Recurrent carotid artery stenosis following endarterectomy:: Natural history and risk factors

Objectives. To establish the incidence of restenosis (RES)following carotid endarterectomy (CEA) and evaluate clinical and technical factors related to its development. Design. Prospective non-randomised cohort study, Patients and methods. Two hundred and twenty-four patients with 243 CEA between May 1998 and December 2002, were subjected to clinical and haemodynamic follow-tip, median follow-up 23 months (1-56). There was selective use of a shunt (17.3%) and patch (61.7%). RES (>= 50%) and severe restenosis, >= 70%, (sRES) were defined as peak systolic velocities of >= 150 and >= 300 cm/s (or >= 250 cm/s with diastolic velocity >100 cm/s), respectively. Rates of RES, symptom development and mortality were analysed using Kaplan Meier curves. Cox's regression model (hazards ratio/95% Cl) was used to evaluate prognostic factors. Results. We detected 13 sRES (5.3%) (median time 6.1 months) and 30 (12.3%) moderate stenosis (mRES) (median time 3.7 months). Cumulative freedom from sRES at 23 months was 94.2%. Five sRES detected in the first 45 days after the procedure were deemed to be residual restenosis (rRES). Five (38.4%) sRES were symptomatic, 15.3% progressed to occlusion. Patient survival was 98.0 and 96.4% at 12 and 24 months, respectively. Independent risk factors for sRES:female sex (HR: 3.3, 95% Cl 1.1-10 p = 0.04) and diabetes (HR: 4.5, 95% Cl 1.4-13.9 p = 0.008). Conclusions. Carotid restenosis appears early, is usually low-grade and mostly asymptomatic. Although few stenoses; progress to occlusion, women and diabetic patients were at highest risk.