Endoscopic ultrasonography for diagnosing anomalous pancreaticobiliary junction

Endoscopic Ultrasound and Intraductal Ultrasound in the Diagnosis of Biliary Tract Diseases: A Narrative Review

Endoscopic ultrasound (EUS) and intraductal ultrasound (IDUS) play very important roles in the field of biliary tract disease. Because of their excellent spatial resolution, the detection of small lesions and T- or N-staging of tumors have become possible. Additionally, contrast-enhanced EUS and the new imaging technique of detective flow imaging are reported to be useful for differential diagnosis. Furthermore, EUS-guided tissue acquisition is used not only for pathological diagnosis but also to collect tissue samples for cancer genome profiling. This review provides an overview of diagnosis utilizing the features and techniques of EUS and IDUS.

Utility of Contrast-Enhanced Harmonic Endoscopic Ultrasonography to Diagnose Pancreaticobiliary Maljunction

BACKGROUND

Detection of a common channel outside the duodenal wall is important in diagnosing pancreaticobiliary maljunction (PBM). The present study evaluated the utility of contrast-enhanced harmonic endoscopic ultrasonography (CH-EUS) in diagnosing PBM.

METHODS

This single-center retrospective study enrolled 45 patients who were diagnosed with PBM or high confluence of pancreatobiliary ducts (HCPBD) between January 2007 and December 2021. The diagnostic sensitivities of contrast-enhanced computed tomography (CE-CT), magnetic resonance imaging (MRI), and CH-EUS for diagnosing PBM were analyzed. Imaging findings were evaluated by two reviewers blinded to the clinicopathological results.

RESULTS

Based on diagnostic criteria, 33 patients were diagnosed with PBM and 12 with HCPBD. Compared with the patients with HCPBD, those with PBM had significantly longer common channel (12.5 mm vs. 8.1 mm, P = 0.018) and common bile duct (13.0 mm vs. 8.6 mm, P = 0.049) lengths. The κ-coefficients for differentiating PBM and HCPBD were 0.871 between CE-CT and MRI, 0.330 between CE-CT and CH-EUS, and 0.611 between MRI and CH-EUS. The diagnostic sensitivity of CH-EUS (95.2%) was higher than that of CE-CT (83.3%) and MRI (82.8%), although the differences were not statistically significant.

CONCLUSION

CH-EUS may be useful for the diagnosis of PBM.

Diagnosis and management of choledochal cysts

BACKGROUND

Choledochal cysts (CCs) are rare cystic dilatations of the intrahepatic and/or extrahepatic bile ducts. We review the pathophysiology, diagnosis, and management of CCs.

METHODS

MEDLINE/PubMed and Web of Science databases were queried for "choledochal cyst", "bile duct cyst", "choledochocele", and "Caroli disease". Data were synthesized and systematically reviewed.

RESULTS

Classified according to the Todani Classification, CCs are generally believed to arise secondary to reflux of pancreatic enzymes into the biliary tree due to anomalous pancreaticobiliary duct union. Complications of CCs include abdominal pain, jaundice, cystolithiasis, cholecystitis, pancreatitis, liver abscess, liver cirrhosis and malignant transformation (3-7.5%). Radiological and endoscopic imaging is the cornerstone of CC diagnosis and full delineation of cyst anatomy is imperative for proper management. Management is generally guided by cyst classification with complete cyst excision necessary for CCs with high potential of malignant transformation such as types I and IV. 5-year overall survival after choledochal cyst excision is 95.5%.

CONCLUSION

Most CCs should undergo surgical intervention to mitigate the risk of cyst related complications such as cholangitis and malignant transformation.

Imaging of Pancreaticobiliary Maljunction

Pancreaticobiliary maljunction (PBM) is a congenital malformation in which the pancreatic and bile ducts join outside the duodenal wall, usually forming a long common channel. A major issue in patients with PBM is the risk of biliary cancer. Because the sphincter of Oddi does not regulate the pancreaticobiliary junction in PBM, pancreatic juice frequently refluxes into the biliary tract and can cause various complications, including biliary cancer. Most cancers arise in the gallbladder or dilated common bile duct, suggesting that bile stasis is related to carcinogenesis. Early diagnosis and prophylactic surgery to reduce the risk of cancer are beneficial. The diagnosis of PBM is made mainly on the basis of imaging findings. The development of diagnostic imaging modalities such as multidetector CT and MR cholangiopancreatography has provided radiologists with an important role in diagnosis of PBM and its complications. Radiologists should be aware of PBM despite the fact that it is rare in non-Asian populations. In this review, the authors present an overview of PBM with emphasis on diagnosis and management of PBM and its complications. For early diagnosis, the presence of extrahepatic bile duct dilatation or gallbladder wall thickening may provide a clue to PBM with or without biliary dilatation, respectively. The pancreaticobiliary anatomy should be closely examined if imaging reveals these findings. Radiologists should also carefully evaluate follow-up images in PBM patients even years after prophylactic surgery because residual bile ducts remain at risk for cancer.^©RSNA, 2020.

