Limitations of percutaneous transhepatic cholangioscopy for the diagnosis of the intramural extension of bile duct carcinoma

False-negative factors of percutaneous transluminal clamp biopsy for suspected malignant biliary stricture: 194 cases analyzed from a single center

OBJECTIVE

To study the predictive factors of false negatives in the diagnosis of biliary stricture (BS) by percutaneous transluminal clamp biopsy (PTCB).

METHOD

From January 2016 to January 2021, 194 patients with a high suspicion of malignant tumors due to BS underwent PTCB during biliary drainage at our department. The final diagnosis was confirmed by postoperative pathology, other tissue or cell evidence, or medical imaging follow-up. Univariate and multivariate regression analyses were performed on the pathological results, summarizing the independent risk factors for false-negative value (FNV) to help further clinical diagnosis and treatment.

RESULTS

Of the 194 cases, 176 and 18 cases were finally diagnosed as malignant and benign BS, respectively, compared to 144 and 50 cases by PTCB, including 32 false-negative cases. The sensitivity, specificity, false-positive value, and FNV of PTCB were 81.8%, 100%, 0%, and 18.2%, respectively. Multivariate analysis showed that non-cholangiocarcinoma BS was an independent risk factor for FNV of PTCB (odds ratio 7.5 (95% CI 1.74-32.6), p < 0.01).

CONCLUSION

PTCB is an effective minimally invasive interventional technique for BS diagnosis. Non-cholangiocarcinoma BS is an independent risk factor for FNV.

CRITICAL RELEVANCE STATEMENT

Identifying factors that are predictive of false-negative results by percutaneous transluminal clamp biopsy in the setting of biliary stricture may have a guiding effect on clinical practice.

KEY POINTS

• Factors predictive of false negatives in the diagnosis of biliary stricture etiology by PTCB may aid in the interpretation of results. • Non-cholangiocarcinoma BS is an independent risk factor for FNV on PTCB. • PTCB is an effective minimally invasive interventional technique for BS diagnosis.

Percutaneous transluminal forceps biopsy with an adjustable curved sheath for obstructive jaundice

PURPOSE

To evaluate the feasibility and safety of percutaneous transluminal forceps biopsy (PTFB) with an adjustable curved sheath in patients with obstructive jaundice.

MATERIAL AND METHODS

Forty-two patients who underwent PTFB with an adjustable curved sheath were analyzed retrospectively. Sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV) and accuracy were calculated for all populations and in different situations. Technical success and safety were evaluated.

RESULTS

The technical success rate was 100%. Thirty-five of 42 cases were diagnosed malignant diseases, the sensitivity of PTFB with an adjustable curved sheath was 74.29% (26/35), the specificity was 100%, the positive predictive value was 100%, the negative predictive value was 43.75% (7/16), and the accuracy rate was 78.57% (33/42). There was a better sensitivity for bile duct malignancies when compared with non-bile duct malignancies (p = 0.012). No statistical difference was found in the sensitivity of the upper part of the biliary tree and the lower part of the biliary tree, and none in the sensitivity of different approaches (left vs. right). The complication rate was 11.90%, and no serious complications were observed.

CONCLUSIONS

PTFB with an adjustable curved sheath is an effective and safe technique, without being limited by approaches and obstruction sites.

Percutaneous endobiliary forceps biopsy of biliary strictures for histopathologic examination

PURPOSE

We aimed to investigate the feasibility, accuracy and safety of percutaneous endobiliary cholangio-forceps biopsy of biliary strictures in our institution.

METHODS

A total of 13 percutaneous transhepatic endobiliary biopsies (7 men and 6 women, mean age 66.85±16.76 years) were performed between January 2015 and March 2019 using a transluminal forceps biopsy device. Technical success, rate of complications, number of biopsy specimens, procedure and fluoroscopy time, mean radiation exposure were evaluated; sensitivity and accuracy were calculated.

RESULTS

Technical success, i.e., acquisition of at least three (median, 3.00; range, 3-5) macroscopic representative samples, could be achieved in all 13 biopsies. Access was gained via the right liver lobe in 12 of 13 cases (92.3%). All patients presented blood work indicative of cholestasis prior the intervention, with mean bilirubin 4.72±3.72 µmol/L, mean γ-glutamyl transferase 574.16 ± 360.92 IU/L, and median alkaline phosphatase 407 IU/L (165-1366 IU/L). In 12 of 13 cases (92.3%), biopsied material was sufficient for the pathologist to make a histopathologic diagnosis. Analysis revealed cases of malignancy in eight of 13 cases (61.5%), all of which turned out to be cases of cholangiocarcinoma. In four benign cases (30.8%), diagnosis was considered to be confirmed by further imaging or clinical follow-ups, which showed no signs of progressive disease. There was one case (7.7%) of a false-negative result with proof of malignancy in subsequent surgical tissue extraction. A calculation of diagnostic performance yielded a sensitivity rate of 88.9% and an accuracy rate of 92.3%. There was one case of minor and one case of major complication in our study collective, leading to an overall complication rate of 15.4%.

CONCLUSION

Percutaneous transhepatic biliary drainage (PTBD)-based forceps biopsy via the transhepatic drainage tract in patients with biliary obstruction of unknown origin is a technically feasible and safe technique with good diagnostic value rates. The procedure should be considered in patients not suitable for endoscopic strategies with indication for establishment of PTBD.

Biliary involvement in liver metastases: long-term experience with biliary biopsy from a single center

OBJECTIVE

To investigate long-term results of biliary biopsy performed with transluminal forceps in the setting of metastatic biliary involvement.

MATERIALS AND METHODS

Between September 2014 and June 2019, 25 patients-18 males (72%)-with a mean age of 65 ± 15 years, underwent 26 biliary biopsy procedures with a dedicated forceps system. All patients presented with obstructive jaundice that was suspected of being malignant and underwent pre-procedural magnetic resonance cholangiopancreatography. The biopsies were performed during percutaneous placement of an internal-external biliary drainage catheter, under fluoroscopic guidance.

