Aneurysm growth and hemodynamic stress.

Two cases of intracranial saccular aneurysm related to an arteriovenous malformation (AVM) are illustrated, in which a remarkable growth of the sac over the years was demonstrated angiographically. According to the relevant literature, aneurysm enlargement is correlated to the flow toward the AVM, increasing the intrasaccular turbulence and stress on the wall to which "solitary" aneurysms are usually subjected. The presence of bilateral infundibular widening at the origin of the posterior communicating artery is noted in one of the cases. This finding possibly confirms further the effects of hemodynamic stress.