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AUTHOR AND EDITOR INFORMATION

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Author: Michael AJ Sawyer, MD, Director, Videoendoscopic Surgical Institute of Oklahoma, Consulting Staff, Department of Surgery, Comanche County Memorial Hospital; Consulting Staff, Great Plains Surgical Clinic, Lawton, Oklahoma

Michael AJ Sawyer is a member of the following medical societies: American College of Surgeons, Society for Surgery of the Alimentary Tract, Society of American Gastrointestinal and Endoscopic Surgeons, and Society of Laparoendoscopic Surgeons

Coauthor(s): Manish K Varma, MD, Chief of Interventional Radiology, Department of Radiology, Tripler Army Medical Center; Thomas F Murphy, MD, Chief of Abdominal Imaging Section, Department of Radiology, Tripler Army Medical Center

Editors: Neela Lamki, MD, Professor, Department of Radiology, Sultan Qaboos University, Oman; Adjunct Professor, Department of Radiology, Baylor College of Medicine; Bernard D Coombs, MB, ChB, PhD, Consulting Staff, Department of Specialist Rehabilitation Services, Hutt Valley District Health Board, New Zealand; Abraham H Dachman, MD, FACR, Professor, Department of Radiology, The University of Chicago School of Medicine; Director of CT, Department of Radiology, The University of Chicago Hospitals; 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: bile duct cysts, Caroli's disease, congenital anomalies of the bile ducts, cystic dilatation, extrahepatic biliary tree, intrahepatic biliary radicles, choledochocele, cystic dilation, cyst dilation, cyst dilatation

INTRODUCTION

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Background

Choledochal cysts are congenital anomalies of the bile ducts. They consist of cystic dilatations of the extrahepatic biliary tree, intrahepatic biliary radicles, or both. The first anatomic study of a choledochal cyst in the Western literature was published by Vater and Ezler in 1723. Douglas (1852) is credited with the first clinical report, on a 17-year-old girl who presented with intermittent abdominal pain, jaundice, fever, and a palpable abdominal mass.

Alonso-Lej et al provided the first systematic description of choledochal cysts, based on the clinical and anatomic findings in 96 cases.1 The resultant system classified choledochal cysts into 3 types and outlined therapeutic strategies for each. The classification system for choledochal cysts was further refined by Todani and colleagues and currently includes 5 major types.2

For excellent patient education resources, visit eMedicine's Liver, Gallbladder, and Pancreas Center. Also, see eMedicine's patient education article Gallstones.

Pathophysiology

The pathogenesis of choledochal cysts is most likely multifactorial. Some aspects of the disease are consistent with a congenital etiology, others with a congenital predisposition to acquiring the disease under the right conditions.

The vast majority of patients with choledochal cysts have an anomalous junction of the common bile duct with the pancreatic duct (anomalous pancreatobiliary junction [APBJ]). An APBJ is characterized by the entry of the pancreatic duct into the common bile duct 1 cm or more proximal to where the common bile duct reaches the ampulla of Vater. Miyano and Yamataka have demonstrated such APBJs in more than 90% of their patients with choledochal cysts.3

The APBJ allows pancreatic secretions and enzymes to reflux into the common bile duct. In the relatively alkaline conditions found in the common bile duct, pancreatic proenzymes can become activated. This results in inflammation and weakening of the bile duct wall. Severe damage may result in complete denuding of the common bile duct mucosa.

From a congenital standpoint, defects in epithelialization and recanalization of the developing bile ducts during organogenesis and congenital weakness of the duct wall also have been implicated. The result is formation of a choledochal cyst.

Frequency

United States

Choledochal cysts are relatively rare in the United States and other Western countries. Reported rates range from 1 case per 2 million live births to 1 case per 100,000-150,000 live births.

International

Choledochal cysts are more prevalent in Asia than in the United States and other Western countries. More than 33% of all reported cases are from Japan, where Miyano and Yamataka have reported a prevalence of as high as 1 case per 1000 population.3

Mortality/Morbidity

The morbidities associated with choledochal cysts are age dependent. Infants and children are frequently noted to develop pancreatitis, cholangitis, and histologic evidence of hepatocellular inflammation and damage.

The most worrisome complication of choledochal cysts is cholangiocarcinoma. The reported rate of this malignancy in patients with choledochal cysts is 9-28%.

Race

Persons of Asian ancestry, especially those of Japanese descent, may have a somewhat increased risk. No other ethnic or racial predilection has been well described.

Sex

Choledochal cysts are more prevalent in females. The female-to-male ratio is approximately between 3:1 and 4:1.

Age

Most patients with choledochal cysts have some clinical manifestation of the disease in childhood. Approximately 67% of pediatric patients with choledochal cysts have signs or symptoms related to the cyst before they are 10 years of age. Note that a choledochal cyst may not become clinically apparent until the patient is an adult.

Anatomy

The following discussion of the pertinent anatomy of choledochal cysts is based on the Todani classification, published in 1977.2

  • Type I choledochal cysts - These are the most common, representing 80-90% of the lesions. Type I cysts are dilatations of the entire common hepatic and common bile ducts or of segments of each. They can be saccular or fusiform in configuration. Type I cysts can be divided into 3 subclassifications, including type IA cysts, which are typically saccular and involve all or a major portion of the extrahepatic bile duct (common hepatic duct plus common bile duct).
  • Type II choledochal cysts - These are relatively isolated protrusions or diverticula that project from the common bile duct wall. They may be either sessile or connected to the common bile duct by a narrow stalk.
  • Type III choledochal cysts - Also called choledochoceles, these are found in the intraduodenal portion of the common bile duct.
  • Type IVA cysts - These are characterized by multiple dilatations of the intrahepatic and extrahepatic biliary tree. Most frequently, a large, solitary cyst of the extrahepatic duct is accompanied by multiple cysts of the intrahepatic ducts.
  • Type IVB choledochal cysts - These consist of multiple dilatations that involve only the extrahepatic bile duct.
  • Type V choledochal cysts - These are defined by dilatation of the intrahepatic biliary radicles. Often, numerous cysts are present with interposed strictures that predispose the patient to intrahepatic stone formation, obstruction, and cholangitis. The cysts are typically found in both hepatic lobes. Occasionally, unilobar disease is found and most frequently involves the left lobe.

