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Chronic Venous Insufficiency

Chronic Venous insufficiency (CVI) is a medical disorder, where impaired venous function in the lower extremities causes obstruction of the blood flow to the heart. It is estimated to affect about 50% of the adult population. Here, incompetent valves are unable to prevent the backflow of blood, resulting in accumulation of blood in the lower extremities. This causes venous hypertension resulting in pain, heaviness, swelling, edema and venous ulcers.

If this condition is left untreated, it can lead to tissue hypoxia and secondary lymphoedema. This results in swelling, fibrosis (hardening) and tissue damage, leading to ulcer formation

Ulcers

A venous ulcer is a sore or wound on the lower leg which usually occurs just above the ankle. These ulcers occur due to a breakdown of normal tissue and can be large or small in size. Venous ulcers are related to poor venous outflow and also backflow of blood.About 70% of the ulcers of the lower limb are venous ulcers.

Pressure ulcers result from external pressure, friction or shear forces applied to the skin. Direct external pressure can cause an obstruction to the local circulation while friction may cause the local blood vessels to stretch. Shear stresses are caused by the movement of subcutaneous bone and tissue, which causes deformity and obstruction of the local blood vessels. In all three cases, local circulation is impaired, depriving cells of oxygen and nutrients, so they die.

Seepage of blood cells (RBCs and WBCs) causes iron deposition and secondary inflammation. Ischemia of the skin further exacerbates this problem as oxygenated blood cannot replace the stagnant venous pool and starts to take a diverted path. Generally, ulcers are related to incompetence of perforators just above the ulcer point.
leg ulcer

Characteristics of ulcers

Some common characteristics of ulcers are:

  • Normally occur between the knee and the ankle
  • Generally are superficial
  • Tend to exude
  • Usually associated with pain
  • Surrounding skin tends to be dry and inflamed