Recurrent pyogenic cholangiohepatitis (RPC) is most commonly seen in Southeast Asian populations, characterised by intraductal hepatolithias formation from repeated infection and subsequent stricture formation causing central biliary duct dilatation.
Description
Recurrent pyogenic cholangiohepatitis, also known as Oriental cholangiohepatitis, is a chronic liver disease characterised by recurrent bacterial infection of the biliary tract, often associated with intrahepatic pigment stone formation and biliary strictures.
Pathogenesis
Recurrent pyogenic cholangitis is a chronic biliary tract disease predominantly characterised by the formation of hepatolithiasis within both the intrahepatic and extrahepatic bile ducts. The calculi in RPC are primarily composed of calcium bilirubinate, which unlike cholesterol stones, do not necessarily obstruct the biliary system. Instead, it initiates inflammation causing biliary stricture formation and dilation of the biliary tree. This renders the biliary system susceptible to bacterial invasion, particularly from coliform bacteria originating in the gastrointestinal tract, such as Escherichia coli. The translocation of these bacteria into the biliary system is a critical factor in the acute-on-chronic presentations of cholangitis seen in RPC.
In addition to bacterial involvement, there is an association of RPC with helminthic infections, although the exact role of these infections remains unclear. Chronic infections with trematodes like Clonorchis sinensis and nematodes such as Ascaris lumbricoides are thought to exacerbate the inflammatory process. They may also modulate the host’s immune response, thereby facilitating further bacterial translocation. This interaction between parasitic infections and bacterial invasion contributes to the progression of the disease, leading to epithelial damage, fibrosis, scarring, and the formation of strictures within the biliary tree.
Subtypes
- Primary RPC: Without any prior biliary surgery or known predisposing factors.
- Secondary RPC: Following biliary surgery or due to other identifiable causes like parasitic infections.
Epidemiology, Risk Factors & Associations
- More common in Southeast Asian populations.
- Risk factors include parasitic infections such as liver fluke Clonorchis sinensis and Ascaris lumbricoides, poor nutrition, and low socioeconomic status.
- Associated with chronic liver disease and an increased risk of cholangiocarcinoma.
Clinical Features
- Recurrent episodes of right upper quadrant pain, fever, and jaundice (Charcot’s triad – acute cholangitis)
- History of recurrent cholangitis, liver abscesses, biliary drainage procedures or ERCPs.
- In advanced cases, signs of liver cirrhosis or portal hypertension.
Complications
- Chronic liver damage leading to cirrhosis.
- Increased risk of cholangiocarcinoma.
- Hepatolithiasis and recurrent liver abscesses.
- Biliary strictures and secondary biliary cirrhosis.
- Fulminant abdominal sepsis
- Acute pancreatisis
Pathological Features
Histopathology
- Macroscopic: Intrahepatic bile duct dilatation, stones, and biliary strictures.
- Microscopic: Periductal inflammatory changes with infiltration of periportal spaces with inflammatory cells leading to periductal fibrosis and stricture which could ultimately result in focal liver fibrosis or diffuse biliary cirrhosis. Primarily brown pigmented stones formed from calcium bilirubin, a product of increased rates of bilirubin deconjugation.
Radiological Features
General Features
- Intrahepatic bile duct dilatation, strictures, and stones.
CT
- Intrahepatic biliary duct, mostly central
- Extrahepatic biliary duct dilatation without evidence of external mass-effect
- C+ Arterial/Venous: Highlights the extent of biliary dilatation and strictures. Usually no periductal infiltrative parenchyma changes are seen.
MRI
- MRCP (Magnetic Resonance Cholangiopancreatography)
- Gold standard of non-invasive imaging, can also detect cholangiocarcinoma
- Arrowhead sign – reduced aborisation of the peripheral biliary tree
US
- B-mode: Shows dilated intrahepatic bile ducts and stones.
- Colour Doppler: Assesses vascular complications.
Grading and Staging
- Based on the extent of biliary tract involvement and severity of liver damage.
Diagnosis
- Clinical presentation and history
- Imaging studies (US, CT, MRCP) for visualising biliary changes.
- Laboratory tests showing cholestasis and liver function impairment.
Differential Diagnosis
- Cholelithiasis and choledocholithiasis: Stones primarily in gallbladder or common bile duct.
- Primary sclerosing cholangitis: Chronic inflammation and fibrosis of bile ducts, different epidemiology.
- Cholangiocarcinoma: Malignant tumour of the bile ducts, may coexist with RPC.
Management
- Antibiotic therapy for acute cholangitis episodes.
- Surgical or endoscopic removal of stones and management of strictures.
- Management of complications like liver abscesses and cirrhosis.
- Long-term monitoring for the development of cholangiocarcinoma.