Antithrombotic Therapy in Children: Other Disorders
Endovascular Stents: Endovascular stents are used increasingly to manage a number of congenital heart lesions, including branch pulmonary arteiy stenosis, pulmonary vein stenosis, and coarctation of the aorta, and to treat postsurgical stenosis. Stents can be successfully used in infants <1 year of age. The small vessel size increases the risk of thrombosis. There are no studies assessing the role of anticoagulation or antiplatelet therapy to avoid stent occlusion. Heparin is commonly given at the time of stent insertion, followed by aspirin therapy. Further studies are required to determine the optimal prophylactic anticoagulation required.
Other likely cardiac indications for anticoagulation in children are atrial fibrillation and myocardial infarction. There are only case reports describing antithrombotic therapy for these patients. In the absence of data, guidelines for antithrombotic therapy in adult patients are recommended.
Antithrombotic therapy in pediatric patients is used for several other disorders that are not discussed in this chapter. Readers are referred to other sources for antithrombotic therapy in cardiopulmonary bypass, ex-tracorporeal membrane oxygenation, and continuous veno-venous hemoperfusion. allergy treatment
Atrophie Blanche: Atrophie blanche (livedo vasculitis) is a superficial thrombotic disorder in which antiplatelet therapy may alleviate pain and decrease ulceration, according to a level V study.
Angina, Acute Myocardial Infarction, and Peripheral Artery Disease: Although these are the typical indications for aspirin therapy in adults, they occur rarely in children. To our knowledge, there are no published studies addressing the use of antiplatelet agents in these clinical settings in children.
Hemolytic-Uremic Syndrome: Participation of platelets in the thrombotic microangiopathy of hemolytic-uremic syndrome (HUS) makes the use of antiplatelet agents an attractive possibility. Based on two level V studies, aspirin and dipyridamole have been proposed to result in a more rapid rise in the platelet count in children with HUS. However, a level II study failed to confirm this hypothesis. Furthermore, there is no evidence that aspirin and dipyridamole favorably affect other outcome variables in HUS. A level I study showed no benefit of dipyridamole and heparin treatment over symptomatic therapy alone. Similarly, antiplatelet agents have not been shown to be useful in the related disorder of childhood thrombotic thrombocytopenia purpura.
Homocystinuria: In a level V study, aspirin and dipyridamole were hypothesized to diminish the thromboembolic complications of homocystinuria in patients who are unresponsive to pyridoxine. However, two other level V studies did not support this hypothesis.