Early and long-term results of carotid endarterectomy in diabetic patients

Purpose: To evaluate results of carotid endarterectomy (CEA) in diabetic patients in a large single-center experience. Methods: Over a 13-year period ending in December 2008, 4305 consecutive CEAs in 3573 patients were performed. All patients were prospectively enrolled in a dedicated database. Interventions were performed in diabetic patients in 883 cases (20.5%; group 1) and in nondiabetics in the remaining 3422 (79.5%; group 2). Early results in terms of 30-day stroke and death rates were analyzed and compared. Follow-up results were analyzed with Kaplan-Meier curves and compared with log-rank test. Results: Diabetic patients were more likely to be females and to have coronary artery disease, peripheral arterial disease, hyperlipemia, and arterial hypertension than nondiabetics. There were no differences between the two groups in terms of preoperative clinical status or degree of carotid stenosis. Interventions were performed under general anesthesia with somatosensory-evoked potentials (SEPs) monitoring in 67% of the patients in both groups, while the remaining interventions were performed under clinical monitoring. Shunt insertion (14% and 11%, respectively) and patch closure rates (79% and 76%, respectively) were similar between the two groups. There were no differences between the two groups in terms of neurological outcomes, while the mortality rate was higher in group 1 than in group 2 (P = .002; odds ratio [OR], 3.5; 95% confidence interval [CI], 1.5-8.3); combined 30-day stroke and death rate was significantly higher in group 1 (2%) than in group 2 (0.9%; P = .006; 95% CI, 1.2-3.9; OR, 2.2). At univariate analysis, perioperative risk of stroke and death in diabetic patients was significantly higher in patients undergoing intervention with SEP cerebral monitoring (95% CI, 0.9-39.9; OR, 5.9; P = .01), and this was also confirmed by multivariate analysis (95% CI, 1.1-23.1; OR, 8.3; P = .04). The same analysis in nondiabetics demonstrated that again the need for general anesthesia significantly increased perioperative risk, but this was not significant at multivariate analysis. Follow-up was available in 96% of patients, with a mean duration of 40 months (range, 1-166 months). There were no differences between the two groups in terms of estimated 7-year survival (87.3% and 88.8%, respectively; 95% CI, 0.57-1.08; OR, 0.8) and stroke-free survival (86.8% and 88.1%, respectively; 95% CI, 0.59-1.07; OR, 0.8). Diabetic patients had decreased severe ( >70%) restenosis-free survival rates at 7 years than nondiabetics (77.4% and 82.2%, respectively; 95% CI, 0.6-1; OR, 0.8; P = .05). Univariate analysis demonstrated again that the use of instrumental cerebral monitoring significantly decreased stroke-free survival in diabetics (P = .01; log rank, 10.1), and this was also confirmed by multivariate analysis (95% CI, 1.7-17.7; OR, 5.4; P = .005). Conclusions: In our experience, the presence of diabetes mellitus increases three-fold the risk of perioperative death after CEA, while there are no differences with nondiabetics in terms of perioperative stroke. However, the rate of stroke and death at 30 days still remains below the recommended standards. During follow-up, this difference becomes negligible, and results are fairly similar to those obtained in nondiabetics. Particular attention should be paid to patients undergoing intervention under general anesthesia, who seem to represent a subgroup of diabetics at higher perioperative risk, suggesting neurologic monitoring should be used when possible. (J Vasc Surg 2011;53:44-52.)