Venous leg ulcers
Venous leg ulcers are the most common cause of leg ulceration with estimates ranging from 37 – 81 percent2,3,4. Venous leg ulcers have an immense socioeconomic impact.
Venous hypertension leads to a myriad of microangiopathological changes. In the most severe cases skin breaks down and an ulcer develops.
The primary cause of venous leg ulceration is venous hypertension resulting from venous disease.
There are other theories that contribute to the development of lower leg venous ulceration:
- Microcirculatory disturbances
- Fibrin cuff theory
- The trap hypothesis
- Hypoxia to the gaiter region
- White cell trapping
- The role of tissue proteinases
- Fibroblasts in chronic venous insufficiency
There are more than 40 perforators connecting the deep and superficial veins.
The venous pumping system consists of muscle in the distal calf and the foot pumps. Muscular contraction is the main activator of the pump system.
In the normal lower leg in the supine position, blood flows slowly through the veins and the pressure in the ankle is 70 – 100mmHg falling to 10 – 20mmHg during walking and 55mmHg while sitting.
If the valves of the superficial and perforator veins are incompetent blood oscillates up and down in the segments. This results in venous reflux, leading to ambulatory venous hypertension and oedema during exercise.
The more extensive and distal the venous reflux the greater the risk of ulcer formation.
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