You are in: eMedicine Specialties > Radiology > GASTROINTESTINAL Cholangitis, Primary SclerosingArticle Last Updated: Jan 4, 2008AUTHOR AND EDITOR INFORMATIONAuthor: Ali Nawaz Khan, MBBS, FRCS, FRCP, FRCR, LRCP, Chairman of Medical Imaging, Professor of Radiology, NGHA, King Fahad National Guard Hospital, King Abdulaziz Medical City, Riyadh, Saudi Arabia Ali Nawaz Khan is a member of the following medical societies: American Institute of Ultrasound in Medicine, Radiological Society of North America, Royal College of Physicians, Royal College of Physicians and Surgeons of the United States, Royal College of Radiologists, and Royal College of Surgeons of England Coauthor(s): Sumaira MacDonald, MBChB, PhD, MRCP, FRCR, Lecturer, Sheffield University Medical School; Endovascular Fellow, Sheffield Vascular Institute; Aali J Sheen, MBChB, FRCS, Specialist Registrar, Department of HPB Surgery, Manchester Royal Infirmary Oxford Road Manchester UK Editors: Eric P Weinberg, MD, Associate Professor, Department of Radiology, University of Rochester Medical Center, Strong Memorial Hospital; Bernard D Coombs, MB, ChB, PhD, Consulting Staff, Department of Specialist Rehabilitation Services, Hutt Valley District Health Board, New Zealand; Arnold C Friedman, MD, FACR, Associate Chairman, Department of Radiology, University of Florida Health Science Center; Chief, Department of Radiology, Shands-Jacksonville Hospital; Robert M Krasny, MD, Consulting Staff, Department of Radiology, The Angeles Clinic and Research Institute; John Karani, MBBS, FRCR, Consulting Staff, Department of Radiology, King's College Hospital, London Author and Editor Disclosure Synonyms and related keywords: PSC, primary sclerosing cholangitis, cholangitis, bile duct stricture, fibrosis of the bile duct, jaundice, biliary cirrhosis, inflammatory bowel disease, liver transplantation, gallbladder disease, pancreatitis INTRODUCTIONBackgroundPrimary sclerosing cholangitis (PSC) is a chronic, progressive, inflammatory disease characterized by fibrosis of the bile ducts. The cause is unknown, but a hypersensitivity reaction is implicated. Patients present with abnormalities of liver function tests and progressive intermittent obstructive jaundice, which may be associated with fever chills, night sweats, pain, and itching. A liver biopsy, endoscopic retrograde cholangiopancreatogram (ERCP), or percutaneous cholangiogram can help achieve diagnosis. The term primary is used to distinguish this condition from bile duct strictures that are secondary to bile duct injury, cholelithiasis, ischemia, and chemical injury.1, 2, 3, 4, 5 PathophysiologyPSC is a progressive inflammatory disease causing multifocal strictures of both the intrahepatic and extrahepatic bile ducts. The etiology is unknown, but a hypersensitivity reaction is speculated. PSC is often associated with inflammatory bowel disease, such as ulcerative colitis (50-74%) and Crohn disease (13%).6 This may account for the genetic predilection. Other associations include cirrhosis, chronic active hepatitis, pericholangitis, steatosis of the liver, pancreatitis, retroperitoneal and mediastinal fibrosis, Peyronie disease, Riedel thyroiditis, hypothyroidism, and retro-orbital pseudotumor.1 The distribution of biliary system involvement varies, but the common bile duct (CBD) is almost always involved, with or without involvement of the intrahepatic bile ducts and, in some patients, the gallbladder and pancreas. Intrahepatic pigment stones are present in 8% of patients.6 Histologically, the disease can be classified into 4 stages.
