Aprotinin Does Not Diminish Blood Loss in Elective Operations for Infrarenal Abdominal Aneurysms: A Randomized Double-Blind Controlled Trial

Surgery for abdominal aneurysm is associated with substantial blood loss. In cardiac surgery, aprotinin, a fibrinolysis inhibitor, has shown to reduce blood loss significantly. Our aim was to assess the effect of aprotinin, when administered during elective surgery of infrarenal abdominal aneurysm, on coagulation, blood loss, and morbidity. A double-blind randomized trial was performed on 35 consecutive patients. They were randomized to either an aprotinin or a placebo group. The aprotinin group received 2,000,000 kallikrein inhibiting units (KIU) of aprotinin (500,000 KIU in 50 mL NaCl 0.9%) as a starting dose, followed by 500,000 KIU per hour during the operation. The placebo group received equal amounts of only NaCl 0.9%. During the operation and 24 hr thereafter, blood samples were taken to assess coagulation factors. Blood loss was measured in suction devices and swabs. All patients were followed until their discharge from the hospital. Statistical analysis was performed by independent t-test or Mann-Whitney U-test and chi-squared test. There was no significant difference in the amount of blood loss or the amount of blood products administered between the two groups. Morbidity and mortality were also comparable. In both groups, consumption of clotting factors could be detected, indicating activation of the coagulation cascade. However, in the aprotinin group, the α₂-antiplasmin level was raised during surgery, indicating inhibition of fibrinolysis. Administration of aprotinin during elective operations for infrarenal aortic aneurysm induces inhibition of fibrinolysis. However, it does not significantly reduce blood loss or the need for blood products.