Transpapillary intraductal US prior to biliary drainage in the assessment of longitudinal spread of extrahepatic bile duct carcinoma

Practice guidelines for managing extrahepatic biliary tract cancers

Backgrounds/Aims

Reported incidence of extrahepatic bile duct cancer is higher in Asians than in Western populations. Korea, in particular, is one of the countries with the highest incidence rates of extrahepatic bile duct cancer in the world. Although research and innovative therapeutic modalities for extrahepatic bile duct cancer are emerging, clinical guidelines are currently unavailable in Korea. The Korean Society of Hepato-Biliary-Pancreatic Surgery in collaboration with related societies (Korean Pancreatic and Biliary Surgery Society, Korean Society of Abdominal Radiology, Korean Society of Medical Oncology, Korean Society of Radiation Oncology, Korean Society of Pathologists, and Korean Society of Nuclear Medicine) decided to establish clinical guideline for extrahepatic bile duct cancer in June 2021.

Methods

Contents of the guidelines were developed through subgroup meetings for each key question and a preliminary draft was finalized through a Clinical Guidelines Committee workshop.

Results

In November 2021, the finalized draft was presented for public scrutiny during a formal hearing.

Conclusions

The extrahepatic guideline committee believed that this guideline could be helpful in the treatment of patients.

Advanced Imaging of the Biliary System and Pancreas

Despite advances in noninvasive techniques for imaging the pancreaticobiliary system, several disease processes including indeterminate biliary strictures as well as neuroendocrine tumors, inflammatory pseudotumors, and complex cysts of the pancreas remain difficult to characterize. New endoscopic imaging technologies have emerged to address these challenges. Cholangioscopy and intraductal ultrasound (IDUS) are powerful tools to characterize subtle biliary concretions and strictures. Confocal Laser Endomicroscopy (CLE) and Optical Coherence Tomography (OCT) are emerging approaches for the most difficult biliary lesions. Contrast harmonic endoscopic ultrasound (CH-EUS), elastography, and 3D-EUS are improving the approach to subtle pancreatic lesions, particularly in the context of indeterminate tissue sampling. Pancreatoscopy, pancreatic IDUS, and intracystic CLE hold promise to further improve the assessment of pancreatic cysts. We aim to comprehensively review the emerging clinical evidence for these innovative endoscopic imaging techniques.

A novel technique for mapping biopsy of bile duct cancer

BACKGROUND : Accurate preoperative assessment of the longitudinal extension of perihilar cholangiocarcinoma (PHCC) is essential for treatment planning. Mapping biopsies for PHCC remain challenging owing to technical difficulties and insufficient sample amounts. The aim of this study was to investigate the usefulness of a novel technique for mapping biopsies of PHCC. METHODS : Our novel method focused on a biliary stent delivery system for mapping biopsies. Fifty patients with PHCC undergoing endoscopic transpapillary mapping biopsy using the novel method were reviewed from August 2015 to June 2019. RESULTS : The median number of biopsy samples was six (range 1 - 17), and the rate of adequate sampling was 91.4 % (266 /291). Biopsy from the intrahepatic bile duct was possible in 82.0 % of patients (41 /50), and negative margins were confirmed in the resected specimens from 34 /39 patients who underwent surgery (87.2 %). None of the patients had post-endoscopic retrograde cholangiopancreatography pancreatitis. CONCLUSIONS : With our novel method, accurate assessment of the longitudinal extension of PHCC might be expected with minimal trauma to the duodenal papilla.

Controversies in EUS: Do we need miniprobes?

This is the fifth in a series of papers entitled "Controversies in EUS." In the current paper, we deal with high-resolution catheter probes, otherwise known as EUS miniprobes (EUS-MPs). The application of miniprobes for early carcinomas in the entire intestinal tract, for subepithelial lesions, and for findings in the bile duct and pancreatic duct as well as endobronchial use is critically discussed. Submucous lesions, especially in the colon, but also early carcinomas in special cases are considered the most important indications. The argument is illustrated by numerous examples.

Form-Vessel Classification of Cholangioscopy Findings to Diagnose Biliary Tract Carcinoma's Superficial Spread

We aimed to evaluate a newly developed peroral cholangioscopy (POCS) classification system by comparing classified lesions with histological and genetic findings. We analyzed 30 biopsied specimens from 11 patients with biliary tract cancer (BTC) who underwent POCS. An original classification of POCS findings was made based on the biliary surface's form (F factor, 4 grades) and vessel structure (V-factor, 3 grades). Findings were then compared with those of corresponding biopsy specimens analyzed histologically and by next-generation sequencing to identify somatic mutations. In addition, the histology of postoperative surgical stumps and preoperative POCS findings were compared. Histological malignancy rate in biopsied specimens increased with increasing F- and V-factor scores (F1, 0%; F1, 25%; F3, 50%; F4, 62.5%; p = 0.0015; V1, 0%; V2, 20%; V3, 70%; p < 0.001). Furthermore, we observed a statistically significant increase of the mutant allele frequency of mutated genes with increasing F- and V-factor scores (F factor, p = 0.0050; V-factor, p < 0.001). All surgical stumps were accurately diagnosed using POCS findings. The F-V classification of POCS findings is both histologically and genetically valid and will contribute to the methods of diagnosing the superficial spread of BTC tumors.

Endoscopic Perspective in Cholangiocarcinoma Diagnostic Process

Cholangiocarcinoma is a malignancy arising from the epithelial lining of the intrahepatic or extrahepatic biliary tract. Timely diagnosis is challenging due to its silent clinical course. As reliable laboratory markers are lacking, diagnostic imaging plays a pivotal role. While cross-sectional imaging studies are usually conclusive for intrahepatic lesions, endoscopy plays an essential role in cases of extrahepatic tumors. Rational utilization of different diagnostic methods based on available evidence is needed. This article focuses on the diagnostic role of advanced biliary endoscopy, including endoscopic retrograde cholangiopancreatography, cholangioscopy, endoscopic ultrasonography, and intraductal sonography.

Survey of preoperative management protocol for perihilar cholangiocarcinoma at 10 Japanese high-volume centers with a combined experience of 2,778 cases

BACKGROUND

In Japan, strategies for preoperative management of perihilar cholangiocarcinoma (PHC) have evolved over the last decade; the operative mortality has significantly reduced to <5%.

