Practical Approaches to the Current “ On - Pump ” Redo Coronary Artery Bypass Surgery 2

The mortality (5–15%) [ 1 ] and morbidity are higher for redo coronary artery bypass grafting (CABG) operations than for primary CABG procedures. There are multiple causes for the higher mortality of patients in need of repeat CABG, including left ventricular dysfunction as coronary artery disease (CAD) has progressed and decreased function of multiple organs with advancing age. Several risk stratifi cation models have evolved, over the years, to objectively assess the preoperative risk of patients undergoing cardiac surgery, and a patient can be wellinformed about his or her surgical risk prior to the procedure. Whichever risk stratifi cation method is used, risk stratifi cation only gives a general guide to morbidity and mortality, and the individual’s outcome depends on whether or not problems occur during the intraoperative course. Advanced age, chronic obstructive lung disease, low serum albumin levels, renal failure, and preoperative hemodialysis for management of renal failure are all predictors of higher morbidity and mortality after cardiac procedures. The timing of surgery (i.e., elective, urgent, and emergent procedures) is also a clear, independent predictor of higher mortality. Starting in 1967, after the number of primary coronary artery bypass surgeries performed per year increased, the number of redo CABG procedures performed yearly also increased slowly from 2 to 3% to as high as 15% in high-volume centers at the peak period of CABG utilization. Redo CABG was needed in 2.5% of patients within the fi rst 5 years of primary surgery and increased to 17% within 12 years after the fi rst CABG revascularization procedure. Percutaneous catheter interventions and medical therapy have progressed simultaneously and decreased the need for isolated redo coronary bypass. Balloon angioplasty, atherectomy, and stent placement for the management of vein graft atherosclerosis have certainly changed the need for repeat CABG. While most centers performed at least 15% of their revascularization procedures in1990s for recurrent CAD, this volume has signifi cantly decreased in most surgical centers, especially over the last 5 years. Additionally, our appreciation of the benefi ts of repairing a leaking mitral valve secondary to ischemic CAD or treating calcifi c aortic stenosis in the elderly has created combined procedures that are more common in the present era than redo CABG alone. Younger age at the time of the primary revascularization is a good predictor of the need for a second operation during the patient’s lifetime. The need for redo CABG also depends very heavily on the type of conduit used for the fi rst operation, V. R. Machiraju, MD ( ) Department of Cardiothoracic Surgery , University of Pittsburgh Medical Center , Pittsburgh , PA , USA e-mail: [email protected] Practical Approaches to the Current “On-Pump” Redo Coronary Artery Bypass Surgery 2