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Original Article Predictive factors for the necessity of peroral cholangioscopy-guided lithotripsy in the endoscopic treatment of cystic duct confluence stones: a retrospective study in Japan
Kazuaki Miyamotoorcid, Takahisa Ogawaorcid, Shinsuke Koshitaorcid, Yoshihide Kannoorcid, Hiroaki Kusunoseorcid, Toshitaka Sakaiorcid, Keisuke Yonamineorcid, Fumisato Kozakaiorcid, Haruka Okanoorcid, Yuto Matsuokaorcid, Kento Hosokawaorcid, Hidehito Sumiyaorcid, Kei Itoorcid
Clinical Endoscopy 2026;59(2):280-287.
DOI: https://doi.org/10.5946/ce.2025.195
Published online: January 9, 2026

Department of Gastroenterology, Sendai City Medical Center, Sendai, Japan

Correspondence: Kazuaki Miyamoto Department of Gastroenterology, Sendai City Medical Center, 5-22-1, Tsurugaya, Miyagino-ku, Sendai 983-0824, Japan E-mail: kazuaki.m@openhp.or.jp
• Received: June 22, 2025   • Revised: September 20, 2025   • Accepted: September 23, 2025

© 2026 Korean Society of Gastrointestinal Endoscopy

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (https://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

