Chapter 37: Disorders of the Vascular System

Peripheral artery disease results from atherosclerotic narrowing of arteries, predominantly affecting the lower extremities and causing intermittent claudication during activity that resolves with rest. The condition progresses through risk factors including smoking, diabetes, hypertension, and advanced age, with diagnosis confirmed through ankle-brachial index measurement and management focused on risk factor modification, exercise rehabilitation, antiplatelet therapy, and surgical revascularization in severe cases. Deep vein thrombosis involves thrombus formation in deep veins according to Virchow's triad mechanism, encompassing venous stasis, endothelial injury, and hypercoagulable states, with the life-threatening complication of pulmonary embolism occurring when clots dislodge. Diagnostic approaches employ Wells' criteria and compression ultrasonography, while treatment centers on anticoagulation with warfarin or direct oral anticoagulants, supplemented by mechanical prophylaxis and vena cava filtration when anticoagulation is contraindicated. Chronic venous insufficiency develops from valvular incompetence leading to venous reflux, blood pooling, and progressive skin changes including stasis dermatitis and ulcer formation. All three conditions require comprehensive assessment using specific diagnostic modalities and multimodal management strategies balancing pharmacological intervention with lifestyle modification and patient education regarding activity, compression, and complication prevention.