George T. Pisimisis1
, Carlos F. Bechara1
, Neal R. Barshes1
, Dimitrios Katsavelis2
, Peter H. Lin1
, Panos Kougias11Baylor College of Medicine, Vascular Surgery and Endovascular Therapy, Houston, TX; 2Creighton University, School of Health Professions, Omaha, NE.
Screening for common carotid artery (CCA) stenosis with duplex ultrasound (DUS) velocity criteria alone is limited due to within-patient and between-patients hemodynamic variability. This study aims to introduce and establish inter-CCA velocity ratio criteria to predict moderate and high-grade CCA stenosis.
METHODS: Retrospective review of 143 consecutive patients who had computed tomography angiography (CTA) and DUS peak-systolic velocity (PSV) measurements of bilateral CCA, independently recorded, between 2008-2012. Inter-CCA PSV ratios were calculated and paired with respective unilateral CCA diameter stenosis (uDS) and bilateral differential CCA diameter stenosis (dDS). A quadratic regression model was fitted to predict uDS and dDS. Receiver operating characteristic (ROC) curve was used to determine optimal ratios for ≥50% and ≥80% CCA stenosis. The study excluded patients with carotid artery occlusion and patients with bi-directional or dampened CCA flow, parameters that can readily predict severe proximal occlusive disease.
RESULTS: From a total 143 patients, 19 patients had ≥50% uDS, 7 ≥80% uDS, 11 ≥50% dDS and 4 ≥80% dDS. Inter-CCA PSV-ratio predicted uDS (r2=0.69, p<0.0001) and dDS (r2=0.87, p<0.0001) (Figure 1). ROC curves for ≥50% and ≥80% unilateral CCA stenosis showed optimal threshold CCA ratio ≥1.9 with 96% accuracy, 84% sensitivity and 98% specificity (area under curve=0.924, 95% CI: 0.867, 0.961) and ratio ≥3.7 with 98% accuracy, 72% sensitivity and 100% specificity (area under curve=0.993, 95% CI: 0.962, 0.998), respectively.
CONCLUSIONS: Duplex ultrasound based inter-CCA PSV-ratio can accurately predict unilateral and differential CCA stenosis. This parameter can be used as adjunct screening tool for moderate and high-grade CCA stenosis.
AUTHOR DISCLOSURES: N. R. Barshes: Nothing to disclose; C. F. Bechara: Nothing to disclose; D. Katsavelis: Nothing to disclose; P. Kougias: Nothing to disclose; P. H. Lin: Nothing to disclose; G. T. Pisimisis: Nothing to disclose.
Posted April 2013