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  • Background/Aims
    The treatment of cystic duct confluence stones often requires peroral cholangioscopy (POCS)-guided lithotripsy. This study evaluated the efficacy of endoscopic treatment for cystic duct confluence stones and identified predictive factors for the need for POCS-guided lithotripsy.
  • Methods
    This retrospective cohort study included 38 patients with cystic duct confluence stones treated endoscopically between September 2007 and December 2023. The primary outcome was the rate of complete stone removal. Secondary outcomes included the number of sessions, total procedure time, adverse events, and predictive factors for POCS-guided lithotripsy.
  • Results
    The complete stone removal rate was 100%. POCS-guided lithotripsy was required in 50% of the cases. The mean number of sessions needed for stone removal was 2.05. The mean procedure time was 93.9 minutes. The incidence of adverse events was 13%. Multivariate analysis showed that a minor axis length of the stone relative to the distal bile duct diameter greater than 1.2 was an independent predictive factor for requiring POCS-guided lithotripsy.
  • Conclusions
    Endoscopic treatment is highly effective for cystic duct confluence stones. However, POCS-guided lithotripsy was necessary when the minor axis of the stone relative to the distal bile duct diameter exceeded 1.2.
  • Keywords: Cystic duct confluence stone; Electrohydraulic lithotripsy; Impacted stone; Peroral cholangioscopy-guided lithotripsy
The European Society of Gastrointestinal Endoscopy guidelines recommend that all bile duct stones should be treated, regardless of whether they are symptomatic or asymptomatic.1 Endoscopic retrograde cholangiopancreatography (ERCP) is the first-line treatment for bile duct stones. The standard technique is endoscopic sphincterotomy, followed by stone extraction using a basket or balloon catheter.2,3 However, so-called difficult bile duct stones, such as large stones, multiple stones, stones impacted at the cystic duct confluence (cystic duct confluence stone), and intrahepatic bile duct stones, sometimes cannot be completely removed using standard techniques alone.4,5 Mechanical lithotripsy (ML) and endoscopic papillary large balloon dilatation (EPLBD) are simple and effective techniques for difficult bile duct stones.6-8 However, these techniques are often ineffective for cystic duct confluence stones. When a stone is impacted at the cystic duct confluence, it blocks the advancement of guidewires and devices upstream, making it impossible to capture and crush the stone with a mechanical lithotripter. Recently, the usefulness of peroral cholangioscopy (POCS)-guided lithotripsy using electrohydraulic lithotripsy (EHL) or laser lithotripsy (LL) for difficult bile duct stones has been reported.9-13 With POCS-guided lithotripsy, stones can be crushed without inserting a device upstream of the impacted stones, making the method effective even for cystic duct confluence stones.
However, POCS-guided lithotripsy is more complicated than ML or EPLBD. Consequently, the procedure time is usually longer when it is performed.14 Additionally, it is more expensive. To date, no studies have investigated predictive factors requiring POCS-guided lithotripsy in the endoscopic treatment of cystic duct confluence stones. Therefore, we aimed to evaluate the efficacy of endoscopic treatment for cystic duct confluence stones and to identify predictive factors for the need for POCS-guided lithotripsy.
Study designs
This retrospective cohort study was conducted at Sendai City Medical Center.
Patients
We searched a prospective database for records between August 2006 and December 2023. Patients diagnosed with cystic duct confluence stones based on cholangiographic findings were included. Patients who met the following criteria were excluded from the study: (1) patients who underwent other endoscopic procedures, such as extracorporeal shock wave lithotripsy and surgery; and (2) patients for whom complete stone removal was not attempted and who underwent only permanent biliary drainage because of the possibility that procedures, including ML and POCS-guided EHL, were highly invasive in patients with multiple concomitant diseases.
Definitions
A cystic duct confluence stone was defined as a stone impacted at the cystic duct confluence based on cholangiographic findings. Procedure time was defined as the interval from duodenoscope insertion to complete stone removal. POCS-related procedure time was defined as the interval from cholangioscope insertion to withdrawal. Complete stone removal was defined as confirmation of stone absence in the common bile duct (CBD) using balloon-occluded cholangiography. Procedure-related adverse events, including post-ERCP pancreatitis (PEP), acute cholangitis, perforation, and bleeding, were defined according to the Consensus Criteria of the American Society of Gastrointestinal Endoscopy lexicon.15
The size of the stones and the diameter of the distal bile duct were measured using cholangiography images (Fig. 1). The site of the cystic duct confluence was also assessed using cholangiography. The minor axis was defined as the maximum transverse diameter, and the major axis as the diameter orthogonal to the minor axis. The distal CBD diameter was measured 1 cm proximal to the ampulla.16 Low cystic duct confluence was defined as the cystic duct joining the CBD at the distal third.17
Endoscopic procedures
A flowchart of the treatment strategies for cystic duct confluence stones is shown in Figure 2. Endoscopic procedures for patients without surgically altered anatomy or with Billroth I reconstruction were performed using a side-viewing duodenoscope (TJF260, JF260V, or TJFQ290V; Olympus Co.). For patients with surgically altered anatomy other than Billroth I reconstruction, procedures were performed using a short-type single-balloon enteroscope (SIF-H290S; Olympus Co.).
Nonsteroidal anti-inflammatory drugs (diclofenac sodium suppository, 25 mg or 50 mg) were administered to all patients before the procedure to prevent PEP. Prophylactic intravenous antibiotics were administered at the discretion of the endoscopist. In cases where POCS-guided lithotripsy was performed, intravenous antibiotics were administered to all patients immediately after the procedure if they had not received prophylactic intravenous antibiotics.
