[Functional anatomy of the venous system of the lower limbs]

Surgical techniques including CHIVA and ambulatory phlebectomy and angiographic methods provide a new approach to the anatomy of the venous system in the lower limbs. The endothelium develops fibrous folds of the intima which form valves preventing backward flow. Staged pairs of valves are found throughout the network. The venous wall has three layers: the inner layer, the intima, acts as a mechanical barrier and regulates coagulation and vasomotricity and plays an important role in exchanges. Venous constriction is produced by the middle layer, the media, and the adventitia, the outer layer, connects the vein to surrounding supportive tissue. The anatomy of the venous system in the lower limbs is divided into a superficial network lying over the superficial aponevrosis. This system drains the teguments. The deep system, below the aponevrosis, drains all the blood flow coming from the muscles. These two systems are connected by perforating veins with valves guaranteeing one-way flow. Communicating veins link together the different veins within each network.