A basic understanding of congenital extrahepatic portosystemic shunt: incidence, mechanism, complications, diagnosis, and treatment

Abstract

Extrahepatic portosystemic shunt belongs to a family of rare vascular abnormalities. The clinical importance and manifestations of this vascular abnormality range from asymptomatic cases to liver or metabolic dysfunctions of various degrees. Congenital extrahepatic portosystemic shunt, also termed as Abernethy malformation, is a very rare congenital vascular malformation in which splenomesenteric blood drains into a systemic vein, bypassing the liver through a complete or partial extrahepatic shunt. So far, limited cases of congenital extrahepatic portosystemic shunt have been reported. In this review, incidence, mechanisms, complications, diagnoses and treatments of congenital extrahepatic portosystemic shunt are described.

Portosystemic shunt, a rare cause of neonatal cholestatic hepatitis. A case report

“…T h e i n c i d e n c e i s e s t i m a t e d t o b e 1:30 000/50 000 newborns. 1,3,4 Diagnosis may be prenatal or postnatal in the context of a patient under study because of increased galactose levels detected during newborn screening tests, cholestatic hepatitis, delayed growth or other associated complications. Occasionally, it may be an incidental finding.…”

“…Given this diagnosis, a comprehensive search should be performed to detect vascular, renal, visceral, skeletal, and cardiac abnormalities. [2][3][4][5] The most frequently described malformations are atrial or ventricular septal defect, persistent ductus arteriosus, patent foramen ovale, aortic coarctation, tetralogy of Fallot, and valvular heart disease. 6 These associations suggest a prenatal defect during cardiac and abdominal vascular development, or the presence of adaptive changes in the heart in response to the hyperdynamic effect of PSS.…”

Adult‐onset noncirrhotic hyperammonemic encephalopathy probably caused by splenorenal shunts

“…He did not, however, have congenital heart disease, polysplenia, or skeletal anomalies. He was discharged on day 33 with mild cognitive dysfunction and normal ammonia level, indicating persistent cognitive impairment associated with hyperammonemic encephalopathy 1,2 …”

“…Upper endoscopy revealed no gastroesophageal varices. Amino acid analysis for urea cycle revealed no abnormalities; thus, he was diagnosed with noncirrhotic hyperammonemic encephalopathy, most likely due to splenorenal shunts, 1 , 2 which were treated with branched‐chain amino acids, lactulose, and kanamycin sulfate without any endovascular or surgical intervention. He did not, however, have congenital heart disease, polysplenia, or skeletal anomalies.…”

“…He was discharged on day 33 with mild cognitive dysfunction and normal ammonia level, indicating persistent cognitive impairment associated with hyperammonemic encephalopathy. 1 , 2 …”