ISCHEMIA

Critical Limb Ischemia

[ Critical Limb Ischemia

Introduction

Critical limb ischemia is a disease in which the arteries of the lower limb of the body experience severe blockage. The blockage in the arteries causes a reduction in the rate of blood flow and this disease is a serious type of peripheral arterial disease but it do not occurs commonly in the people. Limb ischemia is usually caused due to atherosclerosis and this condition commonly occurs due to narrowing and hardening of arteries. This hardening can occur because of deposition of plaque which is the fatty deposits of the body. Critical limb ischemia is a condition in which the patient suffers from extreme pain in the feet and especially in toes and the pain also continues in the resting condition. The complication in the disease can lead to unhealed sores and legs. These complications can further result in the amputation of the affected part of the body or limb in the condition of limb ischemia (DAVIS, 2013, pp.1).

Path physiology

Mainly the condition of Critical limb ischemia is caused by obstructive atherosclerotic disease but it can also be caused by several other disorders like thromboembolic disease, cystic adventitial disease and many more. The process of Critical limb ischemia is a difficult and chronic process in which the microvascular and thermavascular systems of the body are affected and their sourrounding tissues are also damaged. The first response of the body in the critical limb ischemia is in the form of capillary sprouting and angiogenesis. Other responses include arteriogenesis which facilitates the enlargement of the collaterals that help in increasing the flow of blood to the affected ischemic limb. All these responses are not able to supply the required quantity of oxygen and blood to the limb and because of this reason the arterioles become insentsitive to those stimuli which are provasodilatory and they also become vasodilated. This phenomenon is also called as vasomotor paralysis and it is due to the vasorelaxing factor which is chronic and it is present in the patient who has obstructed vessels. The people who are suffering from critical limb ischemia have thin walls, less cross sectional area and reduced ratio of lumen and wall when it is compared with controls (Varu et al., 2010, pp.230-241). All of these changes result in the formation of edema which is a big problem for the patients of critical limb ischemia and these patients have to maintain a dependent position of limbs to reduce the pain. The edema of limb aggravates further due to the impaired vasomotor control. The hydrostatic pressure in the distal end of the limb is increased which compresses the compromised capillaries and the transport of nutrients to the tissues is inhibited. Impairment in the function of micro vessels also brings changes in the macro vessels. The integrity of the blood vessels is maintained by the endothelium and the role of endothelium includes control of vascular permeability, modulation of vascular tone and it also works as an antithrombogenic ...