Local Microcirculation in Chronic Venous Incompetence and Leg Ulcers

Abstract

Most chronic leg ulcers (90 to 95%) are caused by incompetence of the deep venous system and/or the perforators of the lower leg. Superficial venous incompetence does not give rise to necrotic skin ulcers. The primary cause of venous leg ulcers is the marked increase in pressure that builds up in the deep veins of the lower leg during walking. This pressure is transformed to the skin vessels through the ankle perforators, out to the nutritional vascular bed of the skin. The intracapillary pressure increases tremendously and this causes the capillaries to dilate and become tortuous. The blood elements leak out through the capillary wall into the surrounding tissue and form a specific microedema, which gives rise to an effective nutritional block between the capillaries and the skin cells. This microedema is most probably the main cause of the development of venous leg ulcers.