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

INTRODUCTION

As the aging population grows worldwide,the rates of endoscopic retrograde cholangiopancreatography (ERCP) among the elderly are increasing.In particular,common bile duct stones (CBDS) are the most common indication for ERCP,and endoscopists often perform ERCP for CBDS in the elderly with poor Eastern Cooperative Oncology Group performance status (ECOG-PS) score[1],which is an objective index of activity in daily life,in clinical practice.Although several studies have reported that the safety and efficacy of ERCP for elderly patients aged ≥ 80-90 years were comparable to those in younger patients,the performance status (PS) score varied in the previous studies[2-10].

PS is an important tool utilized for the clinical determination of the indications and strategies of ERCP for CBDS in elderly patients.Evidence available from studies evaluating the safety and efficacy of ERCP for biliopancreatic diseases in patients with a poor PS score is limited[11,12].Furthermore,few studies have investigated the safety and efficacy of ERCP for CBDS in patients with a poor PS score.In the present study,we assessed the safety and efficacy of ERCP for CBDS in patients with a PS score of 3 or 4 in comparison with those having a PS score of 0-2.

MATERIALS AND METHODS

Patients and study design

The data of patients with native major duodenal papilla who had undergone therapeutic ERCP for CBDS between April 2012 and February 2020 at Kumamoto Chuo Hospital,Saiseikai Kumamoto Hospital,and Kumamoto City Hospital in Japan were retrospectively reviewed.The exclusion criteria were (1) failure to detect CBDS during ERCP;(2) history of therapeutic ERCP;and (3) and a gastrointestinal tract that has already been surgically altered such as by employing Billroth II or Rouxen-Y reconstruction.The institutional review boards of the participating institutions approved this study and opt-out consent was applied.One-to-one propensity score matching analysis was performed to adjust for confounding factors between patients with a PS score of 0–2 and patients with a PS score of 3 or 4,and the safety and efficacy of ERCP for CBDS were compared between these two groups.

Outcomes and definitions

The man then turned into a hen, and began to search for the grain of barley, but this again changed itself to a pole-cat, and took off the hen s head with a single snap14

Post-ERCP complications included post-ERCP pancreatitis (PEP),bleeding,cholangitis,perforation,and aspiration pneumonia.These complications and their severity were diagnosed based on a lexicon for endoscopic complications[13].When several complications were noted in the same patient,the most severe complication was selected for analysis.

Successful cases of complete stone removal or permanent biliary stent placement were considered a therapeutic success in this study.

Procedure

ERCP was performed in the prone or semi-prone position using side-viewing duodenoscopes (Olympus JF-260,TJF-260V;Olympus Medical Systems,Tokyo,Japan).Midazolam with pethidine hydrochloride was used for the purpose of sedation by the endoscopist.We determined the doses of midazolam and pethidine hydrochloride based on our sedation protocol using the data pertaining to the age and weight of patients.In patients aged 75-89 years and weighing <70 kg,the dose of pethidine hydrochloride and midazolam was 17.5 mg-35 mg and 1 mg,respectively.In patients aged 75-89 years and weighing ≥ 70 kg,the dose of pethidine hydrochloride and midazolam was 17.5 mg-35 mg and 2 mg,respectively.In patients aged ≥ 90 years,the dose of pethidine hydrochloride and midazolam was 17.5 mg and/or 1 mg,respectively,regardless of the weight of the patients.

But she was a brave girl and full of spirit, and soon made up her mind that the best thing she could do was to go to the nearest town and become a servant

A total of 1343 patients met the inclusion criteria for this study.Altogether,1113 and 230 patients were included in the groups with a PS score of 0-2 and 3-4,respectively.Details of patients’ characteristics are presented in Table 1.Significant differences were noted in age,sex,indications of ERCP for CBDS,a history of cerebrovascular diseases,a history of multiple underlying diseases,antithrombotic treatment,non-dilated common bile duct (CBD),antibiotics,trainee involvement,difficult cannulation,EST,EPBD,EPLBD,use of balloon catheter,large stones,protease inhibitor,and rectal non-steroidal anti-inflammatory drugs.No significant differences were noted in patients’ characteristics between the two groups after propensity score matching.

Statistical analysis

Chi-squared test or Fisher’s exact test was used for categorical variables,and Welch’s

-test was used for continuous variables.A multivariate logistic regression model employed variables with

values <0.20 in the univariate analyses to identify the predictive factors for post-ERCP complications.

