Carotid endarterectomy in diabetic patients: Does the need for insulin treatment affect early and late outcomes?

Aim. The aim of this study was to evaluate early and late results of carotid endarterectomy (CEA) in diabetic patients in a large single center experience, with particular attention to the effect of the medical management of diabetes on early and late outcomes. Methods. Over a nine-year period ending in December 2008, 2982 consecutive CEAs were performed. Patients were diabetics in 634 (21.5%) cases; diabetes was insulin-requiring in 79 cases (group 1) and oral agent-controlled in 555 cases (group 2). Early results in terms of intraoperative neurological events and 30-day stroke and death rates were analyzed and compared between the two groups. Follow-up results were analyzed with Kaplan Meyer curves and compared with log-rank test. Results. Patients of group 1 were more likely to be asymptomatic (64 cases, 81%) than patients of group 2 (380 cases, 68%; P=0.02). Interventions were performed under general anaesthesia in 39% of patients in group 1 and in 57% of patients in group 2 (P=0.003). Shunt insertion (14% and 15%, respectively) and patch closure rates (91% and 87%, respectively) were similar between the two groups. Cumulative 30 day-stroke and death rate in diabetics was 1.9%, significantly higher than in non-diabetics (0.7%). There were no differences in terms of intraoperative neurological events (1.1% and 0.5%, respectively) between group 1 and 2, and also 30-day stroke and death rates were similar between the two groups (1.2% and 1.9%, respectively). Univariate analysis for the risk of stroke and death at 30 days in diabetics demonstrated that only general anaesthesia and female sex increased perioperative risk and multivariate analysis confirmed only general anaesthesia to be independently associated with poorer early outcomes. Median duration of follow-up was 22 months (range 1-110). Estimated 36-month survival, freedom from ipsilateral neurological events and freedom from severe (>70%) restenosis rates in diabetics were 95.7%, 98.5% and 93%, respectively, and were poorer than in non-diabetics. There were no differences between the two groups in terms of survival, freedom from ispilateral neurological symptoms and from severe restenosis. Conclusions. In our experience the need for insulin treatment does not seem to affect early and late results of carotid endarterectomy in diabetics, who however represent a subset of patients at higher surgical risk.