Color-coded duplex sonography of experimentally induced multilevel stenosis. Evaluation of poststenotic Doppler spectrum.

Abstract

The authors evaluated the influence of a proximal arterial stenosis on the poststenotic doppler spectrum of a second, distal stenosis and determined duplex parameters, which permitted description of the severity of the distal stenosis. Moderate (ie, 50%) and severe (ie, 90%) stenoses of the distal aorta and the distal iliac arteries of 10 pigs were created surgically and characterized by angiography. All possible combinations of moderate and severe stenoses were examined. The Doppler spectrum was depicted in the distal iliac and distal femoral arteries of both limbs and analyzed by use of maximum and minimum flow velocity (Vmax, Vmin), acceleration index (modified Handa index), acceleration time, and pulsatility index. In cases of moderate as well as severe proximal stenosis, acceleration index, acceleration time, and pulsatility index of the poststenotic curve of the distal stenosis were significantly reduced (P < 0.05). Independent of the severity of the proximal stenosis, differentiation of moderate as well as severe distal stenosis was possible (P < 0.05) with these parameters. Despite interference of spectral curves in proximal and distal stenosis, duplex sonography enabled the differentiation of experimental aortic iliac multilevel stenosis.