Muise and colleagues published a report on the association of choledochal cyst with biliary atresia.4 Eighty-eight cases have been reported worldwide. Type 1 biliary atresia (common bile duct) was seen in 76% of these cases. Type 3 biliary atresia (porta hepatis) accounted for 22%, and type 2 biliary atresia (common hepatic duct) was present in the remaining 2%. Poor outcomes were significantly more common, statistically, when choledochal cyst was associated with type 3 biliary atresia.

Clinical Details

Some patients do not present with the disease until adulthood. In many adult patients, subclinical bile duct inflammation and biliary stasis have been ongoing for years. Adults with choledochal cysts can present with hepatic abscesses, cirrhosis, recurrent pancreatitis, cholelithiasis, and portal hypertension.

The clinical history and presentation of a patient with a choledochal cyst varies with the patient's age. Overt, dramatic signs and symptoms are more common in infancy, whereas manifestations are more subtle and protean in adulthood.

Infants frequently come to clinical attention with jaundice and the passage of acholic stools. If this presentation occurs in early infancy, a workup to exclude biliary atresia may be initiated. Infants with choledochal cysts can have a palpable mass in the right upper abdominal quadrant; this may be accompanied by hepatomegaly.

Children in whom the condition is diagnosed after infancy present with a different clinical constellation, which includes intermittent bouts of biliary obstructive symptoms or recurrent episodes of acute pancreatitis. Children in whom biliary obstruction is present may also have jaundice and a palpable mass in the right upper quadrant. The correct diagnosis is occasionally more difficult in children with pancreatitis. Often, the only clinical symptoms are intermittent attacks of colicky abdominal pain. Eventually, an analysis of biochemical laboratory values reveals elevations in amylase and lipase levels. This leads to the proper diagnostic imaging workup.

Adults with choledochal cysts frequently complain of vague epigastric or right upper quadrant abdominal pain. Indeed, the most common symptom in adults is abdominal pain. A classic clinical triad of abdominal pain, jaundice, and a palpable right upper quadrant abdominal mass has been described in adults with choledochal cysts, although this is found in only 10-20% of patients. Cholangitis can be part of the clinical presentation in adult patients with biliary obstruction.

Choledochal cysts not appearing until adulthood can be associated with a number of serious complications resulting from long-standing biliary obstruction and recurrent bouts of cholangitis. Such complications include cholelithiasis, severe pancreatitis, hepatic abscesses, hepatic cirrhosis, and portal hypertension.

Preferred Examination

According to Miyano and Yamataka, the preferred initial radiologic examination in the diagnostic workup of a choledochal cyst is an abdominal ultrasonography (US) scan.3 US scanning is noninvasive and involves no radiation exposure, and its findings are sensitive and specific for the diagnosis. Clinically, these features make sense. Patients with choledochal cysts most often have symptoms referable to the hepatobiliary system, and most US operators are familiar with the anatomy of this area.

Once a preliminary diagnosis is made using US scanning, other supportive studies may be ordered, including abdominal computed tomography (CT) scans, magnetic resonance imaging (MRI) studies, or magnetic resonance cholangiopancreatographic (MRCP) examinations. These studies demonstrate the cyst with more precise anatomic detail. In addition, important anatomic relationships to surrounding structures are better defined than with other modalities.

Limitations of Techniques

US scanning is an excellent choice for initial imaging, but it does have limitations, including the fact that its effectiveness is dependent on operator experience, that cysts on US images may be misinterpreted as the gallbladder or other structures, and that US scanning suffers decreased sensitivity in the presence of overlying bowel gas, pancreatitis, cholangitis, or other inflammatory processes. Differentiating a choledochal cyst from a hepatic cyst, hepatic abscess, acute fluid collection, or pancreatic pseudocyst may be difficult.

If the diagnosis is unequivocal with US scanning, other supportive studies are usually required to adequately plan the surgical approach. If doubt remains despite sonographic evidence suggestive of the diagnosis, CT scanning or MRI/MRCP provides the details needed to confirm the diagnosis.


DIFFERENTIALS

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Pseudocyst, Pancreatic

Other Problems to Be Considered

Hepatic cyst
Cholangiocarcinoma
Choledocholithiasis
Cholangitis
Gallbladder duplication


RADIOGRAPH

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Findings

Plain abdominal radiographs are of little use in the diagnosis of choledochal cysts. They offer no specific information related to this diagnosis. In patients presenting with abdominal pain, radiographs are frequently ordered as part of the standard workup. At most, radiographs may suggest displacement of an adjacent hollow viscus, such as the duodenum, by a mass.

Degree of Confidence

Plain abdominal radiographs are not specific for the diagnosis. If a choledochal cyst is suggested on the basis of the history, physical examination findings, and laboratory results, a confirmatory radiologic examination should be performed. The initial examination of choice is abdominal US scanning. This study should be able to depict a cystic mass in the right upper abdominal quadrant with high sensitivity and specificity. If the diagnosis remains equivocal, a CT scan or MRI can be performed.

False Positives/Negatives

False-positive and false-negative rates are high if the diagnosis is based on plain abdominal radiographs. Plain radiographs simply cannot depict choledochal cysts well. Many other masses or inflammatory processes can produce the same clinical picture, which cannot be differentiated by using plain images. Examples of these processes include an acute fluid collection associated with acute pancreatitis, a pancreatic pseudocyst, and choledocholithiasis or cholangitis.


CT SCAN

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Findings

Abdominal CT scanning is useful in the diagnostic algorithm for choledochal cysts. CT scanning is highly accurate and offers a great deal of information that is helpful not only in confirming the diagnosis but also in planning surgical approaches.

