Natural history of chronic bilateral internal carotid artery occlusion.

Chronic bilateral ICA occlusion was found in 15 of 3200 patients studied with duplex scanning during a six years period. Ten of these patients had a history of stroke. Mean follow-up was 28.9 months. Six patients died during follow-up, coexisting cardiac ischaemia being the major cause of death. Two patients suffered a stroke (one fatal) resulting in an annual stroke rate of 5.5%, three patients continued to have TIAs and 5 remained asymptomatic. Chronic bilateral ICA occlusion is not always associated with neurological deficit. Coronary ischaemia, more than stroke is the leading cause of death in these patients.