ALBERT

Description: Objective To identify renal transplant patients at a higher risk for allograft thrombosis and develop a risk stratification protocol for post-operative anticoagulation. Background According to the North American Pediatric Renal Transplant Cooperative Study data, vascular thrombosis is responsible for 12% of renal transplant failures. Congenital and acquired prothrombotic disorders have recently been found to play a major role in defining outcome of the renal transplants. Methods In 2007, we initiated universal screening for acquired and congenital thrombophilic risk factors for all renal transplant patients prior to transplant. They were assigned a risk category (Level I-IV) based on the presence of thrombophilic risk factors and their post-operative anticoagulation plan was pre-determined based on their risk level (Table). Low-dose unfractionated heparin drip was initiated a few hours after the transplant and titrated to achieve a 1.5 fold aPTT level. Anticoagulation was changed to low molecular weight heparin (LMWH) on day 2–4, when the risk of major bleed was over, and the serum creatinine had normalized. Result Nine patients have been screened and 8/9 were found to be at high risk for thrombosis (Level II or III). The prothrombotic risk factors identified were Prothrombin gene mutation (2), MTHFR (8), Lupus anticoagulant (2) and low protein S (2). Five patients have undergone renal transplant, and have been treated with LMWH post-operatively as per plan, with successful outcome. No patient has developed allograft thrombosis. 1/5 patients developed a peri-renal hematoma requiring evacuation, but completed prophylactic LMWH therapy. Conclusion Renal allograft thrombosis is preventable. Universal screening can stratify risk and allow an effective intervention to reduce that risk. Our Institution has developed a unique risk stratification protocol to identify patients at high risk for allograft thrombosis and prevent this complication by post-operative anticoagulation. Risk Categorization and Management Plan Risk Level Thrombophilia Management Level I Evidence of Thrombophilia (other than MTHFR) and previous thrombosis Heparin postoperatively and then LMWH bid for 6 months Level II Evidence of Thrombophilia (other than MTHFR), No history of thrombosis Heparin postoperatively, LMWH bid for 3 months, then qd for 3 months Level III MTHFR with normal homocysteine Heparin postoperatively, then LMWH qd for 3 months Level IV No evidence of thrombophilia No anticoagulation