Successful treatment of a ruptured enlarged infundibular widening of the posterior communicating artery--case report.

A 67-year-old female with a history of hypertension and cerebral infarction presented with subarachnoid hemorrhage (SAH) (Hunt and Kosnik grade 4). Brain computed tomography (CT) revealed a clot dominantly on the right (Fisher's classification Group 4). Cerebral angiography showed funnel-shaped widenings at the origins of the bilateral posterior communicating arteries. The maximum diameter of the widening was greater than 3 mm, so this widening was called an enlarged infundibular widening. Angiography showed a small bulge protruding posterolaterally from the wall of the right enlarged infundibular widening, and the right posterior communicating artery arose from the apex of the enlarged infundibular widening. Based on the findings of the brain CT and cerebral angiography, the diagnosis was SAH due to rupture of the right enlarged infundibular widening. Approximately 12 hours after the onset, the clot was evacuated through the right pterional approach. Bleeding from the small bulge of the right enlarged infundibular widening occurred intraoperatively, so a right-angled ring clip was applied parallel to the right internal carotid artery to obliterate the rupture point. Postoperatively, she was discharged without neurological deficit, and follow-up CT showed no other new infarction. We recommend clipping rather than wrapping or coating for similar cases of ruptured enlarged infundibular widening.