Progression of Thrombosis under Low Molecular Weight Heparin without Heparin-Induced Thrombocytopenia in a young Man: a Case Report

Low molecular weight heparins (LMWHs) have been proven to be efficacious and safe in the treatment and prophylaxis of thrombosis in adults. LMWHs also appear to offer a safe and effective form of anticoagulation in children [5,9,13,15], but in contrast to adults randomized clinical trials comparing LMWHs with unfractionated heparins (UFHs) and vitamin K antagonists for the prevention and treatment of thromboembolic events are lacking. According to clinical experiences with LMWHs in children [5,9,11,15] for prophylaxis of thrombosis plasma anti-Xa activities between 0.2 and 0.4 IU/ml measured 4 h after application are needed for effective prevention of thrombus apposition or recurrence of thrombosis. We report on a 16-year-old boy who suffered from an incomplete thrombosis of the left popliteal vein and developed an extended complete vein thrombosis during secondary thrombosis prophylaxis with nadroparin. At that time the anti-Xa activity was in the prophylactic range, the patient wore a compression stocking and was completely mobilized.