eMedicine Specialties > Radiology > Gastrointestinal

Caroli Disease

Author: William J Romano, MD, FRCPC, Director, Interventional Radiology Research, Department of Radiology, William Beaumont Hospital; Clinical Assistant Professor, Department of Radiology, Wayne State University School of Medicine
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Updated: Apr 6, 2009

Introduction

Background

Caroli disease is a nonobstructive dilatation of the intrahepatic bile ducts, which was first described in 1958 by the French physician Jacques Caroli. This is a rare congenital disorder that classically causes saccular ductal dilatation, which usually is segmental. Caroli disease is associated with recurrent bacterial cholangitis and stone formation.

Presentation

Demographics

• Caroli disease is rare but most often affects females.
• Complications of Caroli disease often manifest in young adults, leading to the diagnosis. Caroli disease can occur in children. As imaging techniques improve, earlier diagnosis may be possible. Prenatal diagnosis with fetal ultrasound has been reported.¹  The average age of patients at diagnosis is 22 years. 
• Morbidity is common and is related to complications of the disease. These include cholangitis, sepsis, choledocholithiasis, and cholangiocarcinoma. These morbid conditions often prompt the diagnosis. Portal hypertension also may be present. These problems can severely affect the patient's quality of life.
• Mortality in Caroli disease is indirect and caused by complications. After cholangitis occurs, a large proportion of patients die within 5-10 years.

The names of the intrahepatic biliary radicles are based on the lobes and segments of the liver that they drain. The right and left main ducts and segmental branches from these main channels subtend their respective liver segments. Liver segments are typically named on the basis of divisions related to the blood supply and venous drainage.

The extrahepatic ductal anatomy includes the cystic duct and the common hepatic and common bile ducts.

Caroli disease involves congenital cystic dilatation of the intrahepatic biliary radicles of the liver. It is believed to have an autosomal recessive inheritance pattern. It may be associated with autosomal recessive polycystic kidney disease. The likely mechanism involves an in utero event that arrests ductal plate remodeling at the level of the larger intrahepatic bile ducts. Insufficient resorption of the ductal plates leads to the formation of multiple primitive bile ducts surrounding the central portal vein. These enlarge, dilate, and become ectatic. This effect may be segmental. In addition to the intrahepatic involvement, extrahepatic bile duct dilatation may occur — perhaps as a consequence of recurrent cholangitis and gallstone passage — as may choledochal cysts.²

Two forms of Caroli disease exist: a simple or classic type and a second type (termed Caroli syndrome) that is associated with congenital hepatic fibrosis .³

Signs and symptoms

Patients may have bilirubinemia and abdominal pain. They generally are febrile. Other complaints, such as nausea and vomiting, may be nonspecific. Liver function test results may be abnormal and include elevated alkaline phosphatase levels. On examination, patients may have hepatomegaly, especially if they have hepatic fibrosis. Portal hypertension related to this may cause variceal bleeding. Elevation in white blood cell counts and positive blood culture results suggest sepsis and cholangitis. Patients may have long symptom-free periods. Malignancy occurs in approximately 7% of patients.

Other etiologies for these symptoms should be excluded. The differential diagnosis can include sclerosing cholangitis, Oriental cholangitis, choledochal cyst, and hydatid disease.

Complications

The complications of Caroli disease, especially recurrent bouts of cholangitis, may be the first clinical manifestations of the disorder. Intrahepatic calculi and abscesses are common. Stone passage can cause pancreatitis.

Treatment

Treat any diagnosed complication. Therapy depends on the clinical manifestations and the location of the biliary abnormality. Antibiotic treatment with broad-spectrum agents is extremely important. Prophylactic antibiotics have had poor and unpredictable results. The addition of oral agents such as ursodeoxycholic acid has no definite benefit. Prevention of the complications is ideal, but no method has been proven effective.

The most common and often first interventional radiologic procedure is percutaneous transhepatic cholangiography (PTC), which reveals dilated segmental intrahepatic biliary radicles. No obstruction is present in the extrahepatic biliary tree. Bile samples can be used for culturing and sensitivity determinations.

Drainage procedures with endoscopic retrograde cholangiopancreatography (ERCP) or percutaneous transhepatic cholangiography (PTC) are important, and sphincterotomy can aid biliary drainage and stone removal or subsequent passage and may decrease bouts of cholangitis. ERCP reveals dilated segmental intrahepatic biliary radicles. No obstruction is present. Stones may be noted. If the process is confined to one lobe, lobectomy completely relieves the symptoms. Internal surgical bypass (choledochojejunostomy, Roux-en-Y, hepaticojejunostomy) is helpful in diffuse forms of the disease. No cure for the disease exists.

