Coronary Artery Bypass Graft Redo

Advances with percutaneous coronary interventions have led to a reduction in repeat coronary artery bypass grafting. As the population ages, the risk profile of these patients increases, creating a challenging situation for the surgeon and the team involved. Redo sternotomy increases the risk of mortality due to the increased risk of graft injury and subsequent myocardial injury upon sternal re-entry.Redo coronary revascularisation provides a peculiar challenge to cardiac surgeons and carries one of the highest mortality rates amongst redo cardiac surgeries, either isolated or in combination with other pathologies. This requires the establishment of a solid indication in the absence of any other alternative as well as specific work up to obtain the relationship between different anatomical structures, including previous patency and location of grafts.Another challenge that the surgeon faces in this situation is that of myocardial preservation in the presence of patent coronary artery grafts. During cardiopulmonary bypass, the most common way to preserve the myocardium is by applying a cross-clamp to the ascending aorta diverting the blood from the heart-lung machine away from the heart towards the rest of the body and infusing a cold, potassium-rich solution in the aortic root to perfuse the coronaries and arrest the heart in diastole; bringing down the metabolic activity.The presence of patent grafts maintains a continuous flow of normal warm blood with low potassium content to the heart, which negates the protective effects of cardioplegia and restores electrical activity leading to a resumption of cardiac contractility. The isolation of any patent grafts is, therefore, crucial for a successful redo CABG to allow for a safe procedure.