Fibrinolysis-adjusted perioperative low-dose aprotinin reduces blood loss in bypass operations.
BACKGROUND
Postoperative bleeding still remains a serious problem in bypass surgery. This study evaluated fibrinolysis and perioperative low-dose antifibrinolytic regimens adjusted to the time course of fibrinolysis.


METHODS
In a prospective, randomized study of 42 patients undergoing bypass grafting, patients received low-dose aprotinin (group A; n = 14) or low-dose tranexamic acid (group TA; n = 14) intraoperatively and postoperatively, respectively, with no antifibrinolytics for comparison (group C; n = 14). Parameters of procoagulation, fibrinolysis, and activated factor VII were measured preoperatively, intraoperatively, and postoperatively. Blood loss was determined up to 24 hours.


RESULTS
The level of thrombin-antithrombin III complex was significantly decreased postoperatively in the treatment groups (group A and TA versus C: 25 +/- 14 and 19 +/- 10 microg/L, respectively, versus 40 +/- 21 microg/L; p < 0.05). Levels of plasmin-antiplasmin complexes were significantly decreased postoperatively in group A (607 +/- 231 microg/L) versus group C (825 +/- 225 microg/L) (p < 0.05) but were increased in group TA (1,145 +/- 394 microg/L) versus group C (p < 0.05). At all times intraoperatively and postoperatively, levels of D-dimers were significantly decreased in group A and group TA versus control (p < 0.001), indicating that fibrinolysis persists after the operation. Intraoperatively, the factor VIIa level decreased significantly in group A (20 +/- 8 mU/mL) versus group C (31 +/- 15 mU/mL) (p < 0.05), but not in group TA (32 +/- 15 mU/mL). Blood loss was significantly lower in group A (135 +/- 37 mL) and group TA (155 +/- 71 mL) versus group C (354 +/- 170 mL) (p < 0.001).


CONCLUSIONS
This low-dose aprotinin regimen adjusted to perioperative fibrinolysis reduces blood loss significantly in coronary bypass grafting. For further progress in this subject, clinical investigations of individual fibrinolysis-adjusted antifibrinolytic treatment seems warranted.
Misfeld
M
M
Department of Cardiac Surgery, Medical University of Lübeck, Germany.
Dubbert
S
S
Eleftheriadis
S
S
Siemens
H J
HJ
Wagner
T
T
Sievers
H H
HH
D000368:Aged; D000933:Antifibrinolytic Agents / Q000008:administration & dosage*; D007611:Aprotinin / Q000008:administration & dosage*; D001780:Blood Coagulation Tests; D016063:Blood Loss, Surgical / Q000517:prevention & control*; D001026:Coronary Artery Bypass; D005260:Female; D005342:Fibrinolysis; D006490:Hemostatics / Q000008:administration & dosage*; D006801:Humans; D007432:Intraoperative Period; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D011446:Prospective Studies; D014148:Tranexamic Acid / Q000008:administration & dosage
D000933:Antifibrinolytic Agents; D006490:Hemostatics; D014148:Tranexamic Acid; D007611:Aprotinin