Vascular anomalies associated with hepatic shunting.

Congenital vascular anomalies affecting the liver have been described in the scientific literature for decades. Understanding these malformations begins with knowledge of hepatic vascular embryology. Surgeons have applied numerous classification systems to describe both intrahepatic and extrahepatic shunts, which can confuse the reader and clinician. In our experience, focusing on one classification system for extrahepatic shunts and one for intrahepatic shunts is better. Today many patients with these shunts carry good long-term prognosis thanks to advances in imaging to better detect shunts earlier and classify them. Timely intervention by skilled radiologists and surgeons have also limited complications arising from dynamic shunts and can avoid a liver transplant. Congenital hepatic shunts are not the only vascular condition affecting the liver. Hereditary hemorrhagic telangiectasia, also known as Osler Weber Rendu syndrome, particularly type 2, may have varying severity of hepatic involvement which warrants longitudinal care from an experienced hepatologist. Lastly, congenital hemangiomas, often first identified on the skin and oral mucosa, also can affect the liver. While most will resolve in infancy and childhood, the pediatric hepatologist must understand how and when to treat persistent lesions and their complications. This article serves as a concise reference to help clinicians better care for patients with these rare conditions.