Introduction

In endoscopic retrograde cholangiopancreatography (ERCP)-related procedures, selective biliary cannulation is the most basic procedure and the most difficult to master. The device to improve the success rate of selective biliary cannulation is one of the most awaited innovations in the field of biliopancreatic diseases.
Texture and Color Enhanced Imaging (TXI) is a novel imaging technique that can create enhanced endoscopy images. TXI mode optimizes image structure, brightness, and tonality, the factors that construct and delineate mucosal surface images.
In this study, we aimed to reveal the factors using TXI influencing the difficulty of selective biliary cannulation.

Aims & Methods

This was a multicenter, retrospective study conducted at Kindai University Faculty of Medicine and Saitama International Medical Center.
Patients with naïve papilla for whom selective biliary cannulation was attempted between June and October 2022 were included in this study. A duodenoscope (TJF290V, Olympus Medical Systems, Tokyo, Japan) and EVIS X1 system (Olympus Corporation) were used for ERCP.
Papillary morphology evaluation was performed first with white light imaging (WLI) and then with TXI in all cases, and each evaluation was documented. TXI and WLI were used alternately in each case as the imaging mode during biliary cannulation.
The primary endpoint was the success rate of selective biliary cannulation.
Secondary endpoints included the ability to assess the morphological classification of the papilla, the time required for selective biliary cannulation, and the rate of first-touch cannulation (FTC).
For the morphological classification of the papilla, the agreement rate between the gold standard, as judged by three experienced endoscopists after ERCP, and the evaluation with WLI alone and with TXI were analyzed, respectively.
For the time required for selective biliary cannulation, it was defined as the time from the time the catheter was removed from the scope to the time of successful biliary cannulation. FTC was defined as the first attempt that led to successful biliary cannulation.

Results

Between the two groups of 57 patients in the TXI group and 56 patients in the WLI group, the concordance rate for the morphological classification of the papilla was 0.87 for TXI, better than 0.71 for WLI.
There was no difference between the two groups (TXI vs. WLI) in either the success rate of biliary cannulation (98.3 vs. 98.2%) or time required for biliary cannulation (median) (7.5 vs. 7.0 min), but the rate of FTC tended to be higher in TXI (42.1 vs. 25.0%).
Multivariate analysis (OR (95%CI), p-value) revealed the following characteristics: non-separate type papilla (0.25 (012-0.49), 0.0002), smaller papilla (0.43 (0.18-1.02), 0.083), longer oral protrusion (0.51 (0.35-0.80), 0.0024), and the presence of diverticula (0.52 (0.31-0.86), 0.0071) were factors contributing to a longer time required for biliary cannulation.
In trainee-specific analysis, the overall success rate of biliary cannulation was 69.7% (62/89), whereas the factors contributing to biliary cannulation failure were a long oral protrusion (0.21 (0.07-0.58), 0.0024) and the presence of a diverticulum (0.31 (0.09-1.02), 0.054) in multivariate analysis.

Conclusion

The factors affecting the difficulty of selective biliary cannulation were the non-separate type of papilla, the longer oral protrusion, and the presence of a diverticulum. TXI is expected to contribute to selective biliary cannulation by allowing the endoscopist to more accurately determine whether the papilla is a separate type or not than WLI.

Disclosure

There is no conflict of interest regarding this study.

Introduction

Endoscopic retrograde cholangiopancreatography (ERCP) still plays an important role in the diagnosis and treatment of biliopancreatic disease. Especially for inexperienced endoscopists, transpapillary biliary cannulation is difficult, and thus the success rate of selective bile duct cannulation is low. Understanding the exact morphology and opening of the common bile duct is important for determining the success of bile duct cannulation. Texture and color enhancement imaging (TXI) is an imaging technique that optimizes three mucosal surface elements: structure, brightness, and color tone, and has been reported to enhance slight changes in structure and color tone that are difficult to see with white light imaging (WLI). Therefore, we aimed to investigate whether TXI mode 1 could improve papillary recognition by trainees inexperienced in ERCP.

Aims & Methods

This retrospective single-center study was conducted in Japan and used electronic medical records to extract data regarding participants’ age, sex, and the endoscopic procedure they underwent. We included 31 patients with naive major duodenal papilla in the study. According to the Inomata classification, the papilla of Vater was classified into one of six categories. We classified the papillae into two groups to determine their distinctive qualities: the separate and septal type groups. The trainees were defined as unskilled endoscopists with less than 100 cases and less than 3 years of ERCP experience, while experienced endoscopists were defined as those with more than 1000 cases and more than 10 years of ERCP experience. Trainee endoscopists (n = 4) evaluated and identified the papilla according to the Inomata classification using WLI and TXI. The degree of agreement with the evaluation of supervising physicians (n = 4) was examined using the McNemar test. This study was approved by the Institutional Review Board of Saitama Medical University International Medical Center (2021–203).

