gms | German Medical Science

Introduction: The Abernethy Malformation is a very rare congenital malformation of the portal venous system, in terms of a portosystemic shunt, first described by the British surgeon John Abernethy in 1793. Due to a hypoplastic or absent intrahepatic portal vein, blood from the spanchnic venous system and spleen is directed into the inferior vena cava, completely or partially bypassing the liver. There are two types of Abernethy Malformation. Abernethy Malformation Type I is characterized by a total absence of intrahepatic portal venous branches. Two subtypes A and B can be distinguished, depending on if the mesenterial and splenic vein build a common trunk (B), or drain separately into the inferior vena cava (A). In patients with an Abernethy Type II, hypoplastic intrahepatic portal veins can be found, but with a side to side shunt to the inferior vena cava, such as a persisting Ductus venosus Arantii. Congenital portosystemic shunts frequently coexist with other anomalies like malformations of the large vessels and heart, biliary atresia, polysplenia or skeletal anomalies. They also appeared to correlate with nodular lesions of the liver. Most common diagnostic imaging are ultrasound and MRI of the abdomen. At what age an Abernethy Malformation is detected, depends on severity of shunt-conditioned symptoms and afflictions caused by concomitant disease. Hepatopulmonary syndrome and Hepatoencephalopathy are well known complications in patients with portosystemic shunts, that arise from an accumulation of toxic substances in the mesenteric blood that reach arterial circulation instead of being metabolized in the liver.

Material and methods: At our hospital, two children with an Abernethy Malformation are followed up regularly at the Center of Pediatrics. A boy who presented with an episode of somnolence at the age of 7, appeared to suffer from a Type II Abernethy Malformation. Without any specific therapy, the child is doing well for years already. The other patient, a female infant, showed up several congenital anomalies, including an Abernethy Type Ib and a persistent Ductus venosus. The girl underwent an extensive heart operation at the age of 18 months and never needed any further therapy according to the portosystemic shunt.

Conclusion: Once an Abernethy Malformation is diagnosed in a child, further examinations are necessary to detect any coexisting congenital anomalies or liver lesions. Moreover, the patients need to be checked on neurological symptoms and pulmonary restriction. Several treatment options for portocaval shunts have been discussed in the last decades, but there is no definite therapy that is accurate for every patient. Shunt coiling and ligation in case of an Abernethy Type II have been reported, but the results vary considerably. Liver transplantation can be a curative treatment in patients with a Type I and/or liver tumor, but can’t be seen as a standard as well. In any case, the decision of treatment must be considered carefully and taken individually for every patient.