Semin intervent Radiol 2020; 37(02): 140-149
DOI: 10.1055/s-0040-1709155
Review Article
Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Dangerous Extracranial–Intracranial Anastomoses: What the Interventionalist Must Know

Lorenzo Rinaldo
1  Department of Neurosurgery, Mayo Clinic, Rochester, Minnesota
Waleed Brinjikji
1  Department of Neurosurgery, Mayo Clinic, Rochester, Minnesota
2  Department of Radiology, Mayo Clinic, Rochester, Minnesota
› Author Affiliations
Further Information

Publication History

Publication Date:
14 May 2020 (online)


The extracranial and intracranial circulations are richly interconnected at numerous locations, a functional connectivity which underlies their impressive capacity for adaptive plasticity in the setting of vasoocclusive disease. While evolutionarily beneficial, these connections can also result in inadvertent communication with the intracranial circulation during embolization of extracranial vessels, potentially resulting in stroke or cranial nerve palsy. While these anastomoses are always present to a certain extent, flow through them occurs under predictable circumstances, and thus embolization of the extracranial vasculature can be performed safely when knowledge of functional anatomy is combined with adherence to basic principles. Herein, we will review the anatomy of known extracranial–intracranial anastomoses and strategies for avoidance of unwanted intracranial embolization. We will also review the vascular supply to cranial nerves most at risk during common neurointerventional procedures, as well as blood supply to mucosal structures.