Objective: To report an unusual case of progressive cyanosis post Fontan operation due to porto-systemic venous shunt and the result of its treatment.
Material and Method: A patient with diagnosis of progressive cyanosis post Fontan operation from porto-systemic venous shunt at QSNICH.
Results: This is a case of twelve years old girl, who had diagnosis of situs solitus, levocardia, atrio-ventricular concordant, ventriculo-arterial concordant, hypoplastic right ventricle with large ventricular septal defect. She had pulmonary artery banding at 4 months of age followed by a non-fenestrated extra-cardiac conduit Fontan performed at 7 years and 7 months of age. During the first year of post operation, her systemic oxygen saturation (SpO2) was 93-94% after which it decreased to 87%, 84%, 75% at 1.5, 2.5 and 3 years after surgery, respectively. Clinically she also had progressive dyspnea on exertion. Diffuse pulmonary arterio-venous malformation was demonstrated by contrast echocardiogram during cardiac catheterization. Cardiac magnetic resonance angiography showed abnormal extra-hepatic portal vein to inferior vena cava shunt. After balloon test occlusion in the cath lab, which showed no change in the portal venous pressure, complete occlusion of this portosystemic venous shunt was performed by using Amplatzer Vascular Plug II. Her systemic oxygen saturation increased to 83% with functional class I at one-year post occlusion.
Conclusion: The present report an unusual case of progressive cyanosis post Fontan operation due to pulmonary arteriovenous malformation, which was secondary to congenital extra-hepatic porto-systemic shunt. The venous blood from the intestinal and splenic veins was partially bypassing the liver into inferior vena cava. The patient’s clinical condition and SpO2 improved after transcatheter occlusion of the shunt with the device.

Keywords: Fontan operation, Cyanosis, Congenital extra-hepatic porto-systemic shunt, Pulmonary arterio-venous malformation