An investigation into the sensitivity of endoscopic ultrasound in the diagnosis of malignant bile duct in patients with idiopathic acute pancreatitis

Introduction and Objective

Acute pancreatitis (AP) is an inflammatory process of the pancreas characterized by abdominal pain and increased pancreatic enzymes. This disease is diagnosed clinically. Endoscopic ultrasound (EUS), which is a technique with high sensitivity and specificity, is used to diagnose biliary disease. This study aimed to determine the sensitivity of EUS in the diagnosis of malignant bile duct in patients with idiopathic AP.

Methods

This descriptive study was performed on 146 patients with pancreatitis hospitalized in the gastrointestinal tract section of the Imam Khomeini Hospital of Ahwaz Jundishapur University of Medical Sciences. The collected data were analyzed by the SPSS 22.0 and the significance level of the test was <0.05.

Results

According to the results, 79 (54%) out of the 146 patients were female and 67 (46%) were male. The mean and standard deviation of the patients' age were 52.5 and 19.6 years, respectively. The findings showed that the sensitivity and specificity of the EUS were 33% and 99%, respectively. Compared to the endoscopic retrograde cholangiopancreatography (ERCP), the sensitivity and specificity of the abdominal ultrasound were 62% and 62.5%, respectively. Compared to the ERCP, the sensitivity and specificity of EUS were 92% and 50%, respectively.

Conclusion

The findings of this study showed that the sensitivity and specificity of EUS were higher than those of abdominal ultrasound. Moreover, EUS was the preferred method to detect common bile duct stones (CBDS).

Capability of Radial- and Convex-Arrayed Echoendoscopes for Visualization of the Pancreatobiliary Junction

Background/Aims

Although both radial- and convex-arrayed endoscopic ultrasonography (EUS) scopes are widely used for observational EUS examinations, there have been few comparative studies on their power of visualization. The aim of this study was to evaluate the capability of these EUS scopes for observation of the pancreatobiliary junction.

METHODS

The rate of successful visualization of the pancreatobiliary junction was retrospectively compared between a radial-arrayed and a convex-arrayed echoendoscope, from a prospectively maintained database. Study periods were defined as January 2010 to December 2012 for the radial group, and February 2015 to October 2016 for the convex group because the respective scope was mainly used during those periods.

RESULTS

During the study period, 1,660 cases with radial EUS and 1,984 cases with convex EUS were recruited. The success rates of observation of the pancreatobiliary junction were 80.0% and 89.5%, respectively (p&lt;0.0001).

Conclusions

The capability of visualization of the pancreatobiliary junction in observational EUS was found to be better with a convex-arrayed than with a radial-arrayed echoendoscope.

Specialized Imaging and Procedures in Pediatric Pancreatology: A North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition Clinical Report

OBJECTIVES

An increasing number of children are being diagnosed with pancreatitis and other pancreatic abnormalities. Dissemination of the information regarding existing imaging techniques and endoscopic modalities to diagnose and manage pancreatic disorders in children is sorely needed.

METHODS

We conducted a review of the medical literature on the use of the following imaging and procedural modalities in pediatric pancreatology: transabdominal ultrasonography (TUS), computed tomography (CT), magnetic resonance imaging (MRI)/magnetic resonance cholangiopancreatography (MRCP), endoscopic ultrasonography (EUS), and endoscopic retrograde cholangiopancreatography (ERCP). Recommendations for current use and future research were identified.

RESULTS

TUS offers noninvasive images of the pancreas but has limitations to details of parenchyma and ductal structures. CT offers improved detail of pancreatic parenchyma, solid masses, and traumatic injuries, but requires relatively high levels of ionizing radiation and does not adequately assess ductal anatomy. MRI/MRCP offers detailed intrinsic tissue assessment and pancreatic ductal characterization, but requires longer image acquisition time and is relatively poor at imaging calcifications. EUS provides excellent evaluation of pancreatic parenchyma and ductal anatomy, but can be subjective and operator dependent and requires sedation or anesthesia. EUS offers the capacity to obtain tissue samples and drain fluid collections and ERCP offers the ability to improve drainage by performing sphincterotomy or placing pancreatic stents across duct injuries and strictures.

