title: Prevalence of asymptomatic carotid stenosis in patients undergoing infrainguinal bypass surgery.
abstract: BACKGROUND
  The prevalence of asymptomatic carotid stenosis in patients with lower-extremity ischemia is unknown. This report represents the largest carotid screening program to date of patients undergoing leg bypass.
  
  
  METHODS
  Patients undergoing infrainguinal bypass from 1987 through 1993 on the vascular surgery service at Oregon Health Sciences University, Portland, underwent routine carotid duplex examinations to detect the presence of asymptomatic carotid stenosis.
  
  
  METHODS
  During the study period, 352 patients underwent infrainguinal revascularization for ischemia, of whom 225 (64%) had no prior carotid surgery, carotid arteriography, or cerebrovascular symptoms. There were 117 men and 108 women, with a mean age of 67 years. The indication for surgery was limb salvage in 67% and claudication in 33% of patients.
  
  
  RESULTS
  Sixty-four patients (28.4%) who required lower-extremity revascularization had hemodynamically significant asymptomatic carotid artery stenosis or occlusion; 12.4% had stenosis of 60% or greater, the qualifying level for randomization in the Asymptomatic Carotid Atherosclerosis Study. Based on these findings, eight patients with carotid stenosis of 80% or greater underwent elective carotid endarterectomy. There were no postoperative neurologic events in the 225 leg bypass patients. By multivariate logistic regression analysis, the presence of carotid bruit (P < .001) and the presence of rest pain (P = .006) were associated with carotid stenosis of 50% or greater. Limiting screening to patients with carotid bruit, limb salvage indications for surgery, and/or advanced age excluded significant numbers of patients with stenosis; thus, these were not effective screening strategies.
  
  
  CONCLUSIONS
  Screening carotid duplex scanning is indicated in patients who require lower-extremity revascularization.
authors.affiliation: Department of Surgery, Oregon Health Sciences University, Portland, USA.
authors.forename: A T
authors.initials: AT
authors.lastname: Gentile
authors.forename: L M
authors.initials: LM
authors.lastname: Taylor
authors.forename: G L
authors.initials: GL
authors.lastname: Moneta
authors.forename: J M
authors.initials: JM
authors.lastname: Porter
mesh_terms: D000368:Aged; D001157:Arterial Occlusive Diseases / Q000150:complications* / Q000601:surgery; D016893:Carotid Stenosis / Q000150:complications* / Q000000981:diagnostic imaging; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D018579:Patient Selection; D011150:Popliteal Artery / Q000601:surgery; D011300:Preoperative Care; D015995:Prevalence; D011446:Prospective Studies; D018616:Ultrasonography, Doppler, Duplex