METHODS

A questionnaire was sent to 10 institutions based on their case volume. Questionnaire was based on: (1) preoperative biliary drainage, (2) bile replacement, (3) role of synbiotics, (4) remnant liver volume enhancement, (5) predicted remnant liver function, (6) imaging, (7) nutrition, and (8) role of Inchinkoto.

RESULTS

The median case volume was 226 (range 105-889) cases, respectively. Eight institutions preferred endoscopic nasobiliary drainage and two preferred endoscopic biliary stenting for biliary drainage. Nine used bile replacement within 2-3 days of biliary drainage. Four used synbiotics preoperatively. The median cutoff value for future remnant liver volume and serum total bilirubin, at which portal vein embolization (PVE) is done, is <40% and <4 mg/dl. The median interval between PVE and surgery was 3-4 weeks. To predict remnant liver function, indocyanine green retention (n = 8) and clearance rate (n = 2) were mainly used. Five used Inchinkoto to improve liver function. Nine used multidetector computed tomography and direct cholangiography for surgical planning.

CONCLUSION

With appropriate preoperative management of PHC, surgical morbidity and mortality can be reduced. This survey can provide recommendations to improve PHC perioperative outcomes.

Comparison of intraductal ultrasonography-directed and cholangiography-directed endoscopic retrograde biliary drainage in patients with a biliary obstruction

BACKGROUND/AIMS

Endoscopic retrograde biliary drainage (ERBD) has become a standard procedure in patients with a biliary obstruction. Intraductal ultrasonography (IDUS) has emerged as a new tool for managing extrahepatic biliary diseases. IDUS-directed ERBD can be performed without conventional cholangiography (CC). The goal of this study was to assess the effectiveness and safety of IDUS-directed ERBD compared to CC-directed ERBD in patients with an extrahepatic biliary obstruction.

METHODS

A total of 210 patients who had undergone IDUS-directed ERBD (IDUS-ERBD, n = 105) and CC-directed ERBD (CC-ERBD, n = 105) between October 2013 and April 2014 were analyzed retrospectively. The primary outcome measure was the procedural success rate. Secondary outcome measures included clinical outcomes, total procedure time, radiation exposure time, and overall complication rates.

RESULTS

The total technical success rate of ERBD was 100% (105/105) in the IDUS-ERBD and CC-ERBD groups. Mean procedure time was slightly prolonged in the IDUS-ERBD group than that in the CC-ERBD group (32.1 ± 9.9 minutes vs. 28.4 ± 11.6 minutes, p = 0.023). Mean radiation exposure time was one-third less in the IDUS-ERBD group than that in the CC-ERBD group (28.0 ± 49.3 seconds vs. 94.2 ± 57.3 seconds, p < 0.001). No significant differences in complication rates were detected between the groups.

CONCLUSIONS

IDUS-ERBD was equally effective and safe as CC-ERBD in patients with an extrahepatic biliary obstruction. Although IDUS-ERBD increased total procedure time, it significantly decreased radiation exposure.

Intraductal ultrasonographic anatomy of biliary varices in patients with portal hypertension

BACKGROUND AND OBJECTIVES

The term, portal biliopathy, denotes various biliary abnormalities, such as stenosis and/or dilatation of the bile duct, in patients with portal hypertension. These vascular abnormalities sometimes bring on an obstructive jaundice, but they are not clear which vessels participated in obstructive jaundice. The aim of present study was clear the bile ductal changes in patients with portal hypertension in hopes of establishing a therapeutic strategy for obstructive jaundice caused by biliary varices.

MATERIALS AND METHODS

Three hundred and thirty-seven patients who underwent intraductal ultrasound (IDUS) during endoscopic retrograde cholangiography for biliary abnormalities were enrolled. Portal biliopathy was analyzed using IDUS.

RESULTS

Biliary varices were identified in 11 (2.7%) patients. IDUS revealed biliary varices as multiple, hypoechoic features surrounding the bile duct wall. These varices could be categorized into one of two groups according to their location in the sectional image of bile duct: epicholedochal and paracholedochal. Epicholedochal varices were identified in all patients, but paracholedochal varices were observed only in patients with extrahepatic portal obstruction.

CONCLUSION

IDUS was useful to characterize the anatomy of portal biliopathy in detail.

Preoperative assessment of longitudinal extension of cholangiocarcinoma with peroral video-cholangioscopy: a prospective study

BACKGROUND AND AIM

Preoperative assessment of longitudinal extension of cholangiocarcinoma (CCA) is essential for making decisions concerning surgical resection and selecting operative procedures. We evaluated the accuracy of peroral video-cholangioscopy (PVCS) in diagnosing longitudinal extension of CCA.

METHODS

Patients with CCA who underwent preoperative PVCS were considered for this study. We evaluated the accuracy of PVCS in diagnosing longitudinal extension of perihilar cholangiocarcinoma (PCCA) and distal extrahepatic cholangiocarcinoma (DCCA) to the secondary biliary radicles and confluence of the hepatic ducts, respectively, on the hepatic side and to the intrapancreatic common bile duct on the papillary side. Diagnostic accuracy was determined by comparing the results with those of histopathological analyses of surgical specimens.

RESULTS

Forty-three consecutive patients were enrolled. The cholangioscope could not be advanced into the hepatic side in eight of the 25 patients with PCCA and in five of the 18 patients with DCCA. The accuracy of PVCS in diagnosing longitudinal extension of CCA on the hepatic and papillary sides was 82.4% and 92.0%, respectively, in patients with PCCA and 92.3% and 100%, respectively, in patients with DCCA. PVCS accurately detected longitudinal extension of CCA to the hepatic and papillary sides that was not detected previously by endoscopic retrograde cholangiography in 20.0% and 11.6% patients, respectively.

CONCLUSIONS

PVCS proved useful for the preoperative assessment of longitudinal extension of CCA. Therefore, it can aid surgeons in deciding surgical resectability and selecting operative procedures. This, in turn, may impact overall patient prognosis.

