Coronary artery bypass grafting (CABG) is a surgical procedure to improve poor blood flow to the heart caused by narrowing or blocking of arteries due to the build-up of plaque. These arteries called coronary arteries are blood vessels responsible for supplying blood, oxygen, and nutrients to the heart tissue. When these arteries are blocked or narrowed due to the accumulation of plaque – fatty material within the walls of the arteries – the heart is restricted or has a limited supply of oxygen-rich blood, causing severe symptoms including a heart attack in severe cases.
This plaque is formed in the arteries when the inner walls of the arteries are damaged or injured due to several factors such as an unhealthy diet, smoking, high blood pressure, high cholesterol, diabetes, and a sedentary lifestyle. This plaque – a build-up of fat, cholesterol, calcium, and other substances – tends to stick to the inner walls of the arteries, restricting the blood flow and thereby causing a system malfunction.
Factors that increase the chances of a blockage or narrowing in the arteries include:
- Increasing age
- Sex – Men are more prone than women
- Family history of heart disease or problems
- High blood pressure
- High cholesterol level
- Overweight or obesity
- Physical inactivity
- High stress
- Unhealthy diet
A coronary artery bypass grafting redirects the blood flow to the narrowed or blocked artery by using healthy blood vessels from the leg veins, arm or chest and connecting them with the blood vessels that are beyond the blocked or narrowed artery – causing a bypass for the compromised artery to relive the blood flow as a new passage is able to supply oxygen-rich blood to the blocked area. Depending on the severity of the case, one or more blood vessels may be used to bypass the affected artery. In one case, four major blocked arteries can be bypassed at once.
Coronary artery bypass grafting is a very successful surgical procedure and one of the prime methods used to correct blockages, leakages or narrowing of the coronary arteries. It is an open surgery also popularly known as bypass surgery, coronary artery bypass surgery or heart bypass surgery.
Types of Coronary artery bypass grafting
Traditional Coronary artery bypass grafting: This is the most common method used to treat blockages of the main artery by opening the chest bone to access the heart and stop it to connect it to a heart-lung bypass machine. This machine keeps supplying blood and oxygen to the tissue to keep the heart alive, meanwhile allowing the surgeon to relieve the blockage. Post the surgery, blood flow is restored and the heart starts beating properly.
Off-pump coronary artery bypass grafting: This is similar to a traditional coronary artery surgery, the heart is accessed via an incision in the chest bone but it is not stopped and neither is placed on a bypass machine, instead the blockage is treated on the beating heart.
Minimally-invasive coronary artery bypass grafting: A fairly new but minimally invasive procedure that uses several small incisions on the left side of the chest, between the ribs to access the heart instead of a large cut in the chest bone. This procedure primarily restores blood flow to the blood vessels in front of the heart. However, it is not effective in severe cases or cases that have more than one or two blocked or narrowed arteries.
Why is it done?
A coronary artery bypass grafting may be done if you have a blocked artery causing symptoms such as:
- Severe chest pain
- Shortness of breath
- Abnormal heart rhythm
- Swollen hands and feet
- Severe indigestion
However, in many cases there might not be any symptoms due to the initial stage; however, eventually with the increased build-up of plaque and blockage, symptoms will tend to show. In some cases, the symptoms are very last minute and often result in a heart attack and if the blood flow is not restored to the affected area within a stipulated time, the heart tissue will die, causing death.
A doctor might also recommend a coronary artery bypass grafting in the below cases:
- When there is more than one compromised artery causing the left chamber of the heart to dysfunction
- When the main artery in the left chamber of the heart is the affected one
- When there is acute chest pain even while light physical work because of several artery blockages
- When procedures such as angioplasty (removal of blockage through inflated balloon) and stenting (placing a small wire mesh to keep the artery open) have failed or you have experienced restenosis (narrowing of the arteries even after placement of stent).
- When a person has suffered a heart attack and is responding to any other treatment
Goals of the surgery
A coronary artery bypass surgery is done to relieve symptoms affecting the quality of life. It aims to fulfil goals such as:
- Decreasing angina
- Ability to undertake physical activities
- Resuming an active lifestyle
- Improving the heart’s pumping process
- Improving the chances of survival
- Lowering the risk of heart attack and stroke
- Improving the quality of life
However, even after a coronary artery bypass grafting, one has to make strict modifications in lifestyle, habits, and diet such as regular medications, healthy diet, physical exercise, no smoking, no alcohol, less stress, healthy weight, and follow-up tests – to ensure that the heart is healthy.
A coronary artery bypass surgery can have some complications during or after the procedure, such as:
- Bleeding during or after the surgery
- Irregular heart rhythm
- Infection at the incision site
- Blood clots
- Memory loss
- Kidney problem
- Breathing problem
- Graft failure
- Heart attack
There can be more risks depending on the health of each patient. However, generally, the risks are very low if the health of the patient is good. In cases, where the patient has chronic health conditions, or this procedure was performed as an emergency treatment, the chances of risks increase.
Post the surgery, most people tend to remain symptom-free for at least 10-15 years. However, after that, the artery or the graft may need to be revisited through another surgery or angioplasty, as per need. That said, the longevity of a coronary artery bypass grafting is dependent on the patient’s efforts to maintain a healthy lifestyle, eat healthy food, avoid alcohol, avoid smoking, do exercise, maintain a healthy weight, manage stress, control diabetes, and other health problems. Regular heart check-ups also are a great medium to keep a check on the heart’s heart and handle problems before they occur.