The Vasculab manoeuvre: simulating walking in venous investigations

Abstract

The Vasculab manoeuvre (VA) is a dynamic manoeuvre, specifically designed to study the physio-pathology of the venous calf muscle pump (CMP). It could be defined a simulated “in situ” step and adopts a simplified scheme of the walking step. The patient rolls forward on the leading foot, standing on the toes of both feet (systole, S) and can remain in this position to perform a sustained systole (SS) or can relax, shifting the weight on the other side (diastole, D). VA observations require a training period, while the patient must be provided a set of simple instructions, in order to get the knee extension and the spontaneous rolling on the foot plant. BMode ultrasound shows that in all examined cases MGVs are compressible in systole. A set of CMP specific measurements can be performed, like the refilling time and the stroke volume. VA is the only manoeuver to perform an ultrasound venous investigation in movement. In diastole the refill occurs by capillary inflow (vis a tergo) while reflux comes from incompetent veins. MGVs are taken as a model for the CMP, while the endo-venous compartment of the calf is used as a volumetric model of the leg. VA is a simply executable manoeuvre, which however hides a complex physiopathology, providing the estimation of the CMP parameters. In addition, VA can be used also in several types of plethysmography.