On Sundays my father always wore that dull（，） gray apron1（） – the one with the race cars all over it. The ritual2（，） began after breakfast when Dad always announced: Go ahead everyone. I ll take care of the dishes! With that my mother disappeared into the folds of the Sunday paper. Off came the suit coat he had worn to church that morning. Up went the shirtsleeves（） . On went that apron. For the next hour Dad did the dishes, singing ballads3（，） like I Had a Hat When I Came In and Who Put the Chow in Mrs. Murphy s Chowder?

One-to-one propensity score matching with a caliper of 0.2 was performed to adjust for confounding factors associated with post-ERCP complications between patients with a PS score of 0-2 and patients with a PS score of 3 or 4.Factors presented in Table 1 were used to construct propensity scores using the logistics regression model.

All statistical analyses were performed using EZR version 1.53 (Saitama Medical Center,Jichi Medical University,Saitama,Japan),a graphical user interface for R software (The R Foundation for Statistical Computing,Vienna,Austria,version 4.1.0)[14].Two-sided

values <0.05 were considered statistically significant.

Job embraced life in unexpected, simple ways. He showed up for work, on time. He never bragged2 about（，） himself, and he loved only one woman—his wife, Molly. Job filled a void（，） in my life. He was principled and straightforward3 in my world of dishonor and lies. He loved me as his very own grandchild, even though he was a year younger than my father.

RESULTS

Patient characteristics

When a trainee with experience of <200 ERCP procedures performed ERCP,an experienced endoscopist supervised them.After biliary cannulation using a standard ERCP catheter and a 0.025-inch guidewire,biliary stent placement or stone removal after endoscopic sphincterotomy (EST),endoscopic papillary balloon dilation (EPBD),or endoscopic papillary large balloon dilation (EPLBD) was performed.The treatment strategy for complete stone removal or permanent biliary stent placement was decided upon by the endoscopist.

The primary outcome was the rates of post-ERCP complications and the rate of technical success such as complete stone removal and permanent biliary stent placement.

Endoscopic retrograde cholangiopancreatography-related complications

ERCP-related complications in all patients and propensity score-matched patients are presented in Table 2.The overall ERCP-related complication rates in all patients and propensity score-matched patients in the groups with a PS score of 0-2 and 3-4 were 9.0% (100/1113) and 7.0% (16/230;

=0.37)and 4.6% (9/196) and 6.6% (13/196;

=0.51),respectively.In all patients,complications were more severe in the group with a PS score of 3-4 than in the group with a PS score of 0-2 (

=0.063),although this finding was not statistically significant.In the propensity score-matched patients,complications were significantly more severe in the group with a PS score of 3 or 4 than in the group with a PS score of 0-2 (

=0.042).The incidence rate of each complication,including PEP,bleeding,cholangitis,perforation,and aspiration pneumonia,was not significantly different between the two groups in all patients and propensity score-matched patients.Among all patients,the severity of PEP was significantly higher in patients with a PS score of 3 or 4 than in those with a PS score of 0-2 (

=0.034),and the severity of other complications was not significantly different between the two groups.Among the propensity score-matched patients,the severity of each complication was not significantly different between the two groups.

Therapeutic success rates of ERCP and mean procedure time

Therapeutic success rates of ERCP and mean procedure time are presented in Table 3.Therapeutic success rates,including successful complete stone removal and permanent biliary stent placement,in all patients and propensity score-matched patients were 98.5% (1096/1113) and 97.4% (224/230;

=0.26)and 97.4% (191/196) and 97.4% (191/196;

=1.0),respectively.The rates of successful complete stone removal in all patients and propensity score-matched patients between patients with a PS score of 0-2 and 3 or 4 were 1064/1113 (95.6%) and 200/230 (87.0%;

<0.001) and 92.3% (181/196) and 87.8%(172/196;

=0.18),respectively.The rates of successful permanent biliary stent placement in all patients and propensity score-matched patients between the group with a PS score of 0-2 and 3 or 4 were 2.9%(32/1113) and 10.4% (24/230;

<0.001) and 5.1% (10/196) and 9.7% (19/196;

=0.12),respectively.Mean procedure times were not significantly different in all patients and propensity score-matched patients between the two groups (

=0.42 and

=0.77,respectively).

Predictive factors for ERCP-related complications after ERCP for CBDS

The results of univariate and multivariate analyses for risk factors of ERCP-related complications for CBDS are presented in Table 4.In univariate analysis,there was a significant difference in indications of ERCP for CBDS,absence of antibiotics,prolonged procedure,difficult biliary cannulation,pancreatic injection,contrast-assisted cannulation,prophylactic pancreatic stent placement,normal serum bilirubin level,and pancreatic guidewire-assisted cannulation.In multivariate analysis,indications of ERCP for CBDS and absence of antibiotics were significant risk factors for ERCP-related complications.

