Venous Drainage Of The Lower Limb PDF

VENOUS DRAINAGE OF THE LOWER LIMB • They can be divided into two groups – deep and superficial: • Deep veins are located underneath the deep fascia of the lower limb, accompanying the major arteries. • Superficial veins are found in the subcutaneous tissue. • They eventually drain into the deep ve...

VENOUS DRAINAGE OF THE LOWER LIMB • They can be divided into two groups – deep and superficial: • Deep veins are located underneath the deep fascia of the lower limb, accompanying the major arteries. • Superficial veins are found in the subcutaneous tissue. • They eventually drain into the deep veins. Deep Veins of the Lower Limb • The deep venous drainage system of the lower limb is located beneath the deep fascia of the lower limb. • As a general rule, the deep veins accompany and share the name of the major arteries in the lower limb. • Often, the artery and vein are located within the same vascular sheath – so that the arterial pulsations aid the venous return. The Foot and Leg • The main venous structure of the foot is the dorsal venous arch, which mostly drains into the superficial veins. • Some veins from the arch penetrate deep into the leg, forming the anterior tibial vein. • On the plantar aspect of the foot, medial and lateral plantar veins arise. • These veins combine to form the posterior tibial and fibular veins. • The posterior tibial vein accompanies the posterior tibial artery, entering the leg posteriorly to the medial malleolus. • Tom • Dick • And • Very • Nervous • Harry • On the posterior surface of the knee, the anterior tibial, posterior tibial and fibular veins unite to form the popliteal vein. • The popliteal vein enters the thigh via the adductor canal. The Thigh • Once the popliteal vein has entered the thigh, it is known as the femoral vein. • It is situated anteriorly, accompanying the femoral artery. • The deep vein of the thigh (profunda femoris vein) is the other main venous structure in the thigh. • Via perforating veins, it drains blood from the thigh muscles. • It then empties into the distal section of the femoral vein. • Via perforating veins, it drains blood from the thigh muscles. • It then empties into the distal section of the femoral vein. • The femoral vein leaves the thigh by running underneath the inguinal ligament, at which point it is known as the external iliac vein. The Gluteal Region • The gluteal region is drained by inferior and superior gluteal veins. • These empty into the internal iliac vein. Clinical Relevance: Deep Vein Thrombosis • Deep vein thrombosis (DVT) is the formation of the blood clot within the deep veins of the lower limbs, causing blockage of the vessel. • Locally, this causes pain, swelling and tenderness of the affected limb. Clinical Relevance: Deep Vein Thrombosis • The main complication of a DVT is pulmonary embolism. • The thrombus can become dislodged, and travel into pulmonary circulation. Clinical Relevance: Deep Vein Thrombosis • Pulmonary occlusion prevents blood from returning to the heart, resulting in mechanical shock. • Patients that are considered high risk of developing a DVT undergo prophylactic treatment to prevent thrombosis. Superficial Veins of the Lower Limb • The superficial veins of the lower limb run in the subcutaneous tissue. • There are two major superficial veins – the great saphenous vein, and the small saphenous vein. The Great Saphenous Vein • The great saphenous vein is formed by the dorsal venous arch of the foot, and the dorsal vein of the great toe. • It ascends up the medial side of the leg, passing anteriorly to the medial malleolus at the ankle, and posteriorly to the medial condyle at the knee. • As the vein moves up the leg, it receives tributaries from other small superficial veins. • The great saphenous vein terminates by draining into the femoral vein immediately inferior to the inguinal ligament. • Surgically, the great saphenous vein can be harvested and used as a vessel in coronary artery bypasses. The Small Saphenous Vein • The small saphenous vein is formed by the dorsal venous arch of the foot, and the dorsal vein of the little toe. • It moves up the posterior side of the leg, passing posteriorly to the lateral malleolus, along the lateral border of the calcaneal tendon. • It moves between the two heads of the gastrocnemius muscle and empties into the popliteal vein in the popliteal fossa. Clinical Relevance: Varicose Veins • In the lower limbs, venous blood flows from the skin to superficial veins, which drain into the deep veins. • With the veins there are valves that prevent back flow of blood. • If these valves become incompetent, blood can flow back into the superficial veins. • This results in an increased intra-luminal pressure, which the veins cannot withstand, causing them to become dilated and tortuous. • This condition is known as varicose veins. Therapy options • Vein ligation, stripping, and avulsion – making an incision in the groin (or popliteal fossa) and identifying the responsible vein, before tying it off and stripping it away. • Foam sclerotherapy – injecting a sclerosing (irritating) agent directly into the varicosed veins, causing an inflammatory response that closes off the vein. • Thermal ablation – heating the vein from inside (via radiofrequency or laser catheters), causing irreversible damage to the vein which closes it off.