CT scans of a choledochal cyst demonstrate a dilatated cystic mass with clearly defined walls that is separate from the gallbladder. The fact that this mass arises from or actually is the extrahepatic bile duct usually is clear from its location and its relationships to surrounding structures. The cyst is typically filled with bile, which produces waterlike attenuation. Depending on the patient's age and clinical history, the wall of the cyst can appear thickened, especially if multiple episodes of inflammation and cholangitis have occurred.

Most patients with choledochal cysts have undergone abdominal US imaging prior to CT scanning. US findings suggest the diagnosis in most patients and may be conclusive in many. According to Lipsett and colleagues, CT scanning confirms an unclear diagnosis and provides information concerning the relationships of the cyst to surrounding structures.5 These include the portal vein, duodenum, and liver. In addition, CT scanning is superior to US scanning in defining the extent of the cyst in the extrahepatic biliary system and in detecting intrahepatic disease.

CT cholangiography is one of the CT imaging techniques that have been used in the diagnosis of choledochal cysts. Spinzi and colleagues published a case report describing CT cholangiography in the diagnosis of a type I choledochal cyst in an adult.6 The cyst and its extent were demonstrated clearly. The authors did note the need to use retrograde biliary contrast enhancement or intravenous contrast enhancement, and they stated that MR cholangiography may one day obviate CT cholangiography.

Lam and colleagues investigated the use of CT cholangiography versus MR cholangiography in the diagnosis of choledochal cysts in children.7 They examined 14 children and had good results with both techniques.

Satisfactory visualization of the biliary tree was achieved in 93% of patients by using CT cholangiography and in 100% of patients by using MR cholangiography. CT cholangiography adequately depicted 10 (91%) of 11 choledochal cysts, whereas MR cholangiography showed 100% of the cysts. Intrahepatic stones were detected, with sensitivities of 83% and 67% for CT and MR cholangiography, respectively. Specificities were 100% for both. CT cholangiography demonstrated the pancreatic duct and the common pancreatobiliary channel in 64% of patients, whereas MR cholangiography depicted these features in 46%. Postoperatively, CT cholangiography was better for surveillance of the hepaticojejunostomy.

The authors recommended the use of MR cholangiography as the confirmatory imaging study in children with choledochal cysts because it does not require breath holding, is noninvasive, does not require the administration of contrast material, and is not associated with ionizing radiation.

Degree of Confidence

CT scans can be relied on with a high degree of confidence. They provide a great deal of information concerning choledochal cysts and their relationships to surrounding structures. Typically, the only preoperative study that may be considered after a confirmatory CT scan is endoscopic retrograde cholangiopancreatography (ERCP). ERCP often provides additional information concerning the pancreatic duct and the distal extent of the choledochal cyst. ERCP can provide more detailed information concerning the epithelium of the cyst and detect the presence of associated tumors or strictures.

False Positives/Negatives

False-positive and false-negative results are rare. If any question remains concerning the diagnosis after a CT scan, ERCP can be performed. Of note, Kepczyk and colleagues published a case report of a choledochal cyst that mimicked a pancreatic pseudocyst.8 The diagnosis remained in doubt after US and CT scanning. The patient's presenting symptoms were those of acute pancreatitis.


MRI

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Findings

Use of MRI and MRCP techniques is increasing dramatically for the noninvasive diagnosis of biliary and pancreatic diseases. Choledochal cysts are no exception. These cysts appear as large fusiform or saccular masses that may be extrahepatic, intrahepatic, or both, depending on the type of cyst. They produce a particularly strong signal on T2-weighted images. Associated anomalies of the pancreatic duct, its junction with the common bile duct, and the long common channel formed by the 2 are usually well demonstrated on MRI/MRCP images.

Miyano and Yamataka used non–breath-hold MRCP to diagnose choledochal cysts in 3 children who presented with abdominal pain and elevated serum amylase levels or with a suspected choledochal cyst on sonograms.3 In all patients, the choledochal cyst was demonstrated clearly. In 2 of 3 patients, APBJs were demonstrated, along with lengthy common channels. The size of the cyst precluded imaging these in the third patient. ERCP also failed to depict the APBJ and common channel in the third patient. The authors concluded that MRCP may be as effective as ERCP in diagnosing choledochal cysts, and it may replace ERCP one day.

Lee and Lee et al compared MRCP and ERCP in 46 patients with various extrahepatic biliary diseases, including choledochal cysts. ERCP was performed in 13 patients, followed by MRCP, and MRCP was performed in 33 patients, followed by ERCP. MRCP findings were diagnostic in 98% of patients. In patients with biliary obstruction, MRCP correctly showed the level of obstruction in 91%, compared with 83% for ERCP (P <.05). The overall diagnostic accuracy rates were similar between the groups.

Sugiyama and colleagues tested the efficacy of MRCP in the diagnosis of APBJ, with results confirmed by means of ERCP.9 APBJ was identified in 82% of patients in whom ERCP had been used to demonstrate the presence of this anomaly. Choledochal cysts were diagnosed in 7 patients. All of the cysts were visualized with MRCP. MRCP studies failed to depict 1 gallbladder carcinoma and 1 case of hyperplasia of the gallbladder mucosa. The authors concluded that MRCP was an accurate technique for the diagnosis of APBJ and choledochal cysts. Yu and colleagues confirmed these results in 2004.10

Irie and associates published the results of using MRCP in the diagnosis of choledochal cysts in 16 patients.11 They found that MRCP defined the proximal bile duct better than ERCP but that defects in the distal common bile duct were missed with MRCP in 2 pediatric patients. APBJ was delineated in all 6 adult patients but was missed in 6 of 10 pediatric patients. The authors concluded that MRCP is an important noninvasive diagnostic study for choledochal cysts but that it should not replace ERCP, especially in children.