CONCLUSIONS

Various imaging modalities may be used in pediatric pancreatology, but TUS and MRI/MRCP are favored. Interventional therapeutic maneuvers primarily involve use of ERCP and EUS. Future research is necessary to optimize equipment, expertise, and appropriate indications.

Pancreaticobiliary maljunction and biliary cancer

Pancreaticobiliary maljunction (PBM) is a congenital malformation in which the pancreatic and bile ducts join anatomically outside the duodenal wall. Japanese clinical practice guidelines on how to deal with PBM were made in 2012, representing a world first. According to the 2013 revision to the diagnostic criteria for PBM, in addition to direct cholangiography, diagnosis can be made by magnetic resonance cholangiopancreatography (MRCP), 3-dimensional drip infusion cholangiography computed tomography, endoscopic ultrasonography (US), or multiplanar reconstruction images by multidetector row computed tomography. In PBM, the common channel is so long that sphincter action does not affect the pancreaticobiliary junction, and pancreatic juice frequently refluxes into the biliary tract. Persistence of refluxed pancreatic juice injures epithelium of the biliary tract and promotes cancer development, resulting in higher rates of carcinogenesis in the biliary tract. In a nationwide survey, biliary cancer was detected in 21.6% of adult patients with congenital biliary dilatation (bile duct cancer, 32.1% vs. gallbladder cancer, 62.3%) and in 42.4% of PBM patients without biliary dilatation (bile duct cancer, 7.3% vs. gallbladder cancer, 88.1%). Pathophysiological conditions due to pancreatobiliary reflux occur in patients with high confluence of pancreaticobiliary ducts, a common channel ≥6 mm long, and occlusion of communication during contraction of the sphincter. Once the diagnosis of PBM is established, immediate prophylactic surgery is recommended. However, the surgical strategy for PBM without biliary dilatation remains controversial. To detect PBM without biliary dilatation early, MRCP is recommended for patients showing gallbladder wall thickening on screening US under suspicion of PBM.

Choledochal or pancreatic cyst? Role of endoscopic ultrasound as an adjunct for diagnosis: a case series

BACKGROUND

Choledochal cysts (CC) are a cystic dilation of the intra- or extrahepatic biliary tree. They are rare, and are associated with a risk of malignant transformation. Due to the close proximity to the pancreas, Type II CC, in which a diverticular outpouching is connected to the extrahepatic bile duct via a narrow stalk, can be difficult to differentiate from pancreatic cysts. The aim of this study was to determine the role of endoscopic ultrasound (EUS) in the diagnosis of Type II CC.

METHODS

A retrospective review of all patients seen in the Multidisciplinary Pancreatic Cyst Clinic at Johns Hopkins Hospital from November 2010 to March 2014 was performed to identify patients classified as having Type II CC on computed tomography (CT) or magnetic resonance imaging (MRI) who also underwent EUS. Patient demographics, clinical presentation, imaging, and follow-up were recorded.

RESULTS

Four female patients with median age of 52 years, three of whom were identified as having Type II CC and one as equivocal for CC on MRI, and two as having Type II CC, one equivocal for CC and one as branch-duct intraductal papillary mucinous neoplasm on CT. On EUS, no communication was seen in any cases between the CC and common bile duct. EUS-guided fluid aspiration from each cyst demonstrated clear fluid with undetectable bilirubin and either elevated CEA or amylase confirming the diagnosis of pancreatic cyst.

CONCLUSIONS

EUS is a useful tool for the differentiation of equivocal cases of CC. It can show a very small separation as little as 1 mm between two structures, and cyst fluid analysis can be performed and used to further differentiate between biliary cysts and other cystic structures.

