"Simulated walking" in the duplex evaluation of the system. The clinical and instrumental crrelations

The goals of non-invasive duplex vascular diagnosis of the venous system of the lower limbs are: 1) To make evaluation of the venous system during deambulation feasible under physiological, pathological and post-surgical or elastocompressive conditions. Moreover, any such evaluation must be achieved using a standardized, easy, highly reproducibly method which is inexpensive and utilizes the diagnostic instruments available. 2) To achieve detailed, selective localization of the valvular and parietal dysfunctions at the basis of any reflux pathology. 3) To identify and quantify venous flux and reflux during deambulation. The present work gives the results achieved over the period of one year after a new method simulating deambulation (Walk System 1 patented) was set up for several utilizations, principally correlated to the use of conventional duplex scanning in studying the venous system. The main purpose of the Walk System 1 is step simulation to uncover the location and extent of venous disease. This application test of: a pneumatic pump which compresses the calf to 100-120 mmHg in 0.3 sec thus simulating muscolar pumping during deambulation; standard 40 mmHg compression of the foot in order to rule out any hemodynamic involvement of the foot pump venous system. We can use this pump in the hemodynamic component, a part, during the step simulation, with synchronism with calf pump in TVP prophylaxis or in vascular therapy; an easy-to-use application software able to quickly pulsed Doppler data of flux and reflux by means of the flux and reflux orthodynamic indices or with measures in ml/sec. The study was performed on 80 lower limbs in normal subjects in order to define the normality range and in 380 lower pathologic limbs. The study has yielded a clinical-instrumental correlation between the hemodynamic data observed during inflation-deflation of the calf cuff, positioning the pulsed Doppler sample volume in the saphenous vein in the saphenous-femoral ostium zone and the underlying venous morphology. The results have made it possible to determine physiological S-F reflux and to establish 4 pathological classes of orthodynamic S-F reflux, each class corresponding to a specific range in the orthodynamic reflux index (class 0 = 0 < RI < 0.25; class 1 = 0.25 < RI < 2; class 2 = 2 < RI < 3.5; class 3 = 3.5 < RI < 6; class 4 = RI > 5) and to a particular morphological conditions.