Sphincterotomy for Biliary Sphincter of Oddi Disorder and idiopathic Acute Recurrent Pancreatitis: THE RESPOND LONGITUDINAL COHORT.

Objective: Sphincter of Oddi Disorders (SOD) are contentious conditions in patients whose abdominal pain, idiopathic acute pancreatitis (iAP) might arise from pressurization at the sphincter of Oddi. The present study aimed to measure the benefit of sphincterotomy for suspected SOD. Design: Prospective cohort conducted at 14 U.S. centers with 12 months follow-up. Patients undergoing first-time ERCP with sphincterotomy for suspected SOD were eligible: pancreatobiliary-type pain with or without iAP. The primary outcome was defined as the composite of improvement by Patient Global Impression of Change (PGIC), no new or increased opioids, and no repeat intervention. Missing data were addressed by hierarchal, multiple imputation scheme. Results: Of 316 screened, 213 were enrolled with 190 (89.2%) of these having a dilated bile duct, abnormal labs, iAP, or some combination. By imputation, an average of 122/213 (57.4% [95%CI 50.4-64.4]) improved; response rate was similar for those with complete follow-up (99/161, 61.5%, [54.0-69.0]); of these, 118 (73.3%) improved by PGIC alone. Duct size, elevated labs, and patient characteristics were not associated with response. AP occurred in 37/213 (17.4%) at a median of 6 months post-ERCP and was more likely in those with a history of AP (30.9 vs. 2.9%, p<0.0001). Conclusion: Nearly 60% of patients undergoing ERCP for suspected SOD improve, although the contribution of a placebo response is unknown. Contrary to prevailing belief, duct size and labs are poor response predictors. AP recurrence was common and like observations from prior non-intervention cohorts, suggesting no benefit of sphincterotomy in mitigating future AP episodes.Key Messages: WHAT IS ALREADY KNOWN ON THIS TOPIC: It is not clear if the sphincter of Oddi can cause abdominal pain (Functional Biliary Sphincter of Oddi Disorder) and idiopathic acute pancreatitis (Functional Pancreatic Sphincter of Oddi Disorder), and whether ERCP with sphincterotomy can ameliorate abdominal pain or pancreatitis.WHAT THIS STUDY ADDS: Using multiple patient-reported outcome measures, most patients with suspected sphincter of Oddi disorder improve after ERCP with sphincterotomy.Duct size, elevated pancreatobiliary labs, and baseline patient characteristics are not independently associated with response.There is a high rate of recurrent acute pancreatitis within 12 months of sphincterotomy in those with a history of idiopathic acute pancreatitis.HOW THIS STUDY MIGHT AFFECT RESEARCH, PRACTICE, OR POLICY: Since a discrete population with a high (> 80-90%) response rate to sphincterotomy for suspected pancreatobiliary pain could not be identified, there is a need for additional observational and interventional studies that include phenotyping of patients using novel imaging or biochemical biomarkers.There remains a pressing need for quantitative nociceptive biomarkers to distinguish pancreatobiliary pain from other causes of abdominal pain or central sensitization.Discovery of blood-, bile-, or imaging-based biomarkers for occult microlithiasis and pancreatitis may be helpful in predicting who is likely to benefit from sphincterotomy.

Severe Acute Pancreatitis Prediction: A Model Derived From a Prospective Registry Cohort.

Background Severe acute pancreatitis (SAP) has a mortality rate as high as 40%. Early identification of SAP is required to appropriately triage and direct initial therapies. The purpose of this study was to develop a prognostic model that identifies patients at risk for developing SAP of patients managed according to a guideline-based standardized early medical management (EMM) protocol. Methods This single-center study included all patients diagnosed with acute pancreatitis (AP) and managed with the EMM protocol Methodist Acute Pancreatitis Protocol (MAPP) between April 2017 and September 2022. Classification and regression tree (CART®; Professional Extended Edition, version 8.0; Salford Systems, San Diego, CA), univariate, and logistic regression analyses were performed to develop a scoring system for AP severity prediction. The accuracy of the scoring system was measured by the area under the receiver operating characteristic curve. Results A total of 516 patients with mild (n=436) or moderately severe and severe (n=80) AP were analyzed. CART analysis identified the cutoff values: creatinine (CR) (1.15 mg/dL), white blood cells (WBC) (10.5 × 109/L), procalcitonin (PCT) (0.155 ng/mL), and systemic inflammatory response system (SIRS). The prediction model was built with a multivariable logistic regression analysis, which identified CR, WBC, PCT, and SIRS as the main predictors of severity. When CR and only one other predictor value (WBC, PCT, or SIRS) met thresholds, then the probability of predicting SAP was >30%. The probability of predicting SAP was 72% (95%CI: 0.59-0.82) if all four of the main predictors were greater than the cutoff values. Conclusions Baseline laboratory cutoff values were identified and a logistic regression-based prognostic model was developed to identify patients treated with a standardized EMM who were at risk for SAP.

