Postoperative bleeding after AB0-incompatible living donor kidney transplantation.

Background: Since 2007, we have performed 14 AB0-incompatible (AB0i) living kidney transplantations to increase the number of living kidney transplantations.

Methods: To prevent clotting, donor kidneys were perfused with an HTK/heparin solution with heparin washed out immediately pretransplantation. However, in 4/14 recipients, significant postoperative diffuse hemorrhage occurred with the need for surgical intervention in 3 patients. To analyze the cause of postoperative diffuse bleeding, sequentially before and after opening the graft anastomosis, we prospectively performed coagulation studies: partial thromboplastin time (PTT), thrombin time, thromboplastin time, fibrinogen, antithrombin, D-dimers, plasminogen, and thrombelastography.

Results: We found no clotting disturbances owing to blood group-specific immunoadsorption. However, 3/4 patients with bleeding complications showed elevated PTT values even 2 hours after opening the anastomosis, which was proven to be a heparin effect by in vitro application of heparinase. Hyperfibrinolysis and disturbances of platelet aggregation were not detected. Because of these results, we lowered the heparin dose administered after donor nephrectomy from initially 10,000-20,000 to 4000 IU resulting in significantly lower PTT values at 2 hours (34.6 ± 4.5 s among patients 6-14 vs 69.0 ± 16.3 s among patients 1-5; P = .012). There were no further bleeding complications. Lowering the heparin dosage had no impact on graft function: serum creatinine at discharge of 1.5 ± 0.1 versus 1.6 ± 0.2 mg/dL.

Conclusion: Our data indicated that postoperative hemorrhage after AB0i kidney transplantation was associated with the amount of heparin used for graft perfusion after donor nephrectomy. The use of antifibrinolytic agents may be harmful; no hyperfibrinolysis takes place in the AB0i transplant setting.