Development of Clinical Prediction Rule for the Requirement of Endoscopic Papillary Large Balloon Dilation (Eplbd) On Endoscopic CBD Stone Clearance

Chote Wongkanong, Jayanton Patumanond, Thawee Ratanachu-ek, Sunhawit Junrungsee, Apichat Tantraworasin


This study included patients with CBD stones who underwent ERCP at Pattani Hospital between August 2017 and December 2021. Retrospective cohort data was collected and patients were categorized into two groups: bile duct stones successfully treated by endoscopic biliary sphincterotomy and extraction compared to the former method combined with EPLBD. We explored potential predictors using multivariable logistic regression. The chosen logistic coefficients were transformed into a scoring system based on risk with internal validation via bootstrapping procedure.


Choledocholithiasis is one of the most common gastrointestinal diseases, occurring in approximately 10% to 20% of gallstone patients [1, 2]. Since the introduction of endoscopic biliary sphincterotomy (EST) in 1974 [3, 4], endoscopic biliary sphincterotomy and stone extraction has been widely used as the primary method of treatment for patients with common bile duct (CBD) stones, with an 80–96% success rate [5, 6]. However, bile duct stone removal with standard biliary sphincterotomy plus stone extraction has a 15% failure rate [7].

Materials and methods

In this study, a model was developed to predict the technical difficulty of endoscopic CBD stone extractions. Therefore, the candidate predictive factors used in the prediction model were selected based on factors associated with CBD stone and CBD’s anatomy that is known to influence technical difficulty.


The participants were divided into two groups: 76 (49.03%) patients were in the non-difficult group defined as having the successful stone extraction by endoscopic sphincterotomy plus stone extraction and 79 (50.97%) patients were in the difficult group defined as having successful stone extraction by additional EPLBD combined with EST plus stone extraction. The success rate for the non-difficult group in the first session was 73.68%, whereas the success rate for the difficult group was 44.30%. In the non-difficult group, the median of overall session attempts until success is 1 session (IQR = 1.0, 2.0), and in the difficult group, it is 2 sessions (IQR = 1.0, 2.0).


The difference in diameter between the CBD stone and the distal bile duct, which exceeds 2 mm, was a strong predictor for required EPLBD. We categorized the difference in diameter between the CBD stone and the distal bile duct into two groups based on Sharma et al., implying that stones wider than the distal CBD diameter by more than 2 mm, regardless of stone size, may require an additional stone removal procedure [19]. Furthermore, and the cut-off point of the difference in diameter, which has a high specificity to discriminate between non-difficult CBD stones and the difficult groups in our data, hence the cut-off point of the difference in diameter at two milli-meters was reasonably considered as our predictor.


This study showed a simple score derived from four stone and CBD-related predictors: stone diameter, the difference between stone and distal CBD diameter, stone shape, and distal CBD arm length. Patients with a DCSS score of 5 or more had a high probability of EPLBD for stone removal. Therefore, it was suggested that patients with difficult CBD stones be referred to a hospital with available equipment. Conversely, in the case of a low probability of EPLBD, endoscopic sphincterotomy and stone extraction can be used for treatment.

Citation: Wongkanong C, Patumanond J, Ratanachu-ek T, Junrungsee S, Tantraworasin A (2023) Development of clinical prediction rule for the requirement of endoscopic papillary large balloon dilation (EPLBD) on endoscopic CBD stone clearance. PLoS ONE 18(3): e0282899.

Editor: Roberto Coppola, Campus Bio Medico University, ITALY

Received: November 24, 2022; Accepted: February 25, 2023; Published: March 16, 2023

Copyright: © 2023 Wongkanong et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Data Availability: All relevant data are within the paper and its.

Funding: The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Competing interests: The authors have declared that no competing interests exist.

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