Coronary artery disease: treatment with procedures and surgery

2021-05-17 04:29 PM

Angina is relieved in most patients. In addition, in patients whose hearts were not severely damaged prior to surgery, coronary artery bypass grafting can provide patients with a normal expectation of survival.

Coronary-aortic bypass surgery

In many patients with coronary ischemia, areas of coronary artery constriction located at only a few sporadic sites are obstructed by atherosclerotic disease, while coronary arteries elsewhere remain normal or nearly intact. normal. In the 1960s, a surgical procedure known as aortic-coronary bypass or coronary artery bypass graft (CABG) was developed in which part of a vein under the skin was removed from an arm or leg. and then grafted from the root of the aorta to the side of the peripheral coronary artery beyond the point of atherosclerotic plaque occlusion. One to five such grafts are usually performed.

Angina is relieved in most patients. In addition, in patients whose hearts were not severely damaged prior to surgery, coronary artery bypass grafting can provide patients with a normal expectation of survival. However, if the heart is already severely damaged, the bypass procedure may not be worth it.

Angioplasty and stenting

Since the 1980s, a procedure has been used to open partially blocked coronary vessels before they become completely blocked. This procedure, called angioplasty, is performed as follows: A small catheter with a balloon, about 1 mm in diameter, is inserted through radiographic guidance into the coronary system and pushed through the coronary artery. partially blocked artery until the balloon portion of the catheter constricts to the point of partial occlusion. The balloon is then inflated with high pressure, distending the clogged artery. After this procedure is performed, vascular blood flow is usually 3- to 4-fold increased, and more than 75% of patients who undergo the procedure experience remission of coronary ischemic symptoms for at least several years, although many patients end up requiring coronary bypass surgery.

Small stainless-steel mesh tubes called “stents” are sometimes placed inside coronary arteries that are dilated by angioplasty to keep the artery open, thereby preventing its re-stenosis. Within a few weeks of placing a stent in a coronary artery, an endothelium usually grows on the metal surface of the stent, allowing blood to flow smoothly within the stent. However, restenosis of an obstructed coronary artery occurs in about 25 to 40 percent of patients treated with angioplasty, usually within 6 months of the initial procedure. The stenosis is usually caused by the formation of too much scar tissue that develops beneath the healthy new endothelium that has grown on the stent. Slow-release stents (relief stents) can help prevent the overgrowth of scar tissue.

Newer procedures for opening atherosclerotic coronary arteries are constantly being experimentally developed. One of these procedures uses a laser beam from the tip of a coronary catheter to target atherosclerotic lesions. The laser effectively dissolves the damage without significantly damaging the rest of the artery wall.