What is primary sclerosing cholangitis (PSC)?
PSC is a chronic condition resulting from obstruction of bile flow in the liver because of inflammation and fibrosis of the bile ducts.
What causes PSC?
The cause of PSC is unknown. Recent data support both genetic and acquired factors. The literature has described familial occurrence of both PSC and chronic ulcerative colitis. There is also evidence suggesting a genetic component. Currently PSC has been linked most closely with alterations in immune mechanisms.
What are the symptoms of PSC?
The symptoms of PSC are gradual onset of progressive fatigue and pruritus (itching) followed by jaundice. Fever and right upper quadrant pain are other manifestations.
PSC may also be detected on routine blood tests during physical examinations. These abnormal values would prompt more extensive workups such as cholangiography.
How is PSC diagnosed?
Asymptomatic patients with PSC may be discovered by abnormal biochemical tests of liver function (alkaline phosphatase, total bilirubin levels).
Radiographic studies might include endoscopic retrograde cholangiopancreatography (ERCP) or transhepatic cholangiography. Both of these procedures are capable of demonstrating diffusely distributed strictures of the intrahepatic and/or extrahepatic bile ducts. On X-ray biliary ducts have a characteristic beaded appearance due to short and annular strictures with intervening segments of slightly dilated ducts.
Liver biopsy is useful in the diagnosis of PSC. Bile duct proliferation, inflammation and ductal obliteration are consistent with a diagnosis of PSC.
How is PSC treated?
If the patient has no symptoms and is in the early stages, as confirmed by liver biopsy, observation would be a reasonable choice. In this case the prognosis is very good and there is no specific therapy available.
If the patient is having symptoms or the biopsy of the liver shows a more progressive disease, then the treatment should be directed toward treating the symptoms, complications and underlying liver disease and possible evaluation for liver transplantation.
What are the medical therapies used to treat the underlying liver disease?
In general medical therapy has been disappointing. Agents such as cupruretic therapy, immunosuppressive therapy such as steroids, azathioprine, methotrexate and anti-fibrotic agents such as colchicine have not been shown to be effective in randomized controlled trials. Ursodeoxycholic acid has been shown to improve the abnormal biochemical test of liver function only.
What are the complications of PSC?
The complications associated with PSC are recurrent cholangitis and bacteremia and cholangiocarcinoma.
What is recurrent cholangitis and how is it treated?
Recurrent cholangitis refers to repeated episodes of bacterial infection of the bile. Patients with PSC are predisposed to this condition because high grade strictures cause obstruction to bile flow facilitating bacterial growth. Treatment of this condition is by the use of antibiotics and relief of the biliary obstruction.
Why do strictures form and how are they treated?
Whatever the mechanism of PSC, it results in inflammation of the bile ducts, which leads to fibrosis (scar tissue) resulting in strictures. The strictures can lead to elevations in bilirubin levels, recurrent cholangitis or pruritus.
To relieve the obstruction, balloon dilation of the ducts may be performed. Dilation may be performed by endoscopy or by a percutaneous transhepatic route. A plastic stent may be inserted into the duct to keep it patent. Surgery may also be an option.
What is my risk of developing cholangiocarcinoma?
Cholangiocarcinoma (cancer of the intra- and/or extrahepatic bile ducts) may develop in up to 10 to 15 percent of patients with PSC.
What is the treatment for cholangiocarcinoma?
If the patient has a surgically resectable tumor and is not a candidate for liver transplantation, surgical resection of the liver may be considered. Unfortunately, most patients present with advanced disease and treatment is therefore palliative to relieve obstruction. This may be performed by placement of either endoscopic or transhepatic stents.
Are there any other surgical procedures available for the treatment of PSC?
Liver transplantation is currently accepted as the best therapy for end-stage liver disease. Although data is still evolving, recent results suggest a five-year survival rate of about 60 percent. This should be a serious consideration for any patient with PSC or any other for of life-threatening liver disease.
Biliary tract reconstructive procedures, such as choledochoduodenostomy (attaching the common bile duct to the duodenum) or choledochojejunostomy with (attaching the common bile duct to the jejunum) is performed to alleviate symptoms.