Can recurrent stenosis after carotid endarterectomy be prevented by low-dose acetylsalicylic acid? A double-blind, randomised and placebo-controlled study

Abstract

Recurrent stenosis (> 50%) after carotid endarterectomy is reported with a frequency ranging from 7-20%. 232 patients undergoing carotid endarterectomy were randomised to low-dose acetylsalicylic acid (ASA, 75 mg daily) or placebo (identical tablets). The treatment was started the day before surgery and continued for 6 months. All patients were followed clinically for 1 year. Doppler examination was performed preoperatively (n = 230) and postoperatively (n = 228) and at follow-up at 2 (n = 220) and at 6 months (n = 174) after surgery. The degree of stenosis was estimated from the maximum Doppler frequency shift in the internal carotid artery. Recurrent stenosis of 30% or more was detected in 85 of the 220 patients (38.6%) at 2 months, and at 6 months in 73 of the 174 examined patients (42.0%). Stenosis > 50% was seen in 16 patients (9.2%) and occlusion was found in four patients (1.8%) at 6 months. No difference between the low-dose ASA-treated group (n = 112) compared to the placebo group (n = 108) was seen regarding recurrent stenosis. Women had an increased risk of recurrent stenosis (p < 0.001), whereas other factors such as age, hyperlipidaemia, diabetes and smoking were not associated with increased risk. Importantly, the number of neurological events did not differ between those with or without restenosis. Therefore, the indications for surgery of asymptomatic recurrent stenosis are questionable. The progress of arteriosclerosis in the contralateral carotid artery did not differ between the treatment groups.