Japanese clinical practice guidelines for pancreaticobiliary maljunction

There have been no clinical guidelines for the management of pancreaticobiliary maljunction (PBM). The Japanese Study Group on Pancreaticobiliary Maljunction (JSPBM) has proposed to establish clinical practice guidelines on how to deal with PBM, with the support of the Japan Biliary Association (JBA). Because the body of evidence-based literature is relatively small, we decided to create guidelines based on the consensus of experts, using the medical literature for reference. A total of 46 clinical questions (CQs) were considered by the members of the editorial committee responsible for the guidelines. The CQs covered distinct aspects of PBM: (1) Concepts and Pathophysiology (10 CQs); (2) Diagnosis (10 CQs); (3) Pancreatobiliary complications (9 CQs); and (4) Treatments and prognosis (17 CQs). Statements and comments for each CQ were prepared by the guidelines committee members and collaborating partners. The CQs were completed after review by members of the editorial committee, meetings of this committee, public comments on the homepages of the JSPBM and the JBA, public hearings, and assessment and approval by the guidelines evaluation board. PBM includes cases where the bile duct is dilated (PBM with biliary dilatation) and those in which it is not (PBM without biliary dilatation). In these guidelines, PBM with biliary dilatation is defined as being identical to congenital biliary dilatation of Todani type I (except for type Ib) and type IV-A, both of which are accompanied by PBM in almost all cases. These guidelines are created to provide assistance in the clinical practice of PBM management; their contents focus on clinical utility, and they include general information on PBM to make this disease more widely recognized.

Diagnostic accuracy of endoscopic ultrasonography in patients with inconclusive magnetic resonance imaging diagnosis of biliopancreatic abnormalities

AIM

To determine the sensitivity and specificity of endoscopic ultrasonography (EUS) in patients with inconclusive magnetic resonance imaging/magnetic resonance cholangiopancreatography (MRI/MRCP) in pancreatobiliary abnormalities.

METHODS

During 10 months, patients with pancreatobiliary diseases referred to endoscopic retrograde cholangiopancreatography (ERCP) because of inconclusive MRI/MRCP diagnosis were scheduled to undergo endoscopic ultrasonography. Patients were divided into four major groups: patients with (i) resectable periampullary neoplasms who were referred to a surgeon, (ii) unresectable periampullary cancer who underwent ERCP for biliary stenting, (iii) bile duct stone who were referred to ERCP for stone extraction, and (iv) normal pancreatobiliary tract. Reference standards for comparison were ERCP, surgery, a biopsy confirming malignancy, or the clinical course during follow up (at least 12 months) in cases without evidences of malignancy.

RESULTS

One hundred and seven patients (51 men; mean [SD] age 60.0 [15.5]) were included in the study. Final diagnoses were common bile duct (CBD) stone (n = 24), periampullary neoplasms (n = 46), others (n = 23) and no pathologic findings (n = 14). EUS determined the staging for clinical decision-making in 47 patients with neoplasms which showed that tumors in 34 patients (79.1%) were unresectable (advanced stage). After EUS, 47 patients (43.9%) did not require ERCP. The accuracy of EUS for the diagnosis of CBD stone and periampullary neoplasms were 96.3% and 99.1%, respectively.

CONCLUSIONS

EUS is a useful modality in cases of inconclusive MRI/MRCP indicating pancreatobiliary disorders.

[The usefulness of endoscopic ultrasonography in the diagnosis of choledocholithiasis without common bile duct dilatation]

BACKGROUND/AIMS

Endoscopic retrograde cholangiopancreatography (ERCP) is the most accurate modality in diagnosis of choledocholithiasis. However, it carries some complications. Endoscopic ultrasonography (EUS) is less invasive than ERCP and used for the diagnosis of choledocholithiasis. Recent studies showed that a usefulness of EUS for the diagnosis of small choledocholithiasis without common bile duct (CBD) dilatation. For such a reason, ERCP is being replaced by EUS in the diagnosis of bile duct stones. The aim of this study was to investigate the accuracy of EUS for the diagnosis of choledocholithiasis without CBD dilatation.

METHODS

A total of 66 patients with suspected choledocholithiasis without CBD dilatation were enrolled. EUS were performed in all cases within 48 hours after computed tomography (CT) or ultrasonography (US). Final diagnosis was obtained by ERCP or clinical course (minimum 6 months follow-up). We analyzed the accuracy of US, CT, and EUS, respectively.

RESULTS

CT and US were performed in 51 and 15 cases, respectively. CBD stones were detected in 23 (35%) patients by ERCP. EUS showed 100% sensitivity, 95% specificity, 92% positive predictive value, and 100% negative predictive value for identifying CBD stones. CT or US showed 26%, 93%, 67%, and 70%, respectively. There were no EUS-related complications.

CONCLUSIONS

EUS was more effective than CT or US and as accurate as ERCP for the diagnosis of small choledocholithiasis without CBD dilatation. Thus, EUS may help to avoid unnecessary diagnostic ERCP and its complication.