Matos and colleagues compared MRCP with ERCP in 8 patients.12 In this series, ERCP and MRCP findings were completely correlated with respect to the type of cyst (type I, n = 7; type IV, n = 1) and the presence of an APBJ and a common channel in all patients. The authors concluded that MRCP provides information equivalent to that derived from ERCP.

Kim, Lim, and colleagues compared MR cholangiography with conventional cholangiography in 13 patients with choledochal cysts.13 MR cholangiography was superior for complete imaging of the cyst (P = .03). Detection rates for the APBJ (P = .641) and bile duct stones (P = .375) were not significantly different. The authors concluded that MR cholangiography was equivalent or superior to conventional cholangiography in the evaluation of choledochal cysts.

De Backer and colleagues described MRI/MRCP findings in a patient with a choledochocele in whom US- and CT-scan findings failed to indicate a diagnosis.14 The MRI techniques revealed a distal common bile duct cyst in the duodenal intramural portion of the duct, which was seen protruding into the duodenal lumen.

Matsufuji and coinvestigators employed secretin-stimulated MRCP to dynamically study pancreatobiliary reflux in patients with known choledochal cysts.15 Six patients were studied. MRCP images were obtained at 1-minute intervals for 15 minutes after the administration of secretin. Increased common bile duct signal intensity was detected in only 50% of these studies. The clinical relevance of this technique is currently not well established.

Degree of Confidence

On the basis of reported results, MRCP appears to be a reliable study in the diagnosis of choledochal cysts, with diagnostic accuracy of 82-100%. In preparation for surgery, particularly when information is needed concerning the location of the APBJ and the length of the common channel, another study, such as ERCP, should be performed.

False Positives/Negatives

Differentiating a choledochal cyst from a pancreatic pseudocyst or other cystic lesions of the pancreas may be difficult using MRI findings. No normal anatomic variants mimic a choledochal cyst.

False-negative findings of the absence of the APBJ and the common pancreatobiliary channel are possible. In addition, small neoplasms of the gallbladder and bile duct may be missed.


ULTRASOUND

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Findings

US scanning is the initial screening examination of choice in patients with choledochal cysts. Pertinent findings include a cystic extrahepatic mass. Depending on the skill of the operator, the specific type or class of choledochal cyst may be identified. Newer, high-resolution US machines help clinicians make such diagnoses. Furthermore, advances in US technology have enabled ultrasonographers to make the diagnosis in the antenatal period.

US scan findings are diagnostic in many patients; however, in the preoperative period, complementary studies, such as ERCP, CT scans, or MRI/MRCP, may be helpful in delineating details of the surrounding anatomy, the location of an APBJ, and the length of the common pancreatobiliary channel.

Abdominal US scan findings can help in detecting associated conditions and complications of choledochal cysts, such as choledocholithiasis, intrahepatic biliary dilatation, portal vein thrombosis, gallbladder or biliary neoplasms, pancreatitis, and hepatic abscesses.

The importance of abdominal US scanning in this disease process is highlighted by the fact that US scan findings initially suggested the diagnosis in many of the studies dealing with other diagnostic modalities referenced in this article.

In surgical series with a total of 140 patients, US scanning was used early in the diagnostic algorithm.16, 17, 18 In these studies, US scan findings, although sensitive, were routinely confirmed by using another study or procedure, such as CT scanning, hepatoiminodiacetic acid scanning, or ERCP.

Miyano and Yamataka confirmed that US scanning is the initial radiologic study of choice to be used if a choledochal cyst is suggested.3 The authors recommended the use of CT scanning or MRI to better delineate the relationship of the cyst to the surrounding structures.

Saing and colleagues described their results in 84 patients with choledochal cysts. These authors relied on US scanning to make the initial diagnosis in all patients.19 Follow-up CT scans were obtained in 80% of patients, and the authors used percutaneous transhepatic cholangiograms to evaluate suspected intrahepatic biliary stones or to examine strictures in the postoperative period. ERCP was used in 33% of patients.

Lee and colleagues reviewed results in 162 pediatric patients undergoing US examinations for biliary tract dilatation.20 A total of 112 patients had choledochal cysts. Mean bile duct diameter was greatest in patients with choledochal cysts versus other pathologies (21.4 vs 10.0 mm for biliary atresia with associated cystic dilatation, 8.5 mm for secondary causes of bile duct dilatation, and 4.4 mm for normal variants, P <.001).

Mackenzie and colleagues reported on 3 children who had a prenatal US diagnosis of extrahepatic cystic masses.21 Biliary atresia with an associated cystic mass was present in 2 patients. A type I choledochal cyst was present in 1 patient. All 3 patients were explored surgically and underwent corrective surgery within 2 weeks. The authors concluded that prenatal US scanning led to accurate diagnoses and expeditious, definitive therapy in all patients. These findings were reinforced in a 2004 study conducted by Chen and colleagues.22

Benhidjeb and colleagues, reporting in 1996, described a new case of antenatal US diagnosis of a choledochal cyst and reviewed 15 previously reported cases.23 The cyst was demonstrated on US examination in the 29th week of gestation. The literature review revealed that this diagnosis has been made using US as early as the 15th week of gestation. The lesions appear as sonolucent cysts in the region of the porta hepatis. The authors stated that the advantage of antenatal diagnosis is that it facilitates early, definitive surgical therapy, precluding the development of complications, such as cholangitis, hepatic abscesses, and cirrhosis.

A 2004 study by Sgro and colleagues described the utility of ultrasound in the prenatal diagnosis of Caroli disease.24

Degree of Confidence

US scanning is sensitive in the demonstration of a cystic lesion in the region of the porta hepatis. If such a lesion is visualized, US scanning frequently may provide enough information to make the diagnosis of a choledochal cyst.

In most patients, a complementary study is necessary. CT scanning and MRI provide detailed information concerning relationships to surrounding anatomic structures. ERCP or percutaneous transhepatic cholangiography provides more anatomic detail regarding the duct.

