Understanding Carotid Endarterectomy
A brain stroke happens when the blood circulation to a part of the brain is affected. There are several reasons for this, but a common one is a block in the carotid artery, which is one of the main pathways for blood circulation to the brain. These blocks – called ‘plaques’ are usually the result of atherosclerosis, and are like what happens in the blood vessels in the heart, which results in a heart attack.
A block in the carotid artery in early stages can present with features of a reduction in blood circulation to the brain, usually in the form of a reversible weakness of the face, arm or leg, difficulty in speaking, and a reversible loss of vision in one eye. Severe forms of the block can completely obstruct blood circulation through the artery and can result in actual damage to the brain, which is then called a ‘stroke’.
The obstructing plaque can be detected by a doppler study of the blood vessels of the neck, CT angiography or MR angiography. An occasional patient may need to undergo an angiography as an additional procedure.
Once detected, treatment is directed to both controlling the atherosclerosis that causes the plaque, and managing the obstruction. Atherosclerosis is managed by diet control and drugs called ‘statins’ to control the blood lipid levels. Patients are usually given drugs that reduce he ability of the blood to clot, usually aspirin or similar classes of drugs, which reduce the impact of the plaque. In smaller plaques, this treatment is likely to be sufficient.
However, in plaques that cause more obstruction to the blood vessel, medical treatment alone is insufficient in preventing a stroke. The preferred way of overcoming the block is to do a surgical procedure called endarterectomy, in which the artery is opened surgically and the offending plaque is physically removed, the artery is then closed with very fine sutures. Several studies from many centers in the world have shown that endarterectomy gives superior and more robust long term results.
An alternative to this is a procedure called angioplasty and stent, which uses a balloon to stretch the narrowed segment of the artery and places a metal mesh called a stent within to hold it open. This procedure is preferred when a patient has a high risk for undergoing a surgical procedure, or the anatomy is unfavorable to the conduct of an endarterectomy.