Oncological benefit of preoperative endoscopic biliary drainage in patients with hilar cholangiocarcinoma

Due to advances in endoscopic equipment and techniques, preoperative endoscopic biliary drainage (EBD) has been developed to serve as an alternative to percutaneous transhepatic biliary drainage (PTBD). This study sought to clarify the benefit of EBD in comparison to PTBD in patients who underwent radical resections of hilar cholangiocarcinoma. One hundred and forty-one patients underwent radical surgery for hilar cholangiocarcinoma between 2000 and 2008 were retrospectively divided into two groups based on the type of preoperative biliary drainage, PTBD (n = 67) or EBD (n = 74). We investigated if the different biliary drainage methods affected postoperative survival and mode of recurrence after median observation period of 82 months. The survival rate for patients who underwent EBD was significantly higher than those who had PTBD (P = 0.004). Multivariate analysis revealed that PTBD was one of the independent factors predictive of poor survival (hazard ratio: 2.075, P = 0.003). Patients with PTBD more frequently developed peritoneal seeding in comparison to those who underwent EBD (P = 0.0003). PTBD was the only independent factor predictive of peritoneal seeding. In conclusion, EBD might confer an improved prognosis over PTBD due to prevention of peritoneal seeding, and is recommended as the initial procedure for preoperative biliary drainage in patients with hilar cholangiocarcinoma.

Advanced techniques for endoscopic biliary imaging: cholangioscopy, endoscopic ultrasonography, confocal, and beyond

Cholangioscopy, endosonography, and confocal microscopy represent important technologies that expand biliary imaging beyond a level previously realized by noninvasive modalities (ultrasonography, computed tomography, and magnetic resonance cholangiopancreatography) and endoscopic retrograde cholangiopancreatography. Endoscopic ultrasonography has shown efficacy for the evaluation of indeterminate biliary strictures; however, this modality seems most reliable for distal bile duct abnormalities and in the setting of a moderate to high pretest probability for malignancy. Further refinement of these technologies, validation of their respective diagnostic criteria, and study within the context of comparative, randomized trials are needed and will contribute greatly to expedient patient care.

Usefulness of Intraductal Ultrasonography in the Diagnosis of Cholangiocarcinoma and IgG4-Related Sclerosing Cholangitis

The technique of intraductal ultrasonography (IDUS) of the bile duct with a thin-caliber probe and a ropeway system has provided excellent images of the bile duct and periductal structures and is an easy transpapillary approach. In addition, once the guide wire is inserted into the bile duct, IDUS and transpapillary biopsy after endoscopic retrograde cholangiopancreatography can be performed in a single session. Here, we review the usefulness of IDUS in the diagnosis of cholangiocarcinoma and IgG4-related sclerosing cholangitis.

Focal intrahepatic strictures: a review of diagnosis and management

INTRODUCTION

Focal intrahepatic strictures are becoming more common owing to more prevalent and accurate cross-sectional imaging. However, data relating to their management are lacking. The purpose of the present review was to synthesize the current evidence regarding these lesions and to formulate a strategy for diagnosis and management.

METHODS

A literature search of relevant terms was performed using Medline. References of papers were subsequently searched to obtain older literature.

RESULTS

Focal intrahepatic strictures involve segmental hepatic ducts and/or left and right main hepatic ducts during their intrahepatic course. Most patients are asymptomatic while the minority present with vague abdominal pain or recurrent sepsis and only rarely with jaundice. Investigations used to distinguish benign from malignant aetiologies include blood tests (CEA, Ca19.9), imaging studies [ultrasonography (US), computed tomography (CT), magnetic resonance cholangiopancreatography (MRCP) and fluorodeoxyglucose-positron emission tomography (FDG-PET)], endoscopic modalities [endoscopic retrograde cholangiopancreatography (ERCP)/endoscopic ultrasound (EUS)/cholangioscopy] and tissue sampling (brush cytology/biopsy).

CONCLUSIONS

A focal intrahepatic stricture requires thorough investigation to exclude malignancy even in patients with a history of biliary surgery, hepatolithiasis or parasitic infection. If during the investigative process a diagnosis or suspicion of malignancy is demonstrated then surgical resection should be performed. If all diagnostic modalities suggest a benign aetiology, then cholangioscopy with targeted biopsies should be performed.

Endoscopic retrograde cholangioscopy and advanced biliary imaging

Developments in endoscopic retrograde cholangioscopy provide multiple new advanced methods of biliary imaging. Cholangioscopy provides direct visualization of epithelium with white light as well as advanced modalities, such as narrow band imaging and autofluorescence. In vivo histologic images can be achieved with confocal endomicroscopy. Cross-sectional imaging is also possible with intraductal ultrasonography and optical coherence tomography. This article describes these advanced imaging techniques, which can be used together to assist in the diagnosis of biliary strictures and lesions.

Preoperative evaluation of the longitudinal extent of borderline resectable hilar cholangiocarcinoma by intraductal ultrasonography

BACKGROUND AND AIM

In patients with hilar cholangiocarcinoma (HC), longitudinal tumor extent is important for curative resection. The purpose of this study was to evaluate the longitudinal extents of HC using transpapillary intraductal ultrasonography (IDUS) for optimal surgical planning.

METHODS

From July 2006 to April 2010, a total of 42 patients with borderline resectable HC were enrolled at Samsung Medical Center, a tertiary referral hospital in Seoul, Korea. All patients were evaluated using multi-detector computed tomography (MDCT), endoscopic retrograde cholangiopancreatography (ERCP) and IDUS. The new modified Bismuth Type (MBT) classification, in which the traditional Bismuth type IV stage is divided into stages IVa and IVb, was used to determine whether the tumor invaded the left lateral section. Among the subtypes of HC, the periductal infiltrative type (PDI) and intraductal papillary neoplasm of the bile duct (IPN-B) were compared. The accuracies of CT, ERCP, and IDUS were assessed through comparison with the postoperative histology findings.

RESULTS

A total of 42 patients were prospectively enrolled, and the tumor extent could be assessed histologically in 30 patients. The accuracies of CT, ERCP, and IDUS were 66.6%, 60%, and 90%, respectively. The accuracy of IDUS was 85.7% in 21 patients with PDI and 100% in nine patients with IPN-B.

CONCLUSIONS

Hilar cholangiocarcinoma staging based on IDUS findings was highly accurate. We therefore highly recommend using IDUS for optimal surgical planning in patients with borderline resectable HC.

