Off-Pump Coronary Artery Bypass Grafting. State of the Art 2006 and Results in Comparison with Conventional Coronary Artery Bypass Strategies
Adverse clinical consequences associated with conventional coronary artery bypass surgery (CCAB) have largely been attributed to cardiopulmonary bypass circuit (CPB), hypothermic cardiac arrest, aortic cannulation, and cross-clamping. Consequently, there has been a growing interest in safer alternatives to CCAB including off-pump beating-heart bypass surgery.
Initial concerns regarding completeness of revascularization at the lateral wall were addressed by using modern stabilizers and heart positioning devices. First studies tended to be nonrandomized clinical reports rather than controlled clinical trials with the potential risk of unba lanced baseline characteristics leading to biases in favor of OPCAB. Since these early reports, several randomized trials including mixed-risk patient populations have been completed. Most of them failed to reveal superiority of OPCAB concerning mortality and major perioperative morbidity due to statistically underpowered design to detect clinically important but infrequent adverse outcome events. Likewise, in most of the recently published meta-ana lyses of randomized trials no difference in early mortality, myocardial infarction or stroke rate was found, but OPCAB was superior regarding blood loss, transfusion requirement, rethoracotomy, ventilation time, ICU (intensive care unit) and hospital stay and resource utilization as illustrated in Table 1.
Most of the large observational studies comparing OPCAB and CCAB strategies demonstrated a benefit of OPCAB concerning early mortality, myocardial infarction and stroke rate as summarized in Table 2. However, in few published follow-up studies no significant differences concerning recurrence of angina, reintervention rate und late mortality were found.
The decision between OPCAB and CCAB has to weigh several factors, including the likely risks and benefits of the two approaches for the particular patient, the experience of the surgeon, the complexity of the coronary disease, and the required coronary revascularization.
