Abstract

Aim: Conventional cardiopulmonary bypass (CCPB) remains the standard technique for coronary artery bypass grafting (CABG) but is associated with a systemic inflammatory response resulting from blood contact with artificial surfaces and the blood–air interface. Miniaturized cardiopulmonary bypass (MCPB) was developed to mitigate these adverse effects, whereas off-pump coronary artery bypass (OPCAB) avoids extracorporeal circulation altogether. However, direct comparisons of these three perfusion strategies remain limited. The primary objective of this study was to compare perioperative and early postoperative outcomes among patients undergoing elective isolated CABG using CCPB, MCPB, or OPCAB. Secondary objectives included the comparison of baseline demographic characteristics, coronary anatomy, and preoperative clinical variables to assess the comparability of the study groups.
Material and Methods: We retrospectively analyzed 213 consecutive patients who underwent isolated elective coronary artery bypass grafting at a single institution between May 2013 and May 2018. According to the perfusion strategy used, patients were allocated to the conventional cardiopulmonary bypass (CCPB; n = 118), miniaturized cardiopulmonary bypass (MCPB; n = 62), or off-pump coronary artery bypass (OPCAB; n = 33) groups. Baseline demographic and preoperative characteristics were compared to ensure group comparability, while perioperative characteristics and early postoperative outcomes were evaluated to assess the clinical impact of each perfusion strategy.
Results: Baseline demographic and preoperative characteristics were comparable between groups. Patients undergoing OPCAB received fewer distal anastomoses and fewer venous grafts than patients undergoing CCPB or MCPB (both p < 0.001) and demonstrated a significantly lower postoperative lactate index (p = 0.010). Operative duration was longer in the MCPB group than in the CCPB and OPCAB groups (p = 0.009). Perioperative blood transfusion was more frequently required in the CCPB group than in the MCPB and OPCAB groups (p < 0.001). Compared with MCPB, CCPB was associated with higher postoperative creatinine index (p = 0.020), greater inotropic requirements 6 hours after ICU admission (p = 0.009), and increased mediastinal drainage (p = 0.001). Rates of major postoperative complications did not differ significantly among the three techniques.
Conclusion: CCPB, MCPB, and OPCAB all provided satisfactory early clinical outcomes following isolated CABG. MCPB combined several advantages of conventional and off-pump surgery by reducing transfusion requirements, postoperative renal dysfunction, inotropic support, and postoperative bleeding while maintaining the benefits of an arrested-heart procedure. The optimal perfusion strategy should be individualized according to patient characteristics, coronary anatomy, and surgical expertise. Larger prospective studies are warranted to confirm these findings.

Key words: Coronary artery bypass grafting, conventional cardiopulmonary bypass, miniaturized cardiopulmonary