Synergistic effect of independent risk factors for post-endoscopic retrograde cholangiopancreatography pancreatitis: a multicenter retrospective study in Japan.

Background/Aims: This study aimed to examine the synergistic effect of independent risk factors on post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP). Methods: This multicenter retrospective study included 1,273 patients with native papillae who underwent ERCP for bile dust stones in Japan. Independent PEP risk factors were identified using univariate and multivariate analyses. Significant risk factors for PEP in the multivariate analysis were included in the final analysis to examine the synergistic effect of independent risk factors for PEP. Results: PEP occurred in 45 of 1,273 patients (3.5%). Three factors including difficult cannulation ≥10 minutes, pancreatic injection, and normal serum bilirubin level were included in the final analysis. The incidences of PEP in patients with zero, one, two, and three factors were 0.5% (2/388), 1.9% (9/465), 6.0% (17/285), and 12.6% (17/135), respectively. With increasing risk factors for PEP, the incidence of PEP significantly increased (1 factor vs. 2 factors, p=0.006; 2 factors vs. 3 factors, p=0.033). Conclusions: As the number of risk factors for PEP increases, the risk of PEP may not be additive; however, it may multiply. Thus, aggressive prophylaxis for PEP is strongly recommended in patients with multiple risk factors.

Sublingual immunotherapy for cedar pollinosis possibly triggers eosinophilic esophagitis.

Sublingual immunotherapy (SLIT) is an effective and popular treatment for cedar pollinosis. Although SLIT can cause allergic side effects, eosinophilic esophagitis (EoE) is a lesser-known side effect of SLIT. A 26-year-old male with cedar pollinosis, wheat-dependent exercise-induced anaphylaxis, and food allergies to bananas and avocados presented with persistent throat itching, difficulty swallowing, heartburn, and anterior chest pain 8 days after starting SLIT for cedar pollinosis. Laboratory examination showed remarkably elevated eosinophils, and esophagogastroduodenoscopy revealed linear furrows in the entire esophagus. Histological examination of an esophageal biopsy specimen revealed high eosinophil levels. The patient was strongly suspected with EoE triggered by SLIT. The patient was advised to switch from the swallow to the spit method for SLIT, and the symptoms associated with SLIT-triggered EoE were reduced after switching to the spit method. This case highlights the importance of recognizing SLIT-triggered EoE as a potential side effect of SLIT for cedar pollinosis, especially with the increasing use of SLIT in clinical practice. EoE can occur within a month after initiating SLIT in patients with multiple allergic conditions, as observed in our case. Furthermore, the spit method should be recommended for patients who experience SLIT-triggered EoE before discontinuing SLIT.

Comparison of Outcomes between a Basket Catheter and a Balloon Catheter for Endoscopic Common Bile Duct Stone Removal.

INTRODUCTION: Evidence for the outcomes of endoscopic retrograde cholangiopancreatography (ERCP) between a basket catheter and a balloon catheter for endoscopic common bile duct stone (CBDS) removal is lacking. This study aimed to compare ERCP outcomes using a basket catheter and a balloon catheter for endoscopic CBDS removal. METHODS: This multicenter retrospective study included 904 consecutive patients with native papilla who underwent endoscopic stone removal for CBDS ≤10 mm using a basket catheter and/or a balloon catheter at three institutions in Japan. ERCP outcomes between the basket and balloon groups were compared using inverse probability of treatment weighting (IPTW) method. RESULTS: ERCP-related adverse events occurred in 6.5% (29/449) and 7.7% (35/455) of patients in the basket and balloon groups, respectively (IPTW-adjusted p = 0.52). The incidences of post-ERCP pancreatitis, cholangitis, and perforation were similar in the basket and balloon groups (3.8% vs. 2.9%, 1.3% vs. 0.9%, and 0.7% vs. 0.7%, respectively). However, bleeding incidences were significantly higher in the balloon group than in the basket group (3.3% vs. 0.7%, IPTW-adjusted p = 0.012). Successful complete stone removal at one ERCP session using a single catheter was achieved in 17.8% (80/449) in the basket group and in 81.3% (370/455) in the balloon group (IPTW-adjusted p < 0.001). DISCUSSION: A balloon catheter is more likely to complete stone extraction for CBDS ≤10 mm with a single catheter at one endoscopic stone removal session. However, the risk for post-ERCP bleeding is higher in the balloon group than in the basket group.

Post-endoscopic Retrograde Cholangiopancreatography Pancreatitis after Conservative Treatment for Symptomatic Bile Duct Stones.

