Coronary Artery Bypass Graft Surgery (CABG) is now widely accepted as one of the most effective treatments for improving the survival and quality of life of patients with coronary artery disease. The coronary arteries supply nutrients and oxygenated blood to the heart. A disease named atherosclerosis can harden the plaque to build up in the coronary arteries. Arteries are narrowed by this plaque build up over time, which can limit the blood flow to the heart and cause chest pain. The plaque can also form blood clots that may completely block the blood flow to the heart via one of the arteries and cause a heart attack.
Surgeons perform this kind of surgery to remove blockages in the coronary arteries. It is performed in two different ways: the traditional one, which is called the on-pump CABG and, the newer one, which is called the off-pump CABG.
On-Pump CABG- It is a time-honoured procedure that is performed while the heart is stopped. The rest of the body requires blood supply when the heart is blocked. Therefore, surgeons use the heart-lung machine or a pump (commonly known as a cardiopulmonary bypass machine). This artificial circulation system does the work of the heart and the lungs. To drain the impure blood to the pump, where it is purified and pumped back into the patient, pipes are placed in the heart. Thus, the heart can safely halt with the help of specialised medications that not only keep it still but also nourish it. Then, bypass grafts are created from other arteries and veins in the patient’s body that provide an alternative route for blood flow around the blockage. These bypass grafts are sewn by hand with fine needles and sutures, using magnification. In the end, the heart is restarted. The pipes are removed, and the cardiopulmonary bypass machine is disconnected once the heart resumes its adequate functions.
Nowadays, on-pump CABG is considered a safe procedure with a rare risk of death or complications. The average risk of this method to a low-risk patient is 1% to 2%.
However, some possible complications of this procedure are: stroke, kidney or liver failure, decrease in higher mental functions and bleeding. Common side effects of this procedure are kidney dysfunction, gastrointestinal distress and cardiac abnormalities.
CABG has a much lower postoperative morbidity and mortality rate, particularly when compared to other procedures.
Off-Pump CABG- It is the newer method of performing CABG. in this procedure, the surgeons do not use the heart-lung machine, and it is performed with the heart beating. This procedure has another name as “beating heart surgery”. This procedure is made in use to restore the blood flow to the coronary arteries. The doctor takes an artery or a vein from another part of the body and then uses the vessel to bypass the blocked part of the artery and restore the normal blood flow to the heart. While definitely eradicating the placement of special pipes for the machine, use of artificial circulation and excessive manipulation of the aorta, this method introduces a new complexity of attaching grafts to the heart while it is constantly beating and filled with blood. Suturing can be done on a comparatively immobile platform, thanks to special devices that mechanically stabilise the relevant portion of the heart. Although, there are some concerns that constant motion can lead to poor grafting and can jeopardise the quality of these grafts. Despite these concerns, surgeons who have adapted and perfected this method have shining examples.
The proposed advantages of this technique are a lower risk of stroke, neurocognitive dysfunction, organ dysfunction, and atrial fibrillation have not been confirmed by extensive clinical trials. The chances of death and complications from this technique are about 1% to 2%, similar to that of on-pump CABG. This is a kind of minimally invasive surgery, which is performed to reduce pain and recovery time.
Out of these two methods, on-pump CABG is the oldest and time-honoured technique. Advancement in technology allows on-pump CABG to be done with low mortality and morbidity and with outstanding results. This technique is still the most widely used method. Off-pump CABG is a newer technique with the proposed advantages of lower complications rates. With expert hands, the results of this highly specialised off-pump method can be excellent. The choice should be left in the surgeon’s hands performing the procedure and on the patient concerning their comfort levels, as both the methods seem to have equally effective outcomes.