Reoperations for cardiac surgery following prior sternotomy are associated with elevated morbidity and mortality. Major adverse events occurring in the intraoperative and perioperative setting are often predictable but may still occur despite careful attention and surgical detail. As cardiac reoperations are fundamentally different from routine, nonreoperative cases, the general approach to patient selection, preoperative assessment, and surgical technique should be modified from that commonly employed in the routine, nonreoperative setting. In fact, certain advantages may be derived from a protocol-driven approach to reoperations to improve surgical technique and patient outcomes. This chapter reviews general principles that apply to the preoperative and intraoperative management of patients undergoing cardiac reoperations following prior sternotomy.

Performance of cardiac operations after prior sternotomy continues to confer an increased risk of operative mortality and morbidity. Recent trends indicate that the performance of cardiac reoperations has been affected by an increase in patient life expectancy and by improved patient outcomes following primary cardiac operations. While evidence demonstrates that the number of patients requiring reoperations for valvular disease has increased, those requiring reoperations for coronary disease has decreased due to improved secondary medical management and evolving surgical techniques. Mortality rates, nonetheless, remain elevated for a variety of cardiac reoperations, including those with prior coronary artery bypass grafting (CABG) and cardiac valve procedures. In a retrospective review of 946 cardiac reoperations performed at our institution from 1995 to 2010, the overall operative mortality was 8.2%. According to recent estimates from the Society of Thoracic Surgeons and other single institutions, mortality for reoperative aortic valve replacements (AVRs) range from 5% to 14%; however, we have recently demonstrated that improved outcomes for reoperative AVRs can be achieved and may, in fact, be comparable to that of primary operations (2.0% vs. 3.5%; P = 0.65). We believe that the improved outcomes for cardiac reoperations observed over time are due to enhanced approaches to patient assessment and selection as well as intraoperative management.

Patient selection and assessment for cardiac surgery following previous sternotomy begins with a comprehensive history and physical exam. A thorough medical history should be conducted to include not only an extensive cardiovascular history but also a detailed history related to prior cardiac surgical interventions or surgical procedures within the thorax and mediastinum. Specifically, special attention should focus upon the type, date, and nature of prior cardiac operations, prior incisions and thoracic approach, and postoperative complications following prior cardiac operations, including respiratory failure, tracheostomy, and sternal wound infections. In addition, a prior history of mediastinal infections, previous chest irradiation, number of cardiotomies, prior pericardiectomy, number, conduit type, and location of previously performed CABGs, and prior implanted valve size and type should be considered. Previous operative notes must be carefully reviewed.

A complete physical exam should be performed. Particular attention should be paid to important findings related to a prior cardiac procedure. In addition to routine physical exam techniques, prior surgical scars on the chest should be assessed for location and extent of healing. Whether a prior cardiac procedure was performed through standard full or partial median sternotomy, thoracotomy, or other minimally invasive approaches often provides valuable insight into the degree of underlying scar tissue that may be encountered upon resternotomy and which may alter existing mediastinal anatomy. Degree of prior wound healing and overall appearance of prior scars may provide additional insight into the setting of prior wound infection, breakdown, or deep sternal wound infection. Potential graft conduit sites should also be considered during the performance of the physical exam for reoperative cases requiring myocardial revascularization. This assessment includes evaluation of both upper and lower extremity venous and arterial conduit sites, including the performance of bilateral Allen tests to assess for collateral flow in patients who may be candidates for radial artery CABGs. Similarly, peripheral vascular access sites for potential femoral or axially cardiopulmonary bypass cannulation should be assessed for patency, prior scars, and ease of access.