CME Endoscopy in Ulcerative Colitis CME 5-SA Therapy for Ulcerative Colitis CME Adherence Issues in the Treatment of Ulcerative Colitis FrequencyUnited StatesPrevalence of the disease in the general population is 1%, as compared with 4% in patients with inflammatory bowel disease.6, 7 Mortality/MorbidityThe course of PSC is prolonged, with progressive jaundice. Death eventually ensues as a result of secondary biliary cirrhosis. The mainstay of treatment remains unsatisfactory, with conventional surgery rarely contemplated and steroid therapy of little use. Avoid surgical procedures, because they may complicate or even preclude future liver transplantation. Prolonged biliary drainage and bile duct dilatation by percutaneous transhepatic biliary stenting or ERCP may provide relief of symptoms. Over the past decade, liver transplantation has emerged as the treatment of choice for patients with end-stage primary sclerosing cholangitis, with many centers reporting 1-year patient and graft survival of 90-97% and 85-88%, respectively. However, specific complications to primary sclerosing cholangitis remain a problem.8, 9 Inflammatory bowel disease complicates approximately 75% of the patients with primary sclerosing cholangitis, with an increased risk of large bowel cancer both pretransplantation and posttransplantation. Furthermore, symptoms from inflammatory bowel disease may become more severe following transplantation prompting proctocolectomy. The results of liver transplantation in patients with primary sclerosing cholangitis complicated by cholangiocarcinoma are disappointing. However, patients who are found to have an incidental cholangiocarcinoma have a low incidence of recurrence. The incidence of both acute and chronic rejection, hepatic artery thrombosis, and subsequent bile duct strictures appears to be higher in patients undergoing liver transplantation for primary sclerosing cholangitis. At least 20% of patients undergoing liver transplantation develop recurrentprimarysclerosingcholangitiswithin5 years.8 RaceNo racial predilection exists, although the Japanese have reported 2 age peaks in their population at 20-30 years and 50-70 years.7, 10 SexMale-to-female ratio is 7:3.6 AgeMost patients are younger than 45 years, with an age range of 21-67 years.6 AnatomyThe right and left hepatic ducts unite at the porta hepatis to form the common hepatic duct (CHD), which enters the free edge of the lesser omentum. The CHD is joined by the cystic duct, forming the CBD. The main left and right bile ducts lie anterior to the left and right portal veins. The hepatic artery branch usually lies anterior to the right portal vein but is often posterior to the left portal vein. In the liver, the bile ducts run with the portal vein and hepatic artery branches in a common sheath (ie, the portal triad). The CBD is approximately 8 cm long. It lies in the free edge of the lesser omentum, usually situated anterolateral to the portal vein. It then passes behind the superior part of the second part of duodenum and traverses the head of the pancreas to the end at the duodenal papilla. Behind the duodenum, the CBD lies anterior to the portal vein with the gastroduodenal artery on its left side. Behind the head of the pancreas, the CBD lies on the inferior vena cava. At this point, the CBD receives the common pancreatic duct and turns to the right to enter the duodenum. Just below the porta hepatis, the right branch of the hepatic artery is usually visible passing between the CHD anteriorly and the portal vein posteriorly. The upper limit of the normal diameter for the CBD is 5 mm; 6-7 mm is regarded as equivocal, and greater than 7 mm usually is pathologic, although bile duct diameter increases in elderly persons and post cholecystectomy. The normal bile duct is 4 mm or less in diameter in 95% of the adult population. In 98% of the adult population, the CHD is 5 mm or less in diameter at the porta hepatis, while at the head of the pancreas, the CBD normally shows slight narrowing. The intrahepatic duct just proximal to the CHD measures 2-3 mm in diameter. The cystic duct lies posterior to the CBD in 95% of the population and anterior to the CBD in 5%. The cystic duct runs in a common sheath with the CBD before their lumina unite; thus, cholecystectomy leaves a variable length of cystic duct in situ. The CBD is distensible and responsive to fluctuation in prandial bile flow. It enlarges slowly with age at a pace equal to that of the hepatic artery and equal to half that of the portal vein. The duct is slightly larger in children with contracted gallbladder, in contrast to findings in adults. Often, a discrepancy exists between the CBD diameter measurements demonstrated using ERCP and ultrasound (US). This finding has been attributed to the variable cross section of the CBD, which is oval in 70% of patients. Standard US technique involves measuring the anteroposterior (AP) diameter of the CBD. The AP diameter for oval and round ducts is similar, but the transverse diameter of an oval duct is greater. Thus, a discrepancy is found between ERCP and US findings when AP diameters are measured on US and conventionally transverse diameters are measured on ERCP. In addition, ERCP involves the injection of contrast, during which the biliary system is stretched by the pressure of injection. Since transverse CBD measurements using US correlate better with disease than conventional AP diameters, transverse measurements can be useful in confirming or excluding bile duct dilatation when AP diameters are larger than normal. Postcholecystectomy CHD and CBD dimensions usually are slightly greater than they are prior to surgery. The normal postcholecystectomy CHD mean diameter is 0.52 cm at the porta hepatis and 0.62 cm at the CBD. Patients with gallstones also tend to have larger extrahepatic bile ducts, although this does not always mean that gallstones are noted within the bile ducts at the same examination. Clinical DetailsInitially, patients come under observation because of abnormal liver function test results demonstrating raised alkaline phosphatase, gamma-glutamyltransferase, and mildly elevated bilirubin levels. All patients eventually present with chronic obstructive jaundice. Patients with known inflammatory bowel disease may present with raised liver enzymes before the onset of jaundice. Of patients with PSC, 10-15% may present with fever, night sweats, chills, itching, and right upper quadrant pain. In 53% of patients, a history of previous biliary surgery and/or recurrent pancreatitis also is found.6 Preferred ExaminationUS is the initial examination of choice in patients presenting with jaundice and right upper quadrant pain. The liver may demonstrate nonspecific abnormalities on US, which infrequently leads to definitive diagnosis. The primary role of US is in helping clinicians make the diagnosis of other bile duct mechanical obstructions, such as gallstones and neoplasia.11 ERCP and percutaneous transhepatic cholangiography (PTC) remain the preferred investigations. Advances in software have improved the diagnostic quality of magnetic resonance cholangiopancreatography (MRCP),12 and although preliminary studies indicate that MRCP may be sensitive and specific in PSC, larger studies are required before it replaces traditional invasive methods.11, 13, 14, 15, 16, 17, 18 Limitations of TechniquesBoth ERCP and PTC are invasive and can potentially cause ascending cholangitis. Recent technical advances have improved MRCP such that third- and fourth-order intrahepatic bile ducts can be resolved, but appearances remain nonspecific. CT scans also demonstrate nonspecific changes. Indistinguishable features may occur with cholangiocarcinoma and other forms of cholangitis. DIFFERENTIALSChemotherapy-induced Cholangitis Cholangitis, Recurrent Pyogenic Cholelithiasis Crohn Disease Ulcerative Colitis Other Problems to Be ConsideredSclerosing cholangiocarcinoma
RADIOGRAPHFindingsPlain radiographs have little role to play in the diagnosis of PSC. Cholangiography in PSC is performed using either PTC or ERCP. ERCP is preferable because of its higher success rate in the absence of dilated intrahepatic bile ducts.
