Pathophysiology of venous return
During normal venous return, blood drains from the long and short saphenous veins near the skin surface, via the connecting perforator veins to the deep popliteal and femoral veins.1
Superficial veins
- Thin walled and unsupported by surrounding muscle
- Vulnerable to damage e.g. varicosities caused by increasing hydrostatic pressure when venous return is compromised
Superficial veins (Long and
short saphenous)
Communicating veins
- Drain blood from the superficial veins into the deep veins
Communicating veins
(Perforators)
Deep veins
- Thick walled
- Surrounded by calf muscle
The movement of the blood back towards the heart is helped by:
- Pressure exerted by the calf muscle
- A series of valves within the vein, which keep the blood flowing in one direction
Deep veins (popliteal
and femoral)
Normal veins with competent valves, preventing backflow.
Damaged veins with incompetent valves, allowing backflow
If the valves within the veins become incompetent, the blood flow is no longer unidirectional. Most significantly, backflow occurs between the deep and superficial veins. The thin walled superficial veins become stretched and the valve cusps no longer meet. As a consequence, the hydrostatic pressure within the superficial veins increases1.
Over time, the increase in hydrostatic pressure in damaged veins, if not treated, can lead to1:
- Varicose veins
- Chronic venous insufficiency
- Oedema
- Lipodermatosclerotic changes
- Varicose eczema
- Leg ulceration
Click here to find out how the use of graduated compression hosiery can help avoid the consequences increased hydrostatic pressure in the venous systems of the leg.
- Johnson S. Compression hosiery in the prevention and treatment of venous leg ulcers. J Tissue Viability 2002; 12 (2): 67-74