Reoperative Coronary Artery Bypass Surgery: The Role of On-Pump and Off-Pump Techniques on Factors Affecting Hospital Mortality and Morbidity

Purpose: Short term results of on-pump and off-pump techniques in patients undergoing reoperative coronary artery bypass grafting (redo CABG) were investigated in this study. 

Methods: A total of 14.430 patients have undergone isolated coronary artery bypass grafting in our clinic from 1998 to 2010. Of these patients, 105 patients who have undergone redo CABG, 53 (50.5%) were operated with cardiopulmonary bypass (on-pump) and 52 (49.5%) without cardiopulmonary bypass (off-pump). Early results for which on or off-pump techniques were independent risk factors were determined with logistic regression analysis. 

Results: Overall mortality in patients undergoing redo CABG was 12.3% with a 11.5% mortality in the off-pump group and 13.2% mortality in the on-pump group and the difference was not statistically significant (p >0.05). Blood product transfusion requirement (p <0.05, OR: 3.620, 95% CI: 1.295-10.119), new onset atrial fibrillation rhythm (AFR) (p <0.05, OR: 13.357, 95% CI: 1.656-107.721), prolonged ventilation (p <0.05, OR: 9.066, 95% CI: 1.091-75.323) and duration of hospitalization (p <0.01, OR: 5.252, 95% CI: 1.784-15.459) were significantly higher in the on-pump group. The number of patients with postoperative low cardiac output was significantly higher in the off-pump group (p <0.05, OR: 5.337, 95% CI: 1.094-26.043). The ratio of complete bypass was significantly higher in the on-pump group compared to the off-pump group (p <0.05, OR: 2.913, 95% CI: 1.204-7.046). 

Conclusion: Despite the lower morbidity and mortality in the off-pump group, the rate of target vessel bypass grafting was lower. Off-pump technique may be considered as a safer option for cardiopulmonary bypass in the high risk population.