Introduction: Endoscopic retrograde cholangiopancreatography (ERCP) for asymptomatic common bile duct stones (CBDS) has been associated with an increased risk of post-ERCP pancreatitis (PEP). Patients with asymptomatic CBDS at the time of ERCP include those with incidentally discovered CBDS (group A) and previously symptomatic patients with CBDS who became asymptomatic after conservative treatment for symptomatic CBDS, including obstructive jaundice or acute cholangitis (group B). In this study, we aimed to examine PEP risk in group B by comparing PEP risks between groups A, B, and currently symptomatic patients (group C). Methods: In this multicenter retrospective study, we examined 77 patients in group A, 41 patients in group B, and 1225 patients in group C who had native papillae. PEP incidence rates between asymptomatic patients at the time of ERCP (groups A and B) and symptomatic patients (group C) were compared using one-to-one propensity score matching. Bonferroni's correction analysis was also performed to compare PEP incidence rates among the three groups. Results: As per our findings, PEP incidence rate in propensity score-matched groups A and B was significantly higher than that of propensity score-matched group C (13.2% [15/114] versus 4.4% [5/114], respectively, P = 0.033). In groups A and B, PEP incidence rates were 11.7% (9/77) and 14.6% (6/41), respectively. PEP risk in group B was similar to that in group A (P = 1.0). PEP incidence in group B was significantly higher than PEP incidence in group C (14.6% (6/41)) vs. 2.9% (35/1225)) (P = 0.005)). Conclusions: ERCP for previously symptomatic patients with CBDS who became asymptomatic after conservative treatment for symptomatic CBDS may increase the risk of PEP compared with ERCP for currently symptomatic patients. Thus, ERCP should be performed before patients become asymptomatic using conservative treatments if patients can tolerate ERCP procedures.

Unnecessary endoscopic retrograde cholangiopancreatography associated with the spontaneous passage of common bile duct stones into the duodenum: a multicenter retrospective study.

BACKGROUND: Unnecessary endoscopic retrograde cholangiopancreatography (ERCP) after spontaneous passage of common bile duct stones (CBDSs) should be avoided. This study aimed to examine the cumulative diagnosis rate and the predictive factors of spontaneous CBDS passage during the interval between the imaging diagnosis and ERCP. METHODS: This multicenter retrospective study included 1260 consecutive patients with native papilla diagnosed with CBDSs using imaging modalities. Predictive factors and cumulative diagnosis rate of spontaneously passed CBDSs during the interval between imaging diagnosis and ERCP were analyzed. RESULTS: The overall cumulative diagnosis rate of spontaneous CBDS passage was 6.2% (78/1260) during a mean interval of 5.0 days. In the multivariate analysis, CBDS sized < 6 mm on diagnostic imaging, solitary CBDS on diagnostic imaging, intervals between the imaging diagnosis and ERCP, and nondilated common bile duct (< 10 mm) were the significant factors associated with spontaneous CBDS passage. Specifically, the cumulative diagnosis rate of spontaneous passage was significantly higher in patients with solitary and CBDSs sized < 6 mm than in those with other CBDSs (14.4% [54/376] vs. 2.7% [24/884], P < 0.001). In both the asymptomatic and symptomatic groups, the cumulative diagnosis rate of the spontaneous passage of CBDSs was significantly higher in patients with solitary and CBDSs sized < 6 mm on diagnostic imaging than in those with multiple and/or CBDSs sized ≥ 6 mm on diagnostic imaging during a mean interval of 20.5 and 2.4 days, respectively (asymptomatic group: 22.4% [15/67] vs. 3.5% [4/113], P < 0.001, symptomatic group: 12.6% [39/309] vs. 2.6% [20/771], P < 0.001). CONCLUSIONS: Solitary and CBDSs sized < 6 mm on diagnostic imaging can often lead unnecessary ERCP due to spontaneous passage. Preliminary endoscopic ultrasonography immediately before ERCP is recommended, especially in patients with solitary and small CBDSs on diagnostic imaging.

Low Detection Rates of Bile Duct Stones During Endoscopic Treatment for Highly Suspected Bile Duct Stones with No Imaging Evidence of Stones.