Degree of ConfidenceAppearances of the terminal bile ducts vary, particularly on ERCP, and overinterpretation is common. To tackle this problem, numerous views are obtained at various stages of contrast filling, which may help resolve equivocal changes. Radiographic distinction between a cholangiocarcinoma and sclerosing cholangitis occasionally may be impossible, because the diagnostic specificity of intrahepatic bile duct changes remains controversial. False Positives/NegativesAscending cholangitis, AIDS-related cholangiopathy, cholangiocarcinoma, chemotherapy-induced cholangitis, eosinophilic cholangitis, recurrent pyogenic cholangitis, cholangitis secondary to parasites, and primary biliary cirrhosis can produce similar radiographic appearances. CT SCANFindings
Degree of ConfidenceIntrahepatic bile duct changes on CT scans reflect cholangiographic features with pruning and beading of the ducts. Skip dilatations, defined as isolated dilatation of the intrahepatic bile ducts, are strongly suggestive of PSC; however, ductal delineation and demonstration of strictures can be difficult in the early stages using US or CT scans. CT has a complementary role to that of cholangiography; moreover, do not use CT as a screening examination. False Positives/NegativesBeading, pruning, irregularity, and asymmetry of the intrahepatic bile ducts as demonstrated on CT scans are not specific for PSC. Similar CT changes may be found in other forms of cholangitis and cholangiocarcinoma. MRIFindingsBiliary tract, liver parenchymal, and pancreatic features suggestive of PSC have been reported using MRI.21, 22
Gadolinium-based contrast agents (gadopentetate dimeglumine [Magnevist], gadobenate dimeglumine [MultiHance], gadodiamide [Omniscan], gadoversetamide [OptiMARK], gadoteridol [ProHance]) have recently been linked to the development of nephrogenic systemic fibrosis (NSF) or nephrogenic fibrosing dermopathy (NFD). For more information, see the eMedicine topic Nephrogenic Fibrosing Dermopathy. Degree of ConfidenceThe numbers of patients with PSC studied using MRI have been small; thus, the reliability of the changes described above is uncertain. MRCP may be used, but the extent of intrahepatic disease may be estimated incorrectly because ductal distention cannot be achieved using MRCP. False Positives/NegativesMRI features of PSC are not specific and may occur with cholangiocarcinoma and other forms of cholangitis. ULTRASOUNDFindingsSonographically, biliary abnormalities are not usually visible, unless biliary dilatation is associated.
Degree of ConfidenceUS appearances of PSC are nonspecific; seldom can a confident diagnosis of PSC be made using US alone. The primary role of US is in the diagnosis of other causes of obstructive jaundice. False Positives/NegativesThe differential diagnosis includes cholangiocarcinoma and other causes of ascending cholangitis and primary biliary cirrhosis. In addition to PSC, bile duct wall thickening is associated with hepatic clonorchiasis, Oriental cholangiohepatitis, biliary ascariasis, peribiliary cysts, and AIDS-related cholangiopathy. NUCLEAR MEDICINEFindingsRadionuclide scanning using technetium-99m (99mTc) iminodiacetic acid compounds shows multiple focal areas of persistent activity distributed in the liver parenchyma. The clearance rate of the isotope through the liver is markedly prolonged, with gallbladder visualization achieved in 70% of patients.6, 23 Degree of ConfidenceSpecificity of 99mTc iminodiacetic acid scanning is low, but it is a valuable technique to use for quantifying biliary kinetics. False Positives/NegativesProlonged isotope transit time may occur in other causes of hepatic dysfunction; similarly, nonvisualization of the gallbladder may occur with cystic duct obstruction and chronic gallbladder disease. INTERVENTIONPatients with CBD strictures presenting with recurrent attacks of cholangitis can derive short-term benefit from endoscopic or percutaneous balloon dilatation. Many of these patients have pigment stone impaction at the site of the stricture. With successful placement of a guidewire across the stricture balloon, dilatation is usually straightforward. Although this results in the immediate relief of symptoms, the long-term benefit of stricture dilatation is unclear.24, 25, 26 Medical/Legal Pitfalls
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Cholangitis, Primary Sclerosing excerpt Article Last Updated: Jan 4, 2008 | |||||||||||||||||||||||||||||||||||||||||||||||||