An absent right and persistent left superior vena cava in an infant requiring extracorporeal membrane oxygenation therapy.

A persistent left superior vena cava (PLSVC) is the most common anomaly of the major veins. However, an absent right superior vena cava and PLSVC is much less common; fewer than 100 cases have been reported in the world literature in patients with situs solitus. This rare variation was encountered in a newborn requiring extracorporeal membrane oxygenation (ECMO) for meconium aspiration and interfered with venous cannulation. The anomaly was not suspected before an unusual cannula position was observed on the chest radiograph, and it was confirmed by bedside venography. Adequate venous cannulation was obtained through the anomalous vessel using a flexible catheter, allowing for an uneventful ECMO course. The epidemiology and embryology of this incidental anomaly are reviewed, and the methods used to circumvent the difficulties it presented in this case are described.