RESULTS

The technical success rate was 96% (corresponding to 25 of the 26 procedures). The histological diagnosis was inflammatory biliary stricture in five cases, pancreatic adenocarcinoma in six, liver metastases from colorectal cancer in eight, and hepatocellular carcinoma in three, the biliary mucosa being categorized as normal in three cases. In one case, the sample was considered insufficient and the procedure was successfully repeated, after which a diagnosis of pancreatic adenocarcinoma was made. Over a follow-up period of 6-48 months, there were five false-negative results: two findings of inflammatory biliary stricture were later identified as liver metastases from breast and gastric cancer, respectively; and all three patients in which the biliary mucosa was categorized as normal were subsequently diagnosed with metastatic hilar lymph nodes. The procedure was found to have a sensitivity of 77%, a specificity of 100%, and an overall accuracy of 80%. The complication rate was 11.5% (mild, transient hemobilia occurring in three cases).

CONCLUSION

Percutaneous transluminal forceps biopsy is a safe, effective, minimally invasive procedure for histological characterization in patients presenting with obstructive jaundice due to a non-primary biliary tumor.

Application of photodynamic therapy for liver malignancies

Liver malignancies include primary and metastatic tumors. Limited progress has been achieved in improving the survival rate of patients with advanced stage liver cancer and who are unsuitable for surgery. Apart from surgery, chemoradiotherapy, trans-arterial chemoembolization and radiofrequency ablation, a novel therapeutic modality is needed for the clinical treatment of liver cancer. Photodynamic therapy (PDT) is a novel strategy for treating patients with advanced cancers; it uses a light-triggered cytotoxic photosensitizer and a laser light. PDT provides patients with a potential treatment approach with minimal invasion and low toxicity, that is, the whole course of treatment is painless, harmless, and repeatable. Therefore, PDT has been considered an effective palliative treatment for advanced liver cancers. To date, PDT has been used to treat hepatocellular carcinoma, cholangiocarcinoma, hepatoblastoma and liver metastases. Clinical outcomes reveal that PDT can be considered a promising treatment modality for all liver cancers to improve the quality and quantity of life of patients. Despite the advances achieved with this approach, several challenges still impede the application of PDT to liver malignancies. In this review, we focus on the recent advancements and discuss the future prospects of PDT in treating liver malignancies.

The role of percutaneous transhepatic biliary biopsy in the diagnosis of patients with obstructive jaundice: an initial experience

Objective

To evaluate the accuracy of percutaneous transhepatic biliary biopsy (PTBB) in patients with suspected biliary obstruction.

Materials and methods

This was a retrospective analysis of 18 patients with obstructive jaundice who underwent PTBB. In each patient, three to ten fragments were collected from the lesion. The final diagnosis was confirmed in the pathology report. We also reviewed analyses of the results of laboratory tests performed before the procedure, as well as the Bismuth classification, clinical outcome, complications occurring during the procedure, access route, and materials used.

Results

Technical success was achieved in 100% of the PTBB procedures. Among the 18 patients clinically diagnosed with bile duct stenosis, the pathological analysis confirmed that diagnosis in 17. In one case, the pathological findings were considered false-negative. The predominant tumor was cholangiocarcinoma (seen in 50% of the cases). Sixteen of the procedures (88.9%) were performed without complications. Transient hemobilia occurred in one case, and cholangitis occurred in another.

Conclusion

PTBB is a safe, viable, simple technique with a high rate of true-positive results for the definitive diagnosis of obstructive jaundice.

Peroral cholangioscopy by SpyGlass DS versus CHF-B260 for evaluation of the lateral spread of extrahepatic cholangiocarcinoma

Background and study aims  A newly developed peroral cholangioscopy (POCS) system, SpyGlassDS has high maneuverability. This study aimed to evaluate acceptability of the accuracy of SpyGlassDS accompanied by simultaneous POCS-guided biopsy compared with that of a traditional POCS scope, CHF-B260, to diagnose the lateral extent of extrahepatic cholangiocarcinoma (LEC). Patients and methods  Patients who underwent surgical resection after preoperative examinations to diagnose LEC were evaluated. POCS by CHF-B260 was performed if there was discrepancy between preceding fluoroscopy-guided biopsy findings and other examinations between January 2004 and September 2015 (group A, n = 56); and POCS plus POCS-guided mapping biopsy by SpyGlassDS was performed in all surgical candidates between October 2015 and December 2017 (group B, n = 20). The main outcome measure was the accuracy of overall preoperative diagnosis (OPD) of LEC defined based on all examinations, including POCS. Results  Accuracy of OPD for the liver side and the ampullary side was 93 % and 100 %, respectively, in group A, and 84 % and 100 %, respectively, in group B ( P  = 0.37 for the liver side; P , not available for the ampullary side). Diagnostic accuracy of simple optical evaluation by POCS for the liver side and the ampullary side was 83 % and 100 %, respectively, in group A, and 58 % and 88 %, respectively, in group B ( P  = 0.29 for the liver side; P  = 0.40 for the ampullary side). Conclusions  POCS by SpyGlassDS was found to be acceptable and could be a standard approach for diagnosis of LEC.

Biliary Interventions: Tools and Techniques of the Trade, Access, Cholangiography, Biopsy, Cholangioscopy, Cholangioplasty, Stenting, Stone Extraction, and Brachytherapy

Therapeutic access to the biliary system is generally limited to endoscopic or percutaneous approaches. A variety of percutaneous transhepatic biliary interventions are applicable for the diagnosis and treatment of biliary system pathologies, the majority of which may be performed in conjunction with one another. The backbone of nearly all of these interventions is percutaneous transhepatic cholangiography for opacification of the biliary tree, after which any number of therapeutic or diagnostic modalities may be pursued. We describe an overview of the instrumentation and technical approaches for several fundamental interventional procedures, including percutaneous transhepatic cholangiography and internal/external biliary drainage, endobiliary biopsy techniques, cholangioscopy, cholangioplasty and biliary stenting, biliary stone extraction, and intraluminal brachytherapy.

