Cholangiopancreatoscopy for targeted biopsies of the bile and pancreatic ducts

Pancreatoscopy-Guided Endotherapies for Pancreatic Diseases

Per-oral pancreatoscopy (POP) is a pancreas-preserving modality that allows for targeted pancreatic duct interventions, particularly in cases where standard techniques fail. POP specifically has an emerging role in the diagnosis, risk stratification, and disease extent determination of main duct intraductal papillary mucinous neoplasms (IPMNs). It has also been successfully used for laser ablation of IPMNs in poor surgical candidates, lithotripsy for complex stone disease, and laser stricturoplasty. As experience with POP increases beyond select referral center practices, further studies validating POP efficacy with long-term follow-up will help clarify when POP-guided intervention is most beneficial in relation to surgical intervention.

Recent Advancement in Diagnosis of Biliary Tract Cancer through Pathological and Molecular Classifications

Biliary tract cancers (BTCs), including intrahepatic, perihilar, and distal cholangiocarcinomas, as well as gallbladder cancer, are a diverse group of cancers that exhibit unique molecular characteristics in each of their anatomic and pathological subtypes. The pathological classification of BTCs compromises distinct growth patterns, including mass forming, periductal infiltrating, and intraductal growing types, which can be identified through gross examination. The small-duct and large-duct types of intrahepatic cholangiocarcinoma have been recently introduced into the WHO classification. The presentation of typical clinical symptoms, as well as the extensive utilization of radiological, endoscopic, and molecular diagnostic methods, is thoroughly detailed in the description. To overcome the limitations of traditional tissue acquisition methods, new diagnostic modalities are being explored. The treatment landscape is also rapidly evolving owing to the emergence of distinct subgroups with unique molecular alterations and corresponding targeted therapies. Furthermore, we emphasize the crucial aspects of diagnosing BTC in practical clinical settings.

Interventional gastroenterology in oncology

Cancer is one of the foremost health problems worldwide and is among the leading causes of death in the United States. Gastrointestinal tract cancers account for almost one third of the cancer-related mortality globally, making it one of the deadliest groups of cancers. Early diagnosis and prompt management are key to preventing cancer-related morbidity and mortality. With advancements in technology and endoscopic techniques, endoscopy has become the core in diagnosis and management of gastrointestinal tract cancers. In this extensive review, the authors discuss the role endoscopy plays in early detection, diagnosis, and management of esophageal, gastric, colorectal, pancreatic, ampullary, biliary tract, and small intestinal cancers.

Per oral cholangiopancreatoscopy in pancreatico biliary diseases - Expert consensus statements

AIM: To provide consensus statements on the use of per-oral cholangiopancreatoscopy (POCPS).

METHODS: A workgroup of experts in endoscopic retrograde cholangiopancreatography (ERCP), endosonography, and POCPS generated consensus statements summarizing the utility of POCPS in pancreaticobiliary disease. Recommendation grades used validated evidence ratings of publications from an extensive literature review.

RESULTS: Six consensus statements were generated: (1) POCPS is now an important additional tool during ERCP; (2) in patients with indeterminate biliary strictures, POCS and POCS-guided targeted biopsy are useful for establishing a definitive diagnosis; (3) POCS and POCS-guided lithotripsy are recommended for treatment of difficult common bile duct stones when standard techniques fail; (4) in patients with main duct intraductal papillary mucinous neoplasms (IPMN) POPS may be used to assess extent of tumor to assist surgical resection; (5) in difficult pancreatic ductal stones, POPS-guided lithotripsy may be useful in fragmentation and extraction of stones; and (6) additional indications for POCPS include selective guidewire placement, unexplained hemobilia, assessing intraductal biliary ablation therapy, and extracting migrated stents.

CONCLUSION: POCPS is important in association with ERCP, particularly for diagnosis of indeterminate biliary strictures and for intra-ductal lithotripsy when other techniques failed, and may be useful for pre-operative assessment of extent of main duct IPMN, for extraction of difficult pancreatic stones, and for unusual indications involving selective guidewire placement, assessing unexplained hemobilia or intraductal biliary ablation therapy, and extracting migrated stents.

Cholangioscopy in liver disease

Since its introduction, cholangioscopy has been used diagnostically and therapeutically. The working channel size has increased, permitting direct visualization for tissue sampling and to guide application of lithotripsy for difficult stones. Cholangioscopy utilizes endoscope and catheter-based systems. The application of slim gastroscopes for direct cholangioscopy provides better image resolution than conventional systems. Cholangioscopy has proven effective in the management of large biliary stones and for the diagnosis and exclusion of biliary tumors. Commercially available cholangioscopes are fiberoptic; those with digital video technology remain in a prototype development phase. This review covers available cholangioscope technologies, indications, technique, efficacy, and complications.

High-definition confocal endomicroscopy of the common bile duct

BACKGROUND

Probe-based confocal laser endomicroscopy (pCLE) of the common bile duct (CBD) is a new procedure that can be used for assessing indeterminate billiary strictures. The CBD has been examined using the CholangioFlex miniprobe (Mauna Kea Technologies, Paris, France), which has a lateral resolution of 3.5 μm and diameter of <1.0 mm. However, larger-diameter higher-resolution confocal probes are available. We aimed to determine if pCLE of the CBD with the high-definition GastroFlex(UHD) miniprobe (UHDp) was feasible. This probe has a lateral resolution of 1 μm and an outer diameter of 2.6 mm.

