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Chronic disease of the peripheral veins includes a spectrum of diseases ranging from edema and tenderness to venous ulceration (Box 174-1).
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Anatomy
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Veins are thin-walled, distensible, and collapsible structures that function to transport blood toward the heart and act as a reservoir for preventing intravascular volume overload. Microscopically, veins consist of an intima, media, and outer collagenous adventitia. All peripheral veins contain endothelium lined, semilunar, venous valves, which promote unidirectional blood flow toward the heart. Vascular endothelium is described in detail in Chapter 165 and the anatomy of the venous system of the lower extremities is described in Chapter 249.
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Chronic venous disease is extremely common. Although estimated costs and time lost from work have not been objectively assessed in over two decades, estimates state that 6–7 million people in the United States have evidence of venous stasis and that it accounts for 1% to 3% of the total health care budgets in countries with developed health care systems.1
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Risk factors for chronic venous disease include heredity, age, female sex, obesity, pregnancy, prolonged standing, and greater height.2
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Etiology and Pathogenesis
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Venous ulcer occurs after failure of the calf muscle pump (Fig. 174-1). The heart pumps blood down to the foot; the calf muscle pump (when upright), returns venous blood to the heart. Venous blood from the skin and subcutis collects in the superficial venous system including the greater and lesser saphenous veins and its tributaries, moves through the fascia in a series of “perforating” or “communicating” veins, and fills the muscle-enveloped deep venous system. With muscle contraction, the deep veins are compressed; one-way valves in the deep system allow the now high pressure flow to move against ...