Esophageal Perforation and Pneumomediastinum Due to Delayed Diagnosis of Esophageal Lichen Planus.

Esophageal involvement of lichen planus is an under-reported and under-diagnosed manifestation that should prompt immediate treatment given its high rate of complications. We highlight a rare case of a 62-year-old Caucasian woman with history of known oral lichen planus and esophageal strictures presumed to be secondary to gastroesophageal reflux disease, that presented with esophageal food impaction resulting in perforation and subsequent pneumomediastinum after esophagogastroduodenoscopy (EGD). Further workup, including a repeat EGD, revealed that the esophageal strictures were rather a complication of lichen planus. The patient was started on oral, topical steroids and underwent serial esophageal dilations with improvement. Esophageal lichen planus should be high on the differential, especially in patients with involvement of other mucous membranes and strictures refractory to therapy. Complications such as recurrent esophageal strictures and perforation may be preventable with early diagnosis and adequate treatment.

Soft self-expandable metal stent to treat painful pancreatic duct strictures secondary to chronic pancreatitis: a prospective multicenter trial.

BACKGROUND AND AIMS: Fully covered self-expandable metal stents (FCSEMSs) may offer a treatment option for pain associated with a dilated pancreatic duct (PD) in chronic pancreatitis (CP), but optimal patient selection and FCSEMS design, efficacy, and safety remain uncertain. We studied an investigational pancreatic FCSEMS for treatment of CP-associated pain. METHODS: Patients with painful CP, a dominant distal PD stricture, and PD dilation upstream were enrolled in a prospective, multicenter, single-arm trial studying 6-month indwell of a 4- to 6-cm-long soft pancreatic FCSEMS. Primary efficacy and safety endpoints were pain reduction 6 months after FCSEMS indwell (performance goal ≥53%) and PD stenting-related serious adverse events (SAEs), respectively (performance goal <32%). The primary efficacy endpoint was assessed in patients with sufficiently severe and frequent pain at FCSEMS placement as a first stent or in exchange of a plastic stent. RESULTS: Among 67 patients (mean age, 52.7 ± 12.5 years; mean time since CP diagnosis, 6.4 ± 6.4 years), 34 (50.7%) had plastic stent placement within 90 days of FCSEMS placement, and 46 patients were eligible for the primary efficacy endpoint analysis. Technical success was 97.0% (65/67). The observed primary efficacy (26.1%, 12/46) and safety endpoints (31.3%, 21/67) failed to meet the a priori study hypotheses. Study stent migration occurred in 47.7% of patients (31/65). CONCLUSIONS: Six-month treatment with an FCSEMS did not lead to an expected degree of pain reduction, and migrations and SAEs were common. Further study is needed to clarify optimal decompressive strategy, FCSEMS design, and patient selection. (Clinical trial registration number: NCT02802020.).

Per-oral pancreatoscopy-guided lithotripsy vs. extracorporeal shock wave lithotripsy for treating refractory main pancreatic duct stones in chronic pancreatitis: Protocol for an open-label multi-center randomized clinical trial.

BACKGROUNDS/OBJECTIVES: Patients with chronic pancreatitis may develop pancreatic duct stones that can obstruct outflow leading to ductal hypertension and pain. Both endoscopic retrograde pancreatography (ERP) with per-oral pancreatoscopy (POP) and intraductal lithotripsy and extracorporeal shock wave lithotripsy (ESWL) are feasible options to attempt ductal stone clearance. This study aims to compare POP-guided lithotripsy with ESWL in the management of refractory symptomatic main pancreatic duct stones. METHODS: This is an open-label, multi-center, parallel, randomized clinical trial. Patients with chronic pancreatitis and main pancreatic duct stones ≥5 mm who fail standard ERP methods for stone removal will be eligible for this study. In total, 150 subjects will be randomized 1:1 to either ESWL or POP. A maximum of 4 sessions of either ESWL or POP will be allowed in each arm, with crossover permitted thereafter. The primary outcome is complete stone clearance and secondary outcomes include quality of life, pain scores, number of interventions, and daily opiate requirements. CONCLUSIONS: This study aims to answer the question of which lithotripsy method is superior in removing refractory pancreatic duct stones while addressing the effects of lithotripsy on quality of life and pain in patients with chronic calcific pancreatitis (ClinicalTrials.gov NCT04115826).

