Value of Doppler multi-level segmental pressure index in the diagnosis and hemodynamic characterization of totally occlusive aorto-iliac-femoro-popliteal lesions.

Four-level lower limb Doppler S.P.I. (upper thigh; above knee; below knee; above ankle) were evaluated in 275 limbs, 110 of which showed totally occlusive lesions at one or more levels of the aorto-iliac-femoro-popliteal axis on angiographic examination, 65 showed stenosis less than 50% (sclerotic controls) and 100 did not undergo arteriographic examination since they apparently had no lesions (healthy controls). Analysis of the results-carried out using the Student's t statistical method-showed a drop in the S.P.I. close to or over 0.30 between two adjacent levels and was indicative of the presence of an occlusion in the intermediate area. This method therefore allowed the presence and the position of an isolated lesion to be detected. In the case of multiple lesions in series, the proximal one is detected with certainty, whereas the more distal ones can be recognized but not their exact position and extension. Multiple lesions in series are more hemodynamically significant than isolated ones, and proximal lesions more than distal ones.