Atheromatous Pseudo-occlusion of the Internal Carotid Artery

Between 1978 and 1988, the diagnosis of atheromatous pseudo-occlusion of the internal carotid artery was made in 34 patients by angiography. Results of noninvasive tests were abnormal in 33 of the 34 patients examined. Twenty-five patients had carotid endarterectomy, and the other nine were treated medically. Four of the 34 patients (12%) had significant complications, two related to angiography and two to surgery. Twenty-three of the 25 operated patients were seen in long-term follow-up; 19 (83%) were found to have a patent operated vessel by noninvasive testing. None of the 23 operated patients followed up suffered recurrent neurologic deficits following surgery; two had distant contralateral strokes. Three of the nine patients treated medically (33%) experienced delayed ipsilateral stroke. This study shows that the risks associated with angiography and surgery for atheromatous pseudo-occlusion are significant and are higher than previously reported. (Stroke 1989;20:1168-1173) Highly stenotic but patent internal carotidarteries (ICAs) can easily be misdiag-nosed as occluded by both noninvasive testing and by angiography. Blood flow distal to a site of extreme stenosis may be so minimal that it remains undetected. The term "atheromatou