OBJECTIVE AND IMPORTANCE: A persistent hypoglossal artery, one of the
embryonic carotid-basilar anastamoses that can fail to regress in the
embryo and can be observed past birth, is one of the only congenital a
natomic variations of the internal carotid artery (ICA) that can compl
icate the performance of carotid endarterectomy. When associated with
atherosclerotic carotid artery disease, the recognition and intraopera
tive management of a persistent hypoglossal artery is important. CLINI
CAL PRESENTATION: A 72-year-old man presented with a symptom of transi
ent right hemisphere ischemia, and although ultrasonography indicated
a right ICA stenosis (and no other abnormality), angiography also demo
nstrated that the atherosclerotic plaque extended into the origin of a
large right persistent hypoglossal artery arising 1.5 cm from the ori
gin of the ICA. In this patient, the persistent hypoglossal artery was
the only arterial supply to the basilar artery. INTERVENTION: The pat
ient underwent a right ICA endarterectomy, and intraoperative angiogra
phy was necessary to ensure that the persistent hypoglossal artery was
the vessel shunted during the arterial repair. CONCLUSION: Recognitio
n of the primitive carotid-basilar anastamoses is important to surgeon
s who perform carotid endarterectomy and is not possible with ultrason
ography alone. Intraoperative angiography enables the surgeon to accur
ately catheterize a persistent hypoglossal artery with a carotid shunt
.