DISCUSSION

Several studies reported that ERCP can be performed for biliopancreatic diseases even in elderly patients aged over 80 years[2-10].However,PS is an important factor in deciding the therapeutic strategy in elderly patients with CBDS.Although conservative therapy or therapeutic ERCP can be selected for CBDS in patients with a PS score of 3 or 4,therapeutic ERCP is better because ERCP can resolve CBD obstruction caused by CBDS if ERCP can be performed safely and effectively even in elderly patients with a PS score of 3 or 4.

In parallel with the growing aging population worldwide,endoscopic retrograde cholangiopancreatography(ERCP) is being increasingly used in the treatment of common bile duct stones (CBDS) in patients with a poor performance status (PS).Therefore,determining the safety and efficacy of ERCP for CBDS in patients with a PS scor e of 3 or 4 is essential.

But, sitting lonely, time soon began to hang heavy on her hands. One day she said to the old woman: It is dull for me, grandmother, to sit idly hour by hour. My hands want work to do. Go, therefore, and buy me some flax, the best and finest to be found anywhere, and at least I can spin.

In this study,indications of ERCP for CBDS and absence of antibiotics were significant risk factors for ERCP-related complications in the multivariate analysis.While the patients with acute cholangitis and biliary pancreatitis had a low risk for ERCP-related complications,those with obstructive jaundice without cholangitis and asymptomatic CBDS had a high risk for ERCP-related complications.Therefore,we emphasize that the indication of ERCP for CBDS should be carefully considered in patients with a PS score of 3 or 4.Although patients with acute cholangitis and biliary pancreatitis should be endoscopically treated,conservative treatment or follow-up strategy might be considered as an appropriate alternative in patients without acute cholangitis,especially those with asymptomatic CBDS.Regarding the use of antibiotics,the European Society of Gastrointestinal Endoscopy guidelines suggested the use of antibiotic prophylaxis in selected patients such as immunocompromised patients[16].Antibiotic prophylaxis before ERCP to prevent ERCP-related cholangitis and aspiration pneumonia may be administered in patients with a PS score of 3 or 4 because such patients can be immunocompromised.

And when at last the time came for him to go, and he asked, as he had so often asked before, Beauty, will you marry me? She answered softly, Yes, dear Beast

A previous study revealed that long procedure time was a significant risk factor for ERCP-related complications in patients with a PS score of 4[11].Although not statistically significant,a prolonged ERCP procedure tended to increase ERCP-related complications in this study.Permanent biliary stent placement without CBDS removal is a therapeutic option to shorten the procedure time.However,a randomized control trial demonstrated that long-term biliary complications at a median follow-up duration of 20 mo were significantly higher in the permanent biliary stent placement group(complication rate:36%) than in the complete CBDS removal group (complication rate:14%)[17].Another retrospective study at a median follow-up duration of 623 d showed similar results[18].Therefore,complete CBDS removal should be considered at first,and permanent biliary stent placement can be an option in patients with a PS score of 3 or 4 for whom a short prognosis is predicted,who have an underlying disease that is severe,and who are expected to receive prolonged ERCP procedures such as for large and multiple CBDS.

Unlike the results of previous reports[11,12],the rates of aspiration pneumonia were not different between the two groups,and there were no cardiovascular complications in this study.Our sedation protocol using the data pertaining to the age and weight of patients may be attributed to a low incidence of aspiration pneumonia in patients with a PS score of 3 or 4 in this study.Furthermore,careful vital sign monitoring was performed during ERCP,particularly in patients with poor PS.

In this study,we examined the outcomes of ERCP in patients with CBDS,which is the most common indication for ERCP.The rates of therapeutic success,including complete stone removal and permanent biliary stent placement,were comparable between patients with a PS score of 0-2 and those with a PS score of 3 or 4.Although the rates of overall and each ERCP-related complication were not different between the two groups,complications were generally observed to be more severe in patients with a PS score of 3 or 4.Therefore,ERCP for CBDS can be performed effectively in patients with a PS score of 3 or 4.However,endoscopists should try their best to reduce the occurrence of ERCP-related complications because these complications can be more severe in patients with a PS score of 3 or 4.

There are several limitations of this study.First,this was a retrospective study that included specialized centers in Japan.Second,although we balanced patients’ characteristics using one-to-one propensity score matching,some unmeasured confounding factors may exist.Therefore,some selection bias may not be excluded.Third,long-term outcomes of ERCP were not examined in this study.Future multicenter studies including large patient cohorts from institutions with different ERCP experiences are warranted to confirm the safety and efficacy of ERCP for CBDS in patients with a PS score of 3 or 4.

