Varicose veins – The Pathophysiology

Varicose veins – The Pathophysiology
    • A drawing showing the normal condition of the three venous systems of the lower extremity. The long and the short saphenous veins of the superficial system, and the femoral and posterior tibial veins of the deep system are shown with their competent bicuspid valves that permit blood to flow only toward the heart. The communicating system of veins between these two systems, the superficial and the deep, are shown with their competent valves that permit blood to flow only from the former to the latter.
      • The venous pressure in a normal extremity with competent venous sys­tems is demonstrated by cannulating a superficial vein at the ankle. Note that in the standing position it is equal to the pressure of a column of blood from the level of the heart to the point the venipuncture has been done, so that in a six-foot tall individual it almost equals the systolic arterial pressure.
      • The venous pressure in the same extremity is determined in the walking state. Note that it tends to approach zero. This indicates that the venous heart of the lower extremity is competent, with all the venous valves of the three systems functioning.
    • A drawing showing the abnormal condition of the superficial and com­municating veins in the majority of patients with varicose veins. Note that the long saphenous vein has become dilated, resulting in incompetence of its valves. In ad­dition, the communicating veins between it and the deep veins (most frequently just below the knee and at the ankle level) are likewise incompetent. The deep veins and the short saphenous veins are not affected, although they may be in the more extensive varicose conditions.
      • The venous pressure in an extremity with superficial varicose veins is shown. Note that the standing pressure is the same as in the normal extremity.
      • The pressure in the walking state, however, does not reduce but may even increase slightly. This is due to incompetence of the valves of the long saphenous vein and perhaps some of the communicating veins, resulting in mild decompensa­tion ofthe venous heart of the lower extremity.
      • Note that if the long saphenous vein is occluded by finger pressure below the knee, the venous pressure falls. This determines that the valves of the deep ve­nous and communicating system are competent, and that only the superficial sys­tem is diseased.

Varicose veins - The Pathophysiology

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