Characterization and natural history of congenital intrahepatic portosystemic shunts.

Congenital intrahepatic portosystemic shunts are rare vascular malformations in which abnormal communications are created between the portal veins and the hepatic veins or the inferior vena cava system. Diagnosis is made by prenatal or postpartum ultrasound. Published data regarding presentation, symptoms, and prognosis is scarce. This study aimed to better understand the natural history and the course of the intrahepatic portosystemic shunts. Data were collected from children in two medical centers who were diagnosed with congenital intrahepatic portosystemic shunts on either prenatal or postnatal sonographic screening. The subjects' medical information was collected including demographics, medical background, and sonographic and clinical outcome. Blood test results including ammonia levels and liver function tests were documented, as well as the sonographic dimensions of the shunt vessels and the spleen size. The data were analyzed using various statistical methods. Twenty-three children with portosystemic shunts were found and reviewed. Eight children were excluded from the study since records and follow-up were insufficient. Fifteen patients were included in the study (six females). All had intrahepatic shunt diagnosed either by prenatal screening or postnatal abdominal ultrasound and had more than one ultrasound and repeated blood tests. Shunt closure was observed in all children within a mean of 114.31 ± 115.05 days (median 84). There was no correlation between liver enzymes, ammonia, and ultrasound vascular and splenic diameters to time to closure. None of the children had any hepatic or other sequelae.Conclusions: Our study suggests that congenital intrahepatic portosystemic shunt is a benign, self-limiting condition in which no correlation between the size of the shunt and the blood ammonia level to the outcome of the shunt was found. This is the first study that correlated radiological measures to the outcome. These results suggest that the treating physician should reassure families and conduct minimal follow-up and interventions in children with such conditions. Further, larger and prospective studies should be done to corroborate these conclusions. What is Known: • Characteristics and natural history of intrahepatic portosystemic shunts are less defined. • The natural course of the intrahepatic malformations varies, but spontaneous, self-resolution of small shunts, usually occures within 1 to 2 years. What is New: • In this study, congenital intrahepatic portosystemic shunt was shown to be benign, self-limiting condition in which all shunts closed within 3 months. • No correlation between the size of the shunt and the blood ammonia level to the outcome of the shunt was found.