Cholangiography was performed at the beginning of the procedure in all patients to confirm the presence of stones. Endoscopic sphincterotomy was performed if it had not already been performed. EPLBD was performed using GIGA, GIGA-II (Century Medical), REN (Kaneka Medix Corp.), or StoneMaster V (Olympus Co.) at the discretion of the endoscopist. At our institution, lithotripsy using ML is prioritized over POCS-guided lithotripsy when necessary. Therefore, ML was initially attempted in this study. If a cystic duct confluence stone could not be captured with ML because of its large size, or if the stone could not be fractured due to hardness after multiple attempts, POCS-guided lithotripsy using an Autolith Touch Biliary EHL Probe (Boston Scientific Japan K.K.) was performed. Cholangioscopy was generally performed by inserting a digital cholangioscope (SpyGlass DS; Boston Scientific Japan K.K.; CHF-B260; Olympus Co.) through the channel of a therapeutic duodenoscope. Between August 2006 and September 2015, in patients without surgically altered anatomy other than Billroth I reconstruction, POCS-guided EHL was performed using the CHF-B260. Since October 2015, after the SpyGlass DS became available, it has been used for POCS-guided EHL procedures. Both cholangioscopic procedures were performed using a two-operator method, with one endoscopist handling the duodenoscope and the other controlling the cholangioscope. After the cholangioscope was inserted into the bile duct, with or without guidewire assistance, the stones were directly visualized with saline irrigation. When the SpyGlass DS was used, saline was infused into the bile duct through dedicated irrigation channels with a water pump controlled by a footswitch. When the CHF-B260 was used, saline was manually infused through the working channel using a syringe with a three-port adaptor, as the CHF-B260 had only one channel for both irrigation and suction. In patients with surgically altered anatomy other than Billroth I reconstruction, a short-type single-balloon enteroscope (SIF-H290S) was inserted directly into the bile duct because its channel was not compatible with the SpyGlass DS or CHF-B260. In these cases, a single operator manually infused saline through the working channel using a syringe. The stones were subsequently extracted using a basket and/or balloon catheter. The POCS-guided EHL strategy did not change throughout the study period.
A temporary plastic biliary stent was placed when complete stone removal could not be achieved during a single session. The stent was withdrawn at the beginning of the next session. Multiple endoscopic sessions were performed until complete stone removal was accomplished.
Outcome measurements
The primary outcome of this study was the complete stone removal rate. Secondary outcomes included the total number of sessions, total procedure time, adverse events, and predictive factors of POCS-guided lithotripsy.
For the analysis of predictive factors requiring POCS-guided lithotripsy, the following were evaluated: age (over 81 years old), sex (female), minor axis of the stone (≥9 mm), diameter of the distal bile duct (≤5 mm), ratio of the minor axis of the stone to the diameter of the distal bile duct (≥1.2 mm), position of cystic duct confluence (low junction), periampullary diverticulum (existence of periampullary diverticulum), and performance of EPLBD. The cutoff values for age, minor axis of the stone, diameter of the distal bile duct, and the ratio of the minor axis of the stone to the diameter of the distal bile duct were determined using receiver operating characteristic curve analysis.
Statistical analysis
Continuous variables were presented as mean values with standard deviations. Categorical variables were expressed as counts with percentages and compared using Fisher’s exact test. Multivariate analysis with multiple logistic regression was performed for variables that showed a p-value <0.05 in univariate analysis. A p-value <0.05 was considered to be statistically significant.
Data analysis was conducted using the statistical software package EZR ver. 1.67 (Saitama Medical Center, Jichi Medical University).
Ethical considerations
This study was approved by the Institutional Review Board of Sendai City Medical Center (approval number: 2023-0018). Written informed consent for the endoscopic procedures was obtained from each patient before the procedure.
Patient characteristics
The characteristics of the patients are summarized in Table 1. A total of 38 patients with cystic duct confluence stones were included in the study. The mean age was 67.6±16.4 years, and 20 patients were female. Two patients had surgically altered anatomies. One patient had undergone gastrojejunostomy, and the other had undergone Roux-en-Y reconstruction after total gastrectomy. The mean sizes of the major and minor axes of the stone were 18.9 and 12.9 mm, respectively. The mean distal bile duct diameter was 9.35 mm. A low cystic duct junction was observed in 12 patients.
Rate of complete stone removal
Complete stone removal was achieved in all patients, with 37% completed in the first session (Table 2). In seven patients, POCS-guided lithotripsy was required during the first ERCP session. The mean number of sessions required for complete stone removal was 2.05. POCS-guided lithotripsy was necessary in 50% of patients. Among patients requiring POCS-guided lithotripsy, EHL was sufficient in a single session for all but two cases. Two patients required two EHL sessions.
Procedure time
The mean total procedure time was 93.9 minutes (Table 2), with a mean of 28.3 minutes for POCS procedures. In patients with altered anatomies, the mean procedure time was 153.0 minutes, slightly longer than in those without altered anatomies (90.6 minutes) (p=0.11).
Adverse events
Adverse events occurred in 13% of sessions. Cholangitis was the most common complication (Table 3). The incidence of cholangitis did not differ significantly between the POCS-guided and non-POCS-guided lithotripsy groups (p=0.41). All adverse events were mild and resolved with conservative management.
Risk factors for requiring POCS-guided lithotripsy
From the univariate analysis of predictive factors for requiring POCS-guided lithotripsy, the minor axis of the stone (≥9 mm) and the ratio of the minor axis of the stone to the distal bile duct diameter (≥1.2) were statistically significant (p=0.03 and p=0.007). In the multivariate analysis, the ratio of the minor axis of the stone to the distal bile duct diameter (≥1.2) was identified as an independent risk factor for requiring POCS-guided lithotripsy (Table 4).
Cystic duct confluence stones are considered “difficult bile duct stones.” Although many studies have reported the effectiveness of endoscopic treatments, including POCS-guided lithotripsy, for difficult bile duct stones, few have focused specifically on cystic duct confluence stones. EPLBD and ML are useful endoscopic techniques for managing difficult bile duct stones.8 However, these techniques are often ineffective for cystic duct confluence stones. International consensus guidelines for EPLBD recommend that the maximal balloon diameter should not exceed that of the distal bile duct.18 However, in cases of cystic duct confluence stones, the stone is often larger than the distal bile duct. In this study, 76% of stones had a minor axis greater than the diameter of the distal bile ducts. Consequently, most cystic duct confluence stones require lithotripsy even after EPLBD. However, ML is often impossible for impacted cystic duct confluence stones because they cannot be captured by the basket. Garg et al.19 reported that impacted stones are a negative factor for stone clearance with ML. For lithotripsy of impacted stones, POCS-guided lithotripsy has proven effective, as proposed by Nakai et al.5