Endoscopic diagnosis of extrahepatic bile duct carcinoma: Advances and current limitations

The accurate diagnosis of extrahepatic bile duct carcinoma is difficult, even now. When ultrasonography (US) shows dilatation of the bile duct, magnetic resonance cholangiopancreatography followed by endoscopic US (EUS) is the next step. When US or EUS shows localized bile duct wall thickening, endoscopic retrograde cholangiopancreatography should be conducted with intraductal US (IDUS) and forceps biopsy. Fluorescence in situ hybridization increases the sensitivity of brush cytology with similar specificity. In patients with papillary type bile duct carcinoma, three biopsies are sufficient. In patients with nodular or infiltrating-type bile duct carcinoma, multiple biopsies are warranted, and IDUS can compensate for the limitations of biopsies. In preoperative staging, the combination of dynamic multi-detector low computed tomography (MDCT) and IDUS is useful for evaluating vascular invasion and cancer depth infiltration. However, assessment of lymph nodes metastases is difficult. In resectable cases, assessment of longitudinal cancer spread is important. The combination of IDUS and MDCT is useful for revealing submucosal cancer extension, which is common in hilar cholangiocarcinoma. To estimate the mucosal extension, which is common in extrahepatic bile duct carcinoma, the combination of IDUS and cholangioscopy is required. The utility of current peroral cholangioscopy is limited by the maneuverability of the “baby scope”. A new baby scope (10 Fr), called “SpyGlass” has potential, if the image quality can be improved. Since extrahepatic bile duct carcinoma is common in the Far East, many researchers in Japan and Korea contributed these studies, especially, in the evaluation of longitudinal cancer extension.

Endoscopic retrograde cholangiopancreatography for non-gastroenterologists: what you need to know

Endoscopic retrograde cholangiopancreatography (ERCP) represents the most powerful and widely employed platform for pancreaticobiliary interventions. Endoscopic retrograde cholangiopancreatography allows diagnosis and treatment of a broad spectrum of diseases of the pancreaticobiliary tree that are both benign and malignant in nature. Endoscopic retrograde cholangiopancreatography continues to evolve rapidly, and non-gastroenterologists need to understand the indications, contraindications, limitations, and role of ERCP to effectively manage and coordinate the care of patients with known or suspected pancreaticobiliary disease. This article will review the role of ERCP in detail to further an understanding of the procedure as a whole and to assess when referral of a patient for an ERCP or other related test is indicated.

Endoscopic retrograde cholangiopancreatography in the diagnosis and management of cholangiocarcinoma

Cholangiocarcinomas (CCAs) are rare malignancies that arise from the biliary epithelium. Intrahepatic CCAs usually present as mass lesions that are asymptomatic or cause nonspecific systemic symptoms such as fatigue, fever, and weight loss. Hilar and extrahepatic tumors most commonly present with jaundice, though cholangitis also can be seen. Tumor markers such as carbohydrate antigen 19-9 and carcinoembryonic antigen have been used to diagnose CCA, but these are nonspecific and may be elevated in infection, inflammation, or any obstruction. Endoscopic retrograde cholangiopancreatography (ERCP) has been used for the diagnosis and management of CCA for many years. This article summarizes the data regarding the application of ERCP in the diagnosis and management of CCA.

The role of endoscopic ultrasonography in the evaluation of pancreatico-biliary cancer

Accurate staging of pancreatico-biliary cancer is essential for surgical planning and for identification of locally advanced and metastatic disease that is incurable by surgery. The complex regional anatomy of the pancreatico-biliary system makes histologic diagnosis of malignancy at this region difficult. The ability to position the endoscopic ultrasound transducer at endoscopy in direct proximity to the pancreas and the bile duct, combined with the use of fine-needle aspiration, enables accurate preoperative staging of cancer, especially cancer too small to be characterized by CT or MRI. Endoscopic ultrasonography (EUS) identifies patients unlikely to be cured by surgery due to vascular invasion or regional nodal metastasis, thereby limiting procedure-related morbidity and mortality. This article focuses on the utility and recent advances of EUS in the evaluation of pancreatico-biliary cancer.

Intraductal ultrasonography combined with percutaneous transhepatic cholangioscopy for the preoperative evaluation of longitudinal tumor extent in hilar cholangiocarcinoma

BACKGROUND AND AIM

In hilar cholangiocarcinoma, an accurate assessment of preoperative resectability is important to optimize surgical resection. We investigated the accuracy of the combination of intraductal ultrasonography (IDUS) and percutaneous transhepatic cholangioscopy (PTCS) for evaluating longitudinal extent in hilar cholangiocarcinoma.

METHODS

Patients diagnosed with hilar cholangiocarcinoma underwent multidetector computed tomography (MDCT) and magnetic resonance cholangiography (MRC) for tumor staging and Bismuth type. Percutaneous transhepatic biliary drainage was performed at the left or right bile duct of the liver section that was anticipated to be preserved in the surgical treatment. After tract dilation, PTCS with cholangioscope-directed biopsy and IDUS were sequentially performed to evaluate Bismuth type. Surgical treatment was executed according to tumor staging and longitudinal tumor extent. Postoperative histological Bismuth types were compared to preoperative Bismuth types based on MDCT, MRC, PTCS with biopsy, and IDUS.

RESULTS

From June 2006 to November 2008, 25 patients with hilar cholangiocarcinoma were enrolled, with 20 of these patients evaluable. The accuracy of MDCT, MRC, PTCS with biopsy, and IDUS for the evaluation of Bismuth type was 80%, 84.2%, 90%, and 85.0%, respectively, in 20 patients, and 82.4%, 82.4%, 94.1%, and 88.2%, respectively, in 18 patients with Bismuth type IIIa, IIIb, or IV cancer. The accuracy of the combination of IDUS and PTCS with biopsy was 95% in 20 patients, and 100% in 18 with Bismuth type IIIa, IIIb, or IV cancer.

CONCLUSIONS

The combination of IDUS and PTCS with biopsy was highly accurate for assessing Bismuth type and may help in the identification of an optimal surgical plan for the treatment of hilar cholangiocarcinoma, especially in Bismuth type IIIa, IIIb, or IV.

