Effect of internal thoracic artery preparation on blood loss, lung function, and pain

Background. Postoperative blood loss, respiratory distress, and pain after coronary artery operation were assessed in a prospective, randomized, clinical study comparing two techniques of internal thoracic artery preparation. Methods. In group A (n = 57) the internal thoracic artery was dissected with the entire surrounding connective tissue after opening the pleura, using routine lateral pleural drainage. In group B (n = 55) a venoarterial pedicle was prepared without surrounding muscle leaving the pleura intact. We assessed blood loss, clinical outcome, lung function, location, intensity, and quality of pain 6 days and 3 months after the operation. Results. Significantly higher blood loss was observed in group A (A, 608 ± 58 mL; B, 470 ± 48 mL; p = 0.027). Forced expiratory volume in 1 second was significantly decreased in group A 6 days after surgery (A, 76.0% ± 1.6%; B, 83.2% ± 1.6%; p = 0.020). The forced expiratory volume in 1 second correlated to inspiratory vital capacity, which confirmed the advantage of the venoarterial technique (A, 0.771 ± 0.021; B, 0.832 ± 0.020; p = 0.003). Vital capacity was significantly higher in the venoarterial group at 3 months (A, 85.2% ± 2.1%; B, 98.5% ± 1.2%; p = 0.009), but not on postoperative day 6. The incidence of pleural effusion and atelectasis was significantly higher in group A (effusion: A, 52.6%; B, 23.6%; p = 0.002; atelectasis: A, 42.1%; B, 20.0%, p = 0.015). Sternal pain (A, 36.8%; B, 9.1%; p = 0.001) and suspenders pain (A, 33.3%; B, 7.3%; p = 0.001) occurred more often in group A. When using a multidimensional pain score, patients in group A experienced significantly sharper (6 days: A, 6.7 ± 0.3; B, 3.3 ± 0.2; p = 0.018; 3 months: A, 3.5 ± 0.3; B, 1.4 ± 0.3; p = 0.046) and more annoying pain (6 days: A, 7.6 ± 0.2; B, 2.7 ± 0.1; p = 0.036; 3 months: A, 6.6 ± 0.3; B, 2.3 ± 0.2; p = 0.040). Conclusions. These results demonstrate that the venoarterial preparation technique is superior to conventional internal thoracic artery preparation regarding postoperative blood loss, lung function, and pain.