Restenosis after carotid endarterectomy in a multicenter regional registry

Abstract

Level I evidence shows conventional carotid endarterectomy (CEA) with patch angioplasty results in lower rates of restenosis. However, whether this information has affected practice patterns and outcomes in real-world vascular surgery settings is unclear. Within the Vascular Study Group of New England (VSGNE), we studied 2981 patients undergoing 2981 first-time CEAs between January 1, 2003, and June 31, 2008. Rates of restenosis (defined by duplex ultrasound imaging at the 1-year follow-up) were estimated using life-table analysis. Cox proportional hazards models were used to identify multivariable predictors of postoperative restenosis ≤ 1 year. Across 58 surgeons and 11 hospitals, we studied 2611 conventional CEAs (88% of all CEAs) and 370 eversion CEAs (12% of all CEAs). Median follow-up was 12.8 months (range, 1-35 months). The proportion of conventional CEAs performed with patching increased from 87% to 96% (P < .001) between 2003 and 2008, whereas eversion CEA declined from 18% to 5% (P < .001). Restenosis occurred in 303 patients (10%); by life-table analysis, the restenosis rate at 1 year was 6.2% (95% confidence interval [CI], 4.7%-6.8%). Restenoses were most commonly noncritical: 50%-79% restenosis in 7.9%, 80%-99% restenosis in 1.7%, and occlusion in 0.5%. Univariate analyses showed significant differences in 80% to 100% restenosis by procedure type (2% in conventional CEA, 6% in eversion CEA, P < .002), the year of procedure (3.2% in 2003, 0% in 2008; P < .03), and use of patching in conventional CEA (2.9% no patch, 1% with patch; P < .008). By multivariable analysis, absence of patching (hazard ratio [HR], 3.2; 95% CI, 1.5-7.0), contralateral internal carotid artery stenosis > 80% (HR, 4.1; 95% CI, 1.4-11.5), and dialysis dependence (HR, 3.5; 95% CI, 1.2-9.8) were independently associated with a higher risk of an 80% to 100% restenosis. Of the 51 patients with 80% to 99% restenosis, 14 underwent reintervention ≤ 1 year, comprising 4 reoperations and 10 carotid artery stent procedures. Of the 15 patients with a carotid occlusion ≤ 1 year, transient ischemic attacks occurred in 2 and a disabling stroke in 1. In our region, restenosis after CEA, especially clinically significant restenosis ≤ 1 year after surgery, decreased slightly over time. This improvement in outcome was associated with several factors, including an increase in patching after conventional CEA, a process of care that was studied and encouraged within our vascular study group. These results highlight the utility of regional quality-improvement efforts in improving outcomes in vascular surgery.