Intraductal ultrasonography (IDUS) for the diagnosis of biliopancreatic diseases

Intraductal ultrasonography (IDUS) is an imaging modality having unique characteristics and suitable for imaging of a narrow ductal cavity, its wall and the neighbouring structures. As IDUS uses high-frequency ultrasound (12-30MHz), its image quality is very high within approximately 2-cm range of radius. The bile duct and the pancreatic duct, therefore, are good targets for the assessment by IDUS. Biliopancreatic IDUS is mainly performed through the papilla of Vater in the same session as endoscopic retrograde cholangiopancreatography (ERCP). Biliary IDUS is possible through the percutaneous transhepatic route as well. Not many comparative studies on biliopancreatic IDUS have been published. Gallbladder IDUS as well as most pancreatic IDUS are still at the level of clinical research. Constant delineation of Oddi's sphincter with the improvement of instruments will expand the use of IDUS for the assessment of the papilla of Vater lesions.

Clinical application of intraductal ultrasound during endoscopic retrograde cholangiopancreatography

Intraductal ultrasound (IDUS) used during endoscopic retrograde cholangiopancreatography (ERCP) can facilitate reliable evaluation of biliary and pancreatic disorders. The smaller diameter, flexibility, and the image quality offered by IDUS devices makes them ideal for evaluating a variety of difficult biliary and pancreatic diseases, especially in undefined strictures, luminal filling defects, and ampullary neoplasms. This article examines the numerous possible roles for IDUS in the evaluation of biliary and pancreatic conditions, as well as in ampullary neoplasms. IDUS is a simple, easy to learn, and safe technique that should be considered an integral tool in the therapeutic endoscopist's armamentarium.

Endoscopic diagnosis of intraductal papillary mucinous neoplasm of the bile duct

BACKGROUND/PURPOSE

Intraductal papillary mucinous neoplasm of the bile duct (IPMN-B) is considered an uncommon tumor. The purpose of this study was to evaluate the diagnostic utility of endoscopic cholangiography (ERC) with subsequent peroral cholangioscopy (POCS) and/or intraductal ultrasonography (IDUS) for this tumor.

METHODS

From December 1991 to November 2006, a retrospective analysis was made of eight patients with IPMN-B. Their clinical features and the endoscopic diagnostic strategy for POCS and IDUS were reviewed.

RESULTS

In all the patients, ERC failed to show papillary tumors, due to coexisting mucin or biliary sludge. POCS was carried out after ERC and it showed the presence and locations of papillary tumors in all patients, except for one with a tumor in the peripheral intrahepatic bile duct (B3). IDUS was performed in seven of the eight patients; in five of these patients, intraductal protruding tumors were clearly visualized, whereas flat tumors were not identified in the remaining two patients. In one of the eight patients, endoscopic nasobiliary drainage did not remove the huge amount of mucin. Hence, this patient required subsequent percutaneous biliary drainage. Six of the eight patients underwent surgical treatment; five patients underwent a hepatic resection with or without extrahepatic bile duct resection and one underwent a pancreaticoduodenectomy. Five of the six operated patients are still alive; one patient died of gastric cancer 90 months after the operation (mean follow-up period, 45.3 months). The two remaining patients, who were considered inoperable due to major medical comorbidities, died of liver failure and cholangitis 3 and 6 months, respectively, after stent placement.

CONCLUSION

ERC failed to delineate intraductal papillary tumors, due to coexisting mucin. The presence and location of papillary tumors were correctly diagnosed by both POCS and IDUS, but POCS may be better than IDUS to diagnose the extent of the tumor.

Preoperative evaluation of the longitudinal spread of extrahepatic bile duct cancer using multidetector computed tomography

BACKGROUND/PURPOSE

The aim of this study was to compare the diagnostic accuracy of multidetector computed tomography (MDCT) and direct cholangiography in evaluating the longitudinal spread of extrahepatic bile duct cancer.

METHODS

Images obtained from a 16-detector row scanner (MDCT) and from direct cholangiography (via either endoscopic naso-biliary drainage or percutaneous transhepatic biliary drainage) of 47 patients with histopathologically proven extrahepatic bile duct cancer were retrospectively interpreted. Differences between measures of longitudinal tumor spread determined by each modality and measures of macroscopic spread in resected specimens were assessed and compared.

RESULTS

Assessments carried out using MDCT differed significantly less from the macroscopic measurements than those made using direct cholangiography (P < 0.0001). Provided the diagnosis was defined as being accurate, based on a diagnostic difference of within +/-5 mm, the diagnostic accuracy of MDCT (96%) was significantly higher than that of direct cholangiography (70%) (P = 0.028). Preoperative evaluation with direct cholangiography resulted in a 30% underestimation of the incidence.

CONCLUSION

MDCT is superior to direct cholangiography for evaluating the preoperative longitudinal extent of bile duct cancer. Consequently, the utility of MDCT for preoperative evaluation of extrahepatic bile duct cancer warrants further examination.

Diagnostic approaches for cholangiocarcinoma

Cholangiocarcinomas arise from the epithelial cells of the bile ducts and are associated with poor prognosis. Despite new diagnostic approaches, the definite diagnosis of this malignancy continues to be challenging. Cholangiocarcinomas often grow longitudinally along the bile duct rather than in a radial direction. Thus, large tumor masses are frequently absent and imaging techniques, including ultrasound, CT, and MRI have only limited sensitivity. Tissue collection during endoscopic (ERCP) and/or percutaneous transhepatic (PTC) procedures are usually used to confirm a definitive diagnosis of cholangiocarcinoma. However, forceps biopsy and brush cytology provide positive results for malignancy in about only 50% of patients. Percutaneous and peroral cholangioscopy using fiber-optic techniques were therefore developed for direct visualization of the biliary tree, yielding additional information about endoscopic appearance and tumor extension, as well as a guided biopsy acquistion. Finally, endoscopic ultrasonography (EUS) complements endoscopic and percutaneous approaches and may provide a tissue diagnosis of tumors in the biliary region through fine-needle aspiration. In the future, new techniques allowing for early detection, including molecular markers, should be developed to improve the diagnostic sensitivity in this increasing tumor entity.

