditions to be tackled within acceptable margins of safety. Advances continue to expand the array of pathologies treatable through less invasive approaches. The benefit to the patient manifested by increased success rates, shorter hospital stays, and reduced morbidity and mortality cannot be overstated. However, the utility of even the most advanced biplanar machine with 3D rotational capabilities is limited without a thorough understanding of the craniocerebral angiographic anatomy. This must include the significant arterial anastomoses and collateral circulatory patterns that should be considered during any intervention. It is collateral circulation that may prevent significant neurologic deficit should parent artery occlusion be required. Conversely, circulatory anastomoses can result in unexpected patterns of infarct distal to the areas of embolization or parent artery occlusion if not appropriately anticipated. The purpose of this chapter is to provide an in-depth review of the normal cerebrovascular angiographic anatomy as well as the significant internal, external, and vertebrobasilar anastomoses to be considered during treatment. The importance of the contribution of individual anatomy in the formulation of any treatment plan is paramount. Because thorough reviews of anatomic variants have been provided elsewhere (1-5), only brief descriptions will be highlighted here where considered relevant.
