The prevalence of carotid artery stenosis in patients undergoing aortic reconstruction

BACKGROUND: Coronary artery disease occurs frequently in patients undergoing aortic reconstruction, and it has been presumed that internal carotid artery occlusive disease is also common. This has led to the practice of screening for and repairing significant carotid lesions in asymptomatic patients prior to aortic reconstruction. The purpose of this study was to determine the true prevalence of internal carotid artery disease in these patients. METHODS: The records of 240 patients who underwent duplex ultrasound screening for carotid artery disease prior to aortic reconstruction were reviewed. Surgery was performed for aortic aneurysm (AA) or aorto-iliac occlusive disease (AO). The prevalence of hyperlipidemia and coronary artery disease was similar between the two groups, but tobacco use, hypertension, and diabetes mellitus differed. RESULTS: Internal carotid artery stenosis ≥50% occurred in 26.7% of the total group (64 of 240 cases). Stenosis ≥50% was more common in the AO group (40 of 101 cases, 39.6%) than the AA group (24 of 139 cases, 17.3%, P 5 0.0001). Severe disease (70% to 99%) was also more common in the AO group than the AA group (9.9% versus 3.6%, P 5 0.0464). CONCLUSION: Internal carotid artery disease occurs commonly in patients undergoing aortic reconstruction, and screening is worthwhile. Significant disease is more common in patients with aorto-iliac occlusive disease than in those with aortic aneursym, although atherosclerotic risk factors occur with varying frequency in the two groups. These findings suggest that additional factors may contribute to the higher prevalence of internal carotid artery stenosis in aorto-iliac occlusive disease. Am J Surg. 1999;178:194– 196. © 1999 by Excerpta Medica, Inc. Atherosclerosis is a systemic disease affecting all segments of the vasculature. Much attention has been given to the coexistence of coronary artery and peripheral vascular disease. For example, 1 out of every 2 patients undergoing peripheral vascular surgery has clinical or angiographic evidence of coronary artery disease. However, less is known about the relationship between internal carotid artery disease (ICAD) and other manifestations of atherosclerosis. Estimates of the prevalence of ICAD in patients undergoing coronary artery bypass surgery range from 4% to 17% depending on patient age and the degree of stenosis. Generally 5% is the accepted prevalence in this population. Furthermore, although it is accepted that stroke is a significant complication of aortic surgery, occurring in 1% to 3% of cases, the prevalence of ICAD in this population is unknown. Screening for ICAD with duplex ultrasound is useful in that it identifies patients with clinically significant disease who benefit from carotid endarterectomy to prevent stroke. In this study, we hypothesized that screening for ICAD in patients undergoing aortic reconstruction would be useful because of the presumed significant prevalence of ICAD in these patients. We further hypothesized that the prevalence of ICAD in patients with aorto-iliac occlusive disease (AO) would be much greater than that in patients with aortic aneurysms (AA), since subjects with AA are not necessarily at risk for significant atherosclerotic occlusive disease.