Effects of minimal invasive coronary artery bypass on pulmonary function and postoperative pain

Background, Minimally invasive direct coronary artery bypass (MIDCAB) requi res substantially smaller incisions than conventional coronary artery bypas s grafting (CABG). We investigated whether this fact may lead to less posto perative pain and improved pulmonary function. Methods. Preoperative and postoperative (days 1, 3, and 5) pulmonary functi on and postoperative pain were assessed in 15 patients undergoing MIDCAB (g roup A) by using a standardized score and were compared with 15 patients ad mitted for CABG (group B). Results. Total operation time (140 minutes versus 189 minutes; p < 0.001) a nd duration of mechanical ventilation (300 minutes versus 840 minutes; p < 0.001) were significantly less in group A. Pulmonary function was comparabl e between the 2 groups on postoperative day 1 (POD 1). Vital capacity was s ignificantly greater in group A on POD 3 (59.7% versus 40.6%; p < 0.001) an d on POD 5 (74.4% versus 53.9%; p < 0.001). Similar results were found for forced expiratory volume in 1 second (group A versus B on POD 3: 56.3% vers us 42.2%; p < 0.05; and on POD 5: 68.4% versus 55.5%; p < 0.01). Postoperat ive pain was significantly higher in group A (POD 1: score 5.5 versus 3.6; POD 3: 4.0 versus 2.9; p < 0.01). Conclusions. MIDCAB procedures lead to better preservation of pulmonary fun ction compared with conventional CABG despite greater postoperative pain. ( C) 2000 by The Society of Thoracic Surgeons.