Extensively spreading intraepithelial bile duct carcinoma causing multiple bile duct strictures: report of three cases

Extensive intraepithelial spread of bile duct carcinoma is a common feature, seen in approximately 18% of all cases. However, this spread is rarely accompanied by bile duct strictures. We herein describe three cases of bile duct carcinoma with multiple bile duct strictures due to extensive intraepithelial spread. In all three cases, the spread of intraepithelial cancer extended into the epithelium of the peribiliary glands along the intrahepatic bile ducts with marked fibrosis on histopathological examination. It is speculated that peribiliary gland involvement by superficially spreading bile duct cancer and subsequent obstructive glandular inflammation with fibrosis might cause intrahepatic bile duct strictures even without interstitial cancer invasion.

Cytological sampling versus forceps biopsy during percutaneous transhepatic biliary drainage and analysis of factors predicting success

PURPOSE

To assess the accuracy of cytological sampling and forceps biopsy in obstructing biliary lesions and to identify factors predictive of success.

METHODS

Consecutive patients (n = 119) with suspected malignant inoperable obstructive jaundice treated with percutaneous transhepatic biliary drainage during 7 years were included (60 male; mean age 72.5 years). All patients underwent forceps biopsy plus cytological sampling by washing the forceps device in cytological solution. Patient history, procedural and pathological records, and clinical follow-up were reviewed. Statistical analysis included chi-square test and multivariate regression analysis.

RESULTS

Histological diagnosis after forceps biopsy was more successful than cytology: Sensitivity was 78 versus 61%, and negative predictive value was 30 versus 19%. Cytology results were never positive when the forceps biopsy was negative. The cytological sample was negative and forceps sample positive in 2 cases of cholangiocarcinoma, 16 cases of pancreatic carcinoma, and 1 case of benign disease. Diagnostic accuracy was predicted by low bilirubin (p < 0.001), aspartate transaminase (p < 0.05), and white cell count (p ≤ 0.05).

CONCLUSIONS

This technique is safe and effective and is recommended for histological diagnosis during PTBD in patients with inoperable malignant biliary strictures. Diagnostic yield is greater when bilirubin levels are low and there is no sepsis; histological diagnosis by way of forceps biopsy renders cytological sampling unnecessary.

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.

Unilateral versus bilateral drainage using self-expandable metallic stent for unresectable hilar biliary obstruction

BACKGROUND

There is no consensus on the choice of either unilateral or bilateral drainage in stent placement for patients with unresectable hilar biliary obstruction. The aim of the present study was to clarify which drainage method is superior.

METHODS

We retrospectively reviewed 82 patients with hilar biliary obstruction who underwent metallic stenting. These patients were divided into a unilateral drainage group (Uni group) and a bilateral drainage group (Bi group).

RESULTS

There was no significant difference between the groups in median survival time, median stent patency period, and median complication-free survival time. The most frequent complication was stent obstruction, followed by cholangitis. Liver abscess was found at a higher frequency in the Bi group (17.6%) than in the Uni group (1.5%) (P=0.0266). There was no significant difference between the groups in the occurrence of two or more complications (P=0.247), life-threatening severe complications (P=0.0577), and stent obstruction by sludge (P=0.0912).

CONCLUSION

When compared with bilateral biliary drainage, unilateral biliary drainage is associated with a lower incidence of liver abscess as well as a comparable outcome of stent patency time and complication-free survival. We therefore propose that hilar biliary obstruction can be treated first by unilateral drainage with a metallic stent and by bilateral drainage only in patients who develop cholangitis in the contralateral biliary tree.

New options of cholangioscopy

In the evaluation of biliary diseases, cholangioscopy is considered as complementary procedure to radiographic imaging. Direct visualization of the bile duct is the premier advantage of cholangioscopy over indirect imaging techniques. However, cholangioscopy has not gained wide acceptance because of several technical limitations such as scope fragility, impaired steerability, limited irrigation, and suction capabilities, as well as the need for two experienced endoscopists. Recent innovations such as the implementation of electronic video cholangioscopes and the development of single-operator systems facilitate the procedure, and promise to increase the diagnostic and therapeutic yield of cholangioscopy.

Diagnostic peroral video cholangioscopy is an accurate diagnostic tool for patients with bile duct lesions

BACKGROUND & AIMS

We evaluated the diagnostic ability of a newly developed peroral video cholangioscopy (PVCS) in patients with pancreaticobiliary disorders.

METHODS

We retrospectively evaluated data from 144 patients with pancreaticobiliary disorders, collected from 5 tertiary referral centers. Endoscopic sphincterotomy (EST) or endoscopic papillary balloon dilation (EPBD) was performed before PVCS. We performed 2 types of PVCS, using a conventional therapeutic duodenoscope. If tissue samples were needed, cholangioscopy-assisted biopsy or fluoroscopy-guided biopsy was performed.

RESULTS

PVCS was advanced into the bile duct in all cases after patients received EST (n = 134 cases), EPBD (n = 2), a combination of EST and EPBD (n = 1), or without treatment of the major papilla (n = 7). Biopsy samples were collected successfully from 112 of 120 cases in which endoscopists considered tissue sampling necessary. Endoscopic retrograde cholangiopancreatography (ERCP)/biopsy correctly identified 83 of 96 malignant lesions and 19 of 24 benign lesions (accuracy = 85.0%; sensitivity = 86.5%; specificity = 79.2%; positive predictive value = 94.3%; negative predictive value = 59.4%). Endoscopic retrograde cholangiopancreatography (ERCP)/biopsy plus PVCS correctly identified 95 of 96 malignant lesions and 23 of 24 benign lesions (accuracy = 98.3%; sensitivity = 99.0%; specificity = 95.8%; positive predictive value = 99.0%; negative predictive value = 95.8%). Procedure-related complications included pancreatitis (4 cases, 2.8%) and cholangitis (6 cases, 4.3%).

