Pleural and pulmonary complications after bilateral internal mammary artery grafting.

The long-term patency of internal mammary artery (IMA) grafts in coronary bypass surgery is superior to that of saphenous vein grafts. To investigate if bilateral IMA grafting increases the complication rate, especially pleural problems, 100 patients with bilateral and 100 with unilateral IMA grafts were retrospectively studied. Preoperatively the groups did not differ in age, previous myocardial infarction, ejection fraction, NYHA classification or previous respiratory disease, but the coronary artery status was poorer in the bilateral IMA group. Postoperative pleural drainage was greater after bilateral IMA grafting (1074 vs. 497 ml, p less than 0.0001). Reoperation was required for bleeding in 10% of the patients with unilateral, and 20% of those with bilateral IMA grafting (p less than 0.05), and more blood was transfused in the latter group (5.9 vs. 4.7 units, p less than 0.01). Pleural effusion at discharge from hospital or 3 months postoperatively, pain in the sternotomy wound, pain on breathing and postoperative use of nitroglycerin did not differ significantly between the groups. Bilateral IMA grafting thus led to more bleeding and reoperations than single IMA grafting, but did not cause excessive pulmonary complications.