False Positives/Negatives

No actual normal variants are mimetic of choledochal cysts. Pathologic conditions in the differential diagnosis include pancreatic pseudocysts, hepatic cysts, and biliary atresia with associated cystic masses. At times, differentiating these lesions may be difficult using US scan findings. In this situation, other confirmatory tests are definitely indicated.

Interestingly, Sato and co-investigators reviewed their US findings in 12 patients with choledochal cysts.25 They found that the cyst diameter changed greatly under compression and cautioned against compressing the structures, since this can lead to confusion in the diagnosis.


NUCLEAR MEDICINE

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Findings

Hepatobiliary scintigraphic modalities are used commonly in the setting of acute cholecystitis and in the investigation of neonatal jaundice. In addition, these techniques are useful in the diagnosis of choledochal cysts.

Kao and co-investigators studied the significance of nonvisualization of the gallbladder on cholescintigraphy in 27 patients with choledochal cysts.26 Nonvisualization of the gallbladder occurred in 18 (67%) of 27 patients at 4 hours after injection of the radionuclide. Most of the patients did not have acute cholecystitis. The authors concluded that nonvisualization of the gallbladder in this patient population is not necessarily indicative of acute cholecystitis and that large choledochal cysts may compress the gallbladder, leading to nonvisualization.

Aigner and colleagues used cholescintigraphy to evaluate postoperative bile flow in infants undergoing cyst resection and hepaticojejunostomy or hepaticoantrostomy.27 A total of 12 patients were examined. No significant differences in bile flow were found between the hepaticojejunostomy group and the hepaticoantrostomy group. Flow was well imaged in all patients. The authors concluded that the method was an effective way to study postoperative bile flow.

Lin and colleagues compared cholescintigraphy (using technetium-99m disofenin) with US scanning in the diagnosis of neonatal jaundice.28 A total of 66 neonates with cholestatic jaundice were entered in the study, which was undertaken principally to determine which modality was superior for differentiating biliary atresia from other causes of neonatal jaundice. Choledochal cysts were present in 3 of the infants. The diagnostic accuracy of cholescintigraphy was superior, but the authors also concluded that US scanning should remain the initial imaging study of choice to exclude such anatomic abnormalities as choledochal cysts.

Johnson and co-investigators used mebrofenin cholescintigraphy to evaluate 58 neonates with jaundice.29 Choledochal cysts were present in 4 of the infants; 3 (75%) of the cysts were detected by cholescintigraphy.

Rajnish and colleagues examined the ability of hepatobiliary scintigraphy to classify choledochal cysts.30 A total of 21 patients with confirmed choledochal cysts (12 type I, 9 type IV) had cholescintigraphic examinations; 2 nuclear medicine specialists were asked to review the scans in an attempt to classify the choledochal cysts according to the Todani classification.

Hepatobiliary scintigraphy correlated with ERCP or surgical diagnosis in 86% of patients. All 12 type I cysts were diagnosed correctly using hepatobiliary scintigraphy. The sensitivity for the diagnosis and classification of type IV cysts was 67% (6 of 9 cases). The difficulty here was the relative inability to diagnose intrahepatic disease in type IV cysts. The authors concluded that hepatobiliary scintigraphy was an effective method to use for help diagnosing type I and type IV choledochal cysts.

Degree of Confidence

Hepatobiliary scintigraphy has reasonably good accuracy in the diagnosis of choledochal cysts. However, it probably should not be relied on as the sole study and should be complemented by ERCP, CT scanning, or MRCP.

False Positives/Negatives

False-negative results can derive from the relative inability to diagnose intrahepatic disease in type IV choledochal cysts. No known normal anatomic variants mimic this disease process.


ANGIOGRAPHY

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Findings

Angiographic techniques are not part of the standard workup for choledochal cysts; however, angiography studies and angiographic interventions can be instrumental and even lifesaving when major vascular complications associated with choledochal cysts occur. Fortunately, these complications are rare, and most experience has been limited to case reports.

Eliscu and Weiss described the case of a 21-month-old girl who developed melena and hematemesis and presented in shock, with a large, palpable mass in the right upper quadrant.31 The patient underwent emergent upper endoscopy, and blood was seen spurting through the ampulla of Vater. Abdominal US scan findings demonstrated a subhepatic mass. The patient then underwent angiography, which revealed a 1.5-cm aneurysm in the right hepatic artery. This was embolized with steel coils, and the patient was stabilized. Subsequently, the diagnostic workup was completed, and 1 month after embolization, the patient underwent uneventful resection of a choledochal cyst and adjacent abnormal artery.

Kirimlioglu and colleagues published the case of a 31-year-old woman who presented to the hospital with nausea, vomiting, jaundice, and abdominal pain.32 US scan findings demonstrated a choledochal cyst. CT scans showed an adjacent 3-cm X 4-cm mass consistent with a blood vessel compressing the gallbladder and bile duct. A celiac angiogram demonstrated a 5-cm X 5-cm aneurysm of the proper hepatic artery. The patient later went into shock when the aneurysm ruptured; however, she was rushed to the operating room for definitive treatment of the cyst and hepatic artery. The patient completely recovered.

Degree of Confidence

Published case reports indicate that angiography is accurate for the diagnosis of vascular complications associated with choledochal cysts. Beyond this, little can be said because of the paucity of case reports and series.

False Positives/Negatives

No false-positive or false-negative results related to the use of angiography in the evaluation or treatment of choledochal cysts have been described.


INTERVENTION

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The treatment for choledochal cysts is surgical. The treatment of choice for a type I choledochal cyst is complete excision of the cyst with construction of a Roux-en-Y biliary-enteric anastomosis to restore biliary continuity with the gastrointestinal tract.

Type II choledochal cysts can usually be excised entirely, and the defect in the common bile duct can be closed primarily over a T-tube. This approach can be used because, typically, type II choledochal cysts are lateral diverticula of the bile duct.