First interobserver agreement of optical coherence tomography in the bile duct: A multicenter collaborative study.

Background and study aims Optical coherence tomography (OCT) is a new technology available for evaluation of indeterminate biliary strictures. It allows under-the-surface visualization and preliminary studies have confirmed standardized characteristics associated with malignancy. The aim of this study is to evaluate the first interobserver agreement in identifying previously agreed upon OCT criteria and diagnosing of malignant versus benign disease. Patients and methods Fourteen endoscopists were asked to review an atlas of reference clips and images of eight criteria derived from expert consensus A total of 35 de-identified video clips were then evaluated for presence of the eight criteria and for final diagnosis of malignant versus benign using the atlas as reference Intraclass correlation (ICC) analysis was done to evaluate interrater agreement. Results Clips of 23 malignant lesions and 12 benign lesions were scored. Excellent interobserver agreement was seen with dilated hypo-reflective structures (0.85) and layering effacement (0.89); hyper-glandular mucosa (0.76), intact layering (0.81), and onion-skin layering (0.77); fair agreement was seen with scalloping (0.58), and thickened epithelium (0.4); poor agreement was seen with hyper-reflective surface (0.36). The diagnostic ICC for both neoplastic (0.8) and non-neoplastic (0.8) was excellent interobserver agreement. The overall diagnostic accuracy was 51 %, ranging from 43 % to 60 %. Conclusions Biliary OCT is a promising new modality for evaluation of indeterminate biliary strictures. Interobserver agreement ranged from fair to almost perfect on eight previously identified criteria. Interobserver agreement for malignancy diagnosis was substantial (0.8). Further studies are needed to validate this data.

Challenges of developing and executing a multi-site registry for a novel device with evolving indications for use.

BACKGROUND: The introduction of new technologies in endoscopy has been met with uncertainty, skepticism, and lack of standardization or training parameters, particularly when disruptive devices or techniques are involved. The widespread availability of a novel endoscopic suturing device (OverStitch™) for tissue apposition has enabled the development of applications of endoscopic suturing. METHODS: The American Gastroenterological Association partnered with Apollo Endosurgery to develop a registry to capture in a pragmatic non-randomized study the safety, effectiveness, and durability of endoscopic suturing in approximating tissue in the setting of bariatric revision and fixation of endoprosthetic devices. RESULTS: We highlight the challenges of the adoption of novel techniques by examining the process of developing and executing this multicenter registry to assess real-world use of this endoscopic suturing device. We also present our preliminary data on the safety and effectiveness of the novel device as it is applied in the treatment of obesity. CONCLUSIONS: The Prospective Registry for Trans-Orifice Endoscopic Suturing Applications (ES Registry) was an effective Phase 4, postmarketing registry aimed at capturing pragmatic, real-world use of a novel device. These findings serve to solidify the role of endoscopic suturing in clinical practice.

Digital Single-operator Cholangioscopy (DSOC) Improves Interobserver Agreement (IOA) and Accuracy for Evaluation of Indeterminate Biliary Strictures: The Monaco Classification.