Intraductal US in the assessment of tumor involvement to the orifice of the cystic duct by malignant biliary obstruction

BACKGROUND

Tumor involvement to the orifice of the cystic duct (OCD) is a risk factor for cholecystitis after metallic stent (MS) placement.

OBJECTIVE

ERCP and intraductal US (IDUS) were used to assess tumor involvement to the OCD.

DESIGN

A prospective consecutive study.

SETTING

The University of Tokyo Hospital, Japan.

PATIENTS AND INTERVENTIONS

Between January 2003 and May 2007, 34 patients with resectable malignant biliary obstruction underwent an ERCP and an IDUS before preoperative biliary drainage.

MAIN OUTCOME MEASUREMENTS

ERCP and IDUS findings were confirmed via a histopathologic analysis of surgical specimens.

RESULTS

An ERCP showed that the cystic duct was opacified in 22 of 34 patients (64.7%). Eight patients were diagnosed with OCD tumor involvement. In the remaining 12 patients, tumor involvement was impossible to evaluate via an ERCP. An IDUS identified tumor involvement to the OCD in all 34 patients. Tumor involvement to the OCD was diagnosed in 12 patients, including 4 patients with previously negative results during an ERCP. Tumor involvement was confirmed by histopathology of surgical specimens. The sensitivity and specificity of detection were 66.7% (8/12) and 63.6% (14/22), respectively, via ERCP, and 100% (12/12) and 100% (22/22), respectively, via IDUS.

LIMITATION

The small sample size.

CONCLUSIONS

IDUS, in addition to ERCP, provides an accurate evaluation of tumor involvement to the OCD in patients with malignant biliary obstruction.

Diagnosis of biliary tract and ampullary carcinomas

Diagnostic methods for biliary tract carcinoma and the efficacy of these methods are discussed. Neither definite methods for early diagnosis nor specific markers are available in this disease. When this disease is suspected on the basis of clinical symptoms and risk factors, hemato-biochemical examination and abdominal ultrasonography are performed and, where appropriate, enhanced computed tomography (CT) and/or magnetic resonance cholangiopancreatography (MRCP) is carried out. Diagnoses of extrahepatic bile duct cancer and ampullary carcinoma are often made based on the presence of obstructive jaundice. Although rare, abdominal pain and pyrexia, as well as abnormal findings of the hepatobiliary system detected by hemato-biochemical examination, serve as a clue to making a diagnosis of these diseases. On the other hand, the early diagnosis of gallbladder cancer is scarcely possible on the basis of clinical symptoms, so when this cancer is found with the onset of abdominal pain and jaundice, it is already advanced at the time of detection, thus making a cure difficult. When gallbladder cancer is suspected, enhanced CT is carried out. Multidetector computed tomography (MDCT), in particular — one of the methods of enhanced CT — is useful for decision of surgical criteria, because MDCT shows findings such as localization and extension of the tumor, and the presence or absence of remote metastasis. Procedures such as magnetic resonance imaging, endoscopic ultrasonography, bile duct biopsy, and cholangioscopy should be carried out taking into account indications for these procedures in individual patients. However, direct biliary tract imaging is necessary for making a precise diagnosis of the horizontal extension of bile duct cancer.

Staging of cholangiocarcinoma: the role of endoscopy

The main question for staging is resectability, which is reliant on vascular, longitudinal, and metastatic spread. Today, accurate staging of perihilar tumors is achieved by non-invasive diagnostic investigations. Direct cholangiography has been the gold standard as a diagnostic procedure in recent decades. Endoscopic retrograde cholangiopancreaticography (ERCP) often only shows the ducts below the obstruction, and visualization of an obstructed part of the biliary tree is often not possible. Direct cholangiography reveals no information about local tumor extension, lymph nodes, or vascular involvement. Because of the given limitations, potential complications (cholangitis, sepsis) associated with direct cholangiography and reduction of the accuracy of subsequent cross-sectional imaging studies, these invasive techniques should only be used in the case of palliative interventions. Endoscopic ultrasonography-guided fine-needle aspiration (EUS-FNA) can be used to assess the nature of biliary strictures and to derive information about the extent of periductal disease and the presence of lymph node metastases. In a study by Fritscher-Ravens, 44 patients with hilar strictures underwent EUS-FNA. The overall diagnostic accuracy, sensitivity, specificity, positive and negative predictive values were 91% (95% CI, 78.4-96.3%), 89% (95% CI, 73.3-96.8%), 100% (95% CI, 63.1-100%), 100% (95% CI, 88.8-100%), and 67% (95% CI, 34.9-90%), respectively. The planned surgical approach was changed in 27 of 44 patients. In 15-20% of cholangiocarcinoma, patients with unremarkable abdominal imaging studies have metastatic lymph node involvement according to EUS evaluation. Due to the risk of peritoneal seeding, however, EUS with FNA is not recommended in patients still with a potential curative tumor.

[Surgical therapy of hilar cholangiocarcinoma]

Surgical resection provides the only chance of cure for patients suffering from hilar cholangiocarcinoma. Due to the central anatomic localization within the liver hilum, established guidelines of oncologic surgery are difficult to apply. Resection of the hilar bifurcation alone or in combination with limited hepatic resection can be performed with low morbidity and low mortality but shows a high rate of local tumor recurrence. Usually, extended resection is required to achieve adequate safety margins. Right trisectionectomy complies best with the basic rules of oncologic surgery while allowing the maximum safety margin. The 5-year survival rates reported after right trisectionectomy range between 20% and 40% and reach 59% in selected patients. The increasing experience with living donor transplantation and recent advances in neoadjuvant tumor therapy may lead to renewed discussion of liver transplantation in hilar cholangiocarcinoma.

Endoscopic therapy of benign biliary strictures

Benign biliary strictures are being increasingly treated with endoscopic techniques. The benign nature of the stricture should be first confirmed in order to ensure appropriate therapy. Surgery has been the traditional treatment, but there is increasing desire for minimally invasive endoscopic therapy. At present, endoscopy has become the first line approach for the therapy of post-liver transplant anastomotic strictures and distal (Bismuth Iand II) post-operative strictures. Strictures related to chronic pancreatitis have proven more difficult to treat, and endoscopic therapy is reserved for patients who are not surgical candidates. The preferred endoscopic approach is aggressive treatment with gradual dilation of the stricture and insertion of multiple plastic stents. The use of uncovered self expandable metal stents should be discouraged due to poor long-term results. Treatment with covered metal stents or bioabsorbable stents warrants further evaluation. This area of therapeutic endoscopy provides an ongoing opportunity for fresh research and innovation.

