#KYJ Wound care series - part 4 Venous Insufficiency

Wound care series part 4.
Venous insufficiency.

In this #KYJ episode we look at venous insufficiency as a cause of leg ulcers and as an inhibitor to healing.

To begin to grasp the impact that venous disease has, we must understand a few truths about leg circulation.  Arteries in legs transport oxygenated blood to the tissues of the legs and feet. Arteries deliver nutrients to the capillary beds that perfuse tissue.  I like to think of arteries as a garden hose, and the capillaries as that soaker-hose weaved around the garden bed.  There is a blood pressure gradient that is highest as blood leaves the heart, that reduces in arteries and almost zero by the time that blood reaches the legs capillaries.
To return that blood to the heart, the veins and muscles of the legs are structured to "pump" blood back.
Three types of veins are featured.
Superficial
Perforating
Deep veins

Superficial veins are often seen as swollen inflamed spiderweb like varicose veins on the feet and ankles of people with venous congestion.  They drain their blood into communicating veins called "Perforating veins" , that take blood from the superficial veins and direct blood flow into the deep veins located deep in the muscle fascia.

Blood is forced along the length of the vein by the action of leg muscle movement.  If there is no leg exercise, this blood pools and congestion occurs, forcing the pressure inside veins to rise.

To ensure blood travels in one direction through veins, veins have one way valves. As congestion and pooling occurs, these valves fatigue and fail.  Venous insufficiency is a combination of high venous pressures from congestion & pooling of blood, and the valves no longer being efficient at transporting blood in the Leg to Heart direction.

Pooling of blood is called 'stasis'. In veins it is referred to as venoustasis.  If there is one thing that pooled blood loves to do, it's coagulate...Badness!

Venous pressures are strongly influenced by gravity.  Standing and sitting for long periods are the leading cause. Once we walk or contract leg muscles, the pump like action promotes momentum of pooled blood and the congestion eases.  This is true for healthy legs, but in patients with long term valve failure walking does little to alleviate pressure.

So what is the link between this venous disease and wounds?  Wounds need a constant clean flow of blood delivering nutrients to the wound bed.  Congestion seen in patients with valve disease or venoustasis slows or stops momentum, stops removal of waste and hence; stops healing.

In many patients with venous insufficiency, their disease actually causes ulceration.  Always on the lower leg and almost always on the medial ankle (malleolus) or anterior shin.

Patients with venous disease often have classic tell tale symptoms.
Ankle swelling
Superficial varicose veins
Spider veins on the inside of their ankle.
Discolouration to their skin ranging from red to rust to purple.
Occasionally slow healing wounds

As congestion increases, red blood cells are forced out of capillaries and fracture in the superficial skin.  The iron in red blood cells oxidises to iron oxide (rust).  It is called haemosiderin and is a permanent rusty discolouration of patients with advanced venous insufficiency .  Sometimes this is called venous eczema .

Next wound care episode we will look at compression as a treatment.

Stay tuned...
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