Extrahepatic portosystemic shunt concealed in congenital heart disease and neurodevelopmental disorder: a case report.

Background: Neurodevelopmental disorders (NDDs) are often associated with congenital heart diseases (CHDs). Congenital portosystemic shunt (CPSS) is a rare abnormality of the portal system in which toxic substances that are not adequately metabolized by the liver circulate throughout the body and can cause non-specific neuropsychiatric symptoms. We describe a case of CHD and NDD in which neuropsychiatric symptoms due to extrahepatic CPSS became evident in adulthood. Case summary: A 24-year-old man underwent a thorough examination for liver dysfunction. He had a history of repaired tetralogy of Fallot and autism spectrum disorder. He was also diagnosed with depression at 21 years of age. Abdominal contrast-enhanced computed tomography revealed an abnormal vessel descending from the main trunk of the portal vein and entering the left common iliac vein, which was diagnosed as a CPSS. Hyperammonaemia, focal nodular hyperplasia of the liver, and high signal intensity in the bilateral globus pallidus on T1-weighted brain magnetic resonance imaging were also observed. Transcatheter occlusion of the CPSS with a multilayer device (Vascular Plug II; AGA Medical Corporation, Plymouth, MN, USA) significantly improved neuropsychiatric symptoms, abnormal blood data, and head and liver lesions. Discussion: Some of the neuropsychiatric symptoms in this patient were thought to have been caused by portosystemic encephalopathy (PSE) associated with CPSS. The symptoms of PSE and NDD are sometimes similar and difficult to differentiate. Although complications of CHD and NDD are common, screening for secondary treatable neuropsychiatric disorders, such as PSE, should be considered.