CONCLUSIONS

PVCS is an accurate diagnostic tool for patients with pancreaticobiliary disorders; resolution was well-defined when combined with biopsy analysis. Prospective multicenter clinical trials should evaluate the clinical utility of PVCS in diagnosis of biliary tract diseases.

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.

Characteristics of bile duct carcinoma with superficial extension in the epithelium

BACKGROUND

Longitudinal tumor extension from the main tumor involves intramural or superficial spread along the bile duct, which influences surgical curability. Identifying the range of superficial extension is difficult by preoperative imaging. To clarify specific characteristics of bile duct carcinoma (BDC) with superficial extension of epithelium in the bile duct, we examined clinicopathologic features and patient outcomes in BDC patients with or without superficial extension who underwent surgical resection.

METHODS

Between 1994 and 2008, we retrospectively examined clinicopathologic findings and outcomes for 42 BDC patients who underwent surgical resection and divided them into two groups: (1) superficial extension (SE) group (n = 10); and (2) non-SE group (n = 32).

RESULTS

In terms of macroscopic growth of the main tumor, the papillary type was more common in the SE group than in the non-SE group, whereas the nodular type was dominant in the non-SE group. The prevalence of cancer-positive findings at the cut end of the bile duct was higher in the SE group. Portal vein invasion was not observed in the SE group, and the prevalence of regional lymph node metastasis was significantly greater in the non-SE group than in the SE group. No patients died of cancer in the SE group, who tended to show better survival than the non-SE group.

CONCLUSIONS

The present results suggest that a good prognosis may be achieved in BDC patients with SE when complete resection is accomplished.

Endoscopic tumor treatment in the bile duct

There is little information in the literature on endoscopic tumor treatment in the bile duct with a curative intention. This article reports on the few cases published and on the authors' own experience with endoscopic retrograde and percutaneous transhepatic cholangioscopic treatment of tumors in the biliary system.

Diagnostic value of image-enhanced video cholangiopancreatoscopy

We summarized past and present results concerning the observation capability of cholangiopancratoscopy using chromoendoscopy, autofluorescence imaging (AFI), and narrow-band imaging (NBI). New generation peroral and percutaneous transhepatic video cholangiopancreatoscopes provide superior quality images. Pilot studies suggest that chromoendocholangioscopy using methylene blue or cholangioscopy using AFI can distinguish benign from malignant bile duct lesions. On the other hand, the NBI system enhances the imaging of certain features such as mucosal structures and microvessels in pancreatobiliary lesions. In patients with main-duct-type intraductal papillary mucinous neoplasm, peroral pancreatoscopy can be used to determine extent of tumor involvement. Although many technical hurdles still need to be overcome, image-enhanced cholangiopancratoscopy appears to be a promising modality to improve diagnostic accuracy of pancreatobiliary diseases, particularly in distinguishing benign from malignant lesions.

The usefulness of percutaneous transhepatic cholangioscopy for identifying malignancies in distal common [corrected] bile duct strictures

The diagnostic accuracy of percutaneous transhepatic cholangioscopy (PTCS) was compared to that of three radiologic modalities in distal common bile duct (CBD) strictures for the evaluation of clinical application. Ninety-five patients who underwent PTCS for the evaluation of distal CBD strictures (35 malignant and 60 benign) whose masses were not obvious from radiologic imagings were included. Confirmative diagnosis could not be reached by endoscopic retrograde cholangiopancreatography (ERCP) or radiologic findings in all cases. Specific findings on the computed tomography (CT), magnetic resonance cholangiopancreatography (MRCP) and direct cholangiography were analyzed among 68 (25 malignant and 43 benign) out of the 95 patients in order to determine the sensitivity and specificity of three radiologic studies for the diagnosis of malignant distal CBD strictures, and to compare those results with those by a combination of PTCS-guided biopsy and tumor vessel observation on cholangioscopy. The sensitivity/specificity of CT, MRCP and direct cholangiography including ERCP in diagnosing malignant distal CBD strictures were 42.9%/65.8%, 53.3%/58.3%, and 70.8%/47.6% respectively, while it was 96%/100% for the combination of PTCS-guided biopsy and tumor vessel. PTCS is a useful method for differential diagnosis of distal CBD strictures, particularly when it is difficult to distinguish benign from malignant strictures by radiologic studies and when peroral approach is not feasible.

Extrahepatic bile duct carcinoma with extensive intraepithelial spread: a clinicopathological study of 21 cases

Extrahepatic bile duct carcinoma occasionally presents with intraepithelial spread for a considerable area around the main tumor. In this study, we compared clinicopathological features of extrahepatic bile duct carcinoma with and without extensive intraepithelial spread (>or=20 mm from the main tumor). Out of 117 cases of extrahepatic bile duct carcinoma, 21 (18%) were found to have extensive intraepithelial spread. Those cases were pathologically characterized by a papillary or nodular main tumor, a more differentiated histological grade, less deep invasion, and infrequent portal vein or hepatic invasion in comparison with cases without intraepithelial spread. Areas of intraepithelial spread histologically consisted of low-papillary growth (17 cases, 81%) and completely flat growth (4 cases, 19%) of carcinoma cells. The former histology corresponded to a macroscopic granular mucosa, whereas the latter growth was hardly detected by gross examination. Immunohistochemically, in 16 of 21 cases (76%), at least one of p53, CEA, and MUC1 was expressed in both the main tumor and the spreading area. Interestingly, patients with intraepithelial spread had a better postoperative prognosis than those without intraepithelial spread (P=0.009). However, three patients had anastomotic recurrence 54-130 months after surgery. In conclusion, intraepithelial-spreading bile duct carcinoma is characterized by papillary or nodular main lesions, a more differentiated histological grade, and less invasiveness. The presence of intraepithelial spread was not an indicator of a poor prognosis, but carcinoma in situ at the bile duct stump could cause late anastomotic recurrence after surgery.

