Isolated origin of the left internal carotid artery from the pulmonary artery.

The authors describe what is, to their knowledge, the first reported case of the anomalous origin of an internal carotid artery from the pulmonary artery. An otherwise asymptomatic 6-year-old girl, who presented with headaches and hypertension, underwent a comprehensive workup that revealed extensive meningeal and cerebral artery anastomoses to the left internal carotid artery--itself arising from the origin of the left pulmonary artery. This unique anatomical anomaly, caused by a disturbed pattern of aortic arch regression, resulted in a right-to-left vascular shunt into the pulmonary artery and a disturbance of intracranial artery flow patterns, complicating the management options.