Results

The concordance rate between the four trainees was evaluated, and Fleiss’ kappa values were calculated for inter-subject coefficient agreement. The two groups (separate group vs. septal group) of papilla agreements were evaluated, and the result for WLI was low (κ = 0.35), whereas the result for TXI was high (κ = 0.75). In addition, comparison of the response concordance rate for the two-step evaluation between WLI and TXI, one of the four trainees showed a significant increase in concordance from 76.7% to 96.7% (p = 0.03). Furthermore, in the comparison test for the kappa coefficient, two of the four trainees showed a significant increase in concordance, from 0.34 to 0.92 (p = 0.01) and from 0.45 to 0.92 (p = 0.02), respectively.

Conclusion

TXI can selectively emphasize the irregularities of the major duodenal papilla and highlight subtle tissue differences, such as the mouth of the bile duct and the pancreatic duct, and slight changes in morphology and color. Observation of the major duodenal papilla using TXI improved the morphology and opening of the papilla and suggested the potential of TXI as a clinical tool. Although more cases need to be accumulated, TXI may help inexperienced endoscopists perform biliary cannulation.

Disclosure

The authors declare no conflicts of interest for this article.

Introduction

Improving the biliary cannulation technique in endoscopic retrograde cholangiopancreatography (ERCP), especially for native papilla, is challenging for trainees. Several previous studies have shown that improving it required a large caseload, usually 350–400 cases, or a special education program. Therefore, we created an e-learning educational video series system to allow trainees to learn biliary cannulation anywhere with ease and conducted a multicenter prospective study to evaluate it.

Aims & Methods

We created 27 educational videos containing biliary cannulation for native papilla with explanations. Twelve endoscopists with less than 6 years of ERCP experience at two general hospitals in Shizuoka, Japan, participated in this educational program using an e-learning system. First, each participant performed 10 biliary cannulations of native papillae with a preceptor, followed by e-learning and additional 10 biliary cannulations of native papillae. Data from 120 biliary cannulations each for pre-e-learning (PR) and pro-e-learning (PO) were compared according to comprehension score (CS), difficult cannulation (DC), failed biliary cannulation (FB), and adverse events (AE). CS was given by the preceptor-to-trainee oral test before biliary cannulation (maximum of six points). DC was defined as biliary cannulation time >300 sec, >5 biliary cannulation attempts, and ≥2 unintended pancreatic duct cannulation. The correlation between CS and DC was analyzed using the Cochran-Armitage test for trends, and receiver-operating characteristic (ROC) curves were used to determine CS's cut-off value.

Results

There were no significant differences in age, gender, and benign/malignant status of patients undergoing biliary cannulation between PR and PO groups. The outcomes are shown in the table. CS was higher in the PR group than in the PR group; however, no significant differences in DC, FB, and AE rates were observed between the two groups. There was a negative correlation between CS and DC (P<0.01), and the cut-off value and area under the ROC curve for CS for DC were scored 4 and 0.72 (95% confidence interval: 0.66–0.78), respectively. On per-participant comparison, CS≥4 became higher after e-learning (P=0.04); however, there were no significant differences in DC, FB, and AE rates.

Conclusion

Our e-learning system could help deepen comprehension of papilla but did not significantly reduce DC, UBC, and AEs. E-learning and technical acquisition may be needed to improve biliary cannulation.

References

1. Sachin Wani, Matthew Hall, Andrew Y Wang et al. Variation in Learning Curves and Competence for ERCP Among Advanced Endoscopy Trainees by Using Cumulative Sum Analysis. Gastrointest Endosc. 2016 Apr;83(4):711-9.e11.
2. Brian S Lim, Joseph W Leung, John Lee et al. Effect of ERCP Mechanical Simulator (EMS) Practice on Trainees' ERCP Performance in the Early Learning Period: US Multicenter Randomized Controlled Trial. Am J Gastroenterol. 2011 Feb;106(2):300-6.
3. James G Bittner 4th 1, John D Mellinger, Toufic Imam et al. Face and Construct Validity of a Computer-Based Virtual Reality Simulator for ERCP. Gastrointest Endosc. 2010 Feb;71(2):357-64. doi: 10.1016/j.gie.2009.08.033.

