Microvascular dysfunction in diabetic foot disease and ulceration.

Diabetic foot disease and ulceration is a major complication that may lead to the amputation of the lower limbs. Microangiopathy may play a significant role in the pathogenesis of tissue breakdown in the diabetic foot. However, the precise mechanisms of this process remain unclear and poorly understood. Microvasculature in the skin is comprised of nutritive capillaries and thermoregulatory arteriovenous shunt flow. It is regulated through the complex interaction of neurogenic and neurovascular control. The interplay among endothelial dysfunction, impaired nerve axon reflex activities, and microvascular regulation in the diabetic patient results in the poor healing of wounds. Skin microvasculature undergoes both morphologic changes as well as functional deficits when parts of the body come under stress or injury. Two important theories that have been put forward to explain the abnormalities that have been observed are the haemodynamic hypothesis and capillary steal syndrome. With advances in medical technology, microvasculature can now be measured quantitatively. This article reviews the development of microvascular dysfunction in the diabetic foot and discusses how it may relate to the pathogenesis of diabetic foot problems and ulceration. Common methods for measuring skin microcirculation are also discussed. (c) 2009 John Wiley & Sons, Ltd.