When the arteries cannot supply the required blood to the heart, the patient needs to be treated via a heart bypass surgery or coronary artery bypass graft surgery (CABG). 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 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 accumulation of plaque – fatty material within the walls of the arteries – the heart is restricted or limited of 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 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.
A heart bypass surgery 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 can 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.
There are particularly three types of heart bypass surgery:
Traditional heart bypass grafting: This is the most common methods 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 heart bypass surgery: This is similar to a traditional heart bypass 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 heart bypass surgery: 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.
The procedure of a Beating Heart Bypass Surgery
Before the procedure, the doctor will assess the condition of the patient via several tests such as chest x-rays, blood, electrocardiogram (ECG) and a coronary angiogram. The doctor will advise the patient on what to eat or how long to stay empty stomach before the surgery. Moreover, medications will also be controlled by the doctor.
Usually, a beating heart bypass surgery can take 3 to 6 hours, depending on how many arteries are involved. The patient is given general anaesthesia and a breathing tube. Then the surgeon makes an incision down the chest to access the heart.
In this type of heart bypass surgery, the surgeon removes a section of the healthy vein or artery from a healthy area of the body. This process is known as a graft. One end of this graft is then attached to a part of the heart, which is above the blockage in the artery. The other end of the graft is linked to the part below the blockage. Once the ends of the graft are attached, the blood flow to the heart is restored.
In a general heart bypass surgery, during this procedure, the heart is stopped and connected a heart-lung bypass machine, which keeps supplying blood and oxygen to the tissue. Thus, keeping the heart alive and meanwhile, allowing the surgeon to relieve the blockage. However, in case of a beating heart bypass surgery, the heart is neither stopped nor placed on a bypass machine; instead, the surgeons operate on the beating heart.
One of the major challenges in a beating heart bypass surgery is that it is very difficult to suture on a beating heart; hence, the surgeons use a stabilization system to keep the heart steady. This stabilization system comprises of a heart positioner and a tissue stabilizer. The former directs and holds the heart in a position to allow easy access to the blocked arteries. On the other hand, the tissue stabilizer holds a small part of the heart, allowing the surgeon to operate on it. This allows the surgeon to perform the heart bypass surgery without actually stopping the heart or using the heart-lung bypass machine.
After the procedure, the patient is kept under observation and is discharged when stabilized. The doctor will also instruct the patient on the diet, lifestyle habits, medications, post-operative care, etc.
Advantages and Disadvantages of a Beating Heart Bypass Surgery
- Fewer blood transfusions
- Can be minimally invasive
- Reduced chances of abnormalities in heart rhythm
- Reduced stay in the hospital
- Alternative treatment for certain patients with health problems and issues
Overall, beating heart bypass surgery is a great alternative treatment for patients who cannot undergo traditional heart bypass surgery. Certain factors such as advancing age, previous stroke, vascular disease, liver disease, or any other critical health issues – can make the heart-lung machine bypass surgery very risky.