Bleeding and Thrombosis in High-Risk Renal Transplantation Candidates Using Heparin

Abstract

The benefits and risks of therapeutic heparin anticoagulation in renal transplant patients with HCSs were confirmed. Higher PTTs and cefotetan antibiotic surgical prophylaxis could contribute to bleeding. The optimal PTT ratio appeared to be 1.5-1.9 to prevent thrombosis and limit bleeding risk.

Evaluation of Heparin Anticoagulation Protocols in Post–Renal Transplant Recipients (EHAP-PoRT Study)

“…4,13 As expected, therapeutic heparin was associated with a higher rate of major bleeding, relative to prophylactic heparin and no heparin anticoagulation: 46%, 3.0%, and 3.4%, respectively. Therapeutic heparin was effective for patients deemed to be at very high risk of thrombosis, and no thrombosis was observed in these patients.…”

“…Major bleeding was defined as hematoma requiring surgical evacuation, retroperitoneal bleeding, intracranial bleeding, documented bleeding requiring 2 or more units of packed red blood cells, or documented bleeding with a drop in hemoglobin level of 20 g/L or more. 4 Thromboses were identified from documentation related to both arterial and venous thromboembolic events.…”

“…Factors that contributed to bleeding appeared to be high partial thromboplastin time (PTT) ratios and antimicrobial prophylaxis with cefotetan, which can disrupt production of vitamin K-dependent clotting factors. Thrombosis occurred in 3 patients with PTT ratios below 1.5; therefore, Mathis and others 4 suggested that the optimal PTT ratio is 1.5-1.9. Kusyk and others 13 conducted a retrospective analysis of 326 renal allograft recipients to compare postoperative courses between patients who did and did not receive early IV UFH.…”

“…3 In addition, these patients may have pre-existing genetic and acquired hypercoagulable states. 4 The process of renal transplant itself also presents significant risk for thrombosis. Perioperative stress can induce platelet aggregation, and the use of calcineurin inhibitors (e.g., cyclosporine A or tacrolimus) for immunosuppression may enhance agonistinduced platelet aggregation through modulation of protein phosphorylation.…”

“…12 Although there have been no randomized controlled trials on the topic of postoperative therapeutic anticoagulation in renal transplant recipients, 3 retrospective studies, summarized in the following paragraphs, have evaluated the use of therapeutic anticoagulation in high-risk patients after kidney transplant. 4,13,14 Mathis and others 4 conducted a retrospective analysis of 725 consecutive renal transplant recipients to identify factors associated with bleeding and thrombosis. Twenty-eight of the patients received UFH 500-1100 units/h starting 1-12 h after the surgery was completed, of whom 18 experienced bleeding; 14 of these bleeding episodes were considered major.…”