Endoscopic management of biliary malignancies

The current status of endoscopic diagnosis and treatment of biliary malignancies is discussed. Three ways are now available to approach the bile duct endoscopically. Endoscopic diagnostic modalities are quite useful for the assessment of local changes because of their high spatial resolution and ability in tissue and bile acquisition for histologic, cytologic, and molecular biologic evaluations. Endoscopic biliary drainage is less invasive and beneficial for patients with obstructive jaundice compared with surgical or percutaneous transhepatic drainage. Continuous evolution should expand its indications.

Intraductal biliary and pancreatic endoscopy: An expanding scope of possibility

Intraductal endoscopy describes the use of an endoscope to directly visualize the biliary and pancreatic ducts. For many years, technological challenges have made performing these procedures difficult. The “mother-baby” system and other various miniscopes have been developed, but routine use has been hampered due to complex setup, scope fragility and the time consuming, technically demanding nature of the procedure. Recently, the SpyGlass peroral cholangiopancreatoscopy system has shown early success at providing diagnostic information and therapeutic options. The clinical utility of intraductal endoscopy is broad. It allows better differentiation between benign and malignant processes by allowing direct visualization and targeted sampling of tissue. Therapeutic interventions, such as electrohydraulic lithotripsy (EHL), laser lithotripsy, photodynamic therapy, and argon plasma coagulation (APC), may also be performed as part of intraductal endoscopy. Intraductal endoscopy significantly increases the diagnostic and therapeutic yield of standard endoscopic retrograde cholangiography (ERCP), and as technology progresses, it is likely that its utilization will only increase. In this review of intraductal endoscopy, we describe in detail the various endoscopic platforms and their diagnostic and clinical applications.

Peroral cholangioscopic diagnosis of biliary-tract diseases by using narrow-band imaging (with videos)

BACKGROUND

Narrow-band imaging (NBI) makes it possible to emphasize the imaging of certain features, such as mucosal structures and mucosal microvessels in GI-tract diseases. Recently, video peroral cholangioscopy (POCS) was developed as a diagnostic modality for better visualization of bile-duct lesions; however, there is no report on POCS by using NBI.

OBJECTIVE

To evaluate the clinical usefulness of POCS by using NBI for the diagnosis of biliary-tract diseases.

DESIGN

Prospective case study.

SETTING

This procedure was performed at Tokyo Medical University Hospital.

PATIENTS

Twelve consecutive patients with biliary-tract diseases, including 7 bile-duct cancers and 5 benign biliary diseases, which revealed 6 bile-duct strictures and 6 filling defects by ERCP.

INTERVENTION

All patients underwent POCS by using NBI.

MAIN OUTCOME MEASUREMENT

Efficacy and safety of this technique.

RESULTS

Twenty-one lesions were evaluated by using POCS with conventional white light imaging and NBI. Although visualization of only 2 lesions (9.5%) was "excellent" by conventional observation, visualization of 12 lesions (57.4%) was "excellent" by NBI observation. Identification of the surface structure and vessels of the lesions by NBI observation was significantly better than with conventional observation (P < .01 and P < .05, respectively).

LIMITATIONS

Maneuverability and fragility of POCS. The current POCS is not equipped with magnification.

CONCLUSIONS

POCS by using NBI may be helpful for the observation of both fine mucosal structures and tumor vessels.

Peroral cholangioscopy for the diagnosis and treatment of biliary diseases

Peroral cholangioscopy with duodenoscopic assistance can allow direct visualization of the bile duct. Several clinical studies suggest the utility of peroral cholangioscopy for the management of various bile duct lesions. Although direct visual observation may be a useful adjunct to endoscopic retro-grade cholangiopancreatography (ERCP) for distinguishing malignant from benign bile duct lesions, the assessment of diagnostic accuracy needs further controlled clinical studies. Intracorporeal lithotripsy with the use of a peroral cholangioscope may be a safe and effective method for difficult-to-treat bile duct stones, including intrahepatic stones. At present, however, the fragility of the fiberscope equipment and technical difficulties hold back its popularity. Preliminary data obtained by using a new videoscope, which provides excellent quality images, are encouraging. Furthermore, it is expected that this videoscope will have longer durability of optical images and better manipulation than previous fiberscopes.

Diagnostic utility of peroral cholangioscopy for various bile-duct lesions

BACKGROUND

We evaluated the utility of peroral cholangioscopy (POCS) for distinguishing malignant from benign biliary disease to cover low sensitivity of tissue sampling.

METHODS

From February 1992 to April 2004, all consecutive patients who underwent POCS to confirm the etiology of biliary disorders were included in this study. Brushing cytology or endobiliary forceps biopsy also was performed. We analyzed the diagnostic accuracy of tissue sampling with or without POCS diagnosis.

RESULTS

A total of 97 patients (66 men, 31 women; mean age 64.2 years) were included. The final diagnosis was confirmed by surgical resection in 44, clinical follow-up in 52, and cytologic study of ascitic fluid in one. On the basis of ERCP findings, there were 76 strictures and 21 filling defects. Forceps biopsy was performed in 25 patients, and brush cytology was performed in 68 patients. In the remaining 4 patients (4 filling defects, which were identified as stones by POCS), tissue samplings were not carried out. ERCP/tissue sampling correctly identified 22 of 38 malignant strictures and all 35 benign lesions except in 3 patients with inadequate samples (accuracy, 78.0%; sensitivity, 57.9%; specificity, 100%). The addition of POCS correctly identified all 38 malignant strictures and 33 of 38 benign lesions (accuracy, 93.4%; sensitivity, 100%; specificity, 86.8%). For the 21 filling defects observed by ERCP, POCS correctly diagnosed all 8 malignant diseases and 13 benign lesions.

CONCLUSIONS

The addition of POCS to tissue sampling improves the diagnostic ability and covers for insufficient sensitivity. POCS is especially useful for diagnosing a filling defect.