Introduction

Despite the advancements in imaging modalities, diagnosis of biliary strictures remains challenging in some cases. Endoscopic retrograde cholangiopancreatography (ERCP) is the current gold standard for diagnosis. However, the pathological diagnosis via ERCP is limited due to the small specimen. Therefore, a novel device for the diagnosis of biliary stricture has been long-awaited. Although high sensitivity and specificity have been reported for probe-based confocal laser endomicroscopy (pCLE) for the diagnosis of biliary strictures using the Miami Classification, it remains uncertain whether confocal miniprobes can be properly applied to the target site with the use of pCLE under fluoroscopic guidance. The aim of the present study was to prospectively evaluate the clinical utility of pCLE under the direct view of peroral cholangioscopy (POCS) for the diagnosis of biliary strictures.

Aims & Methods

Consecutive patients with biliary strictures were included. All patients underwent imaging examination, such as computed tomography, magnetic resonance imaging, or endoscopic ultrasound, and were found to have biliary disorders. We investigated sensitivity, specificity, and accuracy to diagnose malignancy for: 1) ERCP alone, 2) POCS, 3) pCLE under the direct view of POCS, and 4) tissue sampling under the direct view of POCS. pCLE images were interpreted prospectively using the Miami Classification. We also evaluated other outcomes of pCLE under the direct view of POCS.

Results

A total of 30 patients (17 with malignant lesions) were prospectively enrolled.
1) ERCP alone showed 88.2% sensitive, 46.2% specific, and 70% (95% confidence interval [CI], 52.1%–83.3%) accurate.
2) POCS showed 100% sensitive, 76.9% specific, and 90% (95% CI, 74.4%–96.5%) accurate.
3) pCLE under the direct view of POCS showed 94.1% sensitive, 92.3% specific, and 93.3% (95% CI, 78.7%–98.8%) accurate.
4) Tissue sampling under the direct view of POCS showed 82.4% sensitive, 100% specific, and 90% (95% CI, 74.4%–96.5%) accurate.
The POCS could not pass the biliary stricture in four patients, and we could not complete successful observation of the target area. Therefore, the success rate of pCLE under the direct view of POCS was 88.2% (30/34). The median procedural time for pCLE under the direct view of POCS was 42 min (interquartile range [IQR], 31.3–48 min). Accurate diagnosis rate of common bile duct and accurate diagnosis rate of hilar and intrahepatic bile duct were 86.7% (13/15), 100% (15/15) respectively. There was no significant difference among stricture locations (P=0.48). Adverse events occurred in three patients (one with mild pancreatitis, and two with mild cholangitis).

Conclusion

pCLE under the direct view of POCS provided highly accurate and sensitive characterization of biliary strictures and showed the potential for more diagnostic reliability and reduction of delays in diagnosis.

Introduction

Endoscopic biliary drainage (BD) in patients with altered anatomy is a challenging scenario reducing the chance of clinical success compared to standard anatomy. The choice between different BD approaches is still not standardized and relies on local availability and expertise.

Aims & Methods

Aim of this study was to explore the type and the number of endoscopic BD approach in patients with altered anatomy in different Italian centers. This was a retrospective multicenter cohort study within the i-EUS network of biliopancreatic endoscopy. All adult patients with upper GI surgical altered anatomy who underwent endoscopic BD for any indication in the last 5 years were enrolled. Patients with Billroth-I or sleeve gastrectomy were excluded. Patients with duodenopancreasectomy were grouped with patients with BillrothII reconstruction for the statistical analysis. Fisher’s exact test and Mann-Whitney test were used when appropriate.

Results

21 centers participated in the study. All centers were equipped for interventional endoscopic ultrasound (EUS) whereas only 7 centers had also the availability of device-assisted enteroscopy (DAE). 428 patients were enrolled. Clinical and BD techniques characteristics of patients are described in table 1. Indication to BD was not different between patients with Billroth-II (B-II, N=263) or Roux-en-Y (RY, N=165) reconstructions. 16% of patients had at least one previous failed BD attempt. B-II anatomies were more frequently managed transpapillary with a duodenoscope or a forward viewing scope (85%), whereas in case of RY reconstruction BD approach was more heterogeneous. In 68% of RY cases endoscopic BD was performed with a luminal approach (in 43% of cases with standard scopes). In patients who underwent to EUS-BD, hepaticogastrostomy or antegrade stenting were performed in 74% of cases mostly for malignant indications (90%). Type of surgical reconstruction did not affect the clinical success (84% in BII and 79% in RY, p=ns). Interventional EUS demonstrated a higher clinical success compared to DAE (94% vs 73%, p=0.004). The total number of procedures to achieve clinical success was similar between B-II and RY patients. Patients who failed endoscopic BD for whom follow-up was available were managed by PTBD or surgery in 71% and 15% of cases respectively.

Conclusion

Endoscopic BD in altered anatomy has a sub-optimal clinical success compared to standard anatomy. A relevant proportion of patients requires more than one endoscopic attempt to achieve the clinical success. Despite the recent advent, interventional EUS is optioned in a significant proportion of patients and demonstrated a high efficacy in patients with surgically altered anatomy.

