A 23-year-old woman underwent living donor liver transplantation for biliary atresia in 1996. The postoperative course was uneventful, and the patient fared well with tacrolimus-based immunosuppression.
In May 2006, she complained of general fatigue and unconsciousness. The laboratory data showed mild increases in liver enzymes (aspartate aminotransferase, 78 IU/L; alanine aminotransferase, 74 IU/L) and total bile acid (237mol/L), as well as hyperammonemia (NH 3 , 192g/dL). Abdominal contrast-enhanced computed tomography revealed the presence of a large superior mesenteric vein-right renal vein shunt and a splenorenal shunt (Fig. 1). Analysis of liver biopsy samples revealed no evidence of rejection, fibrosis, or cholangitis.
Although the patient had no sign of portal hypertension, frequent admission for hyperammonemic encephalopathy was necessary. Because the hyperammonemia could not be managed with conventional medical treatment, balloon-occluded retrograde transvenous obliteration (B-RTO) was indicated. Pressure measurement revealed no hepatic vein or portal vein stenosis and no portal hypertension. The superior mesenteric vein-right renal vein shunt was occluded with coils (Figs. 2 and3). The clinical symptoms greatly improved after B-RTO, and ammonia and total bile acid levels returned to normal limits. Abdominal computed tomography confirmed complete occlusion of the shunt (Fig. 4).
Although portosystemic shunt is most commonly related to cirrhosis of the liver, it also occurs in patients without a cirrhotic liver, as in our patient. 1 The cause of the portosystemic shunt in this patient is unknown. We suggest 2 possibilities: congenital malformation and postoperative formation. 2,3 B-RTO may represent a safe, effective, and minimally invasive interventional radiology method for the post-liver transplantation treatment of portosystemic shunt without portal hypertension in patients who do not respond to conventional medical treatment.