Risk for stroke after elective noncarotid vascular surgery.

Abstract

Patients undergoing operations to treat peripheral vascular disease have systemic atherosclerosis and are at risk for stroke. However, the incidence and effect of cerebrovascular events on noncarotid vascular surgical outcomes are not well-defined. Patients undergoing common operations for vascular disease from 1997 to 2000 were examined with data from the Veterans Affairs (VA) National Surgery Quality Improvement Project and the VA patient treatment files. Operations studied included abdominal aortic aneurysmectomy (n = 2551), aortobifemoral bypass (n = 2616), lower extremity bypass (n = 6866), and major lower extremity amputation (n = 7442). The incidence of perioperative stroke was determined, and logistic regression analysis was used to identify independent risk factors for stroke. Logistic and linear regression analyses were used to quantify the effect of postoperative stroke on adjusted mortality and length of stay. Odds ratio (OR) and 95% confidence interval (CI) were defined. P <.05 was considered significant. Stroke was uncommon after noncarotid vascular procedures, occurring in only 0.4% to 0.6% of patients. Independent risk factors for stroke include preoperative ventilation (OR, 11; 95% CI, 5.0-22.3; P <.001), previous stroke or transient ischemic attack (OR, 4.2; 95% CI, 2.7-6.4; P <.001), postoperative myocardial infarction (OR, 3.3; 95% CI, 1.3-8.7; P =.009), and need to return to the operating room (OR, 2.2; 95% CI, 1.4-3.5; P =.001). Factors that did not appear to be associated with stroke risk included procedure type, diabetes, renal failure, dialysis dependence, number of transfused units of blood, and hypertension. After controlling for other postoperative complications and comorbid conditions, postoperative stroke significantly increased the risk for perioperative mortality (OR, 6.3; 95% CI, 3.4-11.4; P <.001), with similar magnitude as postoperative myocardial infarction (OR, 6.3; 95% CI, 3.9-10.1; P <.001). Stroke was also associated with a 48% increase in overall length of stay. Stroke after noncarotid peripheral vascular surgery is uncommon, but results in markedly increased mortality and length of stay. Stroke risk is most strongly associated with previous stroke history and greater degree of illness. Patients with these associated conditions deserve particular attention to assessing and medically managing modifiable risk factors.