The superficial veins of the lower limb
The superficial system comprises the great and small saphenous veins. These are of utmost clinical importance as they are predisposed towards becoming varicose and consequently often require surgery. They are also the commonly used conduits for coronary artery surgery. • The great saphenous vein arises from the medial end of the dorsal venous network on the foot. It passes anterior to the medial malleolus, along the anteromedial aspect of the calf (with the saphenous nerve), migrates posteriorly to a handbreadth behind patella at the knee and then courses forward to ascend the anteromedial thigh. It pierces the cribriform fascia to drain into the femoral vein at the saphenous opening. The terminal part of the great saphenous vein usually receives superficial tributaries from the external genitalia and the lower abdominal wall. At surgery these help to distinguish the saphenous from the femoral vein as the only tributary draining into the latter is the saphenous vein. Anteromedial and posterolateral femoral (lateral accessory) tributaries, from the medial and lateral aspects of the thigh, also sometimes drain into the great saphenous vein below the saphenous opening. The great saphenous vein is connected to the deep venous system at multiple levels by perforating veins. These usually occur above and below the medial malleolus, in the gaiter area, in the mid-calf region, below the knee and one long connection in the lower thigh. The valves in the perforators are directed inwards so that blood flows from superficial to deep systems from where it can be pumped upwards assisted by the muscular contractions of the calf muscles. The deep system is consequently at higher pressure than the superficial and thus, should the valves in the perforators become incompetent, the increased pressure is transmitted to the superficial system and these veins become varicose. • The small saphenous vein arises from the lateral end of the dorsal venous network on the foot. It passes behind the lateral malleolus and over the back of the calf to pierce the deep fascia in an inconstant position to drain into the popliteal vein.
The deep veins of the lower limb
The deep veins of the calf are the venae comitantes of the anterior and posterior tibial arteries which go on to become the popliteal and femoral veins. The deep veins form an extensive network within the posterior compartment of the calfathe soleal plexus from which blood is assisted upwards against gravitational forces by muscular contraction during exercise. Failure of this ‘muscle pump’ to work efficiently, as occurs, for instance, during long flights in cramped conditions, may cause deep venous thrombosis (DVT).
So the air pressure therapy blood circulation machine come into the market, the air pressure therapy machine is mainly to promote blood circulation by massing legs,waist,arm, to reach the popurse of lymphatic edema and deep varicose veins treatment.
These are classified as: • Primary:due to inherent valve dysfunction. • Secondary:due to impedance of flow within the deep venous circulation. These can occur in pregnancy or due to obstruction caused by pelvic tumours or previous deep venous thrombosis. In both cases the superficial veins are subjected to increased pressure and become varicose.