Failure of duplex scanning to demonstrate an anomalous branch of the internal carotid artery

Abstract

Advances in non-invasive methods of investigation of the extracranial circulation have created a situation where it is possible to avoid angiography with its at tendant risks in selected cases prior to endarterectomy.1 Experience in vascular laboratories with duplex scanning has led to increasing accuracy and confidence in the results compared with biplanar angiography of the carotid bifurcation. 2 A duplex scan provides anatomical and haemodynamic information by B mode and pulsed Doppler ultrasound. However anatomical information is sometimes limited, as is highlighted by this report. ease with left ventricular impairment. Her neurological condition improved and a prophylactic right carotid endarterectomy was performed some 3 months after the initial presentation. Contrast angiograms were not obtained. At operation difficulty was encountered with an anomalous branch of the internal carotid artery. Despite this, an endarterectomy was successfully performed. From the operative specimen a 3 m m diameter vessel was identified arising from the internal carotid artery [Fig. l(a)]. Just distal to its origin the vessel was dilated and showed marked fibrosis of the intimal and inner medial layers of the endarterectomy specimen [Fig. l(b)]. The internal carotid artery showed the changes of atherosclerosis. There was marked intimal fibrosis and focal calcification but no evidence of an arteritis. The patient made an uneventful post operative recovery.