In this study, the rate of complete stone removal with POCS-guided lithotripsy was 100%, whereas that without POCS-guided lithotripsy was 50%. In other words, complete stone removal was achieved without POCS-guided lithotripsy in 50% of cases. El Menabawey et al.20 reported that a larger stone-to-duct ratio is associated with an increased need for cholangioscopy and that stone location, particularly at the cystic duct, is a factor contributing to this need in difficult biliary stones. In our study, a ratio of the minor axis of the stone to the distal bile duct diameter greater than 1.2 was a predictive factor for requiring POCS-guided lithotripsy.
POCS-guided lithotripsy is not available at all institutions. Therefore, identifying this predictive factor may help determine which patients should be referred to institutions that can perform POCS-guided lithotripsy. Although the measurements of the stone-to-duct ratio in this study were obtained from cholangiographic images, similar measurements can be obtained from magnetic resonance cholangiopancreatography or computed tomography images. Thus, cases requiring POCS-guided lithotripsy can potentially be identified before ERCP.
In this study, the rate of adverse events was 13% (total adverse events/total number of sessions), with cholangitis being the most frequent complication. This result is consistent with previous studies.21,22 It is known that ERCP with cholangiopancreatoscopy may be associated with higher overall adverse event rates. Particularly, cholangitis rates are higher in patients who have undergone cholangioscopy.23 Therefore, at our institution, intravenous antibiotics are administered to all patients undergoing POCS-guided lithotripsy. Among the three POCS devices, SpyGlass DS was most frequently used. SpyGlass DS has a simple irrigation system that can increase biliary pressure, potentially leading to a higher frequency of cholangitis. However, in this study, there was no significant difference in the frequency of cholangitis between the non-POCS and POCS groups (p=0.41). These findings suggest that IV antibiotics may prevent the development of cholangitis.
This study had several limitations. First, it was a retrospective study with a relatively small sample size conducted at a single institution. The prevalence of cystic duct confluence stones in patients undergoing ERCP has not yet been reported. During the study period, 5,580 ERCP procedures were performed for choledocholithiasis, and 1.4% (78/5,580) of these procedures were for cystic duct confluence stones. Mirizzi syndrome, a condition similar to cystic duct confluence stones, has been reported in 1.07% of patients undergoing ERCP.24 Our study excluded Mirizzi syndrome, and therefore, the sample size does not appear too small. Second, stone composition was not considered. Composition may be related to hardness; for example, calcium-rich stones tend to be harder and more difficult to crush using ML. Thus, stone composition may have influenced the decision to use POCS-guided EHL for fragmentation. Third, selection bias may have occurred due to operator discretion. The choice of endoscopic techniques, including EPLBD, ML, and POCS-guided lithotripsy, as well as the timing of their use, was at the discretion of the operator. Because of the retrospective nature of this study, there was no rigorous protocol on how long ML should be attempted before switching to POCS-guided EHL. However, operators typically proceeded to POCS-guided lithotripsy after an average of 15 minutes of ML. Tanisaka and Hawes25 reviewed the progression of POCS and proposed that the SpyGlass Direct Visualization System became the dominant system for cholangioscopy because of its superior functionality and ease of use. During the study period, the cholangioscope used for POCS-guided lithotripsy at our institution changed from CHF-B260 to SpyGlass DS, but the timing of POCS-guided EHL remained consistent.
Fourth, our institution does not have a LL device for POCS-guided lithotripsy. The efficacy and adverse events of POCS-guided EHL and LL have been inconsistently reported. Veld et al.22 found that POCS-guided LL had a higher complete ductal clearance rate than POCS-guided EHL, while the adverse event rates were similar for both. In contrast, Brewer Gutierrez et al.26 have reported no difference in complete duct clearance rates between POCS-guided EHL and POCS-guided LL; however, the procedure times were significantly longer in the EHL group. Although PCOS-guided LL may offer shorter procedure times, we did not perform this procedure.
Fifth, no cost-effectiveness analysis was conducted. In many countries, laparoscopic CBD exploration is widely used to manage cystic duct confluence stones. Tringali et al.27 reported that one-step laparoscopic CBD exploration combined with cholecystectomy reduced hospital costs compared with ERCP followed by laparoscopic cholecystectomy. However, Wandling et al.28 reported that the percentage of patients with choledocholithiasis undergoing laparoscopic CBD exploration has decreased, while the rates of ERCP followed by laparoscopic cholecystectomy have increased in the United States. Similarly, in Japan, the proportion of laparoscopic CBD explorations performed by surgeons has declined, and the procedure is now performed only in institutions with extensive expertise. Our institution currently lacks the capability to perform such operations. Conversely, Sandha et al.29 reported that single-operator POCS for difficult bile duct stones requiring multiple endoscopic procedures had a lower average cost compared with laparoscopic CBD exploration. Nationwide clinical trials are warranted to assess its cost-effectiveness.
In conclusion, for cystic duct confluence stones, POCS-guided EHL is effective for complete stone removal when the stone-to-duct ratio is high, particularly when the minor axis of the stone relative to the distal bile duct is greater than 1.2.
Fig. 1.
Parameter definitions: a, stone size (minor axis); b, stone size (major axis); c, area of the low cystic duct confluence; d, distal bile duct.
ce-2025-195f1.jpg
Fig. 2.
Flowchart of the patients in this study. EST, endoscopic sphincterotomy; EPLBD, endoscopic papillary large balloon dilatation.
ce-2025-195f2.jpg
ce-2025-195f3.jpg
Table 1.
Baseline characteristics of 38 patients
Characteristic Value
Age (yr) 67.6±16.4
Sex (male:female) 18:20
Performance status 0.00 (0.00–4.00)
Charlson comorbidity index 1.00 (0.00–7.00)
Anti-platelet drug use 9 (23.7)
Anti-coagulant drug use 3 (7.9)
Altered anatomy other than Billroth-Ⅰ 2 (5.3)
Periampullary diverticulum 10 (26.3)
Low confluence of cystic duct 12 (31.6)
Stone size (major axis) (mm) 18.9±8.7
Stone size (minor axis) (mm) 12.9±5.7
Diameter of distal bile duct (mm) 9.4±3.1
Stone size (major axis) relative to diameter of distal bile duct 2.2±1.2
Stone size (minor axis) relative to diameter of distal bile duct 1.5±0.6

