Infundibula may be clinically significant.

An infundibulum at the origin of the posterior communicating artery is observed to such an extent that it provokes little interest or comment. Although considered preaneurysmal by some, no serious consideration is given to its surgical removal. We present a patient with a subarachnoid hemorrhage, a middle cerebral artery aneurysm, and bilateral posterior communicating artery infundibula to draw attention to the importance of the infundibulum in certain circumstances.