Imaging features of adult choledochal cysts: a pictorial review

Choledochal cysts are rare congenital anomalies which are principally diagnosed by disproportional dilatation of the extrahepatic bile ducts. In addition, choledochal cysts are believed to arise from the anomalous union of the common bile duct and pancreatic duct outside the duodenal wall which is also proximal to the sphincter of the Oddi mechanism. The various types of choledochal cysts have been classified on the basis of these anomalous unions (Komi classification) and their anatomical locations (Todani classification). The multidetector computed tomography with reformatted imaging, magnetic resonance cholangiopancreatography, and an endoscopic retrograde cholangiography represent the important techniques providing the anatomical resolution and detail required to properly diagnose and classify choledochal cysts and their associated abnormal features of the biliary tree, as well as their pancreaticobile duct union. This study describes the various imaging features of a choledochal cyst in adults according to the various types of anomalous unions of the pancreaticobile duct according to Komi's classification and anatomic location according to Todani's classification. Lastly, we also review and discuss the associated abnormal findings developed in biliary systems.

Congenital choledochal malformation: not just a problem for children

Choledochal cysts remain relatively uncommon in Western Europe and the US, although they are appreciably more common in Asia. Their aetiology remains obscure although abnormalities of the pancreaticobiliary junction may be the primary pathology in some, with biliary dilatation following reflux of activated pancreatic secretions. Most anomalies will present in childhood with obstructive jaundice or abdominal pain; a proportion may only present for the first time during adulthood, and some of these will show malignant transformation. The classical triad of pain, jaundice and a palpable mass is, however, not common. Complete cyst excision, where possible, and biliary reconstruction remain the aims for most types although there is still some controversy about the type of reconstruction. Laparoscopic reconstruction is possible but is still very much an advanced technique. The risk of long-term problems post-surgery is significant. Whether this is due to recurrent pancreatitis secondary to the retained common channel and/or a distal stump, or due to the development of biliary tract malignancy is still a cause for concern and indicates the need for adequate, prolonged follow-up.

Endoscopic ultrasonography for evaluating patients with recurrent pancreatitis

Acute recurrent pancreatitis (ARP) is still a complex diagnostic and therapeutic challenge in clinical practice. In up to 30% of cases of ARP, it is not possible to establish the etiology of the disease. In the other 70%, many factors play an etiological role in ARP: microlithiasis, sphincter of Oddi dysfunction (SOD), pancreas divisum, hereditary pancreatitis, cystic fibrosis, a choledochocele, annular pancreas, an anomalous pancreatobiliary junction, pancreatic tumors or chronic pancreatitis are diagnosed. EUS should be useful in ARP as it is sensitive for diagnosing bile duct stones, gallbladder sludge, pancreatic lesions, ductal abnormalities and chronic pancreatitis. Endoscopic ultrasound (EUS) appears to be diagnostic in the majority of patients with previously unexplained pancreatitis, and offers an alternative to endoscopic retrograde cholangiopancreatography (ERCP) as the initial diagnostic test in patients with ARP.

Role of endoscopic ultrasonography in prevention of unnecessary endoscopic retrograde cholangiopancreatography: a prospective study of 150 patients

OBJECTIVE

The purpose of this study was to evaluate the impact of substituting endoscopic ultrasonography (EUS) for endoscopic retrograde cholangiopancreatography (ERCP) in cases of a low to intermediate risk for choledocholithiasis.

METHODS

During a 16-month period, patients who were referred for suspected choledocholithiasis, biliary colic, or acute biliary pancreatitis on the basis of alterations in liver enzyme values with or without gallstones seen on transabdominal ultrasonography were included. Endoscopic ultrasonography was performed for all patients. Patients with common bile duct stones underwent ERCP. Cholecystectomy was recommended in all patients with symptomatic gallstones. Cases were followed for 12 months.

RESULTS

A total of 150 patients were included. Choledocholithiasis was diagnosed by EUS in 39 patients (26.0%) and was confirmed by ERCP in 30 (77.0%). Fifty-one patients had a normal common bile duct, and follow-up for 12 months showed no abnormalities except in 1 patient. Cholecystectomy without ERCP was recommended for the remaining 60 patients who had symptomatic gallstones or sludge. Endoscopic retrograde cholangiopancreatography was avoided by this approach in 110 patients (73.3%).

CONCLUSIONS

In a low to intermediate risk for choledocholithiasis, EUS can preclude the need for ERCP in most cases.