BACKGROUND: The revised American Society for Gastrointestinal Endoscopy (ASGE) guideline 2019 provides the high-risk criteria for suspected common bile duct stones (CBDSs). AIMS: To evaluate CBDS detection rates during endoscopic retrograde cholangiopancreatography (ERCP) in high-risk patients with suspected CBDSs based on the ASGE guideline 2019. METHODS: This multicenter retrospective study included 1100 consecutive patients who underwent ERCP for suspected CBDSs with any high-risk criteria based on the revised ASGE guideline 2019: Criterion 1, CBDSs on imaging; Criterion 2, clinical ascending cholangitis; and Criterion 3, total bilirubin exceeding 4 mg/dL and dilated common bile duct on imaging. We compared CBDS detection rates during ERCP based on individual and combined high-risk criteria. RESULTS: The CBDS detection rates of patients who met any of the criteria, only Criterion 1, and Criteria 2 or 3 were 86.0% (946/1100), 93.4% (113/121), and 50.0% (106/212), respectively. In patients who met Criteria 1 and 2, 1 and 3, 2 and 3, and all criteria, CBDSs were confirmed during ERCP in 95.1% (490/515), 96.2% (25/26), 55.3% (26/47), and 98.4% (186/189), respectively. The CBDS detection rate during ERCP of patients with at least Criterion 1 significantly exceeded that of patients without at least Criterion 1 [95.7% (814/851) vs. 51.0% (132/259), respectively, P < 0.001]. CONCLUSIONS: Patients with CBDS visualization on imaging have very high CBDS detection rates during ERCP. However, performing ERCP on patients with only clinical predictors, such as cholangitis and dilated CBD with total bilirubin exceeding 4 mg/dL, often results in unnecessary ERCP.

Current approaches and questions yet to be resolved for the prophylaxis of post-endoscopic retrograde cholangiopancreatography pancreatitis.

Prophylaxis is important for post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP), which is the most common and serious complication of ERCP. Although the current guidelines include independent patient- and procedure-related risk factors for PEP and available PEP prophylactic measures, the synergistic effect of these risk factors on PEP should also be considered, given that patients often harbor multiple risk factors. Furthermore, a combination of prophylactic measures is often selected in clinical practice. However, established methods estimating the synergistic effect of independent risk factors on PEP incidence are lacking, and evidence on the impact of combining prophylactic measures on PEP should be discussed. Selection of appropriate candidate patients for ERCP is also important to reduce the incidence of PEP associated with unnecessary ERCP. ERCP indications in patients with asymptomatic common bile duct stones (CBDSs) and in those with suspected CBDSs with no imaging-based evidence of stones are controversial. Further studies are warranted to predict the synergistic effect of independent risk factors on PEP, determine the best prophylactic PEP measures, and identify appropriate candidates for ERCP in patients with asymptomatic CBDSs and those with suspected CBDSs.

Risk prediction of common bile duct stone recurrence based on new common bile duct morphological subtypes.

Stones in the common bile duct (CBD) are reported worldwide, and this condition is majorly managed through endoscopic retrograde cholangiopancreatography (ERCP). CBD stone recurrence is an important issue after endoscopic stone removal. Therefore, it is essential to identify its risk factors to determine the necessity of regular follow-up in patients who underwent endoscopic removal of CBD stones. The authors identified that the S and polyline morphological subtypes of CBD were associated with increased stone recurrence. New morphological subtypes of CBD presented by the authors can be important risk predictors of recurrence after endoscopic stone removal. Furthermore, the new morphological subtypes of CBD may predict the risk of residual CBD stones or technical difficulty in CBD stone removal. Further studies with a large sample size and longer follow-up durations are warranted to examine the usefulness of the newly identified morphological subtypes of CBD in predicting the outcomes of ERCP for CBD stone removal.

Endoscopic retrograde cholangiopancreatography for bile duct stones in patients with a performance status score of 3 or 4.

BACKGROUND: As the aging population grows worldwide, the rates of endoscopic retrograde cholangiopancreatography (ERCP) for common bile duct stones (CBDS) in older patients with a poor performance status (PS) have been increasing. However, the data on the safety and efficacy of ERCP for CBDS in patients with a PS score of 3 or 4 are lacking, with only a few studies having investigated this issue among patients with poor PS. AIM: To examine the safety and efficacy of ERCP for CBDS in patients with a PS score of 3 or 4. METHODS: This study utilized a retrospective multi-centered design of three institutions in Japan for 8 years to identify a total of 1343 patients with CBDS having native papillae who underwent therapeutic ERCP. As a result, 1113 patients with a PS 0-2 and 230 patients with a PS 3-4 were included. One-to-one propensity-score matching was performed to compare the safety and efficacy of ERCP for CBDS between patients with a PS 0-2 and those with a PS 3-4. RESULTS: The overall ERCP-related complication rates in all patients and propensity score-matched patients with a PS 0-2 and 3-4 were 9.0% (100/1113) and 7.0% (16/230; P = 0.37), and 4.6% (9/196) and 6.6% (13/196; P = 0.51), respectively. In the propensity score-matched patients, complications were significantly more severe in the group with a PS 3-4 than in the group with a PS 0-2 group (P = 0.042). Risk factors for complications were indications of ERCP and absence of antibiotics in the multivariate analysis. Therapeutic success rates, including complete CBDS removal and permanent biliary stent placement, in propensity score-matched patients with a PS 0-2 and 3-4 were 97.4% (191/196) and 97.4% (191/196), respectively (P = 1.0). CONCLUSION: ERCP for CBDS can be effectively performed in patients with a PS 3 or 4. Nevertheless, the indication for ERCP in such patients should be carefully considered with prophylactic antibiotics.

