Category Archives: Haemodynamics

Terminal and pre-terminal valves

It is often stated that ultrasound competence of the terminal valve (TV) with incompetence of the pre-terminal valve (PTV) indicates that the source of great saphenous vein (GSV) reflux is from pelvic veins. In consequence, ligation of the sapheno-femoral junction alone will not prevent reflux of pelvic origin from entering the lower segments of the… Read More »

Venous pressure index

In 1977, Mauro Bartolo proposed a technique for the non-invasive measurement of venous pressure which he termed the venous pressure index (VPI). This is performed standing with a flat or cylindrical duplex probe of 8 MHz which may be fixed in position over an ankle vein (GSV, SSV or posterior tibial vein). A pneumatic cuff… Read More »

Reflux and APG

The venous filling index (VFI) of air-plethysmography (APG) is recorded in mL/s. It quantifies filling and is the most useful parameter in the quantification of reflux since the early pioneers like J C Allan et al, in 1964. The VFI represents the rate of increase in calf volume following an elevation to dependency manoeuvre. The… Read More »


A plethysmograph is a device used to measure an alteration in volume in response to a manoeuvre or change in circumstance. It is unable to measure absolute volume or determine the reason for the volume change. Regarding the leg, it can measure the rate of volume reduction in response to leg elevation as well as… Read More »

Foot venous pump

Anatomical dissections provide a unique insight into how veins function. Whilst they cannot demonstrate flow patterns resulting from muscular contraction they are able to illustrate the pathways available for drainage. Flow direction in health can be inferred by the direction of the valves. The foot venous pump (FVP) is a significant contributor to augmenting the… Read More »


Understanding the way valves work have moved on from the simple open and close movement. Their function is to counter the gravitational forces, lower ambulatory venous pressure and facilitate antegrade flow back towards the heart. Therefore, they play a critical role in the maintenance of a healthy venous system. Valve failure leads to retrograde leakage… Read More »