Extracorporeal Membrane Oxygenation Cannula Malposition in the Azygos Vein in a Neonate with Right-Sided Congenital Diaphragmatic Hernia

Malposition of the extracorporeal membrane oxygenation (ECMO) venous cannula in the azygos vein is not frequently reported. We hereby present such a case, which occurred in a neonate with right-sided congenital diaphragmatic hernia. Despite ECMO application, neither adequate flow nor sufficient oxygenation was achieved. On the cross-table lateral chest radiograph, the cannula tip was identified posterior to the heart silhouette, which implied malposition of the cannula in the azygos vein. After repositioning the cannula, the target flow and oxygenation were successfully achieved. When sufficient venous flow is not achieved, as in our case, clinicians should be alerted so they can identify the cannula tip location on lateral chest radiograph and confirm whether malposition in the azygos vein is the cause of the ineffective ECMO.