Contralateral neurologic symptoms after carotid surgery: a nine-year follow-up.

A study was undertaken to observe the long-term clinical behavior of the contralateral, asymptomatic carotid artery of patients after unilateral carotid endarterectomy (UCE). A consecutive series of 182 patients undergoing UCE were followed up for 1 to 9 years (mean 4.2 years). The operated artery was symptomatic in 169 cases (92.8%) whereas in 13 (7.2%) it was asymptomatic but stenotic. Follow-up included an accounting of all hemispheric or focal neurologic events in the territory of the nonoperated artery, as well as associated cardiovascular risk factors. A total of 11 patients (6%) suffered stroke (CVA) and six (3.3%) had transient ischemic attacks (TIAs) in the distribution of the nonoperated carotid artery. By life-table analysis, major neurologic symptoms developed in 11.6% of patients within 5 years. Hypertension was an important prognostic factor: significantly more hypertensive patients had late contralateral neurologic symptoms (p less than 0.05, chi square). The cumulative incidence of CVA and TIA in these patients was 17.3% by life-table analysis at 5 years vs. 9.1% for normotensive patients. Since only a small proportion of the patients studied had a high-grade stenosis of the nonoperated artery, no conclusions could be made regarding its prognostic importance. The relevant published studies are discussed and compared with this report. Guidelines for the management and follow-up of the patient after UCE are discussed.