Factors Predicting Difficult Biliary Cannulation during Endoscopic Retrograde Cholangiopancreatography for Common Bile Duct Stones.

BACKGROUND/AIMS: Difficult biliary cannulation is an important risk factor for post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP). Therefore, this study aimed to identify the factors that predict difficult cannulation for common bile duct stones (CBDS) to reduce the risk for PEP. METHODS: This multicenter retrospective study included 1,406 consecutive patients with native papillae who underwent ERCP for CBDS. Factors predicting difficult cannulation for CBDS were identified using univariate and multivariate analyses. RESULTS: Univariate analysis showed that six factors significantly predicted difficult cannulation: ERCP performed by non-expert endoscopists, low-volume center, absence of acute cholangitis, normal serum bilirubin, intradiverticular papilla, and type of major duodenal papilla. Multivariate analysis identified ERCP performed by non-expert endoscopists (odds ratio [OR], 2.5; p<0.001), low-volume center (OR, 1.6; p<0.001), intradiverticular papilla (OR, 1.3; p=0.007), normal serum bilirubin (OR, 1.3; p=0.038), and absence of acute cholangitis (OR, 1.3; p=0.049) as factors significantly predicting difficult cannulation for CBDS. CONCLUSION: Initial cannulation by an experienced endoscopist, early rescue cannulation, or early takeover by an experienced endoscopist should be considered when performing ERCP for CBDS in the presence of factors predicting difficult cannulation.

Increased post-endoscopic retrograde cholangiopancreatography pancreatitis for choledocholithiasis without acute cholangitis.

BACKGROUND AND AIM: Choledocholithiasis is the most common indication for endoscopic retrograde cholangiopancreatography (ERCP). Identifying risk factors for post-ERCP pancreatitis (PEP) is important for reducing the risk of developing PEP after common bile duct (CBD) stone removal. However, studies examining the risk factors for PEP for CBD stones are scarce. The aim of this study was to examine whether the presence or absence of acute cholangitis is a clinical risk factor for PEP in patients with CBD stones. METHODS: In this multicenter retrospective study, 1539 patients with naïve papillae were divided into patients without and with acute cholangitis. We compared the incidence of PEP between the two groups using one-to-one propensity score matching to adjust for the potential confounding factors of PEP. RESULTS: In the entire cohort, the rates of PEP in patients without and with acute cholangitis were 9.6% (52/542) and 1.8% (18/997), respectively (P < 0.001, odds ratio = 5.8). In the propensity-matched cohort, the rates of PEP in patients without and with acute cholangitis were 8.3% (27/326) and 2.5% (8/326), respectively (P = 0.002, odds ratio = 3.6). The rate of PEP was significantly higher in patients without acute cholangitis than in those with acute cholangitis after adjusting for the confounding factors of PEP. CONCLUSIONS: The absence of acute cholangitis may be an important clinical risk factor for PEP due to CBD stone removal. In patients without acute cholangitis, endoscopists should explain the specific risk of PEP carefully and actively implement prophylaxis against PEP.

Disease-Based Risk Stratification of Postendoscopic Retrograde Cholangiopancreatography Pancreatitis for Common Bile Duct Stones.

