Spontaneous Splenorenal Shunt: An Alternative Cause of Hyperbilirubinemia in Cirrhosis

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Purpose: Purpose: To report an alternative cause of hyperbilirubinemia in cirrhosis. Methods: A 47 year old Caucasian male was referred to our GI Clinic for the evaluation of abnormal liver function tests and cirrhosis. His medical history was significant for hypertension treated by lisinopril. He drank 6-8 beers daily for many years, but quit 2 months earlier. He reported persistent jaundice for the previous 6 months, but denied fever or abdominal pain. Physical exam showed mild splenomegaly, otherwise unremarkable. Laboratory data revealed hemoglobin 12 g/dl, MCV 103 fL, platelets 50-70x103/microliter, INR 1.7, B12 and folate normal, AST/ALT were 2xULN, ALP 160 U/L, total bilirubin 6.0 mg/dl with indirect bilirubin 4.1 mg/dl, GGT 20 U/L, haptoglobin <6 mg/dl, and LDH 330 U/L. Ultrasound liver showed splenomegaly (volume 1200cc)and small ascites. Liver biopsy showed cirrhosis with stage 4 fibrosis. Hematology workup failed to find an underlying hemolytic process. CT scan of abdomen showed massive dilation of splenic venous vasculature, suggestive of spontaneous splenorenal shunt, which explained the observed indirect hyperbilirubinemia. Results: The elevation of portal pressure and resistance in cirrhosis leads to an increased gradient between portal pressure and systemic blood flow, potentially initiating portosystemic (PS) shunt formation. The resultant elevation of vascular endothelial growth factor (VEGF) in this setting is crucial for VEGF-dependent angiogenesis for the formation of spontaneous PS shunts. Splenorenal shunt is the most common spontaneous PS shunt in cirrhosis (found in up to 21% of cirrhotics). Esophageal varices are rarely found in the presence of PS shunts. Abdominal CT scan and ultrasound are helpful in diagnosis of spontaneous PS shunt. Hypersplenism in cirrhosis leads to increased hemolysis in the reticuloendothelial system. In the setting of PS shunting, the unconjugated bilirubin will then fail to be cleared by the liver, resulting in the indirect hyperbilirubinemia observed in this case. Spontaneous PS shunts may cause refractory hepatic encephalopathy, intestinal septicemia and Parkinsonism-like features due to manganese deposition in the brain. Thus, identification of spontaneous PS shunt is critical for providing optimal clinical care in cirrhotic patients. Conclusion: Our case indicates that the spontaneous PS shunt (splenorenal being most common) needs to be considered in patients with possible liver cirrhosis who may have indirect hyperbilirubinemia as a predominant clinical feature. An appropriate, expedited workup should then be undertaken.