Caroli Disease and Caroli Syndrome

A congenital disorder of the intrahepatic bile ducts characterized by intrahepatic dilatation of the biliary tree, which may result in cholangitis, cholelithiasis, sepsis, hepatic failure, and portal hypertension.

Congenital Dilatation of Intrahepatic Bile Ducts; Communicating Cavernous Ectasia of Intrahepatic Bile Ducts; Choledochal Cysts Type V (Todani classification).

The exact incidence is not known but is considered to be very low (probably fewer than 200 cases described in the literature). Caroli syndrome occurs more frequently than Caroli disease (see Clinical Aspects for differentiation). Both forms are more common in females.

Not precisely known. Autosomal recessive has been suggested for both Caroli disease and Caroli syndrome.

In Caroli disease, polycystic segmentation of the larger intrahepatic bile ducts (segmental, left and right) occurs, whereas in Caroli syndrome the ductal abnormalities are more widespread. Both forms are characterized by fibrosis of the portal tracts. Both Caroli disease and Caroli syndrome are thought to originate from a pathologic development in the formation of the ductal plate. The ductal plate originates from hepatocytes surrounding the intrahepatic portal vein branches. Further differentiation during fetal life results in the formation of small tubules, which coalesce to form the intrahepatic biliary tree. Failure of the ductal plate to differentiate are summarized as ductal plate malformations. The anomalous structure of the intrahepatic bile ducts leads to saccular or fusiform dilatation and ectasia with biliary stasis, cholelithiasis, cholangitis with intrahepatic abscesses, and recurrent sepsis.

Diagnosis of exclusion. Fetal ultrasound examination of liver and kidneys during pregnancy has resulted in prenatal diagnosis of Caroli disease/syndrome. However, further radiologic investigations (computed tomography scanning, magnetic resonance imaging, cholangiography), endoscopic retrograde cholangiopancreatography, and liver biopsy may be required to confirm the diagnosis. Approximately half of the patients also have extrahepatic fusiform enlargement of the common hepatic and common bile duct.

The findings in Caroli disease are limited to ectasia or segmental dilatation of the larger intrahepatic ducts. In Caroli syndrome, which is more common than Caroli disease, the pathologic findings include smaller bile ducts and congenital hepatic fibrosis. Caroli disease frequently presents with complications as a result of cholangitis (fever, right upper quadrant pain). The first presentation of Caroli syndrome may result from complications of portal hypertension, most often upper gastrointestinal bleeding. Liver cirrhosis has been described. Overwhelming sepsis with death is not a rare complication for these patients. On examination, jaundice hepatomegaly, splenomegaly, and renal masses associated with renal disease may be found. Although presentation is most frequently in adulthood, childhood and neonatal cases have been described. Patients are at risk for progressive hepatic failure. Caroli disease/syndrome can coexist with medullary sponge kidney, medullary cystic kidney disease, and autosomal recessive polycystic kidney disease (renal cysts, interstitial fibrosis, potential for renal insufficiency). Occasionally, the disorder is limited to one liver lobe (commonly the left) or segment only, and hepatic lobectomy has been used to treat these cases. Liver transplantation has been used for severe cases with whole liver involvement. Compared to the normal population, an up to 100-fold increased risk of cholangiocarcinoma has been reported in these patients, with up to 24% of patients experiencing this type of malignancy at some point in their life.

Preoperative blood work should include a complete blood count (anemia due to chronic infection, bleeding from esophageal varices, or renal failure), thrombocytopenia (secondary to hypersplenism), creatinine, blood urea nitrogen, and liver function tests (bilirubin and transaminases may be normal or only slightly increased).

Anesthetic management is determined by the degree of associated hepatic and renal dysfunction. Central neuraxial anesthesia is contraindicated in the presence of coagulopathy. The risk of surgery has not been specifically assessed in Caroli disease/syndrome. Whereas surgery likely will be tolerated well by patients with normal hepatic function, this usually does not apply to patients with compromised liver function. Anesthesia techniques should aim to maintain hepatic blood flow by preventing low arterial blood pressure and ensuring appropriate intravascular volume. Blood loss from abdominal surgery may be significant in the presence of portal hypertension, and large-bore intravenous access (preferentially in the upper body half), invasive monitoring, and blood products available for transfusion are required. A nasogastric tube must be inserted carefully to prevent trauma to esophageal varices. Postoperative mechanical ventilation may be required.

Broad-spectrum antibiotic coverage is indicated in the presence of active cholangitis. Coagulopathy should be corrected with vitamin K, fresh-frozen plasma, deamino-8-D-arginine vasopressin (DDAVP), and platelets as necessary. Renal dysfunction may require perioperative hemodialysis and/or pharmacologic intervention for potassium control. Hepatic and/or renal dysfunction may affect the volume of distribution, protein binding, and metabolism of drugs. Pseudocholinesterase activity can be altered. Drugs should be selected based on their known properties in the presence of hepatic and renal dysfunction. Nephrotoxic drugs should be avoided.

Polycystic Liver Disease: A form of hepatobiliary fibropolycystic disease characterized by an overgrowth of biliary epithelium and supportive connective tissue. Multiple cysts are present in the liver parenchyma. The condition usually is associated with polycystic kidney disease.

Polycystic Kidney Disease (PKD): Genetic disorder that frequently results in renal failure in childhood. It is the most common genetically determined childhood cystic disease of the kidneys. Congenital malformation of the collecting tubules.

Infantile Polycystic Kidney Disease: Autosomal recessive disorder with onset in the first year of life, characterized by generalized dilation of the collecting tubules resulting in fusiform cysts. Hepatic involvement with proliferation and dilation of the bile ducts leading to hepatic fibrosis occurs. Reported incidence is approximately 1.5-6:1000 pediatric patients.