Contralateral disease progression after carotid endarterectomy

Background. We report the natural history of the carotid artery contralateral to the ipsilateral endarterectomized carotid artery. Methods. The incidence of new symptoms and disease progression of the patent contralateral side after unilateral carotid endarterectomy (CE) was studied by clinical follow-up and serial duplex scanning in 127 patients. Results. During a mean follow-up of 44 months, new hemispheric events occurred in nine (7%) and significant progression was recorded in 27 (21%) patients. In 97 patients with initial stenosis of less than 50% (group I), contralateral progression to greater than 50% was noted in 22% and new symptoms (one transient ischemic attack and one cerebrovascular accident) in 2% of patients; three patients underwent CE. In 30 patients with initial stenosis between 50% and 99% (group II), new symptoms (all transient ischemic attacks) occurred in seven (23%) (group II vs group I; p < 0.003) and nine underwent CE (group II vs group I; p < 0.001). Progression in 26 patients with 50% to 79% stenosis within group II to greater than 80% was noted in 19% of patients (difference not significant compared with group I). Conclusions. Overall, new symptoms occurred in 7% and significant contralateral disease progression in 21% of patients; subsequent CE was performed in 9.4% of patients. Initial presence of greater than 50% contralateral stenosis is a predictor of future hemispheric symptoms, which are likely to be transient ischemic attacks. New symptoms did not necessarily correlate with disease progression. Because disease progression was observed in patients with varying degrees of initial contralateral stenosis, serial clinical and duplex scanning in all patients undergoing unilateral CE is recommended.