Intracranial collateral anastomoses: relevance to endovascular procedures

An in-depth knowledge of intracranial and extracranial collateral anastomoses, overt or hidden, is crucial for an interventionist to devise optimal endovascular strategies to manage a host of pathologic conditions; to ascertain potential pitfalls; and, ultimately, to avoid complications that could have been prevented by a better understanding of underlying vascular anatomy. As the scope and extent of endovascular interventions for cerebrovascular and cranial disease continues to expand, the recognition of these putative anastomoses will continue to become a larger part of diagnostic evaluation and interventional design. This article provides a brief overview of cranial vascular development, followed by specific clinically relevant examples of extracranial and intracranial anastomoses and the internal carotid artery and vertebrobasilar anastomoses.