Carotid endarterectomy for internal carotid artery stenosis associated with persistent primitive hypoglossal artery: efficacy of intraoperative multi-modality monitoring.

INTRODUCTION A persistent primitive hypoglossal artery (PPHA) is a rare vascular anomaly and is usually asymptomatic. However, the PPHA may cause multi-territorial infarction when complicated by internal carotid artery (ICA) stenosis. CASE REPORT We describe a 73-year-old male who simultaneously developed cerebral infarction in both carotid and vertebrobasilar territories due to ICA stenosis associated with an ipsilateral PPHA. The PPHA mainly provided blood flow to the vertebrobasilar territory in this case, because the bilateral vertebral arteries were markedly hypoplastic. He underwent carotid endarterectomy under internal shunting. Intraoperative multi-modality monitoring including angiography, motor evoked potential, and near infrared spectroscopy was very useful to avoid ischemic complications during surgery. The postoperative course was uneventful. CONCLUSION It should be reminded that a persistent carotid-basilar anastomosis can cause multi-territorial cerebral infarction mimicking cardiogenic embolism and may be a candidate for aggressive prophylactic intervention, when occlusive lesions develop in the carotid artery. It is very important to monitor hemodynamic and/or electrophysiological status in both carotid and vertebrobasilar territories in order to perform carotid endarterectomy safely in such cases.