BACKGROUND: Visual characteristics seen during digital single-operator cholangioscopy (DSOC) have not been validated. The aim of this 2-phase study was to define terminology by consensus for the visual diagnosis of biliary lesions to develop a model for optimization of the diagnostic performance of DSOC. MATERIALS AND METHODS: In phase 1 (criteria identification), video-cholangioscopy clips were reviewed by 12 expert biliary endoscopists, who were blinded to the final diagnosis. Visual criteria were consolidated into the following categories: (1) stricture, (2) lesion, (3) mucosal features, (4) papillary projections, (5) ulceration, (6) abnormal vessels, (7) scarring, (8) pronounced pit pattern.During the second phase (validation), 14 expert endoscopists reviewed DSOC (SpyGlass DS, Boston Scientific) clips using the 8 criteria to assess interobserver agreement (IOA) rate. RESULTS: In phase 1, consensus for visual findings were categorized into 8 criteria titled the "Monaco Classification." The frequency of criteria were: (1) presence of stricture-75%, (2) presence of lesion type-55%, (3) mucosal features-55%, (4) papillary projections-45%, (5) ulceration-42.5%, (6) abnormal vessels-10%, (7) scarring-40%, and (8) pronounced pit pattern-10%. The accuracy on final diagnosis based on visual impression alone was 70%.In phase 2, the IOA rate using Monaco Classification criteria ranged from slight to fair. The presumptive diagnosis IOA was fair (κ=0.31, SE=0.02), and overall diagnostic accuracy was 70%. CONCLUSIONS: The Monaco classification identifies 8 visual criteria for biliary lesions on single-operator digital cholangioscopy. Using the criteria, the IOA and diagnostic accuracy rate of DSOC is improved compared with prior studies.

Characteristics of Patients Undergoing Endoscopic Retrograde Cholangiopancreatography for Sphincter of Oddi Disorders.

The concept that sphincter of Oddi dysfunction (SOD) can cause attacks of biliary-type pain in postcholecystectomy patients and those with unexplained recurrent acute pancreatitis, and that endoscopic sphincterotomy can ameliorate symptoms, remains unproven. The Evaluating Predictors and Interventions in Sphincter of Oddi Dysfunction (EPISOD) study of patients without objective evidence for biliary obstruction showed no difference in outcomes between those who underwent sphincterotomy or sham treatment.1 To date, there have been no studies examining the characteristics of patients who still are being offered endoscopic retrograde cholangiopancreatography (ERCP) for SOD since the EPISOD publication, although the absolute number appears to have declined.2.

Digital Cholangioscopic Interpretation: When North Meets the South.

BACKGROUND: Digital single-operator cholangioscopy (DSOC) (SpyGlass DS™, Boston Scientific, MA, USA) allows for high-definition imaging of the biliary tree. The superior visualization has led to the development of two different sets of criteria to evaluate and classify indeterminate biliary strictures: the Monaco criteria and the criteria in Carlos Robles-Medranda's publication (CRM). Our objective was to assess the interrater agreement (IA) of DSOC interpretation for indeterminate biliary strictures using the two newly published criteria. METHODS: Forty de-identified DSOC video recordings were sent to 15 interventional endoscopists with experience in cholangioscopy. They were asked to score the videos based on the presence of Monaco Classification criteria: stricture, lesion, mucosal changes, papillary projections, ulceration, white linear bands or rings, and vessels. Next, they scored the videos using CRM criteria: villous pattern, polypoid pattern, inflammatory pattern, flat pattern, ulcerate pattern and honeycomb pattern. The endoscopists then diagnosed the recordings as neoplastic or non-neoplastic based on the criteria. Intraclass correlation (ICC) analysis was done to evaluate interrater agreement for both criteria set and final diagnosis. RESULTS: Recordings of 26 malignant lesions and 14 benign lesions were scored. The IA using both the Monaco criteria and CRM criteria ranged from poor to excellent (range 0.1-0.76) and (range 0.1-0.62), respectively. Within the Monaco criteria, IA was excellent for lesion (0.75) and fingerlike papillary projections (0.74); good for tortuous vessels (0.7), mucosal features (0.62), uniform papillary projections (0.53), and ulceration (0.58); and fair for white linear bands (0.4). Within the CRM criteria, the IA was good for villous pattern (0.62), flat pattern (0.62), and honeycomb pattern; fair for ulcerated pattern (0.56), polypoid pattern (0.52) and inflammatory pattern (0.54). The diagnostic IA using Monaco criteria was good (0.65), while the diagnostic IA using CRM was fair (0.58). The overall diagnostic accuracy using the Monaco classification was 61% and CRM criteria were 57%. CONCLUSION: The IOA and accuracy rate of DSOC using visual criteria from both Monaco Criteria and CRM are similar. However, some criteria from both sets suffer from poor IA, thus affecting the overall diagnostic accuracy. More formal training and refinements in visual criteria with additional validation are needed to improve diagnostic accuracy. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02166099.

Ablative therapies of the biliary tree.