Endoscopic ultrasound of the upper gastrointestinal tract and mediastinum: diagnosis and therapy

Endoscopic ultrasound (EUS) has developed significantly over the last two decades and has had a considerable impact on the imaging and staging of mass lesions within or in close proximity to the gastrointestinal (GI) tract. In conjunction with conventional imaging such as helical computed tomography and magnetic resonance imaging, the indications for EUS include (1) differentiating between benign and malignant lesions of the mediastinum and upper GI tract, (2) staging malignant tumors of the lung, esophagus, stomach, and pancreas prior to surgery or oncological treatment, (3) excluding common bile duct stones before laparoscopic cholecystectomy, thereby avoiding the need for endoscopic retrograde cholangiopancreatography (ERCP) in some patients, and (4) assessing suspected lesions that are either equivocal or not seen on conventional imaging. In recent years, EUS has charted a course similar to that taken by ERCP, evolving from a purely diagnostic modality to one that is interventional and therapeutic. These indications include (5) obtaining a tissue diagnosis by EUS-guided fine-needle aspiration or trucut-type needle biopsy and (6) providing therapy such as coeliac plexus neurolysis and pancreatic pseudocyst drainage--in many cases, more accurately and safely than conventional techniques. Emerging investigational techniques include EUS-guided enteric anastomosis formation and fine-needle injection therapy for malignant disease.

Diagnostic imaging of carcinomas of the gallbladder and the bile ducts

Early diagnosis and accurate staging of carcinomas of the gallbladder and the bile ducts are helpful in improving the prognosis. Ultrasonography (US), a useful initial modality when exploring the background of jaundice or non-specific gastrointestinal complaints, sensitively reveals bile duct obstruction in particular. In unclear cases, or if US suggests a resectable biliary malignancy, computed tomography (CT), magnetic resonance imaging (MRI) with magnetic resonance cholangiography (MRC) and / or traditional cholangiography often provide additional information, and imaging-guided fine-needle biopsy or an endoscopic brush sample may verify the malignant nature of the tumor. Complementary modalities are usually needed for accurate staging, and traditional cholangiography is often performed for therapeutic purposes as well. Comparative studies of MRI with MRC and multidetector CT in biliary cancers would be welcome.

Duodenal EUS to identify thickening of the extrahepatic biliary tree wall in primary sclerosing cholangitis

BACKGROUND

Diagnosing primary sclerosing cholangitis (PSC) is problematic and requires meeting a burden of proof through clinical, biochemical, radiologic, and histological features. Endoscopic ultrasound yields detailed images of the extrahepatic biliary tree, but its value in contributing to the diagnosis of this condition is unknown.

OBJECTIVES

To determine the potential for transduodenal EUS to detect common bile duct wall thickening in PSC.

DESIGN

A prospective, controlled study with retrospective, blinded data analysis.

SETTING

Single tertiary referral center for inflammatory bowel disease and EUS.

PATIENTS

Four groups of patients were assessed with radial endosonography: PSC (n = 9); inflammatory bowel disease (IBD) with abnormal liver blood tests (n = 21); choledocholithiasis (n = 15); and normal controls (n = 50). Measurements were made of the common bile duct diameter and wall thickness.

INTERVENTIONS

Transduodenal radial EUS of the biliary tree.

MAIN OUTCOME MEASUREMENTS

Common bile duct diameter and wall thickness.

RESULTS

The mean diameter (SD) of the common bile duct for the PSC, IBD, choledocholithiasis, and normal control groups measured 8.9 mm (2.8), 5.4 mm (1.7), 7.2 mm (2.2), and 5.0 mm (1.9), respectively (PSC and choledocholithiasis groups compared to the IBD group, P < .05 for a single test of hypothesis, but correction for the multiple testing of data removed this significance; normal control group P < .005). Mean ductal wall thickness (SD) was 2.5 mm (0.8) for the PSC group, 0.7 mm (0.4) for the IBD group, 0.8 mm (0.4) for the choledocholithiasis group, and 0.8 mm (0.4) for the normal control group, respectively (PSC group compared to the other 3 groups, P < .005).

LIMITATIONS

Assessment of intrahepatic PSC is problematic.

CONCLUSION

Thickening (>1.5 mm) of the common bile duct wall is seen in patients with PSC but not in those with apparently uncomplicated IBD or choledocholithiasis. The results of this study suggest that standard endosonography contributes to the imaging and potentially to the diagnosis of PSC.

The role of endoscopic ultrasonography in the evaluation of pancreatico-biliary cancer

Accurate staging of pancreatico-biliary cancer is essential for surgical planning and for identification of locally advanced and metastatic disease that is incurable by surgery. The complex regional anatomy of the pancreatico-biliary system makes histologic diagnosis of malignancy at this region difficult. The ability to position the endoscopic ultrasound transducer at endoscopy in direct proximity to the pancreas and the bile duct, combined with the use of fine-needle aspiration, enables accurate preoperative staging of cancer, especially cancer too small to be characterized by CT or MRI. Endoscopic ultrasonography (EUS) identifies patients unlikely to be cured by surgery due to vascular invasion or regional nodal metastasis, thereby limiting procedure-related morbidity and mortality. This article focuses on the utility and recent advances of EUS in the evaluation of pancreatico-biliary cancer.

Cholangiocarcinoma and intraductal sonography

The instruments and processing systems of intraductal ultrasonography (IDUS) and 3D-IDUS are developing. IDUS is a reliable method for the evaluation of cholangiocarcinoma, and accurate staging is the most significant role of IDUS. DPR images produced by 3D-IDUS are useful to assess the tumor extension and the relationship with surrounding organs. 3D-IDUS is more useful for the precise diagnosis of cancer extension in cholangiocarcinoma, especially in invasion into the portal vein and pancreas, than CT scan and angiography. Tumor volume calculated with 3D-IDUS should determine the prognosis for the patients and facilitate the evaluation of efficacy of laser therapy.

