The term minimally invasive coronary artery bypass grafting is not well defined. According to one definition, avoidance of cardiopulmonary bypass (CPB) is considered essential in decreasing the morbidity associated with conventional coronary artery bypass grafting (CABG).1 Other authors consider the median sternotomy as a potential source for morbidity, referring to the risk of mediastinitis and the associated delayed return to daily life activities.2 Accordingly, a number of surgical strategies have evolved to avoid the need for extracorporeal circulation and to minimize surgical access. Furthermore, operative strategies as avoidance of aortic manipulation or complete arterial revascularization focus on improved short- and long-term results. At the same time, it was widely recognized that open harvesting techniques for bypass grafts often are associated with wound-healing problems, especially in diabetic patients. As a consequence, endoscopic harvesting techniques for both venous and radial artery grafts have been developed.
For decades, CABG was routinely performed with cardioplegic arrest and using CPB. An empty, nonbeating heart, a bloodless surgical field, and an easy exposure were regarded as essential for success of the procedure. Results were excellent, mortality declined constantly, and standard CABG became the "bread and butter" of our profession.3 Anecdotal reports on the deleterious effects of CPB and systematic reports examining the pathophysiology of extracorporeal circulation started to question the dogma of "the pump is your friend." CPB is associated with (1) a systemic inflammatory response, (2) release of cytokines, (3) activation of the clotting cascade, (4) metabolic changes, (5) microembolization and numerous other adverse effects. Although tolerated in most cases, these effects alone or in combination may cause substantial morbidity and thus affect the results of the procedure. With an ever-aging population and increasing comorbidity, surgeons all over the world sought to further minimize the risk of CABG, and it seemed logical to question the role of CPB in CABG.
The evolution of off-pump coronary artery bypass grafting (OPCAB) is closely linked to the development of stabilizers that became available in the early 1990s. Initially, pure pressure stabilizers were engineered, but it soon became obvious that exposure of the back wall of the heart would require additional means of support. With the introduction of vacuum-assisted stabilizers by the Utrecht group, local myocardial immobilization was greatly facilitated and independent of the area of revascularization and OPCAB gained popularity. Despite better stabilizers, it was recognized that OPCAB requires a team approach and awareness of the sudden hemodynamic changes that may occur during the procedure.
In most centers, general anesthesia is applied, and the patient is intubated. Incidental reports indicate that the operation is also possible on the awake, spontaneously breathing patient under high epidural anesthesia.4 Standard monitoring is applied. In addition, some centers prefer online cardiac output measurement using the PICCO or similar methods.5 A Swan-Ganz catheter is usually not helpful and can potentially cause arrhythmia when the heart is manipulated during the ...