Cholangiocarcinoma, a malignancy of the epithelial cells in the intrahepatic or extrahepatic biliary tree, is often diagnosed at later stages. Median survival duration ranges from 3 to 9 months with a less than ten percent 5-year survival rate. Thus, often treatment strategies are aimed more towards palliation instead of cure. With the majority of patients presenting with unresectable disease at the time of diagnosis, surgical intervention is not feasible, making less invasive endoscopic therapies more suitable. Initially, biliary stents were utilized for biliary decompression to mitigate cholestatic symptoms and prevent cholangitis; however, this strategy did not prove to provide significant survival benefit. Therefore, efforts to treat the tumor burden itself in addition to maintaining biliary patency became a focus of innovation and research in the endoscopic field. This study has led to the advent of therapies such as photodynamic therapy, radiofrequency ablation, and intraluminal brachytherapy. These options combined with biliary stenting have shown to not only offer the benefit of biliary decompression, but also to potentially improve stent patency and survival. Further, there is an anti-tumor effect of each of these modalities, portending an additional benefit in this subset of patients. Despite numerous retrospective and prospective studies assessing these ablative therapies, there is still a paucity of appropriately powered randomized controlled trials, and further research has yet to be done in the field. This review details the current literature entailing endobiliary ablative strategies.

Diagnosis of Secondary Sclerosing Cholangitis by Port Site Metastasis.

Port site metastasis is an uncommon but challenging pathological entity whereby metastatic cancer is discovered at the operative port site after surgery. Secondary sclerosing cholangitis is a multifocal stricture disease of the biliary system as the result of extra-biliary pathology; rarely, it is due to an infiltrative disorder such as neoplasia. This is the first reported case of secondary sclerosing cholangitis that was diagnosed with metastatic cancer following the discovery of port site metastasis after laparoscopic cholecystectomy.

Improving the Standard of Care for All-A Practical Guide to Developing a Center of Excellence.

Pancreatic surgery is one of the more challenging procedures performed by surgeons. The operations are technically complex and have historically been accompanied by a substantial risk for mortality and postoperative complications. Other pancreatic pathologies require advanced therapeutic procedures that are highly endoscopist-dependent, requiring specific, knowledge-based training for optimal outcomes. An increase in diagnosed pancreatic pathologies every year reinforces a critical need for experienced surgeons, gastroenterologists/endoscopists, hospitals, and support personnel in the management of complex pancreatic cases and thus, well-designed Centers of Excellence (CoE). In this paper, we outline the framework for a Pancreas CoE across three developmental domains: (1) establishing the foundation; (2) formalizing the program; (3) solidifying the CoE status. This framework can likely be translated to any disease or procedure-specific service-line and facilitate the development of a successful CoE.

Probe-based confocal laser endomicroscopy in the evaluation of dominant strictures in patients with primary sclerosing cholangitis: results of a U.S. multicenter prospective trial.

BACKGROUND AND AIMS: Patients with primary sclerosing cholangitis (PSC) and dominant biliary strictures carry increased risk for the development of cholangiocarcinoma. Although ERCP-based techniques including brush cytology and intraductal biopsy sampling represent first-line tissue sampling methods for dominant strictures, sensitivity is low. Probe-based confocal laser endomicroscopy (pCLE) offers microscopic-level imaging of subepithelial biliary mucosa. Because data regarding the use of pCLE in PSC are limited, we aimed to investigate its diagnostic performance in dominant strictures. METHODS: This was a multicenter prospective study involving PSC patients with dominant strictures. ERCP with pCLE was performed with use of the Miami classification (2+ criteria for malignant diagnosis) and Paris classification. Final malignant diagnoses required histopathologic confirmation, and benign diagnoses required a minimum of 1 year of follow-up without development of cancer. RESULTS: Fifty-nine patients (mean age, 49 years; 59% men) with 63 strictures were included in the study. Stricture locations included the common bile duct (31.7%), bifurcation (22.2%), and common hepatic duct (19%). Seven patients (11.9%) were found to have cholangiocarcinoma. The sensitivity and specificity of pCLE was 85.7% (95% confidence interval [CI], 42.1-99.6) and 73.1% (95% CI, 58.9-84.4), respectively. Within specific stricture locations, the highest sensitivity was seen at the bifurcation (100%; 95% CI, 2.5-100) and the right hepatic duct (100%; 95% CI, 29.2-100). The lowest sensitivities were seen at the common bile duct (25%; 95% CI, 5.5-57.2) and the left hepatic duct (28.6%; 95% CI, 3.7-70.9). CONCLUSIONS: In this prospective multicenter study, pCLE had a high sensitivity in detecting cholangiocarcinoma, but technical aspects of the probe may limit evaluation in the common bile duct and left hepatic duct. Further evaluation is needed to elucidate the role of pCLE in the algorithm of excluding neoplasia in biliary strictures associated with PSC. (Clinical trial registration number: NCT02736708.).