Therapy for type III choledochal cysts, or choledochoceles, depends on the size of the lesion. Choledochoceles with a diameter of 3 cm or less may be approached endoscopically and effectively treated by means of sphincterotomy. Choledochoceles larger than 3 cm in diameter are often associated with some degree of duodenal obstruction. These cysts are excised surgically by using a transduodenal approach. If the pancreatic duct is found to be entering the choledochocele, it must be reimplanted into the duodenum after the cyst is excised.

For type IV choledochal cysts, the dilatated extrahepatic duct is completely excised, and a Roux-en-Y biliary-enteric anastomosis procedure is performed. No therapy is specifically directed at the intrahepatic ductal disease, except if intrahepatic ductal strictures, hepatolithiasis, or hepatic abscesses are present. In these patients, interventional radiologic techniques can be performed. If the disease is limited to specific hepatic segments or a lobe, these may be resected.

A type V choledochal cyst, or Caroli disease, is defined only by the dilatation of the intrahepatic ducts. If dilatation is limited to a single hepatic lobe, usually the left, the affected lobe is resected. Patients who have bilobar disease and signs of biliary cirrhosis, portal hypertension, or liver failure may be candidates for liver transplantation.

Recently, laparoscopic techniques have been successfully applied to the management of choledochal cysts. Good results have been achieved in both pediatric and adult populations and reported by several groups.33, 34, 35

A case report of embolization of a ruptured hepatic artery pseudoaneurysm was reported (see Angiography). Angiographic techniques with embolization of bleeding vessels seem feasible and can be used in these situations.

Gulati and colleagues described the use of US-guided percutaneous choledochal cystostomy in 2 infants.36 The children presented with severe hepatic function abnormalities, and 1 child had cholangitis. Choledochal cystostomy was successfully performed in each patient to decompress the biliary system until the infants were ready to undergo surgery.

For patients with choledochal cysts, bile duct stone formation or proteinaceous debris collection in the bile ducts is not uncommon because of poor bile flow. Kaneko and co-investigators described their results in connection with external biliary drainage in patients with choledochal cysts and protracted abdominal pain, jaundice, and vomiting.37 Simple external drainage effected resolution of symptoms in several patients. Filling defects were found in the distal bile duct in 22 patients. These resolved spontaneously or with irrigation in 19 patients (86%). In the remaining 3 patients, material in the bile duct was examined after surgery. It was composed mainly of proteinaceous debris (98%). The authors concluded that symptoms and biliary dysfunction are frequently caused by protein plugs or debris in patients with choledochal cysts. They proposed temporary external biliary drainage and bile duct irrigation as a therapeutic strategy to relieve the signs and symptoms.

Patients with choledochal cysts require lifelong follow-up monitoring. They remain at increased risk for development of cholangiocarcinoma, even after complete excision of the cyst.

Medical/Legal Pitfalls

  • Misdiagnosis or the inability to make a diagnosis is associated with medical/legal pitfalls. The key to avoiding the pitfalls is not to place complete reliance on a single test or diagnostic modality.
  • Patients with choledochal cysts have a significant and potentially life-threatening anomaly of the biliary tract. With the possible exception of Caroli disease, surgery is always indicated and is the definitive therapy. Detailed information is required to plan the surgical approach.
  • Radiologists, gastroenterologists, and surgeons should work as a team in treating patients with choledochal cyst. The diagnostic workup should not cease until all are satisfied that enough information is available for operative planning. Such information usually includes data derived through a combination of US and CT scanning, MRI/MRCP, and ERCP.

Special Concerns

  • The first major special concern is the neonate presenting with prolonged jaundice. The workup should proceed expeditiously in these patients, especially to investigate the diagnosis of biliary atresia. Rapid identification of this anomaly and corrective surgical therapy are essential to providing an optimal outcome.
  • If a choledochal cyst is identified, definitive surgical therapy should be performed as soon as feasible. Progressive damage to the bile ducts and to the liver parenchyma is well described in association with these anomalies.
  • An association exists between APBJ and choledochal cysts, cholangiocarcinoma, and carcinoma of the gallbladder. The potential exists for imaging modalities to miss small cancers of the bile ducts and gallbladder; however, definitive surgery should be planned in all patients and should include resection of incidental lesions.


MULTIMEDIA

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Media file 1:  Type I choledochal cyst.
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Media file 2:  Type II choledochal cyst.
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Media file 3:  Type III choledochal cyst.
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Media file 4:  Type IV (A) choledochal cyst.
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Media file 5:  Type V choledochal cyst (Caroli disease).
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Media file 6:  Nuclear medicine scan of a choledochal cyst. Early image shows most of the radionuclide in the liver.
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Media file 7:  Nuclear medicine scan of a choledochal cyst midway through the study, with better filling of the cyst by the radionuclide (see also Image 6).
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Media file 8:  Nuclear medicine scan of a choledochal cyst late in the study, with the cyst completely defined (see also Images 6-7).
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Media file 9:  Computed tomography scan demonstrates a choledochal cyst involving the intrahepatic portion of the common hepatic duct and the main left hepatic duct.
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Media file 10:  Choledochal cyst involving the intrahepatic common hepatic duct.
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Media file 11:  Large, saccular, type I choledochal cyst compressing the adjacent gallbladder.
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Media file 12:  Large type I choledochal cyst and adjacent gallbladder.
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Media file 13:  Computed tomography (CT) CT scan demonstrates the proximity of the duodenum to the distal aspect of a choledochal cyst.
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Media file 14:  Diagnostic sonogram demonstrating a type I choledochal cyst in a 4-month-old child presenting with elevated hyperbilirubinemia and hepatic transaminase levels.
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Media file 15:  Operative cholangiogram delineating choledochal cyst and pertinent associated biliary anatomy.
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Media file 16:  Surgical specimen.
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Media file 17:  Roux-en-Y hepaticojejunostomy to restore biliary-enteric continuity following resection of choledochal cyst
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REFERENCES

