The safety of carotid endarterectomy in diabetic patients: clinical predictors of adverse outcome.

Objectives: Patients with diabetes mellitus have been shown to have an increased incidence of complications after elective major vascular surgery. The objective of this study was to evaluate a large series of diabetic patients undergoing carotid endarterectomy (CEA) to determine if outcome differed from nondiabetic patients and to examine predisposing factors of poor outcome among diabetic patients.

Methods: A retrospective review of a prospectively compiled database was performed. From 1992 through 2000, 2151 CEAs were performed at our institution. Of these, 507 were in diabetic patients (23.6%), and the remaining 1644 procedures were in nondiabetic patients (76.4%).

Results: Diabetic patients were significantly more likely than nondiabetic patients to have hypertension (70.8% vs 64.5%, P = .01) and cardiac disease (54.6% vs 49.1%, P = .03). They were more likely than nondiabetic patients to be symptomatic before surgery (52.5% vs 47.1%, P = .04) and to have sustained a preoperative stroke (21.3% vs 17.7%, P = .07). No differences were noted in other recorded demographic factors or in intraoperative factors between diabetic and nondiabetic patients. Despite these differences, diabetic patients had similar perioperative outcomes compared with nondiabetic patients, including perioperative myocardial infarction (0.6% vs 0.4%, P = NS), perioperative death (0.8% vs 0.5%, P = NS), and perioperative neurologic events such as transient ischemic attack and stroke (3.2% vs 2.4%, P = NS). Among diabetic patients alone, cigarette smoking, general anesthesia, the use of a shunt, and the lack of clamp tolerance while under regional anesthesia predicted adverse perioperative neurologic outcome, and contralateral occlusion was associated with increased perioperative mortality.

Conclusions: Despite an increased prevalence of cardiac disease and preoperative neurologic symptoms among diabetic patients undergoing CEA, the rates of perioperative cardiac morbidity, mortality, and stroke were equal to nondiabetic patients. In contrast to nondiabetic patients, current cigarette smoking appeared to predict increased adverse neurologic outcomes among diabetic patients, and the presence of contralateral occlusion among diabetic patients appeared to predispose them towards increased perioperative mortality. The use of a general anesthetic appeared to increased perioperative neurologic risk among diabetic patients; however, this may be related to surgeon bias in the selection of anesthetic technique. Although diabetic patients may have an increase in complications after other major vascular surgical procedures, the presence of diabetes mellitus does not appear to significantly increase risk.