Coronary Artery Bypass Graft Surgery: The Fourth School of Thought?

Vol 6(1) (2021) 1-3 | jchs-medicine.uitm. edu.my | eISSN 0127-984X https://doi.org/10.24191/jchs.v6i1. 12439 Coronary artery bypass graft (CABG) is one of the most common surgical procedure to be performed in patients with coronary artery blockages in the world. It was initially performed while the heart was still beating, which is recognized as the off-pump technique (OPCAB). However, after the invention of the cardiopulmonary bypass (CPB) machine, CABG surgery began to be performed while the heart is arrested. The CPB machine, temporarily acting as a heart pump, allowed the establishment of an extracorporeal circulation. This, subsequently, became known as the onpump technique. It has now become the gold standard of CABG surgery; with significant improvement in overall patient outcome. However, the usage of CPB machine is not without complications. The deleterious effect of contact of blood with the artificial extracorporeal circuit could result in systemic inflammatory response and coagulopathy and end-organ failure. Suboptimal endocardial and myocardial protection and stroke could also occur due to aortic manipulation during aortic cross clamping and proximal aortic anastomosis. The massive systemic inflammatory response due to prolonged extracorporeal circulation also renders this technique unsuitable for the high-risk patients, especially those with acute myocardial infarction, poor left ventricular function, renal impairment and patients with a high Euroscore [1]. To overcome this, the off-pump technique was re-popularized in the mid 1990’s with much improvement on the technology and better hemodynamic control. For the past 30 years, a lot of debate and studies had been conducted to compare the shortand long-term outcomes between the off-pump and on-pump techniques. Various clinical trials showed conflicting evidence on the efficacy and benefit of off-pump CABG when compared to on-pump CABG. Since the pinnacle of the OPCAB technique in mid-2002, to date, the adoption of OPCAB surgery in USA and Europe is about 15-25%, compared to that in some developing countries in Asia, especially in China, Japan and India, where it ranges from 70 to 100% (partly contributed by the availability of the novel devices, innovative strategies of conducting OPCAB especially on coronary exposure without compromising the hemodynamics [1,5]. The advantage of OPCAB is significant in patients at high risk of complications if put on CPB. Various studies have demonstrated that those patients who are at high-risk benefit substantially from this procedure, particularly those with impaired left ventricular function, advanced age, left main stem disease, chronic renal failure, sleep apnea syndrome, acute myocardial infarction (AMI), atheromatous disease of the aorta and end-organ failure. OPCAB is shown to be beneficial in terms of blood transfusion requirement, reduced acute kidney injury, reduced atrial fibrillation, reduced re-operation for bleeding and respiratory complications [2,8]. The OPCAB technique has been reported to be effective and comparable to onpump procedures performed in patients with Left Main Stem (LMS) disease [9]. However, it has been shown to have similar overall mortality and stroke rate compared to on-pump procedures. In the German off-pump CABG in Elderly (GOPCABE) trial, which included patients of Coronary Artery Bypass Graft Surgery: The Fourth School of Thought?