Carotid Stenosis (Carotid Artery Disease)

 

What Is Carotid Stenosis?

Carotid stenosis is a narrowing of the carotid arteries, the two major arteries that carry oxygen-rich blood from the heart to the brain. Also called Carotid artery disease, Carotid stenosis is a progressive narrowing of the carotid arteries in a process called Atherosclerosis. Normal healthy arteries are flexible and have smooth inner walls. As we age, hypertension and small injuries to the blood vessel wall can allow plaque to build up. Plaque is a sticky substance made of fat, cholesterol, calcium, and other fibrous material. Over time, plaque deposits inside the inner wall of the artery can form a large mass that narrows the lumen, the inside diameter of the artery. Atherosclerosis also causes arteries to become rigid, a process often referred to as "hardening of the arteries."

 

There are three ways in which carotid stenosis increases the risk of stroke:

• Plaque deposits can grow larger and larger, severely narrowing the artery and reducing blood flow to the brain. Plaque can eventually completely block (occlude) the artery
• Plaque deposits can roughen and deform the artery wall, causing blood clots to form and blocking blood flow to the brain.
• Plaque deposits can rupture and break away, traveling downstream to lodge in a smaller artery and block blood flow to the brain.

The goal of treatment is to reduce the risk of stroke. Treatment options for carotid stenosis vary according to the severity of the arterial narrowing and whether you are experiencing stroke-like symptoms or not (asymptomatic).

Surgical treatment is generally recommended for patients who have suffered one or more TIAs or strokes and who have a moderate to high grade of carotid stenosis [2,3]. The aim of surgery is to prevent stroke by removing or reducing the plaque buildup and enlarging the artery lumen to allow more blood flow to the brain.

     

     CAROTID ENDARTERECTOMY

Carotid Endarterectomy is typically indicated for patients who : 

• Have had symptoms (stroke or TIA) and have blockage greater than 50%.
• For patients who have no symptoms (asymptomatic) and have blockage greater than 60%.
• Among patients with moderate blockage of 50 to 69%, surgery reduces the risk of stroke by 6.5% over a five-year period.
• Among patients with high-grade blockage of more than 70%, the risk of stroke is reduced by 80%.

The benefit of Endarterectomy for patients whose stenosis is 50% or less does not outweigh the risks of the procedure.

   

      CAROTID ANGIOPLASTY / STENTING

Carotid Angioplasty/ Stenting is a Minimally Invasive Endovascular procedure that compresses the plaque and widens the lumen of the artery.

It is performed during an angiogram in an interventional radiology suite. A flexible catheter is advanced from the femoral artery in the groin, past the heart, and to the location of the plaque within the carotid artery. Next, a small catheter with an inflatable balloon at the tip is positioned across the plaque. When the balloon is opened, it dilates the artery and compresses the plaque against the arterial wall. The balloon is then deflated and removed. Finally, a self-expanding mesh-like tube called a stent is placed over the plaque, holding open the artery.

Angioplasty / stenting is typically indicated for select patients who have:

• Moderate to high-grade carotid stenosis greater than 70%.
• Have other medical conditions that increase the risk of surgical complications
• Have recurrent stenosis
• Have stenosis that was caused by prior radiation therapy.

     

     CAROTID ARTERY BYPASS

Carotid Artery Bypass is a surgical procedure that reroutes the blood supply around the plaque-blocked area. A length of artery or vein is harvested from somewhere else in the body, usually the saphenous vein in the leg or the ulnar or radial arteries in the arm. The vessel graft is connected above and below the blockage so that blood flow is rerouted (bypassed) through the graft.

Bypass is typically only used when the carotid is 100% blocked (carotid occlusion).

After Carotid Endarterectomy, restenosis can occur in less than two years and is usually not symptomatic. These regrown plaques can be treated with angioplasty and stenting. The plaques may regress with time, and intervention is reserved for stenosis greater than 80%. After two years, restenosis is more often related to progression of atherosclerotic disease. In general, repeat surgery or stenting is advised for symptomatic restenosis or stenosis greater than 80%.