Reoperation for coronary artery bypass grafting: anesthetic challenge

The problem of caring for patients undergoing reoperative coronary revascularization is one that cardiac anesthesiologists will face with increasing frequency. Many thousands of CABG procedures continue to be performed annually with ever-increasing survival rates. Consequently, the population at risk for reoperative CABG is growing, while surgical intervention necessarily follows apace. As one recent long-term, retrospective study showed, patients surviving 12 years after CABG have a reoperative rate of 17.3%. Physicians caring for these patients must recognize that they are not seeing patients with routine CAD, but with a different entity: coronary graft disease (CGD). These patients with CGD are different in many ways from those with native CAD, and these differences must be taken into account when planning for their perioperative care. Cardiologists have strived to check the growth of CGD by aggressive emphasis on modification of coronary risk factors such as tobacco use, hypertension, and hyperlipidemia. In addition, recent interest has been focused on a pharmacologic approach via the platelet-prostaglandin system. Surgeons have also attempted to reduce the incidence of CGD by recognition that significantly improved long-term patency rates can be achieved by the use of the internal thoracic artery as a bypass conduit. Consequently, an expanded role for this vessel in the form of free, sequential, and bilateral ITA grafting is currently being advocated as a surgical solution to the problem of CGD. In contrast, the anesthesiologist probably has little to add to the prevention of CGD, but may be able to contribute to a favorable outcome at reoperation. The medical variables and preoperative characteristics that make reoperative CABG patients different from those presenting for primary CABG should be recognized. A firm appreciation of the nature of graft disease, as well as the surgical intricacies required for correction, can only serve to improve the care offered during these often complex operations. Aggressive, invasive hemodynamic monitoring, constant vigilance for signs of early ischemia, and preparedness for prebypass hemorrhage and postbypass ventricular dysfunction should be made. Furthermore, if anesthesiologists are to contribute to an improved outcome in these patients, strategies must be developed to attenuate cerebral and myocardial damage resulting from hemorrhage and atheroembolic catastrophies that appear to be frequent complications in these challenging surgical patients.