Ministernotomy versus complete sternotomy for coronary bypass operations: No difference in postoperative pulmonary function

Objectives: Less-invasive approaches in cardiac operations offer certain co smetic advantages, but it is unclear whether there are additional positive effects with regard to the postoperative recovery of patients. The aim of t his prospective and randomized study was to ascertain whether partial infer ior midline sternotomy can improve pulmonary function, one of the best quan tifiable parameters of postoperative recovery, after coronary artery bypass operations when compared with the standard full midline approach. Methods: One hundred patients scheduled for elective coronary artery bypass grafting were randomized either for a full median sternotomy (standard ste rnotomy group, n = 50) or for a partial inferior sternotomy (ministernotomy group, n = 50). The following pulmonary features were assessed: vital capa city, forced expiratory volume, percentage of forced expiratory volume from vital capacity, total lung capacity, residual volume, maximum inspiratory pressure, and maximum expiratory pressure. Tests were performed preoperativ ely and on the fourth and tenth postoperative days. Results: On the fourth postoperative day, both groups had a significant dec rease in vital capacity (percentage of predicted values) when compared with preoperative values (preoperative vs fourth day: standard sternotomy group , 87.8% +/- 14.3% vs 42.1% +/- 10.2% [P < .0001]; ministernotomy group, 84. 5% <plus/minus> 14.3% vs 41.5% +/- 11.8% [P < .0001]), with a significant t endency for recovery from the fourth to the tenth postoperative day (fourth vs tenth postoperative day: standard sternotomy group, 42.1% <plus/minus> 10.2% vs 66.3% +/- 12.3% [P = .001]; ministernotomy group, 41.5% +/- 11.8% vs 61.3% +/- 13.1 % [P = .002]). There were no differences in any test resu lts between the groups on either the fourth or the tenth postoperative day. Conclusion: A less-invasive approach for coronary artery bypass operations with a partial inferior sternotomy does not improve early postoperative pul monary function when compared with the conventional approach with a full st ernotomy.