Preoperative therapy of low-dose aspirin in internal mammary artery bypass operations with and without low-dose aprotinin.

The effect of preoperative low-dose aspirin (1 mg/kg of body weight) and intraoperative low-dose aprotinin (2 million kallikrein inactivator units) treatment on perioperative blood loss and blood requirements in patients who undergo internal mammary artery bypass operations is unknown. Therefore, we retrospectively studied 75 matching patients who underwent internal mammary artery operations, and they were allocated to one of three groups: low-dose aspirin and aprotinin treatment (group 1, n = 25), low-dose aspirin treatment without aprotinin (group 2, n = 25), and neither aspirin nor aprotinin treatment (group 3, n = 25). Although the perioperative blood loss was similar, the blood requirements tended to be higher (p = 0.09) in the patients who were treated with aspirin (group 2) than in the control patients (group 3). When aprotinin was added to the priming solution in patients who were treated with aspirin (group 1), blood loss was significantly lower (p < 0.05) than that of group 2 patients but not of control patients. Blood requirements were significantly lower (p < 0.01) than those of patients in groups 2 and 3. Blood products were needed in 29%, 62%, and 75% of patients in groups 1, 2, and 3, respectively.