This review discusses the available scientific evidence of the physiological changes and clinical outcomes with off-pump coronary artery bypass grafting.Off-pump coronary artery bypass grafting is more technically demanding, and its prognostic advantage has not been clearly elucidated. This paper examines the evolution of off-pump coronary artery bypass grafting and the technical challenges of ‘bypassing’ the cardiopulmonary bypass machine. A search of the Medline database of English-language literature yielded a huge number of articles from which those relating to physiological and biochemical changes, and clinical outcomes of coronary artery bypass grafting were selected for this review. There are few prospective randomized trials, mostly studying physiological and biochemical changes, and assessing specific clinical outcomes. Avoidance of cardiopulmonary bypass results in a significantly reduced systemic inflammatory response. Myocardial, renal and neurological functions, amongst others, are better preserved. A rapid advance in beating heart surgery technology occurred in the past 5 yrs enabling off-pump multivessel coronary bypass grafting to be performed with relative technical ease, thereby offsetting the propensity to incomplete revascularization which can be a major setback. The clinical outcome of patients with varying surgical risks who have off-pump coronary artery bypass grafting are comparable to those who have surgical revascularization with cardiopulmonary bypass. With the technical challenges of off-pump coronary bypass grafting surmounted, the simple concept of avoiding cardiopulmonary bypass can yield impressive results that would help to establish the routine use of this technique for myocardial revascularization.

Keywords: Cardiopulmonary Bypass - methods, Clinical Trials, Coronary Artery Bypass - methods, Heart-Lung Machine, Risk, Cardiopulmonary Bypass - methods, Clinical Trials as Topic, Coronary Artery Bypass - methods, Heart-Lung Machine, Risk