Is duplex ultrasonography an effective single modality for the preoperative evaluation of peripheral vascular...

The purpose of this study was to determine whether duplex ultrasonography can be used as an effective modality for the preoperative evaluation of lower-extremity arterial occlusive disease. The records of all patients undergoing both color flow duplex scanning and contrast arteriography of the lower extremities during a 13-month period were reviewed. Comparisons between the two modalities were made at the femoral, popliteal, and tibial artery levels. Sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy were calculated for duplex scanning using angiography as the gold standard. Three hundred fifteen arterial segments were evaluated. Color flow imaging overestimated the degree of stenosis in seven vessels and underestimated the degree of stenosis in four vessels. Overall duplex ultrasonography accurately determined lower-extremity arterial anatomy as defined by contrast arteriography with a sensitivity of 96.9 per cent, a specificity of 96.2 per cent, a positive predictive value of 94.6 per cent, a negative predictive value of 97.8 per cent, and an overall accuracy of 96 per cent. The accuracy of duplex ultrasonography must be determined in each individual vascular laboratory. Once this is satisfactorily accomplished color flow scanning may be used as the single imaging modality for lower-extremity arterial occlusive disease in selected patients deemed to be at high risk for contrast angiography.