Carotid endarterectomy in diabetic patients

Objective: The purpose of the current study was to identify the possible sh ort- and long-term effects of diabetes on the outcome of carotid endarterec tomy. Methods: Medical records were reviewed for 781 carotid endarterectomies (in 734 patients) performed by the same vascular surgeon in a university medic al center between January 1994 and December 1998. Patients were divided two groups: those with diabetes (n = 181 patients; 193 operations) and those w ithout diabetes (n = 553; 588 operations). The two groups were similar with respect to mean age, male-female ratio, and contralateral lesions. The onl y significant differences were a higher prevalence of peripheral vascular d isease and dyslipidemia in the diabetic group and a higher prevalence of he mispheric transient ischemic attacks among the nondiabetic patients. Caroti d color duplex ultrasound scan had been performed in all patients, and in 5 6 patients from the diabetic group and 56 patients from the nondiabetic gro up (matched for age, sex, and contralateral lesions), the distal extension of the lesion from the carotid bifurcation had also been defined. Both of t hese subgroups were fully representative of their respective groups of orig in. Carotid endarterectomy was performed after the induction of general ane sthesia; electroencephalographic monitoring was continuous. Results: Except for the significantly higher prevalence of calcified plaque s in the diabetic patients (P < .0001), the characteristics of the carotid disease in the two groups were similar. In the 56-member subgroups, 73.2% o f the diabetic and 35.7% of the nondiabetic patients (P < .0001) had lesion s extending more than 2 cm beyond the carotid bifurcation. Mean length of p laque beyond the bifurcation was 2.3 +/- 0.09 cm for the diabetic and 1.7 /- 0.08 cm for the non diabetic patients (P < .0001). Diabetes was the only factor significantly correlated with plaque length. In the diabetic subgro up, surgery was characterized by significantly longer carotid arteriotomies (P = .03) and clamp times (P < .003). Operative mortality was 1.5% in the diabetic group (2 myocardial infarctions + 1 stroke) and 0.5% in the non-di abetic group (1 myocardial infarction + 2 strokes; P value not significant) ; stroke rates were 1.5% (3 major strokes) and 0.5% (2 major strokes + 1 mi nor stroke), respectively (P = not significant). Long- term survival (5 yea rs) was not significantly lower among the diabetic patients. Conclusions: Diabetes mellitus does not seem to significantly increase the surgical risk for carotid endarterectomy. The presence of more extensive pl aques has no significant effect on the results of surgery.