METHODS

Eleven consecutive patients undergoing endoscopic retrograde cholangiopancreatography for various indications at a single, large, academic center were included in the study. Examination of the CBD was attempted with the UHDp after injection of 2.5 mL of 10% fluorescein. A 0.035 inch guidewire was first placed into the CBD and the confocal probe was subsequently inserted adjacent to the guidewire. Position of the miniprobe was identified fluoroscopically.

RESULTS

The GastroFlex(UHD) miniprobe was successfully introduced into the CBD in 10 of 11 patients. Cellular structures and individual cell morphology seemed to be more clearly visualized with the UHDp compared with the CholangioFlex probe. No significant side effects except 1 case of mild pancreatitis.

CONCLUSIONS

We demonstrate that high-definition pCLE of the CBD by the GastroFlex(UHD) miniprobe is feasible and may offer improved image quality over the standard CholangioFlex probe. Further studies are needed to see if this improves the diagnostic accuracy of bile duct lesions.

A review on the use of confocal laser endomicroscopy in the bile duct

Background. Current methods to diagnose malignant biliary strictures are of low sensitivity. Probe-based confocal laser endomicroscopy (pCLE) is a new approach that can be used to evaluate in vivo histopathology of the GI tract. This paper is of studies evidencing pCLE's application in the diagnosis of indeterminate biliary strictures. Methods. This paper examined peer-reviewed studies conducted between January 2000 and November 2011. A PubMed search for relevant articles was performed using the following keywords:“pCLE”, “confocal”, “endomicroscopy”, “probe-based confocal laser endomicroscopy”, “and “bile duct”. Further individual review was done to assess the screened articles' relevance to the topic. Results. After individual review, 6 studies were included; with a cumulative sample size of 165, with 75 subjects identified as having a malignancy. These studies included tertiary care centers in Germany, France, and USA, including one multicenter trial. 3 studies assessed pCLE's specificity (range 67%–88%) ,sensitivity (range 83%–98), and accuracy (range 81%–86%). Conclusion. Confocal endomicroscopy is a novel and promising modality for the biliary tree. Further studies need to be conducted both to establish its usefulness for the diagnosis of indeterminate biliary strictures and to understand the histological meaning of the imaging patterns that are observed.

Advances in biomarker research for pancreatic cancer

Pancreatic cancer (PC) is a leading cause of cancer related deaths in United States. The lack of early symptoms results in latestage detection and a high mortality rate. Currently, the only potentially curative approach for PC is surgical resection, which is often unsuccessful because the invasive and metastatic nature of the tumor masses makes their complete removal difficult. Consequently, patients suffer relapses from remaining cancer stem cells or drug resistance that eventually lead to death. To improve the survival rate, the early detection of PC is critical. Current biomarker research in PC indicates that a serum carbohydrate antigen, CA 19-9, is the only available biomarker with approximately 90% specificity to PC. However, the efficacy of CA 19-9 for assessing prognosis and monitoring patients with PC remains contentious. Thus, advances in technology and the detection of new biomarkers with high specificity to PC are needed to reduce the mortality rate of pancreatic cancer.

Polysomy and p16 deletion by fluorescence in situ hybridization in the diagnosis of indeterminate biliary strictures

BACKGROUND

The diagnosis of indeterminate biliary strictures is limited because of the low sensitivity of cytology. However, an accurate diagnosis of malignancy is critical in the management of patients with suspected biliary malignancy. Testing for chromosomal aneuploidy by fluorescence in situ hybridization (FISH) may increase the yield.

OBJECTIVE

To evaluate the diagnostic accuracy of FISH in indeterminate biliary strictures and the additional value of including deletion of 9p21 (p16) in the diagnostic criteria of malignant biliary strictures.

DESIGN

Retrospective review.

SETTING

Academic medical center.

PATIENTS

This study involved 76 consecutive patients who were seen for the evaluation of indeterminate strictures at our institution. These patients were screened, and 50 patients with either a final pathologic diagnosis or ≥ 12 months' conclusive follow-up were included in the analysis.

MAIN OUTCOME MEASUREMENTS

Sensitivity, specificity, and area under the curve (AUC) analysis of cytology alone compared with the presence of FISH polysomy versus FISH polysomy and 9p21 deletion.

RESULTS

The presence of increased copy numbers (polysomy) of chromosome 3, 7, or 17 by FISH increased the sensitivity of brush cytology from 21% to 58%, and when the presence of 9p21 deletion was included, the sensitivity increased to 89%. The specificity of FISH was 97% (vs 100% for cytology). The accuracy of cytology combined with FISH polysomy (AUC = 0.93) or p16 deletion was significantly greater than the accuracy of cytology alone (AUC 0.6; P < .001) or even cytology combined with FISH polysomy (AUC = 0.77; P ≤ .05).

LIMITATIONS

Sample size. There is a relatively high incidence of malignant biliary strictures in the entire cohort but low incidence among primary sclerosing cholangitis patients, and the majority of cancers are cholangiocarcinomas (as opposed to pancreatic).

CONCLUSION

FISH significantly improves the diagnostic accuracy of brush cytology in indeterminate biliary strictures. In our series, the addition of 9p21 deletion to FISH polysomy and cytology further improved sensitivity. This suggests that 9p21 deletion may be added to the diagnostic criteria in indeterminate strictures.

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.