Carotid endarterectomy in diabetic patients

The purpose of the current study was to identify the possible short- and long-term effects of diabetes on the outcome of carotid endarterectomy.

Medical records were reviewed for 781 carotid endarterectomies (in 734 patients) performed by the same vascular surgeon in a university medical center between January 1994 and December 1998. Patients were divided two groups: those with diabetes (n = 181 patients; 193 operations) and those without diabetes (n = 553; 588 operations). The two groups were similar with respect to mean age, male-female ratio, and contralateral lesions. The only significant differences were a higher prevalence of peripheral vascular disease and dyslipidemia in the diabetic group and a higher prevalence of hemispheric transient ischemic attacks among the nondiabetic patients. Carotid color duplex ultrasound scan had been performed in all patients, and in 56 patients from the diabetic group and 56 patients from the nondiabetic group (matched for age, sex, and contralateral lesions), the distal extension of the lesion from the carotid bifurcation had also been defined. Both of these subgroups were fully representative of their respective groups of origin. Carotid endarterectomy was performed after the induction of general anesthesia; electroencephalographic monitoring was continuous.

Except for the significantly higher prevalence of calcified plaques 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% of the diabetic and 35.7% of the nondiabetic patients (P <.0001) had lesions extending more than 2 cm beyond the carotid bifurcation. Mean length of plaque beyond the bifurcation was 2.3 +/- 0.09 cm for the diabetic and 1.7 +/- 0.08 cm for the nondiabetic patients (P <.0001). Diabetes was the only factor significantly correlated with plaque length. In the diabetic subgroup, 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 nondiabetic 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 minor stroke), respectively (P = not significant). Long-term survival (5 years) was not significantly lower among the diabetic patients.

Diabetes mellitus does not seem to significantly increase the surgical risk for carotid endarterectomy. The presence of more extensive plaques has no significant effect on the results of surgery.