The Value of Managing Acute Pancreatitis With Standardized Order Sets to Achieve "Perfect Care".

OBJECTIVES: We aimed to define perfect care index (PCI) metrics and to evaluate whether implementation of standardized order sets would improve outcomes without increasing hospital-based charges in patients with acute pancreatitis (AP). METHODS: This is a retrospective, pre-post, observational study measuring clinical quality, processes of care, and hospital-based charges at a single tertiary care center. The first data set included AP patients from August 2011 to December 2014 (n = 219) before the implementation of a standardized order set (Methodist Acute Pancreatitis Protocol [MAPP]) and AP patients after MAPP implementation from January 2015 to September 2018 (n = 417). The second data set included AP patients (n = 150 in each group) from January 2013 to September 2014 (pre-MAPP) and January 2018 to September 2019 (post-MAPP) to evaluate perfect care between the 2 cohorts after controlling for systemic inflammatory response syndrome at baseline. Length of stay, PCI, and hospital-based charges were measured. RESULTS: The post-MAPP cohort had a significantly shorter length of stay (median, 3 days vs 4 days; P = 0.01). In the second data set, PCI significantly increased after implementation of MAPP order sets (5.3%-35.3%, P < 0.0001). CONCLUSIONS: The MAPP order sets increased the value of care by improving clinical outcomes without increasing hospital-based charges.

An Unsuccessful Randomized Trial of Percutaneous vs Endoscopic Drainage of Suspected Malignant Hilar Obstruction.

Percutaneous transhepatic biliary drainage (PTBD) and endoscopic retrograde cholangiopancreatography (ERCP) are widely accepted but competing approaches for the management of malignant obstruction at the hilum of the liver. ERCP is favored in the United States on the basis of high success rates for non-hilar indications, the perceived safety and superior tissue sampling capability of ERCP relative to PTBD, and the avoidance of external drains that are undesirable to patients. A recent randomized controlled trial (RCT) comparing the 2 modalities in patients with resectable hilar cholangiocarcinoma was terminated prematurely because of higher mortality in the PTBD group.1 In contrast, most observational data suggest that PTBD is superior for achieving complete drainage.2-6 Because the preferred procedure remains uncertain, we aimed to compare PTBD and ERCP as the primary intervention in patients with cholestasis due to malignant hilar obstruction (MHO).

Learning curve for EUS-guided biliary drainage: What have we learned?

BACKGROUND AND OBJECTIVE: EUS-guided-biliary drainage (EUS-BD) is an efficacious and safe option for patients who fail ERCP. EUS-BD is a technically challenging procedure. The aim of this study was to define the learning curve for EUS-BD. METHODS: Consecutive patients undergoing EUS-BD by a single operator were included for a prospective registry over 6 years. Demographics, procedural information, adverse events, and follow-up data were collected. Nonlinear regression and CUSUM analyses were conducted for the learning curve. Technical success was defined as successful stent placement. Clinical success was defined as resolution of jaundice and/or at least a 30% reduction in the pretreatment bilirubin level within a week after placement or normalization of bilirubin within 30 days. RESULTS: Seventy-two patients were included in the study (53% male, mean age 67 years). Technical success was achieved in 69 patients (96%). Clinical success was achieved in 59/69 patients (86%). Seven patients (10%) had adverse events including bleeding (n = 6) and liver abscess (n = 1). The median procedural time was 59 min (range 36-138 min). This was achieved at the 32nd procedure. Procedural durations were further reduced to 50 min and below after the 50th procedure in a nonlinear pattern. This suggests that procedural durations approach a potential plateau after 100 cases. CONCLUSION: Endoscopists experienced in EUS-BD are expected to achieve a reduction in procedural time over successive cases, with efficiency reached at 59 min and a learning rate of 32 cases. Continued improvement is demonstrated with additional experience, with mastery suggested after approximately 100 cases.