Sonographic diagnosis of a common pancreaticobiliary channel in children

BACKGROUND

A common pancreaticobiliary channel is a very rare condition, but its diagnosis is of paramount importance since it can lead to complications that can be prevented.

OBJECTIVE

To illustrate the sonographic diagnosis of a common pancreaticobiliary channel in children referred for abdominal pain or jaundice.

MATERIALS AND METHODS

Four children were diagnosed by ultrasonography and the diagnosis was subsequently confirmed by MRI.

RESULTS

Sonography demonstrated a pancreaticobiliary junction located in the pancreatic head above the sphincter of Oddi. This rare congenital anomaly was confirmed in all patients by MRI.

CONCLUSION

A common pancreaticobiliary channel can be diagnosed by sonography. Nevertheless, our experience is limited, and although sonography can provide an alert and can assist management, it cannot yet replace MRI.

Assessment of Anomalous Pancreaticobiliary Ductal Junction with High-Resolution Multiplanar Reformatted Images in MDCT

OBJECTIVE

The objective of our study was to assess the capabilities of MDCT for the diagnosis of an anomalous pancreaticobiliary ductal junction using high-resolution multiplanar reformatted (multiplanar reconstruction) images.

MATERIALS AND METHODS

This study included nine patients with and 54 without an anomalous pancreaticobiliary ductal junction confirmed on direct cholangiopancreatography. Multiplanar reconstruction images with 0.5-mm continuous slices were generated from isotropic or nearly isotropic pancreatic phase images. By mainly interpreting the multiplanar reconstruction images using the Scrolling mode, two blinded reviewers independently determined whether the confluence of the pancreatic and biliary ducts joined in the pancreatic parenchyma (in other words, outside the duodenal wall). The results were correlated with the findings of direct cholangiopancreatography. The diagnostic capabilities of CT for revealing associated pancreatobiliary diseases were assessed in patients with this anomaly.

RESULTS

Interobserver agreement in the classification of the duct confluence was high (kappa = 0.804). The duct confluence was identified in all patients except four without an anomalous pancreaticobiliary ductal junction. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of CT for diagnosing an anomalous pancreaticobiliary ductal junction were 100% (9 of 9 patients), 87% (47 of 54 patients), 89% (56 of 63 patients), 75% (9 of 12 patients), and 100% (47 of 47 patients) in the final decisions, respectively. CT showed all associated pancreatobiliary diseases except bile duct stones in two patients.

CONCLUSION

MDCT enabled the diagnosis of an anomalous pancreaticobiliary ductal junction by showing whether the pancreatic and biliary ducts join within the pancreatic parenchyma on high-resolution multiplanar reconstruction images.

Role of endoscopic ultrasonography in diseases of the extrahepatic biliary system

Endoscopic ultrasonography (EUS) is one of the most recent advances in gastrointestinal endoscopy. Available EUS devices include echoendoscopes, such as radial scanning and linear array echoendoscopes, and catheter ultrasound probes. Endoscopic ultrasonography has various applications, such as staging of gastrointestinal malignancy, evaluation of submucosal tumors, and has grown to be an important modality in evaluating the pancreaticobiliary system. With regard to the biliary system, EUS is useful for the detection and staging of ampullary tumors, detection of microlithiasis and choledocholithiasis and evaluation of benign and malignant bile-duct strictures. Endoscopic ultrasonography may be used as an adjunct to transabdominal ultrasound for the detection and characterization of gallbladder polyps. In addition, EUS is helpful in the staging of gallbladder cancer as well as in diagnosing anomalous pancreaticobiliary junction with its associated pancreatobiliary diseases. The present paper reviews the current applications of EUS for imaging and intervention in diseases of the extrahepatic biliary system.

Approach to idiopathic recurrent pancreatitis

Acute pancreatitis is caused by acute or chronic alcohol intake or choledocholithiasis in approximately 80% of cases. In the absence of alcohol abuse or gallstones, a variety of established and putative factors must be considered, any of which can cause a single or recurrent attacks of acute pancreatitis. When the underlying cause eludes detection following an initial thorough search and leads to a second attack, the term idiopathic acute recurrent pancreatitis (IARP) is applied. This article discusses IARP and its work-up.