BACKGROUND: Risk stratification of postendoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP) for common bile duct (CBD) stones is needed for clinicians to adequately explain to patients regarding the risk of PEP in advance of ERCP and to proactively take preventive measures in high-risk patients. AIMS: To stratify the risk of PEP for CBD stones based on CBD-related diseases. METHODS: A total of 1551 patients with naïve papilla who underwent ERCP for CBD stones were divided into three groups: Group A: asymptomatic CBD stones, Group B: obstructive jaundice and elevated liver test values without cholangitis, and Group C: mild, moderate, and severe cholangitis. We stratified the risk of PEP by comparing its incidence among the three groups using the Holm's method. Furthermore, we performed one-to-one propensity score matching between Group A and the other groups to examine the risk of PEP in Group A. RESULTS: The incidence rates in Groups A, B, and C were 13.7%, 7.3%, and 1.8%, respectively. The Holm-adjusted p values between Groups A and B, Groups A and C, and Groups B and C were 0.023, < 0.001, and < 0.001, respectively. Propensity score matching revealed that the incidence of PEP was significantly more in Group A than in the other groups (13.3% vs. 1.5%; p < 0.001). CONCLUSIONS: The risk of PEP for CBD stones was stratified into low risk (Group C), intermediate risk (Group B), and high risk (Group A). This simple disease-based risk stratification may be useful to predict the risk of PEP in advance of ERCP.

Endoscopic retrograde cholangiopancreatography-related complications for bile duct stones in asymptomatic and symptomatic patients.

BACKGROUND AND AIM: Current guidelines recommend the removal of common bile duct (CBD) stones by endoscopic retrograde cholangiopancreatography (ERCP) for both asymptomatic and symptomatic patients. We conducted this study because of the limited research comparing the risks of ERCP-related complications between these two groups. METHODS: This retrospective study involved 1491 patients with native major duodenal papilla diagnosed with choledocholithiasis at three institutions in Japan. The rates of ERCP-related complications, including post-ERCP pancreatitis (PEP), cholangitis, bleeding, and perforation, were compared using one-to-one propensity score matching between the asymptomatic and symptomatic patients. RESULTS: Complications were observed in 112 (7.5%) of the 1491 patients (asymptomatic group: 31/172 [18.0%] vs symptomatic group: 81/1319 [6.1%], P < 0.001). The rate of severe complications was higher in the asymptomatic group than that in the symptomatic group (asymptomatic group: 5/31 [16.1%] vs symptomatic group: 3/81 [3.7%], P = 0.036). In the propensity-matched asymptomatic and symptomatic patients, the incidences of PEP, cholangitis, bleeding, and perforation were 18/143 (12.6%) vs 4/143 (2.8%) (P = 0.003); 4/107 (3.7%) vs 6/107 (5.6%) (P = 0.75); 1/140 (0.7%) vs 3/140 (2.1%) (P = 0.62); and 2/140 (1.4%) vs 2/140 (1.4%) (P = 1.0). CONCLUSIONS: ERCP for asymptomatic patients with CBD stones is associated with a higher risk of overall and severe complications than that for symptomatic patients with CBD stones; the overall rate is influenced by the high incidence of PEP in the asymptomatic group. Endoscopists should explain the risk of ERCP-related complications for asymptomatic patients before performing the procedure.

Remaining issues of recommended management in current guidelines for asymptomatic common bile duct stones.

Current guidelines for treating asymptomatic common bile duct stones (CBDS) recommend stone removal, with endoscopic retrograde cholangiopancreatography (ERCP) being the first treatment choice. When deciding on ERCP treatment for asymptomatic CBDS, the risk of ERCP-related complications and outcome of natural history of asymptomatic CBDS should be compared. The incidence rate of ERCP-related complications, particularly of post-ERCP pancreatitis for asymptomatic CBDS, was reportedly higher than that of symptomatic CBDS, increasing the risk of ERCP-related complications for asymptomatic CBDS compared with that previously reported for biliopancreatic diseases. Although studies have reported short- to middle-term outcomes of natural history of asymptomatic CBDS, its long-term natural history is not well known. Till date, there are no prospective studies that determined whether ERCP has a better outcome than no treatment in patients with asymptomatic CBDS or not. No randomized controlled trial has evaluated the risk of early and late ERCP-related complications vs the risk of biliary complications in the wait-and-see approach, suggesting that a change is needed in our perspective on endoscopic treatment for asymptomatic CBDS. Further studies examining long-term complication risks of ERCP and wait-and-see groups for asymptomatic CBDS are warranted to discuss whether routine endoscopic treatment for asymptomatic CBDS is justified or not.

Immediate or Interval Endoscopic Papillary Large-balloon Dilation after Limited Endoscopic Sphincterotomy for Bile Duct Stone Removal.

