Low-dose aprotinin in internal mammary artery bypass operations contributes to important blood saving.

The effect on postoperative blood loss and blood use of blood-saving treatment with or without 280 mg of low-dose aprotinin (2 million kallikrein inactivator units) was studied in 200 consecutive patients undergoing either unilateral or bilateral internal mammary artery bypass grafting. Postoperative blood loss and total units of homologous blood products were similar in patients having either bypass procedure without aprotinin treatment. In patients given aprotinin, postoperative blood loss and use of homologous blood products were significantly lower (p < 0.05). The use of any donor blood product was prevented in 78% of the patients given aprotinin versus only 45% of patients treated without aprotinin. None of the aprotinin-treated patients underwent repeat thoracotomy for excessive bleeding; repeat thoracotomy was indicated in 8% of the patients having bilateral internal mammary artery grafting without aprotinin treatment. These results demonstrate that low-dose aprotinin reduces blood loss and blood use significantly and prevents excessive bleeding.