Persistent primitive hypoglossal artery associated with cerebral aneurysm and cervical internal carotid artery stenosis--case report.

A 71-year-old female had vertigo attacks once or twice a day secondary to vertebrobasilar insufficiency. Left carotid angiography revealed persistent primitive hypoglossal artery (PPHA) associated with a large internal carotid artery (ICA) aneurysm and severe stenosis of the ICA. The bilateral vertebral arteries were hypoplastic. The basilar artery was opacified via the PPHA but not via vertebral arteries. Clipping of the aneurysm was performed first because the risk of rupture of the aneurysm was not negligible. One month after clipping, carotid endarterectomy using a T-shaped shunt system was successfully performed. The postoperative course was uneventful and the vertebrobasilar ischemic attacks did not recur. Left carotid angiography demonstrated complete obliteration of the aneurysm and disappearance of the carotid artery stenosis. Low ICA flow (70 ml/min) and low stump pressure of the PPHA (25 mmHg) strongly suggested low perfusion of the posterior circulation. Carotid endarterectomy may be essential for augmentation of the posterior circulation in patients with PPHA associated with ICA stenosis.