Clinicopathologic review of 58 patients with biliary papillomatosis

BACKGROUND

Biliary papillomatosis (BP) is a rare disease that is characterized by multiple numerous papillary adenomas in the biliary tree. The clinical features and outcome, however, are not well known. The authors retrospectively analyzed their clinicopathologic features and long-term follow-up results.

METHODS

Between March 1995 and January 2003, 58 patients were diagnosed with BP by cholangioscopic and histologic findings at a tertiary referral center, Asan Medical Center (University of Ulsan College of Medicine, Seoul, Korea). The authors retrospectively reviewed the medical records to obtain demographic, radiologic, cholangioscopic, and pathologic data.

RESULTS

The common clinical manifestations at the presentation of patients were repeated episodes of abdominal pain, jaundice, and acute cholangitis. Acute cholangitis was more common in patients with mucin-hypersecreting BP (MBP), whereas patients with nonmucin-producing BP (NMBP) were more asymptomatic (P < 0.05). Papillary adenocarcinoma and mucinous carcinoma were detected in 48 patients (83%) with papillary adenomas. Overall survival rates of NMBP and MBP were 89% and 69% at 1 year, 57% and 37% at 3 years, and 52% and 19% at 5 years, respectively. The mean survival period of NMBP and MBP was 52.27 +/- 6.72 months and 30.84 +/- 8.36 months, respectively.

CONCLUSIONS

BP should be regarded as a premalignant disease with high malignant potential. The pathogenesis of progression from benign to malignant disease may follow the adenomacarcinoma sequence. Although clinical presentations were somewhat different for patients with NMBP and MBP, the long-term survival rate was similar.

Bile duct: analysis of percutaneous transluminal forceps biopsy in 130 patients suspected of having malignant biliary obstruction

PURPOSE

To evaluate percutaneous transluminal forceps biopsy in patients suspected of having a malignant biliary obstruction.

MATERIALS AND METHODS

One hundred thirty consecutive patients (82 men and 48 women; mean age, 59 years) with obstructive jaundice underwent transluminal forceps biopsy during or after percutaneous transhepatic biliary drainage. The lesions involved the common bile duct (n = 58), common hepatic duct (n = 39), hilum (n = 14), ampullary segment of the common bile duct (n = 11), right or left intrahepatic bile duct (n = 5), or the entire extrahepatic bile duct (n = 3). In each patient, three to five specimens (mean, 4.1 specimens) were taken from the lesion with 5.4-F biopsy forceps. The final diagnosis for each patient was confirmed with pathologic findings at surgery, additional histocytologic data, or clinical and radiologic follow-up. Statistical analysis was performed with the chi(2) test; a P value < or =.05 was considered to indicate a significant difference.

RESULTS

Ninety-eight of 130 biopsies resulted in correct diagnoses of malignancy. Five biopsy diagnoses proved to be true-negative. There were 27 false-negative diagnoses and no false-positive diagnoses. The diagnostic performance of transluminal forceps biopsy in malignant biliary obstructions was as follows: sensitivity, 78.4%; specificity, 100%; and accuracy, 79.2%. Sensitivity of biopsy in the 82 patients with cholangiocarcinoma was higher than in the 43 patients with malignant tumors other than cholangiocarcinoma (86.6% vs 62.8%, P <.005). Sensitivity was significantly lower in the ampullary segment of the common bile duct than in other sites (P <.01). No major complications related to the biopsy procedures occurred.

CONCLUSION

Percutaneous transluminal forceps biopsy is a safe procedure that is easy to perform through a transhepatic biliary drainage tract. It provides relatively high accuracy in the diagnosis of malignant biliary obstructions.

MR cholangiography versus cholangioscopy for evaluation of longitudinal extension of hilar cholangiocarcinoma

BACKGROUND

The utility of magnetic resonance cholangiography for assessment of longitudinal tumor extension of hilar cholangiocarcinoma was investigated with reference to findings by percutaneous transhepatic cholangioscopy.

METHODS

Ninety-nine patients with hilar cholangiocarcinoma underwent both magnetic resonance cholangiography and percutaneous transhepatic cholangioscopy. Longitudinal tumor extension was described with the Bismuth-Corlette classification. Hilar cholangiocarcinoma was classified morphologically into stenotic, diffuse sclerosing, and polypoid types based on selective cholangiographic findings obtained during percutaneous transhepatic cholangioscopy. Agreement between percutaneous transhepatic cholangioscopy and magnetic resonance cholangiography according to the Bismuth-Corlette classification was compared. The degree of agreement between magnetic resonance cholangiography and percutaneous transhepatic cholangioscopy according to each morphologic type was also compared in each subgroup without reference to Bismuth-Corlette type.

RESULTS

The overall agreement between magnetic resonance cholangiography and percutaneous transhepatic cholangioscopy with regard to Bismuth-Corlette types was 87.9% (kappa = 0.832, p < 0.01). The agreement of magnetic resonance cholangiography for each Bismuth-Corlette type with reference to percutaneous transhepatic cholangioscopy was as follows: type I (n = 18), 16/18 (88.9%); type II (n = 16), 14/16 (87.5%); type IIIa (n = 23), 19/23 (82.6%); type IIIb (n = 14), 14/14 (100%); and type IV (n = 28), 24/28 (85.7%). The overall agreement between magnetic resonance cholangiography and percutaneous transhepatic cholangioscopy for Bismuth-Corlette type according to selective cholangiographic findings was as follows: stenotic type, 58/61 (95.1%, kappa = 0.929, p < 0.01); diffuse sclerosing type, 12/16 (75%, kappa = 0.619, p < 0.01); and polypoid type, 17/22 (77.3%, kappa = 0.696, p < 0.01).