Values are presented as mean±standard deviation, median (range), or number (%) unless otherwise indicated.

Table 2.
Rate of complete stone removal and detail of procedure
Outcome Value
Rate of complete stone removal 38 (100.0)
Complete stone removal at first session 14 (36.8)
Intervention and devices
 Retrieval balloon catheter 35 (92.1)
 Basket catheter 24 (63.2)
 Mechanical lithotriptor 31 (81.6)
 Endoscopic papillary balloon dilation 6 (15.8)
 Electrohydraulic lithotripsy 19 (50.0)
 Cholangioscope
  CHF-B260 5 (13.2)
  SpyGlassDS 13 (34.2)
  Direct POCS 1 (2.6)
Total procedure time to complete stone removal 93.9±53.8
Total procedure time taken for POCS 28.3±13.4
Number of endoscopic sessions required to complete stone removal 2.1±1.1
Number of sessions taken for POCS 1.2±0.5

Values are presented as number (%) or mean±standard deviation.

POCS, peroral cholangioscopy.

Table 3.
Adverse events
Adverse events Value
Total adverse events (n=78; n, %) 10 (12.8)
 Cholangitis (non-POCS group/POCS group) 7 (1/6)
 Pancreatitis 1
 Bleeding related endoscopic sphincterotomy 1
 Aspiration pneumonia 1

POCS, peroral cholangioscopy.