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  1. Alonso-Lej F, Rever WB, Pessagno DJ. Congenital choledochal cyst, with a report of 2, and an analysis of 94, cases. Int Abstr Surg. Jan 1959;108(1):1-30. [Medline].
  2. Todani T, Watanabe Y, Narusue M, et al. Congenital bile duct cysts: classification, operative procedures, and review of thirty-seven cases including cancer arising from choledochal cyst. Am J Surg. Aug 1977;134(2):263-9. [Medline].
  3. Miyano T, Yamataka A. Choledochal cysts. Curr Opin Pediatr. Jun 1997;9(3):283-8. [Medline].
  4. Muise AM, Turner D, Wine E, et al. Biliary atresia with choledochal cyst: implications for classification. Clin Gastroenterol Hepatol. Nov 2006;4(11):1411-4.
  5. Lipsett PA, Pitt HA, Colombani PM, et al. Choledochal cyst disease. A changing pattern of presentation. Ann Surg. Nov 1994;220(5):644-52. [Medline]. [Full Text].
  6. Spinzi G, Martegani A, Belloni G, et al. Computed tomography-virtual cholangiography and choledochal cyst. Gastrointest Endosc. Dec 1999;50(6):857-9. [Medline].
  7. Lam WW, Lam TP, Saing H, et al. MR cholangiography and CT cholangiography of pediatric patients with choledochal cysts. AJR Am J Roentgenol. Aug 1999;173(2):401-5. [Medline].
  8. Kepczyk T, Angueira CE, Kadakia SC, et al. Choledochal cyst mimicking a pancreatic pseudocyst. J Clin Gastroenterol. Mar 1995;20(2):139-41. [Medline].
  9. Sugiyama M, Baba M, Atomi Y, et al. Diagnosis of anomalous pancreaticobiliary junction: value of magnetic resonance cholangiopancreatography. Surgery. Apr 1998;123(4):391-7. [Medline].
  10. Yu ZL, Zhang LJ, Fu JZ, et al. Anomalous pancreaticobiliary junction: image analysis and treatment principles. Hepatobiliary Pancreat Dis Int. Feb 2004;3(1):136-9. [Medline].
  11. Irie H, Honda H, Jimi M, et al. Value of MR cholangiopancreatography in evaluating choledochal cysts. AJR Am J Roentgenol. Nov 1998;171(5):1381-5. [Medline].
  12. Matos C, Nicaise N, Devière J, et al. Choledochal cysts: comparison of findings at MR cholangiopancreatography and endoscopic retrograde cholangiopancreatography in eight patients. Radiology. Nov 1998;209(2):443-8. [Medline].
  13. Kim SH, Lim JH, Yoon HK, et al. Choledochal cyst: comparison of MR and conventional cholangiography. Clin Radiol. May 2000;55(5):378-83. [Medline].
  14. De Backer AI, Van den Abbeele K, De Schepper AM, et al. Choledochocele: diagnosis by magnetic resonance imaging. Abdom Imaging. Sep-Oct 2000;25(5):508-10. [Medline].
  15. Matsufuji H, Araki Y, Nakamura A, et al. Dynamic study of pancreaticobiliary reflux using secretin-stimulated magnetic resonance cholangiopancreatography in patients with choledochal cysts. J Pediatr Surg. Oct 2006;41(10):1652-6.
  16. Chijiiwa K, Koga A. Surgical management and long-term follow-up of patients with choledochal cysts. Am J Surg. Feb 1993;165(2):238-42. [Medline].
  17. Stringer MD, Dhawan A, Davenport M, et al. Choledochal cysts: lessons from a 20 year experience. Arch Dis Child. Dec 1995;73(6):528-31. [Medline].
  18. Rha SY, Stovroff MC, Glick PL, et al. Choledochal cysts: a ten year experience. Am Surg. Jan 1996;62(1):30-4. [Medline].
  19. Saing H, Han H, Chan KL, et al. Early and late results of excision of choledochal cysts. J Pediatr Surg. Nov 1997;32(11):1563-6. [Medline].
  20. Lee HC, Yeung CY, Chang PY, et al. Dilatation of the biliary tree in children: sonographic diagnosis and its clinical significance. J Ultrasound Med. Mar 2000;19(3):177-82; quiz 183-4. [Medline].
  21. Mackenzie TC, Howell LJ, Flake AW, et al. The management of prenatally diagnosed choledochal cysts. J Pediatr Surg. Aug 2001;36(8):1241-3. [Medline].
  22. Chen CP, Cheng SJ, Chang TY, et al. Prenatal diagnosis of choledochal cyst using ultrasound and magnetic resonance imaging. Ultrasound Obstet Gynecol. Jan 2004;23(1):93-4. [Medline].
  23. Benhidjeb T, Chaoui R, Kalache K, et al. Prenatal diagnosis of a choledochal cyst: a case report and review of the literature. Am J Perinatol. May 1996;13(4):207-10. [Medline].
  24. Sgro M, Rossetti S, Barozzino T, et al. Caroli's disease: prenatal diagnosis, postnatal outcome and genetic analysis. Ultrasound Obstet Gynecol. Jan 2004;23(1):73-6. [Medline].
  25. Sato M, Ishida H, Konno K, et al. Choledochal cyst due to anomalous pancreatobiliary junction in the adult: sonographic findings. Abdom Imaging. Jul-Aug 2001;26(4):395-400. [Medline].
  26. Kao PF, Huang MJ, Tzen KY, et al. The clinical significance of gall-bladder non-visualization in cholescintigraphy of patients with choledochal cysts. Eur J Nucl Med. Nov 1996;23(11):1468-72. [Medline].
  27. Aigner RM, Fueger GF, Schimpl G. Cholescintigraphy in the evaluation of bile flow after Roux-en-Y hepatico-jejunostomy and hepatico-antrostomy in infants with choledochal cysts. Pediatr Radiol. Nov 1997;27(11):850-4. [Medline].