CONCLUSION

There is good overall agreement between magnetic resonance cholangiography and percutaneous transhepatic cholangioscopy on longitudinal extension of hilar cholangiocarcinoma. Especially for the stenotic type of hilar cholangiocarcinoma (based on selective cholangiographic findings), magnetic resonance cholangiography may replace percutaneous transhepatic cholangioscopy in the determination of longitudinal tumor extension. For polypoid or diffuse sclerosing types, however, percutaneous transhepatic cholangioscopy is required for accurate evaluation of longitudinal tumor extension.

Endoscopic management of biliary tract disease

New investigations, evaluation of controversial issues, and advances in technology continue to shape the endoscopic management of biliary disorders. This article discusses recent literature related to the diagnosis and therapy of biliary tract disease. Specifically, the diagnosis and management of choledocholithiasis, complications of biliary endoscopy and potential preventive measures, roles for endosonography in the evaluation of biliary disease, and endoscopic therapy of postoperative liver transplantation complications are reviewed. Recent advances in biliary stents and the use of cholangioscopy in biliary disorders are also assessed.

Multiple bile duct biopsies using a sheath with a side port: usefulness of intraductal sonography

OBJECTIVE

We clarified the number of biopsies required to determine malignancy of the biliary tract on the basis of the type of bile duct tumor.

SUBJECTS AND METHODS

Patients with a biliary tract malignancy (n = 33) and a benign biliary stenosis (n = 3) underwent biopsy via the percutaneous transhepatic route. We performed intraductal sonography using a 20-MHz probe with a 2.0-mm diameter. The sonographic findings were prospectively classified as polypoid, circular, or semicircular. The tip of a long 9-French sheath with a side port was wedged into the stenosis, and six specimens were obtained with a 1.8-mm-diameter forceps with serrated cups.

RESULTS

When cholangiography or intraductal sonography showed a polypoid lesion, the sensitivity of two biopsies was 100% (6/6). When cholangiography showed a stenotic lesion, the sensitivity of nine biopsies (96%, 26/27) was superior to that of two biopsies (74%, 20/27; p < 0.05). When intraductal sonography showed a circular lesion, the sensitivity of three biopsies (100%, 14/14) was superior to that of a single biopsy (64%, 9/14; p < 0.05). When it showed a semicircular lesion, the sensitivity of nine biopsies (92%, 12/13) was superior to that of two biopsies (54%, 7/13; p < 0.05).

CONCLUSION

Bile duct biopsy using a sheath with a side port has a high sensitivity. However, the number of biopsies required depends on the cholangioscopic and intraductal sonographic appearance of the tumor.

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

BACKGROUND

The utility of intraductal US via the transpapillary route prior to biliary drainage in the assessment of longitudinal extension of extrahepatic bile duct carcinoma was investigated.

METHODS

In 19 patients with extrahepatic bile duct carcinoma who underwent surgical resection, an ultrasonic probe (diameter, 2.0 mm; frequency, 20 MHz) was inserted into the bile duct via the transpapillary route prior to biliary drainage. Longitudinal cancer extension along the bile duct was prospectively determined and compared with the histologic findings in the resected specimens.

RESULTS

Results on the hepatic side were as follows: Intraductal US demonstrated more extensive longitudinal cancer spread than cholangiography in 9 of 19 patients with one instance of overdiagnosis. The accuracy of intraductal US in assessing the extent of spread (84%) was superior to that of cholangiography (47%) (p < 0.05). Results on the duodenal side were as follows: In patients with suprapancreatic bile duct cancer (n = 14), intraductal US demonstrated more extensive longitudinal cancer spread than cholangiography in 8 of 14 patients. The accuracy of intraductal US in assessing the extent of the spread (86%) was superior to that of cholangiography (43%) (p < 0.05).

CONCLUSIONS

Transpapillary intraductal US prior to biliary drainage is useful in demonstrating longitudinal extension of bile duct cancer. However, the surgical margins were inaccurate in some patients.

Access for percutaneous transhepatic cholangioscopy in patients with nondilated bile ducts using nasobiliary catheter cholangiography and oblique fluoroscopy

BACKGROUND

Percutaneous transhepatic biliary drainage is required for percutaneous transhepatic cholangioscopy. However, puncture of nondilated bile ducts under ultrasonographic guidance is difficult.

METHODS

In 10 patients with no ultrasonographic evidence of intrahepatic bile duct dilatation, percutaneous transhepatic biliary drainage was performed under fluoroscopic guidance using cholangiography obtained via a nasobiliary drainage catheter. Direct puncture was performed by means of a left ventral approach using oblique C-arm fluoroscopy.

RESULTS

Bile duct puncture was successful in all patients. There were no procedure-related complications. Subsequent cholangioscopy was successful in all patients.

CONCLUSIONS

Direct puncture using nasobiliary drainage cholangiography and oblique fluoroscopy is a useful method when cholangioscopy is necessary in patients with nondilated bile ducts.

Tumor vessel: a valuable cholangioscopic clue of malignant biliary stricture

BACKGROUND

An irregularly dilated and tortuous vessel, the so-called tumor vessel, is considered to be one of the cholangioscopic features that suggest biliary malignancy. This is a prospective analysis of the presence of a tumor vessel as a finding that discriminates between benign and malignant biliary strictures.

METHODS

From August 1997 to August 1998, a total of 63 patients with biliary strictures diagnosed with endoscopic retrograde cholangiography or percutaneous transhepatic cholangiography obtained during percutaneous transhepatic biliary drainage tube placement were included in this study. Strictures were characterized as benign or malignant based on the observation of tumor vessels. The results were compared with those of percutaneous transhepatic cholangiography-guided biopsy and final diagnosis.

RESULTS

Forty-one patients were confirmed to have malignant strictures and 22 had benign biliary strictures. Cancer was confirmed by histopathologic evaluation of biopsies in 33 of 41 patients with malignancy (80.4%). Tumor vessel was seen in 25 of 41 patients with malignancy (61%). No patients with benign stricture had tumor vessels. Of the 8 patients with negative percutaneous transhepatic cholangioscopy-guided biopsies but with a final diagnosis of malignancy, 6 had tumor vessels. Combining the observation of tumor vessel and percutaneous transhepatic cholangiography-guided biopsy resulted in a diagnosis of malignancy in 39 of 41 patients (96%) and significantly increased the rate of preoperative diagnosis when compared with percutaneous transhepatic cholangiography-guided biopsy or presence of tumor vessel alone (p<0.05).