Biochemical and radiological predictors of malignant biliary strictures

AIM: Differentiation of benign biliary strictures (BBS) from malignant biliary strictures (MBS) remains difficult despite improvement in imaging and endoscopic techniques. The aim of this study was to identify the clinical, biochemical and or radiological predictors of malignant biliary strictures.

METHODS: We retrospectively reviewed all charts of patients who had biliary strictures (BS) on endoscopic retrograde cholangiopancreatography (ERCP) or percutaneous cholangiography (PTC) in case of unsuccessful ERCP from March 1998 to August 2002. Patient characteristics, clinical features, biochemical, radiological and biopsy results were all recorded. Stricture etiology was determined based on cytology, biopsy or clinical follow-up. A receiver operator characteristic (ROC) curve was constructed to determine the optimal laboratory diagnostic criterion threshold in predicting MBS.

RESULTS: One hundred twenty six patients with biliary strictures were enrolled, of which 72 were malignant. The mean age for BBS was 53 years compared to 62.4 years for MBS (P = 0.0006). Distal bile duct stricture was mainly due to a malignant process 48.6% vs 9% (P = 0.001). Alkaline phosphates and AST levels were more significantly elevated in MBS (P = 0.0002). ROC curve showed that a bilirubin level of 84 μmol/L or more was the most predictive of MBS with a sensitivity of 98.6%, specificity of 59.3% and a positive likelihood ratio of 2.42 (95%CI: 0.649-0.810). Proximal biliary dilatation was more frequently encountered in MBS compared to BBS, 73.8% vs 39.5% (P = 0.0001). Majority of BBS (87%) and MBS (78%) were managed endoscopically.

CONCLUSION: A serum bilirubin level of 84 μmol/L or greater is the best predictor of MBS. Older age, proximal biliary dilatation, higher levels of bilirubin, alkaline phosphatase, ALT and AST are all associated with MBS. ERCP is necessary to diagnose and treat benign and malignant biliary strictures.

Diagnosis and treatment of cholangiocarcinoma

Epidemiologic studies have demonstrated increasing mortality rates from intrahepatic cholangiocarcinoma during the past decades. Primary sclerosing cholangitis is the most important predisposing condition to the development of cholangiocarcinoma. Improvements in noninvasive diagnostic techniques have led to decreased use of invasive procedures. Magnetic resonance imaging (MRI) has the potential to depict parenchymal, ductal, and vascular tumor involvement. However, diagnosis can be difficult, and often ultrasonography, MRI, CT, and invasive cholangiography are complementary investigations. Genetic aberrations in brush cytology specimens should be explored further in prospective studies. Endoscopic ultrasonography, intraductal ultrasonography, and positron emission tomography are interesting techniques that are under evaluation. Radical surgery with negative histologic margins is the only curative option in cholangiocarcinoma. With more aggressive surgical approaches, including partial hepatectomy, 3-year survival rates of 35% to 50% can be achieved. Liver transplantation for unresectable cholangiocarcinoma was shown to be feasible in pilot studies of highly selected patients.

[Diagnosis of biliary tract carcinoma]

There are several diagnostic tools available in the diagnosis of bile duct cancer. Tumors of the middle and distal part of the extrahepatic bile duct are accessible to endosonography. Endoscopic retrograde cholangiopancreatography (ERC) and percutaneous transhepatic cholangiography (PTC) are the most invasive procedures for diagnosis of bile duct cancer. However, they offer the opportunity to obtain material for cytological or histological investigation. Moreover, bile flow can be assured by inserting endoprostheses during the procedure. Cholangioscopy and/or intraductal ultrasonography can be performed during ERC. They confer to the diagnosis of a malignant bile duct tumor and are the most accurate methods to diagnose the extent of longitudinal spread. Magnetic resonance imaging-cholangiography is an efficient diagnostic procedure which should be used first, if the bile duct tumor is located in the hilar region.

Innovative methods of biliary tract diagnosis: intraductal ultrasound and tissue acquisition

Tissue can be acquired from the bile and pancreatic duct with either brush cytology or biopsy forceps, often without the need for sphincterotomy. Although the diagnosis of malignancy with these sampling techniques is often specific, the sensitivity is limited, and a wide range of diagnostic accuracies has been reported. A combination of biopsy and brush cytology along with some newer techniques in the development stage may increase the sensitivity. Intraductal ultrasound is a newer technique offers the endoscopist the ability to image the bile and pancreatic duct wall, adjacent organs, and vascular structures with a high degree of detail. This visualization can be accomplished during the course of an ERCP or percutaneously under fluoroscopic guidance. Indications for the procedure include detection of choledocholithiasis, differentiation of benign and malignant ductal strictures, pancreaticobiliary tumor staging, and detection of various pancreatic tumors. Continued research into the design of the probes, which could improve durability and extend the depth of penetration, may promote more widespread use of this novel technology.

Endoscopic ultrasound and upper gastrointestinal disorders

Endoscopic ultrasound (EUS) plays a vital role in management of upper gastrointestinal disorders, particularly cancer of the esophagus, pancreas, stomach, lung (via transesophageal mediastinal staging), and bile duct. Endoscopic ultrasound has also been valuable in detection of early chronic pancreatitis (CP). In cancer of the esophagus, the primary role of EUS is to determine whether disease is localized (T1-2, N0) and appropriate for surgery, locally advanced (T3-4, N1, M1a) (which may benefit from chemoradiation with or without surgery), or metastatic. Pancreatic and bile duct cancers are more complex given the controversy over portal vein resection. In centers that resect tumors invading the portal venous system, the role of EUS is limited to tissue confirmation or identification of metastases to the liver or distant lymph nodes. In centers that do not resect the portal vein invasion, EUS plays an important role in local staging. In lung cancer, EUS is emerging as an accurate, nonsurgical alternative to staging the mediastinum through EUS fine-needle aspiration. Endoscopic ultrasound has an important role in diagnosing CP because of its high degree of sensitivity. This has also led to controversy over whether EUS can overdiagnose CP. For these reasons, we recommend the use of a high threshold for EUS and that CP be diagnosed in conjunction with other standard tests (endoscopic retrograde cholangiopancreatography, pancreatic function tests).