With PTC or ERCP, the diagnosis can be made with a high degree of confidence when the large intrahepatic branches have focal or segmental involvement with cystic outpouchings in which the contrast medium collects. False-positive findings are rare with these techniques, and false-negative findings are related to poor filling in the dilated ducts (especially possible with ERCP).

Percutaneous biliary drainage (PBD) with an external catheter or, ideally, an internal/external catheter placed with its distal tip in the duodenum, allows decompression of the biliary tree.

Extracorporeal shock-wave lithotripsy or intraductal electrohydraulic lithotripsy with biliary drainage, stent placement, and liberal sphincterotomy is advocated as an important but aggressive method to treat and prevent choledocholithiasis.

Ultimately, liver transplantation may be required.^4,5,6 This is the best alternative when recurrent cholangitis has not yet developed.

Often, drainage tube placement is indicated, especially if bilirubinemia or possible infection (cholangitis) is present. Internal stent placement may be indicated. Generally, plastic temporary stents are used in nonmalignant conditions; these can be placed percutaneously with fluoroscopic guidance.

Biopsy procedures with brushes or image-guided placement of transabdominal needles may be required to exclude malignant complications. Solid masses can be evaluated or core biopsy samples can be obtained for histologic evaluation.

Preferred Examination

Imaging studies play a major role in the diagnosis of Caroli disease.

• Ultrasonography is widely available and is often  used first in the diagnosis of any process involving the liver; therefore, it is commonly performed early in the workup of patients with Caroli disease. Demonstration of the continuity of the cystic lesions with the bile ducts is paramount in diagnosis.
• Nuclear scintigraphy also may be performed in the initial workup and can be valuable in excluding obstructive causes for intrahepatic duct dilatation that are depicted on cross-sectional images.
• CT imaging is excellent for screening patients.

• MRI can aid in the diagnosis. Also, magnetic resonance cholangiopancreatography (MRCP) can be performed, and images show ductal anatomy well, with additional techniques.
• ERCP can be performed in patients with Caroli disease and can aid in diagnosis. Biliary interventions also can be performed but the intrahepatic ducts can be difficult to access.

• PTC is a more invasive technique that can allow direct visualization of the biliary tree and then therapy with transcutaneous interventions. Drainage catheters may be placed to divert bile. Stones can be removed, or balloon sphincter dilatation can be performed.

Laboratory examinations also are important and include bilirubin level analysis and liver function testing. Elevated white blood cell counts indicate infection, possibly cholangitis. Cultures of the blood, if findings are positive, support a diagnosis of sepsis.

Biopsy of solid liver masses may be performed to aid in the diagnosis of cholangiocarcinoma. Congenital hepatic fibrosis must be diagnosed at histologic examination; this diagnosis can help exclude cirrhosis.

Limitations of Techniques

• Ultrasonography can be limited by air in the adjacent bowel.
• The many reasons for false-positive scintigraphic results are well known, and if biliary obstruction from a complicating factor is present, nuclear scans may be nondiagnostic.
• Artifact can affect CT scans. Not all patients can receive iodinated intravenous (IV) contrast.
• ERCP and PTC are invasive. ERCP cannot be performed if a gastric outlet obstruction or a previous surgical anastomosis (eg, gastrojejunostomy) cannot be crossed. PTC can be difficult if the peripheral ducts are not dilated, or PTC may be contraindicated if the patient has a severe allergy to radiographic contrast media or an uncorrected coagulopathy.
• MRI and MRCP can be hampered by artifact as well as patient factors such as claustrophobia or excessive weight.

Differential Diagnoses

Biliary Atresia

Other Problems to Be Considered

Choledochal cyst
Focal dilatation of the intrahepatic bile ducts
Hereditary ductal dilatation
Association with congenital hepatic fibrosis
Sclerosing cholangitis
Oriental cholangitis
Hydatid disease

• Search for CME/CE on This Topic »

• Caroli Disease (Pediatrics: General Medicine)
• Congenital Hepatic Fibrosis (Pediatrics: General Medicine)
• Choledochal Cyst (Pediatrics: Surgery)
• Choledochal Cysts (Gastroenterology)