CONCLUSION

The presence of tumor vessel may be a valuable cholangioscopic finding that indicates the presence of a malignant biliary stricture. The combination of tumor vessel observation and percutaneous transhepatic cholangiography-guided biopsy may improve the preoperative diagnosis of malignancy.

Detection of telomerase activity in biopsy specimens for diagnosis of biliary tract cancers

BACKGROUND

Telomerase activity is detectable in more than 85% of primary cancers. We determined telomerase activity in biopsy specimens obtained from biliary tract cancers to evaluate the clinical application of telomerase activity detection in combination with p53 immunostaining and routine histologic examination.

METHODS

Biopsy specimens obtained during percutaneous transhepatic cholangioscopy from 13 patients with cholangiocarcinoma, 3 patients with gallbladder carcinoma, and 4 patients with intrahepatic bile duct stones were evaluated by routine histologic examination, p53 immunostaining, and telomerase activity. Semiquantitative determination of telomerase activity was performed using a fluorescence-based telomeric repeat amplification protocol.

RESULTS

Thirteen of 16 specimens of malignant tissue had detectable telomerase activity, whereas no specimen of nonmalignant tissue had detectable telomerase activity. A p53 overexpression was recognized by immunostaining in 9 of 16 samples with cancers. Combining both telomerase activity and p53 overexpression resulted in the detection of all cancer with a sensitivity of 100%. There were no false-positive results by either modality (specificity 100%).

CONCLUSIONS

The detection of telomerase activity in biopsy specimens and p53 overexpression in combination with routine histologic examination may improve the diagnosis of biliary tract cancers. (Gastrointest Endosc 2000;52:380-6).

Double-catheter method to prevent dislodgement during percutaneous transhepatic cholangioscopy

BACKGROUND

We evaluated the utility of the double-catheter method to establish the track for percutaneous transhepatic cholangioscopy (PTCS).

METHODS

Dilatation of the percutaneous transhepatic track to 16F for PTCS was attempted in 105 patients. The results were prospectively analyzed. Using the single-catheter method (n = 22), a 16F PTCS catheter was replaced without the inner catheter. Using the double-catheter method (n = 83), a 7F catheter with a balloon tip was inserted through a 16F PTCS catheter. The balloon was located distal to the major duodenal papilla. The double-catheter method was further subclassified as follows: Method 2A (n = 62), the tip of the outer catheter (16F) was not advanced through biliary stenoses; Method 2B (n = 21), the catheter was advanced through biliary stenoses.

RESULTS

In the patients treated by the double-catheter method, dislodgement of the catheter did not occur, whereas the single-catheter became dislodged in 18% (p < 0.0005). The morbidity of method 2A (0%) was less than that of method 2B (14%) (p < 0.005).

CONCLUSION

The double-catheter method prevents dislodgement of the PTCS catheter. The outer catheter should not be advanced to the biliary stenosis.

How many biopsies should be performed during percutaneous transhepatic cholangioscopy to diagnose biliary tract cancer?

BACKGROUND

The sensitivity of biopsy in the diagnosis of cholangiocarcinoma using percutaneous transhepatic cholangioscopy is not well defined.

METHODS

Patients with a biliary tract malignancy (n = 52) underwent directed biopsy during percutaneous transhepatic cholangioscopy using a 1.8 mm diameter forceps. Histologic findings were correlated with endoscopic appearance.

RESULTS

A diagnosis of carcinoma was made in all four patients with a tumor of the major duodenal papilla and in all 15 patients with a polypoid bile duct tumor with two biopsies from the mass. In 19 patients with stenotic bile duct cancer, a positive diagnosis was made in 95% of cases when three biopsies were taken from the margin of the stenotic area. When cholangioscopy showed a tortuous, dilated vessel (n = 10), the diagnosis of cancer was made with two biopsies taken from the margin of the stenosis. In 14 patients with metastatic bile duct cancer, the diagnosis was made in only 43% of cases when three biopsies were taken from the margin of the stenosis. When combined with results from the three biopsies taken from within the area of stenosis, the sensitivity for diagnosing pancreatic cancer improved from 20% to 60%.

CONCLUSIONS

Directed cholangioscopic biopsies are highly sensitive for the diagnosis of cholangiocarcinoma but less sensitive for cancer metastatic to the bile duct. The numbers and locations of the biopsies required to make a diagnosis of carcinoma depend on the origin and cholangioscopic appearance of the tumor.

Limitation of cholangiography in assessing longitudinal spread of extrahepatic bile duct carcinoma to the hepatic side

BACKGROUND

Preoperative assessment of longitudinal spread of bile duct carcinoma (BDC) to the hepatic side remains a difficult problem for diagnostic imaging.

METHODS

We studied the accuracy of cholangiography in assessing BDC. In 54 patients with extrahepatic bile duct cancer, cholangiographic findings were compared retrospectively with the histological findings of the resected specimens.

RESULTS

Histological examination of specimens indicated longitudinal spread of the tumour to the hepatic side in 22 of 54 patients. The accuracy of cholangiography in assessing the extent of the longitudinal spread was only 34/54 (63%). When the cholangiographic images showed a main tumour with a collapsed edge, there was a significantly higher frequency of longitudinal spread compared with tumours with sharp edges (P< 0.05). In contrast, the accuracy of mapping biopsy under percutaneous transhepatic cholangioscopy (n=24) was 83%.

CONCLUSIONS

Cholangiography cannot accurately assess the extent of the longitudinal spread of bile duct cancer. When cholangiographic images show a tumour with a collapsed edge, preoperative or intraoperative histological examination is essential to determine a suitable surgical line.