Significance of carotid restenosis following endarterectomy

The clinical significance of restenosis after carotid endarterectomy as detected by duplex ultrasound has not been clearly established. To address this problem, we retrospectively evaluated the experience at two university-affiliated hospitals.

All charts of patients with carotid endarterectomies between June 1987 and April 1995 were reviewed. Inclusion required neurological assessment and postoperative duplex ultrasound. Exclusion was based on a known source of cardioembolic disease, or recent (<6 months) myocardial infarction. Primary clinical endpoints were ipsilateral transient ischemic attack (TIA) or ischemic stroke. Contributing vascular risk factors were also identified. The effect of restenosis on event-free survival was analyzed using life tables and Gehan-Wilcoxon rank sum tet. Logistic regression was used to identify independent risk factors for restenosis and vascular events.

One hundred and eighty-seven patients were identified who underwent a total of 207 endarterectomies. Mean follow-up was 30.4 +/- 20.9 months during which a total of 64 vascular events, including 42 TIAs, 18 strokes, and 4 vascular deaths occurred. Of these 21 TIAs and 8 strokes were ipsilateral to the side of endarterectomy. Event rates were compared for patients with ipsilateral high- (>/=50%) and low-grade (<50%) restenosis. These two groups were comparable in terms of baseline risk factors. There was no significant difference in vascular event rates (for either ipsilateral events or events in any vascular territory) between the group with high- and low-grade restenosis. Nor was any such difference in event rates shown for patients who showed ipsilateral progression of carotid disease on serial ultrasound. However, patients operated for symptomatic carotid disease had a significantly higher risk of neurological events (p = 0.035). Logistic regression failed to disclose any other risk factors that were independently predictive of either restenosis or vascular events during follow-up.

This study does not show a difference in vascular event rates for higher grades of carotid restenosis after carotid endarterectomy. Routine surveillance with carotid ultrasound does not appear to identify patients at higher risk for postoperative cerebrovascular events.