Abstract
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.
Keywords
anatomy - endovascular procedures - external carotid artery - interventional radiology