Introduction

A biliary stricture is a narrowing of intrahepatic and/or extrahepatic biliary system with upstream dilatation¹; 70-80% of biliary strictures are malignant¹ therefore histological diagnosis is necessary to distinguish benign from malignant causes and guide management. Strictures without confirmed histology are referred to unexplained biliary strictures². ESGE (European Society of Gastrointestinal Endoscopy) guidelines recommend an integrated diagnostic approach that combines multiple techniques to improve diagnostic accuracy. Endoscopic ultrasound(EUS) has demonstrated high sensitivity for evaluating biliary strictures and unexplained common bile duct (CBD) dilatation, due to its ability to provide high-resolution images of CBD walls and surrounding structures, so is the preferred diagnostic modality for both imaging and tissue acquisition(TA), even in absence of abnormal laboratory test.¹ The introduction of ancillary techniques, as DFI (Detective Flow Imaging), which enables the detection of low-velocity blood flow without the use of contrast media, represents a potential useful addition in the diagnostic algorythm³.

Aims & Methods

The aim of this single-centre retrospective study is to validate the role of EUS-DFI in characterizing unexplained biliary strictures and CBD dilatation. We included consecutive patients (pts) with unexplained biliary strictures/CBD dilatation who underwent biliopancreatic EUS between January 2024 and April 2025 at the Digestive Diseases Unit of Sant’Andrea University Hospital, Rome. During EUS, biliary stricture (lesions or thickening of CBD wall) were described as hypoechoic or isoechoic. DFI was performed to evaluate strictures: if microvascularization was observed, vascular pattern was classified as regular or irregular⁴. Results were compared with the final diagnosis, defined by histopathology and/or ≥6 months clinical follow-up as gold standard. TA was performed with EUS-FNB (fine needle biopsy) and/or ERCP(Endoscopic Retrograde Cholangiopancreatography) intraductal biopsies/brushing.

Results

Of 13 patients included, 8(61.5%) were male, median age 72 (range 56-86). All underwent Magnetic Resonance Imaging/Contrast-Enhanced Computed Tomography as first line imaging: 3(23%) had a perihilar stricture, 9(69%) a medio-distal, 1(8%) had “in toto” CBD thickening. Among the 13 strictures, EUS identified 10(76.9%) lesions, with a mean diameter of 17 mm (median 16 mm; range, 5–35 mm), and 3(23.1%) CBD wall thickening. Twelve (92%) strictures were hypoechoic, 1(8%) was isoechoic. EUS-TA was performed in all pts, revealing 7(54%) cases of malignancies, of whome 5 cholangiocarcinoma and 2 pancreatic ductal adenocarcinoma (PDAC), 3(23%) high-grade dysplasia, and 3(23%) fibroinflammatory disease on histopatological evaluation. All pts underwent DFI-EUS. Microvascularization was detected in 12 cases (92%), with an irregular pattern observed in 9 pts. Among these, 5 (55.6%) were diagnosed with cholangiocarcinoma, 1(11.1%) with PDAC infiltrating CBD, and 3(33.3%) with high-grade dysplasia. The 3 benign strictures demonstrated a homogeneous pattern. One case (8%), corresponding to a PDAC, appeared hypovascular on DFI.

Conclusion

In a small cohort of patients with unexplained or indeterminate biliary strictures, the novel DFI-EUS technique proved to be feasible for assessing microvascularization in CBD stenosis and revealed characteristic irregular patterns or hypovascularization in malignant lesions. Further prospective studies with a larger patient population are needed to confirm these preliminary findings.

References

1. Facciorusso, A. et al. Diagnostic work-up of bile duct strictures: European Society of Gastrointestinal Endoscopy (ESGE) Guideline. Endoscopy 57, 166–185 (2025).
2. Zhang, W., Chai, N., Wu, Q. & Linghu, E. The new criteria for differential diagnosis of indeterminate biliary stricture under super minimally invasive peroral cholangioscopy. Chin Med J (Engl) 137, 255–256 (2024).
3. Yamashita, Y. et al. A Novel Endoscopic Ultrasonography Imaging Technique for Depicting Microcirculation in Pancreatobiliary Lesions without the Need for Contrast-Enhancement: A Prospective Exploratory Study. Diagnostics 11, 2018 (2021).
4. Yamashita, Y. et al. Novel Technique of Endoscopic Ultrasonography for the Differential Diagnosis of Gallbladder Lesions and Intraductal Papillary Mucinous Neoplasms: A Single-Center Prospective Study. Diagnostics 13, 2132 (2023).