Objective Endoscopic papillary large-balloon dilation (EPLBD) with limited endoscopic sphincterotomy (EST) is widely used for removing multiple large common bile duct (CBD) stones. However, the safety and effectiveness of immediate EPLBD after limited EST and EPLBD at an interval after limited EST is unclear. Thus, this multicenter retrospective study was conducted to examine this matter. Methods Propensity score-matching was performed to adjust the baseline characteristics between the immediate and interval EPLBD groups. We compared the incidence of post-endoscopic retrograde cholangiopancreatography (ERCP) complications and the early outcomes of ERCP between the 2 matched groups, which comprised 66 patients each. Results The complete stone clearance rate in each study group was 100%. The overall incidence of post-ERCP complications in the propensity score-matched interval and immediate EPLBD groups was 3/33 (9.1%) and 1/33 (3.0%), respectively (p=0.61). The immediate EPLBD group had significantly fewer mean ERCP sessions for complete stone removal and a significantly lower rate of endoscopic mechanical lithotripsy (EML) usage than the interval EPLBD group [1.6 vs. 2.4 sessions, p<0.001; and 4/33 (12.1%) vs. 12/33 (36.4%), p=0.042, respectively]. Conclusion The incidence of post-ERCP complications in the immediate EPLBD group was not significantly different from that in the interval EPLBD group. Compared with interval EPLBD, immediate EPLBD may result in a reduced number of ERCP sessions for complete stone clearance and reduce the rate of EML usage.

Dual-layer spectral detector computed tomography versus magnetic resonance cholangiopancreatography for biliary stones.

OBJECTIVE: Dual-layer spectral detector computed tomography (DLCT) can detect noncalcified biliary stones. The diagnostic ability of DLCT for detecting biliary stones may be comparable to that of magnetic resonance cholangiopancreatography (MRCP). This study seeks to compare the diagnostic ability for biliary stones between these two imaging modalities. METHODS: This retrospective study included 102 cases with a diagnosis of biliary stones including gallstones (n = 66) and common bile duct (CBD) stones (n = 25) or spontaneously passing CBD stones (n = 11). The reference standard used was operative findings, endoscopic retrograde cholangiopancreatography or follow-up over 6 months. In DLCT, 120-kVp images, 40-keV virtual monoenergetic images and material decomposition images were created. We compared the diagnostic ability of DLCT and MRCP for biliary stones using the McNemar's test. RESULTS: The sensitivity and specificity of DLCT versus MRCP for biliary stones were 91.2% versus 95.6% and 90.9% versus 90.9%. Thus, the sensitivity and specificity were not significantly different (P = 0.25 and P = 1.0). Although in small stones (<9 mm) the sensitivity of calcified stones was not different between DLCT and MRCP (100% versus 92.5%), the sensitivity of noncalcified stones in DLCT was lower than that in MRCP (38.5% versus 100%). CONCLUSION: The diagnostic ability of biliary stones in DLCT appears comparable to that of MRCP in overall cases. However, detecting noncalcified stones less than 9 mm in size is limited in DLCT.

Post-endoscopic retrograde cholangiopancreatography pancreatitis in single-stage endoscopic common bile duct stone removal.

BACKGROUND AND AIMS: Papillary treatment, such as endoscopic sphincterotomy or endoscopic papillary balloon dilation, and subsequent single-stage endoscopic stone removal are often performed for choledocholithiasis; however, the incidence of postendoscopic retrograde cholangiopancreatography pancreatitis (PEP) is unclear. This study aimed to compare the overall incidence of PEP between single- and two-stage stone removal groups and the incidence of PEP between these two groups based on cannulation time. METHODS: We included 897 patients with native papilla who underwent papillary treatment and stone removal for choledocholithiasis with no inflammation or mild-to-moderate acute cholangitis at three institutions between April 2012 and March 2018 in Japan. We performed a propensity-matched analysis and regression adjustment by propensity score to adjust for potential confounding factors. RESULTS: In the propensity-matched analysis with 234 pairs, there was no significant difference in the overall incidence of PEP between single- and two-stage stone removal procedures (15/234, 6.4% vs 6/234, 2.6%, P = 0.072, respectively). Although single-stage stone removal after a cannulation time of ≤15 min was not a significant risk factor of PEP, the procedure after a cannulation time of >15 min was a significant risk factor of PEP as estimated by regression adjustment by propensity score (P = 0.014, 95% CI = 1.4-19.4, odds ratio = 5.2). CONCLUSIONS: Single-stage endoscopic stone removal after a long cannulation time of >15 min increased the incidence of PEP compared with the two-stage stone removal procedure. Thus, single-stage stone removal should be performed in patients with a cannulation time ≤ 15 min.