Colour-coded duplex ultrasonography in selection of patients for transluminal angioplasty

Transluminal angioplasty can be used to relieve symptomatic lower extremity arterial disease with minimal morbidity. This prospective study compares the accuracy of colour-coded duplex ultrasonography with intra-arterial digital subtraction angiography in selection of femoro-popliteal lesions for angioplasty. Isolated, short (< 6 cm) and haemodynamically significant stenosis (> 50% reduction in diameter) were considered for angioplasty. Colour-duplex selection and exclusion was in agreement with angiography in 68 out of 86 lower limbs (79%). The sensitivity, specificity, positive and negative predictive value of colour duplex compared with angiography yielded values of 60.9, 87.5, 60.9 and 85.7%, respectively. The discrepancy between colour duplex and digital subtraction angiography can be partly explained by the tendency of duplex to underestimate the severity and length of disease. It is concluded that colour-coded duplex can be used as a screening tool for lower extremity arterial disease to select appropriate lesions for endovascular procedures. The accuracy of duplex in the present study was not perfect and the decision for further intervention should be based on clinical grounds.