This Article Full Text (PDF) References Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Add to Saved Citations Download to citation manager Request Permissions Request Reprints Add to My Marked Citations Citing Articles Citing Articles via Google Scholar Citing Articles via Scopus Google Scholar Articles by Huber, T. S. Articles by Seeger, J. M. Search for Related Content PubMed Articles by Huber, T. S. Articles by Seeger, J. M. Social Bookmarking                         What's this?

Screening for Carotid Artery Stenosis with the Continuous Wave Doppler Listening Examination

Section of Vascular Surgery, University of Florida College of Medicine, Section of Vascular Surgery, Gainesville Veterans Administration Medical Center

Timothy R. S. Harward

Section of Vascular Surgery, Gainesville Veterans Administration Medical Center, Section of Vascular Surgery, University of Florida College of Medicine

Cindy D. Read

Vascular Diagnostic Laboratory, Shands Hospital at the University of Florida

Stephen G. Werts

Vascular Diagnostic Laboratory, Gainesville Veterans Administration Medical Center, Florida

Timothy C. Flynn

Section of Vascular Surgery, Gainesville Veterans Administration Medical Center, Section of Vascular Surgery, University of Florida College of Medicine

James M. Seeger

Section of Vascular Surgery, University of Florida College of Medicine, Section of Vascular Surgery, Gainesville Veterans Administration Medical Center

The Asymptomatic Carotid Atherosclerosis Study (ACAS) demonstrated that carotid endarterectomy was beneficial for selected asymptomatic patients with carotid artery stenoses greater than 60%. However, the optimal technique for identifying these asymp tomatic lesions remains undefined. Carotid duplex is the current standard, but cost limits its use for screening large populations. This study prospectively examines the audible interpretation of the continuous wave (CW) Doppler signal as a screening tool for carotid artery stenoses.

Carotid artery listening examinations were performed using CW Doppler immedi ately before standard carotid duplex examinations in 207 patients (414 examinations) by two certified vascular technologists. Stenosis in the extracranial internal carotid artery was classified as <50°/a or 50% based on the listening examination alone, and the results were correlated with the duplex findings (duplex 50% stenosis—peak systolic frequency [PSF] 5 KHz). The results were analyzed in two groups to determine whether accuracy improved with experience (phase I: 107 patients; phase II: 100 patients).

The overall sensitivity (95% confidence interval), specificity, positive predictive value, and negative predictive value of the CW Doppler listening examination compared with carotid duplex was 76% (67.4-83.8), 97% (94.4-98.6), 91% (83.0-95.6), and 92% (87.9-94.3), respectively, for the 414 examinations. The sensitivity (phase I: 68% vs phase II: 85%, P<0.05) increased during the second phase of the study although no significant change was noted in the specificity (phase I: 98% vs phase II: 96%, P=0.44), positive predictive value (phase I: 93% vs phase II: 89%, P=0.71), or negative predictive value (phase I: 89% vs phase II: 95%, P=0.11). Twenty-one of the 27 false-negative listening examinations (CW Doppler <50%, duplex 50%) occurred in arteries with stenoses between 50% and 69% (PSF 5-<7 KHz) on duplex. There were only six false- negative examinations among 80 lesions 70% on duplex (PSF 7 KHz). The time (2.1 ±1.0 vs 12.6 ±9.6 min, P<0.05, Student's t test) and cost ($22.95 vs $166.47) of the listening examination were both less than those of duplex.

The CW Doppler carotid listening examination is an accurate, cost-effective alterna tive to the carotid duplex examination for screening asymptomatic patients for significant carotid artery stenoses.

Vascular and Endovascular Surgery, Vol. 31, No. 5, 571-576 (1997)
DOI: 10.1177/153857449703100512


CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?