Clinical outcome of patients with internal carotid artery occlusion: a prospective follow-up study.

PURPOSE: We prospectively evaluated whether, and to what extent, different clinical presentations (symptomatic or asymptomatic) or the presence of atherosclerotic narrowing of the contralateral carotid system modifies the mortality rate and the incidence of nonfatal cerebrovascular events in patients with internal carotid artery (ICA) occlusion.
METHODS: A prospective cohort study was conducted in the Unit Care of Angiology at the University Hospital of Padua in Italy. Consecutive patients with ICA occlusion were eligible for the study. Between 1990 and 1991, 41 such patients were identified at our center. All patients were observed prospectively for a mean of 44.5 months, except for one patient who was lost to follow-up after 12 months. Patients with severe (ie, more than 75%) stenosis of the contralateral internal carotid artery were scheduled for thromboendarterectomy. ICA occlusion was objectively documented in all patients by using a combination of echo-color Doppler scanning and continuous-wave Doppler scanning (periorbital flow).
RESULTS: The overall mortality rate was 22.0% (95% CI, 10.6-37.6), and the stroke-related mortality rate was 7.3% (95% CI, 1.5-19.9). No differences in overall and stroke-related mortality rates were observed between asymptomatic and symptomatic patients. None of the patients experienced nonfatal cerebrovascular events.
CONCLUSION: ICA occlusion seems to represent a relatively benign condition, in both its symptomatic and asymptomatic presentation. The presence of an atherosclerotic stenosis less than 75% of the contralateral ICA does not seem to worsen the prognosis of this condition.