Congenital Hepatic Fibrosis Workup

The following studies are indicated congenital hepatic fibrosis:

• Liver function tests

  • Liver enzyme levels are usually within the reference range when uncomplicated by portal hypertension or cholangitis.^[11]
  • Serum alkaline phosphatase and gamma-glutamyl transpeptidase (GGT) levels may be elevated.
  • In the presence of cholangitis, serum bilirubin levels, alanine aminotransferase (ALT) levels, aspartate aminotransferase (AST) levels, WBCs, and the erythrocyte sedimentation rate (ESR) may be elevated.
• Hypersplenism

  • The presence of leukopenia and thrombocytopenia provides evidence of hypersplenism.
  • Splenic pressure is elevated.
• Renal function

  • Renal dysfunction is present in approximately 20% of patients.
  • In the presence of renal involvement, serum urea and serum creatinine levels are elevated, whereas creatinine clearance is decreased.

Characteristic imaging features are generally present and increased recognition of these findings may obviate the need for routine liver biopsy while preserving diagnostic accuracy. Imaging is used in both initial diagnosis and follow-up of patients. However, the hepatobiliary imaging findings of congenital hepatic fibrosis may not be detected until later. The combination of conventional and high-resolution ultrasonography with magnetic resonance cholangiography allows the definition of the extent of liver and renal disease without requiring ionizing radiation and contrast agents.^[8]

• Ultrasonography

  • This study helps to further support the diagnosis by revealing evidence of a patchy pattern of intense hepatic echogenicity, portal hypertension, splenomegaly, and intrahepatic and extrahepatic biliary cysts and dilatations. It is the first-line modality used in the diagnostic process because of its lack of radiation and its capability of detecting renal and liver abnormalities.
  • Ultrasonographic evaluation should include Doppler flow studies to assess the patency of the portal vasculature.
  • Evidence of nephromegaly and increased echogenicity with polycystic changes add further support to the diagnosis of congenital hepatic fibrosis (CHF)-ARPKD.
  • Ultrasonography of liver and kidneys are also indicated as part of preparation for liver and renal biopsies.
  • Color Doppler ultrasonography assists in evaluating the portal venous system. It shows the direction of portal blood flow and varicose venous collaterals.
• CT scanning: CT scanning of the abdomen is occasionally indicated as part of the imaging studies for further evaluation of hepatic and renal involvement in congenital hepatic fibrosis. CT scanning can demonstrate the abnormal shape and size of the liver. It can also show the peroportal thickening, varices, and splenomegaly. In patients with renal insufficiency, contrast medium is not administered, limiting the study.
• Intravenous pyelography

  • Intravenous pyelography (IVP) findings may be abnormal, revealing nephromegaly and alternation of radiodense and radiolucent streaks radiating from the medulla to the cortex.
  • This study is not mandatory for the diagnosis of congenital hepatic fibrosis with potential renal involvement.
• Splenoportography

  • This study may reveal an abnormality of the intrahepatic portal venous system characterized by duplication of the venous channels.
  • Naturally occurring splenorenal or gastrorenal shunts with increasing collateral formation may also be observed.
• Angiography

  • This test further reveals the details of the vascular anatomy and its patency, as well as the extent of the variceal formation.
  • Transhepatic cholangiography is a safe and direct means of identifying cholangitis.
• MRI and magnetic resonance cholangiopancreatography: Magnetic resonance cholangiopancreatography (MRCP) is described as a sensitive method for detecting biliary abnormalities, even when ultrasonographic findings are normal. It may reveal the unusual distribution of the biliary tree with mild dilatation peripherally and poor visibility centrally. MRI can reveal portal hypertension and periportal fibrosis and may help in the preoperative planning of the affected children with the cholangitic form of congenital hepatic fibrosis, obviating the need for invasive cholangiography.

• Endoscopic examination

  • Upper GI endoscopy is often required in the overall evaluation of patients with congenital hepatic fibrosis, especially in the presence of anemia and/or a history of hematemesis or melena.
  • Endoscopy is helpful to confirm or rule out the presence of varices, erosions, or ulceration.
  • In bleeding varices, the procedure is followed by sclerotherapy or band ligation.
• Liver biopsy

  • The diagnosis of congenital hepatic fibrosis depends on histological liver biopsy findings, preferably obtained through minilaparotomy (wedge liver biopsy) to ensure examination of a sufficient number of portal tracts to support the diagnosis.
  • A percutaneous liver biopsy may produce sufficient tissue to confirm the diagnosis; findings may reveal the histological changes in the portal tracts. Remember that the pathological lesions may not be uniform throughout the liver; therefore, the percutaneous liver biopsy may prove inadequate to support the diagnosis. Furthermore, cases with one-lobe involvement have been reported.
  • Congenital hepatic fibrosis is characterized by fibrous enlargement of the portal tracts, which contain variable numbers of abnormally shaped bile ducts.

• Liver histology, as revealed through the biopsy, reveals extensive hepatic fibrosis. The widened fibrous bands in the portal tract contain an increased number of ectatic and dysplastic branches of the interlobular bile ducts. The irregularly shaped proliferating bile ducts are lined by normal cuboidal epithelium.
• The hepatic lobules are usually normal. See the image below.Histopathology of liver biopsy in congenital hepatic fibrosis, which shows a widened portal tract with bands of fibrous tissue that separate areas of normal hepatic parenchyma. Note the multiple irregularly shaped narrow and elongated bile ducts and the absent lobular and portal inflammation.
• Cholestasis is observed in association with cholangitis. Other findings include portal vein branch hypoplasia and degeneration of the bile duct epithelium. Hypoplasia of the portal vein branches in association with supernumerous hepatic artery branches is also observed.