Idiopathic acute pancreatitis

After routine investigations, including a thorough history, routine laboratory study, and noninvasive imaging with transcutaneous ultrasonogram, 10% to 25% of cases of acute pancreatitis have no readily identifiable cause and are termed idiopathic. But modern medicine has made notable advances in uncovering various causes of acute pancreatitis, and several new diagnostic tools that allow clinicians to less invasively approach the patient without sacrificing the diagnostic yield have been introduced. By being knowledgeable of these new changes and by their proper use in a proper circumstances, clinicians will be able to find the cause more accurately and earlier. This better management will not only improve the well-being of the patients but also reduce the number of "true" idiopathic acute pancreatitis to a minimum.

Idiopathic acute recurrent pancreatitis

Acute recurrent pancreatitis (ARP) results most commonly from alcohol abuse or gallstone disease. Initial evaluation fails to detect the cause of ARP in 10-30% of patients, and as a result the diagnosis of "idiopathic" ARP is given. In these patients, a more extensive evaluation including specialized labs, ERCP, endoscopic ultrasound, or magnetic resonance cholangiopancreatography typically leads to a diagnosis of microlithiasis, sphincter of Oddi dysfunction, or pancreas divisum. Less commonly, hereditary pancreatitis, cystic fibrosis, a choledochocele, annular pancreas, an anomalous pancreatobiliary junction, pancreatobiliary tumors, or chronic pancreatitis are diagnosed. Determining the etiology is important, as it helps to direct therapy, limits further unnecessary evaluation, and may improve a patient's long term prognosis.

Primary gallbladder cancer: recognition of risk factors and the role of prophylactic cholecystectomy

The objective of this article is to review the available literature on the epidemiology, predisposing factors, and conditions associated with primary gallbladder cancer, and to discuss the role of prophylactic cholecystectomy in high-risk patient populations. Gallbladder cancer is a highly malignant tumor with a poor 5-yr-survival rate. It is a tumor of the elderly and has striking genetic, racial, and geographic characteristics, with an extremely high prevalence in Native Americans and Chileans. Cholelithiasis is a well-established risk factor for gallbladder cancer and the risk seems to correlate with stone size. Polyps that are >1 cm, single, sessile, and echopenic are associated with a higher risk of malignancy. Anomalous junction of pancreaticobiliary ducts (AJPBD), especially without choledochal cyst, and porcelain gallbladder are additional factors that predispose to gallbladder cancer. Lesser associations include chronic bacterial infections of the gallbladder, typhoid carrier state, certain occupational and environmental carcinogens, hormonal changes in women, and certain social, dietary, and familial factors. It is important to identify high-risk groups for gallbladder cancer because of the dismal nature of this tumor. In patients with porcelain gallbladder and anomalous junction of the pancreatic and biliary ducts, cholecystectomy is recommended provided that the patient is a good operative candidate. Patients with large solitary polyps or gallstones require close ultrasonic follow-up. With the advent of endoscopic ultrasound it is expected that early changes of malignancy in polyps will be reliably detected, and more patients will potentially be cured with a simple cholecystectomy. Through a MEDLINE/PAPERCHASE search we identified and reviewed articles regarding gallbladder cancer published in English-language journals between 1966 and 1999, using the key words biliary tract and gallbladder diseases, cancer, neoplasms, surgery, cholelithiasis, gallstones, cholecystitis, gallbladder polyps, risk factors, chemical industry, occupational diseases, typhoid, porcelain gallbladder, bacteremia, and precancerous conditions. We also used the bibliography of relevant articles to increase our search. A total of 122 publications were selected using the mentioned data source.

Endoscopic ultrasound in pancreatic diseases. Indications, limitations, and the future

Endoscopic ultrasonography (EUS) is a significant advance in the diagnosis and management of pancreatic disease. This article reviews the application of endosonography for detection of pancreatic masses, staging of pancreatic cancer, detection of pancreatic endocrine tumors, management of cystic pancreatic lesion, diagnosis of chronic pancreatitis, and many other emerging indications. Indications and limitations of endosonography in pancreatic diseases are discussed. The exciting possibilities of EUS-guided intervention in pancreatic diseases and other futuristic indications are explored.

Pancreaticobiliary diseases associated with anomalous pancreaticobiliary ductal union

BACKGROUND

Anomalous pancreaticobiliary ductal union (APBDU) is associated with different pancreaticobiliary diseases. The aim of this study is to clarify the frequency with which it occurs and its several subtypes in various pancreaticobiliary diseases.

METHODS

Radiograms of 1752 subjects who underwent endoscopic retrograde cholangiopancreatography were reviewed independently by two endoscopists. APBDU was diagnosed using recently accepted criteria and divided into B-P and P-B subtypes according to the insertion of biliary and pancreatic ducts.

