Interventional management of an unusual cause of cyanosis in repaired tetralogy of Fallot.

Arterial desaturation following surgical repair of tetralogy of Fallot (TOF) is rare. In most instances, it results from residual right ventricular outflow tract obstruction, causing right-to-left shunt across residual interatrial or interventricular communication. In this report, we present an unusual scenario of arterial desaturation due to a recanalized left cardinal vein in a child with repaired TOF. We also discuss stepwise evaluation that led to successful identification and occlusion of the abnormal venous channel by percutaneous device closure.