Clinical meaning
Venous leg ulcers result from chronic venous insufficiency (CVI) where incompetent venous valves cause sustained venous hypertension in the lower extremities. Normal calf muscle pump function propels blood upward against gravity, with competent valves preventing reflux. When valves fail, blood pools in the dependent veins causing sustained venous pressure of 60-90 mmHg (normal ambulatory pressure 20-30 mmHg). Chronic venous hypertension leads to distension and increased permeability of capillaries, leakage of fibrinogen into pericapillary tissue forming fibrin cuffs that impair oxygen diffusion, trapping of white blood cells and growth factors, and hemosiderin deposition causing characteristic brown skin staining. Venous ulcers account for 70-80% of all leg ulcers and typically occur in the gaiter area (medial lower leg above the medial malleolus). They are shallow, irregularly shaped with moderate to heavy exudate, and surrounded by hemosiderin staining and lipodermatosclerosis. Compression therapy is the cornerstone of treatment, improving venous return and reducing edema.
Exam relevance
Risk factors: - Deep vein thrombosis (DVT) history damaging venous valves - Prolonged standing occupations (healthcare, retail, teaching) - Obesity increasing venous pressure and venous return impairment - Multiple pregnancies increasing venous pressure and valve damage - Previous venous ulcer (recurrence rate 70% without compression)