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Epidemiology
Among the 200,000 coronary bypass operations performed annually in the United States, reoperative coronary artery bypass surgery (redo-CAB) accounts for approximately 5 percent of all isolated coronary artery bypass grafting (CABG) procedures. Recent data from the Society of Thoracic Surgeons database show that there has been a decrease in the number and percentage of redo-CAB procedures (2000, N = 8929, or 6.1 percent; 2009, N = 8189, or 4.3 percent).
Pathophysiology
Reoperative coronary artery surgery is performed for patients in whom there is definite demonstrated myocardial viability with associated symptomatology. A multivariate analysis demonstrated that preoperative angina, use of vein grafts only, previous myocardial infarction, incomplete revascularization, female gender, and smoking at a younger age were independent risk factors for recurrent angina and a potential need for reoperation.
Clinical features
In more recent years, the reoperative candidate population has evolved to include older patients, with diminished left ventricular function, triple-vessel coronary artery disease (CAD), and graft failure becoming the predominant etiologic factors. Recently, however, there appears to be an increase in number of reoperative candidates with progression of their native disease distal to their patent conduit graft sites.
Diagnostics
Diagnostic tests include those used to assess viable myocardium and those used for planning the operation. The tests frequently used for detecting viable myocardium include thallium scintigraphy, dobutamine echocardiography, magnetic resonance imaging, and positron emission tomography. Coronary angiography is the gold standard for determining the need for revascularization and the appropriate targets. Standard computed tomography (CT) can be used to assess the substernal structures. However, with the development of multislice CT and three-dimensional (3-D) reconstruction, accurate pictures of the cardiac anatomy and the relationships of bypass grafts to mediastinal structures as well as the sternum can be demonstrated vividly.
Treatment
Reoperative surgery for CAD requires knowledge of mediastinal structures and a staged entry into the chest with the use of an oscillating saw and scissors for division of the outer and inner tables, respectively. Femoral artery and vein cannulation may be necessary if it is anticipated that cardiac structures are in jeopardy of being injured upon reentry. Careful dissection in the area of previous vein grafts that may be atherosclerotic is important, as downstream debris from these vein grafts is the most common cause of mortality in this high-risk group of patients.
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Coronary artery bypass grafting (CABG) is the most common cardiac surgical procedure, with nearly 200,000 operations performed annually in the United States according to the Society of Thoracic Surgeons (STS) database. Reoperative CABG accounts for approximately 5 percent of all isolated CABG procedures and is often the result of graft failure, progression of native coronary disease, or incomplete revascularization.1,2 Recent STS data show that there has been a decrease in the number and percentage of isolated redo-CABG operations (2000, N = 8929, or 6.1 percent; 2009, N = 8189, or 4.3 percent). There are probably many ...