  28. Lin WY, Lin CC, Changlai SP, et al. Comparison technetium of Tc-99m disofenin cholescintigraphy with ultrasonography in the differentiation of biliary atresia from other forms of neonatal jaundice. Pediatr Surg Int. 1997;12(1):30-3. [Medline].
  29. Johnson K, Alton HM, Chapman S. Evaluation of mebrofenin hepatoscintigraphy in neonatal-onset jaundice. Pediatr Radiol. Dec 1998;28(12):937-41. [Medline].
  30. Rajnish A, Gambhir S, Das BK, et al. Classifying choledochal cysts using hepatobiliary scintigraphy. Clin Nucl Med. Dec 2000;25(12):996-9. [Medline].
  31. Eliscu EH, Weiss GM. Hematobilia due to a pseudoaneurysm complicating a choledochal cyst. AJR Am J Roentgenol. Oct 1988;151(4):783-4. [Medline].
  32. Kirimlioglu V, Yilmaz S, Katz DA, et al. Choledochal cyst spontaneously rupturing the hepatic artery. Dig Dis Sci. Mar 2000;45(3):544-8. [Medline].
  33. Le DM, Woo RK, Sylvester K, et al. Laparoscopic resection of type 1 choledochal cysts in pediatric patients. Surg Endosc. Feb 2006;20(2):249-51.
  34. Jang JY, Kim SW, Han HS, et al. Totally laparoscopic management of choledochal cysts using a four-hole method. Surg Endosc. Nov 2006;20(11):1762-5.
  35. Srimurthy KR, Ramesh S. Laparoscopic management of pediatric choledochal cysts in developing countries: review of ten cases. Pediatr Surg Int. Feb 2006;22(2):144-9.
  36. Gulati MS, Srivastava DN, Paul SB, et al. Pre-operative management of congenital choledochal cyst with ultrasound-guided percutaneous choledochalcystostomy. Australas Radiol. Nov 1999;43(4):514-6. [Medline].
  37. Kaneko K, Ando H, Ito T, et al. Protein plugs cause symptoms in patients with choledochal cysts. Am J Gastroenterol. Jun 1997;92(6):1018-21. [Medline].
  38. Bratu I, Laberge JM, Khalifé S, et al. Regression of antenatally diagnosed localized Caroli's disease. J Pediatr Surg. Sep 2000;35(9):1390-3. [Medline].
  39. Brine DR, Soulen RL. Pancreaticobiliary carcinoma associated with a large choledochal cyst: role of MRI and MR cholangiopancreatography in diagnosis and preoperative assessment. Abdom Imaging. May-Jun 1999;24(3):292-4. [Medline].
  40. Carr-Locke DL, Conn MI, Faigel DO, et al. Technology status evaluation: magnetic resonance cholangiopancreatography: November 1998. From the ASGE. American Society for Gastrointestinal Endoscopy. Gastrointest Endosc. Jun 1999;49(6):858-61. [Medline].
  41. Chen CP. Ultrasound-guided needle aspiration of a fetal choledochal cyst. Ultrasound Obstet Gynecol. Feb 2001;17(2):175-6. [Medline].
  42. Custis K, Brown C, El Younis CM. Common biliary tract disorders. Clin Fam Pract. 2000;2:141-54.
  43. Dinsmore JE, Murphy JJ, Jamieson D. Pediatric surgical images: MRCP evaluation of choledochal cysts. J Pediatr Surg. May 2001;36(5):829-30. [Medline].
  44. Douglas AH. Case of dilatation of the common bile duct. Monthly J M Sci. 1852;14:97.
  45. Gallivan EK, Crombleholme TM, D'Alton ME. Early prenatal diagnosis of choledochal cyst. Prenat Diagn. Oct 1996;16(10):934-7. [Medline].
  46. Groebli Y, Meyer JL, Tschantz P. Choledochocele demonstrated by computed tomographic cholangiography: report of a case. Surg Today. 2000;30(3):272-6. [Medline].
  47. Hewitt PM, Krige JE, Bornman PC, et al. Choledochal cysts in adults. Br J Surg. Mar 1995;82(3):382-5. [Medline].
  48. Hussain SZ, Bloom DA, Tolia V. Caroli's disease diagnosed in a child by MRCP. Clin Imaging. Sep-Oct 2000;24(5):289-91. [Medline].
  49. Jan YY, Chen HM, Chen MF. Malignancy in choledochal cysts. Hepatogastroenterology. Mar-Apr 2000;47(32):337-40. [Medline].
  50. Jan YY, Chen HM, Chen MF. Malignancy in choledochal cysts. Hepatogastroenterology. Jan-Feb 2002;49(43):100-3. [Medline].
  51. Kabra V, Agarwal M, Adukai TK, et al. Choledochal cyst: a changing pattern of presentation. ANZ J Surg. Mar 2001;71(3):159-61. [Medline].
  52. Kim HJ, Kim MH, Lee SK, et al. Normal structure, variations, and anomalies of the pancreaticobiliary ducts of Koreans: a nationwide cooperative prospective study. Gastrointest Endosc. Jun 2002;55(7):889-96. [Medline].
  53. Kim JE, Lee JK, Lee KT, et al. The clinical significance of common bile-duct dilatation in patients without biliary symptoms or causative lesions on ultrasonography. Endoscopy. Jun 2001;33(6):495-500. [Medline].
  54. Kim MJ, Park YN, Han SJ, et al. Biliary atresia in neonates and infants: triangular area of high signal intensity in the porta hepatis at T2-weighted MR cholangiography with US and histopathologic correlation. Radiology. May 2000;215(2):395-401. [Medline]. [Full Text].
  55. Komuro H, Makino SI, Yasuda Y, et al. Pancreatic complications in choledochal cyst and their surgical outcomes. World J Surg. Dec 2001;25(12):1519-23. [Medli