Table 4.
Predictive factor for needing peroral cholangioscopy-guided lithotripsy
Factor Univariate Multivariate OR (95% CI)
p-value p-value
Age (over 81 yr) 1
Sex (female) 0.76
Stone size (minor axis) ≥9 mm 0.03 0.25
Diameter of distal bile duct ≤5 mm 0.32
Stone size (minor axis)/diameter of distal bile duct ≥1.2 0.007 0.007 11.4 (1.96–66.9)
The site of cystic duct confluence: low 0.75
Existence of periampullary diverticulum 1
Performance of EPLBD 0.69

OR, odds ratio; CI, confidence interval; EPLBD, endoscopic papillary balloon dilation.

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    Predictive factors for the necessity of peroral cholangioscopy-guided lithotripsy in the endoscopic treatment of cystic duct confluence stones: a retrospective study in Japan
    Image Image Image
    Fig. 1. Parameter definitions: a, stone size (minor axis); b, stone size (major axis); c, area of the low cystic duct confluence; d, distal bile duct.
    Fig. 2. Flowchart of the patients in this study. EST, endoscopic sphincterotomy; EPLBD, endoscopic papillary large balloon dilatation.
    Graphical abstract

    Fig. 1.

    Fig. 2.

    Graphical abstract

    Predictive factors for the necessity of peroral cholangioscopy-guided lithotripsy in the endoscopic treatment of cystic duct confluence stones: a retrospective study in Japan
    Characteristic Value
    Age (yr) 67.6±16.4
    Sex (male:female) 18:20
    Performance status 0.00 (0.00–4.00)
    Charlson comorbidity index 1.00 (0.00–7.00)
    Anti-platelet drug use 9 (23.7)
    Anti-coagulant drug use 3 (7.9)
    Altered anatomy other than Billroth-Ⅰ 2 (5.3)
    Periampullary diverticulum 10 (26.3)
    Low confluence of cystic duct 12 (31.6)
    Stone size (major axis) (mm) 18.9±8.7
    Stone size (minor axis) (mm) 12.9±5.7
    Diameter of distal bile duct (mm) 9.4±3.1
    Stone size (major axis) relative to diameter of distal bile duct 2.2±1.2
    Stone size (minor axis) relative to diameter of distal bile duct 1.5±0.6
    Outcome Value
    Rate of complete stone removal 38 (100.0)
    Complete stone removal at first session 14 (36.8)
    Intervention and devices
     Retrieval balloon catheter 35 (92.1)
     Basket catheter 24 (63.2)
     Mechanical lithotriptor 31 (81.6)
     Endoscopic papillary balloon dilation 6 (15.8)
     Electrohydraulic lithotripsy 19 (50.0)
     Cholangioscope
      CHF-B260 5 (13.2)
      SpyGlassDS 13 (34.2)
      Direct POCS 1 (2.6)
    Total procedure time to complete stone removal 93.9±53.8
    Total procedure time taken for POCS 28.3±13.4
    Number of endoscopic sessions required to complete stone removal 2.1±1.1
    Number of sessions taken for POCS 1.2±0.5
    Adverse events Value
    Total adverse events (n=78; n, %) 10 (12.8)
     Cholangitis (non-POCS group/POCS group) 7 (1/6)
     Pancreatitis 1
     Bleeding related endoscopic sphincterotomy 1
     Aspiration pneumonia 1
    Factor Univariate Multivariate OR (95% CI)
    p-value p-value
    Age (over 81 yr) 1
    Sex (female) 0.76
    Stone size (minor axis) ≥9 mm 0.03 0.25
    Diameter of distal bile duct ≤5 mm 0.32
    Stone size (minor axis)/diameter of distal bile duct ≥1.2 0.007 0.007 11.4 (1.96–66.9)
    The site of cystic duct confluence: low 0.75
    Existence of periampullary diverticulum 1
    Performance of EPLBD 0.69
    Table 1. Baseline characteristics of 38 patients

    Values are presented as mean±standard deviation, median (range), or number (%) unless otherwise indicated.

    Table 2. Rate of complete stone removal and detail of procedure

    Values are presented as number (%) or mean±standard deviation.

    POCS, peroral cholangioscopy.

    Table 3. Adverse events

    POCS, peroral cholangioscopy.

    Table 4. Predictive factor for needing peroral cholangioscopy-guided lithotripsy

    OR, odds ratio; CI, confidence interval; EPLBD, endoscopic papillary balloon dilation.

    Table 1.

    Table 2.

    Table 3.

    Table 4.

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