What is a deep competitive reflux and why we should study it

Reflux of the GSV is considered the absolute criterion for its incompetence. However, there are 3 specific conditions in which, despite being dilated with all its valves incompetent (destroyed and/or coaptation defect due to excessive dilation of the vein), the GSV does not reflux during diastole of the valvo-muscular pump of the calf. The first of these conditions is what I have called deep competitive reflux, the second is occlusion of the reentry perforators, and the third is dilation due to a compensatory flow by-passing of a deep venous occlusion.