Successful thrombolytic treatment of neonatal arterial thromboses

In Utero Aortic Arch Thrombosis Masquerading as Interrupted Aortic Arch: A Case Report and Review of the Literature

Aortic arch thrombosis is an extremely rare but life-threatening diagnosis that is often misdiagnosed in the neonatal period. Strategies including surgical intervention, systemic anticoagulation, and thrombolysis have been previously described in the treatment of these neonates. We describe the case of a neonate who presented with concern for interrupted aortic arch and was diagnosed with an in utero aortic arch thrombosis. To our knowledge, this is the first reported case with evidence of aortic arch thrombosis in fetal life. The patient underwent successful treatment with systemic thrombolysis with tissue plasminogen activator. A brief review of the literature regarding the diagnosis, treatment, and management of neonatal aortic arch thrombosis is also presented.

Effect of Exogenous Antithrombin Administration on Anti-Xa Levels in Infants Treated With Enoxaparin

OBJECTIVES

Determine the effect of exogenous antithrombin III administration on low molecular weight heparin anti-Xa levels in the context of enoxaparin dosing in infants.

METHODS

A retrospective chart review of infants receiving concomitant antithrombin III and enoxaparin. The primary objective of this study was to determine the median change in anti-Xa level with antithrombin III supplementation. Secondary objectives were to analyze the median change in antithrombin III levels after administration of exogenous antithrombin III, the dosing of antithrombin III, and the dose of enoxaparin throughout therapy. For a safety analysis, any bleeding events were recorded.

RESULTS

The study included 17 patients who received a total of 33 doses of antithrombin III. The median change in anti-Xa levels in infants receiving exogenous antithrombin III was 0.2 units/mL (p < 0.001). The median dose of antithrombin III was 50 units/kg and was administered when patients were receiving a median enoxaparin dose of 1.71 mg/kg. The median increase in antithrombin III levels was 16.5% (p < 0.001).

CONCLUSIONS

These results demonstrated that administration of exogenous antithrombin III to infants who were being treated with enoxaparin results in a significant increase in anti-Xa levels. At this time, there is insufficient evidence to recommend routine administration of antithrombin III to infants on enoxaparin. However, antithrombin III supplementation could be considered a potential option for patients who are unable to adequately achieve therapeutic anti-Xa levels with enoxaparin alone.