Venous Disease and Venous Leg Ulcers
This system relies on the effectiveness of both the calf muscle and the valves. Therefore, any disease or injury that affects the calf muscle will impede the ability of this mechanism and, ultimately, the health of the leg. Poor valve performance can be caused by congenital or familial defect, damage from a previous deep vein thrombosis (DVT), surgery, pregnancy, varicose veins, injury, or a mechanical defect due to a higher obstruction to venous return. Regular ‘chair sleeping’ combined with poor mobility can also significantly impair venous return (Vuolo, 2009).
When either of these mechanisms are sufficiently under-performing on either poor valve performance or muscle disease, blood flow becomes sluggish. This is because there is increased pressure within the veins (venous hypertension). The body requires a pressure gradient between the arteries and the veins in order for the heart to pump blood effectively through arteries and into veins.
The presence of oedema slows down gaseous exchange within the microcirculation. It also results in reduced tissue oxygenation and inadequate toxin removal (EWMA, 2016). Eventually, tissue health suffers, and skin lesions appear, often without any trauma to the tissues. Patients are often unaware of the problem until they notice staining on their clothing.
Mixed Venous and Arterial Disease
It is common for a patient to have both arterial and venous vascular problems. A careful assessment of all lower limb wounds must be undertaken by an experienced practitioner to establish the underlying cause because the management of these wounds must address the underlying issues.
Mixed ulcers will be discussed in detail in Module 4.