The valvular segment of the lower limbs venous system: anatomical, physiological and physiopathological aspects.

The valvular segment is a distinct venous structure, which, from a morphological point of view, is comprised of the following components: the valvular insertion, the valvular gorge entrance orifice, the valvular defile, the valvular gorge exit orifice, the valvular sinus. Endoscopic and echo Doppler examinations are used to identify the normal and the pathological morphology of the valvular segment, and the hemodynamic phenomena occurring at this level. Cusps' integrity and size as well as valvular dynamics are key elements directly involved in shaping the valvular segment in general, and the valvular sinus in particular.