RESULTS

Fifty-nine (8.7%) of 680 subjects with clearly visualized pancreaticobiliary radiograms had APBDU. APBDU was present in 93.8% of patients (15 of 16) with choledochal cyst, 62.5% (5 of 8) with gallbladder cancer, 33.3% (9 of 27) with common bile duct cancer, 50.0% (6 of 12) with gallbladder adenomyomatosis, 13.2% (7 of 53) with biliary pancreatitis, 3.4% (10 of 293) with cholelithiasis, 2.2% (2 of 89) with non-biliary pancreatitis, 2.1% (1 of 47) with hilar cholangiocarcinoma, 1.9% (1 of 54) with pancreatic cancer, and 10.2% (9 of 88) with other miscellaneous disorders. There were 25 patients (42.4%) with the B-P type and 34 patients (57.6%) with the P-B type of APBDU. Patients with choledochal cyst frequently had the B-P type, whereas gallbladder cancer, adenomyomatosis, or biliary pancreatitis frequently coexisted with the P-B type.

CONCLUSION

APBDU is relatively common in patients undergoing endoscopic retrograde cholangiopancreatography at our center. There are a variety of pancreaticobiliary diseases that are associated with APBDU. Its role in these conditions is uncertain and needs to be further delineated.

Anomalous pancreaticobiliary junction without congenital choledochal cyst

BACKGROUND

Anomalous pancreaticobiliary junction (APBJ) without congenital choledochal cyst (CCC) carries a high risk of gallbladder carcinoma development. The aim of this study was to obtain information allowing early diagnosis and appropriate management.

METHODS

The clinical features, imaging findings and surgical outcome of 18 patients with APBJ without CCC were analysed retrospectively.

RESULTS

Fourteen patients had symptoms, including those of acute pancreatitis (five patients). In 16 patients the gallbladder showed abnormalities, including carcinoma (eight) and mucosal hyperplasia (11). Ultrasonography detected gallbladder carcinoma with 100 per cent sensitivity and mucosal hyperplasia with 91 per cent sensitivity. A long common channel was demonstrated by endoscopic retrograde cholangiopancreatography (ERCP) in all patients, endoscopic ultrasonography in nine of ten, and magnetic resonance cholangiopancreatography (MRCP) in five of five. Five of eight patients with gallbladder carcinoma underwent extended cholecystectomy with bile duct excision. Three patients with cancer and eight with no cancer had cholecystectomy alone. None developed bile duct carcinoma or acute pancreatitis after operation. All patients without malignancy remained asymptomatic for a mean follow-up period of 4.7 years.

CONCLUSION

Prophylactic cholecystectomy is recommended for patients with APBJ without CCC. For early diagnosis of APBJ, gallbladder abnormalities on ultrasonography or acute pancreatitis of unknown aetiology should prompt further investigation with ERCP or less invasive imaging modalities such as endoscopic ultrasonography and MRCP.

Diagnosis of anomalous pancreaticobiliary junction: value of magnetic resonance cholangiopancreatography

BACKGROUND

Anomalous pancreaticobiliary junction (a long common channel), with or without congenital choledochal cyst, is frequently associated with biliary tract carcinoma. We assessed the diagnostic value of magnetic resonance cholangiopancreatography (MRCP) for patients with anomalous pancreaticobiliary junction (PBJ).

METHODS

In 159 adult patients with pancreatobiliary disease, breath-hold (1 to 18 seconds) MRCP was performed according to a half-Fourier acquisition single-shot turbo spin-echo sequence. In all patients the length of the common channel demonstrated by MRCP was compared with that demonstrated by endoscopic retrograde cholangiopancreatography. In 11 patients with anomalous PBJ (the common channel > or = 15 mm on endoscopic retrograde cholangiopancreatography), the diagnostic accuracy of MRCP for associated biliary diseases was evaluated.

RESULTS

No complications were encountered in performing MRCP. On MRCP, the length of the common channel was calculated to be 15 mm or longer in nine (82%) of 11 patients with anomalous PBJ. In patients with normal PBJ, MRCP identified PBJ with the channel measuring 0 mm in length. MRCP allowed detailed visualization of congenital choledochal cyst (all seven patients) but failed to depict carcinoma (one patient) and mucosal hyperplasia (five patients) of the gallbladder.

CONCLUSIONS

MRCP is a noninvasive and accurate imaging method for diagnosing anomalous PBJ and congenital choledochal cyst.