Carotid Endarterectomy in a Patient with Persistent Proatlantal Artery

Accessible online at: www.karger.com/ced On admission, a 37-year-old man presented with an acute right-sided sensorimotor hemiparesis and nonfluent aphasia (NIH Stroke Scale score 11) persisting for more than 12 h. As cerebrovascular risk factors, the patient exhibited untreated arterial hypertension and chronic nicotine abuse (42 pack-years). Cranial computer tomography revealed a left-sided posterior border zone infarction. An electrocardiogram on admission, subsequent ECG monitoring and transthoracic echocardiography indicated no significant pathological findings. Extracranial color-coded duplex sonography revealed an occlusion of the left internal carotid artery (ICA) directly after the bifurcation. About 1.5 cm more distally, a high-frequency flow signal in projection on the lumen of the left ICA ( fig. 1 ) was detected. Transcranial duplex sonography showed a diminished blood flow velocity of the left middle and anterior cerebral arteries. The left vertebral artery was hypoplastic. Digital subtraction angiography confirmed the extracranial occlusion of the left ICA. Furthermore, it revealed a persistent proatlantal intersegmental artery originating from the V 3 segment of the vertebral artery and discharging into the ICA distally from the carotid occlusion ( fig. 2 ). In addition, the patient presented a fetal blood supply type (with hypoplastic P 1 segments), i.e. the posterior arteries were supplied by the intracranial distal internal artery via the posterior communicating arteries. An additional hypoplasia of the right A 1 segment made an anterior cross-flow impossible and led to the critical situation that the entire left hemisphere was supplied only by the persistent intersegmental proatlantal artery. Fluctuation and slight deterioration of the patient’s neurological symptoms despite hypertensive systolic blood pressure values between 160 and 200 mm Hg and additional small-sized infarcts of terminal vessels demarcated in a follow-up cranial computer tomography emphasized the critical hemodynamic situation. A revascularization procedure was seen as indicated. The patient underwent thrombendarterectomy (TEA) of the occluded left ICA 6 days after the onset of stroke symptoms. Afterwards, the neurological deficits did not improve in general but fluctuations were no longer observed and the patient could be transferred to a Cerebrovasc Dis 2007;23:458–459