In conclusion,ERCP for CBDS in patients with a PS score of 3 or 4 can be performed effectively.Thus,endoscopists should not be reluctant to perform ERCP for CBDS in patients with a PS score 3 or 4.Nevertheless,the indication of ERCP for CBDS,particularly in patients with asymptomatic CBDS,requires careful consideration,and antibiotics should be used before ERCP in patients with a PS score of 3 or 4.

CONCLUSION

ERCP for CBDS in patients with a PS score of 3 or 4 can be performed effectively.Thus,endoscopists should not be reluctant to perform ERCP for CBDS in patients with a PS score 3 or 4.Nevertheless,the indication of ERCP for CBDS,particularly in patients with asymptomatic CBDS,requires careful consideration,and antibiotics should be used before ERCP in patients with a PS score of 3 or 4.

ARTICLE HIGHLIGHTS

Research background

Only a few studies are available on the association between poor PS and ERCP-related complications.Previous studies reported that the rate of overall ERCP-related complications was not different between patients with a PS score of 0-2 and 3 or 4 having biliopancreatic diseases[12,15] but the rates of aspiration pneumonia and heart failure were higher in patients with a PS score of 3 or 4 than in patients with a PS score of 0-2[12].Another retrospective study reported that the risk of pulmonary and severe complications was high,although ERCP could be performed effectively in patients with a PS score of 4[11].These studies included not only patients with CBDS but also patients with various biliopancreatic diseases.

Research motivation

PS is an important tool to elucidate the indications and strategies of ERCP for CBDS in elderly patients.However,few studies examined the safety and efficacy of ERCP for CBDS in patients with a poor PS.

Research objectives

To examine the safety and efficacy of ERCP for CBDS in patients with poor PS,which is defined as a PS score of 3 or 4.

Research methods

We reviewed the medical records of three institutions in Japan from April 2012 to February 2020.The exclusion criteria were (1) failure to detect CBDS during ERCP;(2) history of therapeutic ERCP;and (3)and an already surgically altered gastrointestinal tract including Billroth II or Roux-en-Y reconstruction.Finally,we identified 1343 patients with choledocholithiasis who met the inclusion criteria for the study,and 1113 and 230 patients had PS scores of 0-2 and 3 or 4,respectively.One-to-one propensity score matching was performed to compare the safety and efficacy of ERCP for CBDS between patients with PS scores of 0-2 and 3 or 4.

I think my life has been long enough now, and I won t visit Seoul anymore. But would it be too much to ask if I wanted you to come to visit me once in a while? I miss you so much. And I was so glad when I heard you were coming for the reunion. But I decided9 not to go to the school…for you. I m so sorry that I only have one eye, and I was an embarrassment for you.

Research results

The overall ERCP-related complication rates in all patients with PS scores of 0-2 and 3 or 4 were 9.0%(100/1113) and 7.0% (16/230;P=0.37),respectively.In the propensity score-matched group,the overall ERCP-related complication rates were 4.6% (9/196) and 6.6% (13/196;P=0.51) among patients with PS scores of 0-2 and PS 3-4,respectively,and complications were significantly more severe in the group with a PS score of 3-4 than in the groups with a PS score of 0-2 (P=0.042).In multivariate analysis,risk factors for ERCP-related complications were indication of ERCP and absence of antibiotics (P <0.001 and P=0.034,respectively).Particularly,absence of acute cholangitis including asymptomatic CBDS,was associated with increased risk of ERCP-related complications.Therapeutic success rates,including complete CBDS removal and permanent biliary stent placement,in propensity score-matched patients with PS scores of 0-2 and 3 or 4 were 97.4% (191/196) and 97.4% (191/196),respectively (

=1.0).

Research conclusions

ERCP for CBDS can be performed effectively in patients with a PS score of 3 or 4.The rates of ERCPrelated complications were similar between the patients with PS scores of 0-2 and 3 or 4;however,their severity was higher in the group with a PS score of 3 or 4 than in the group with a PS score of 0-2.The indication of ERCP for CBDS,particularly in patients with asymptomatic CBDS,requires careful consideration,and antibiotics should be administrated before ERCP in patients with a PS score of 3 or 4.

Whenever he was discouraged or faced difficult problems he would open the box, take out an imaginary4 kiss, and remember the love of this beautiful child who had put it there

Research perspectives

The retrospective study design that included specialized centers in Japan was an important limitation of this study.Future multicenter studies including large patient cohorts from institutions with different ERCP experiences are warranted to confirm our findings.

We would like to thank the staff involved in ERCP at the participating institutions,including Drs.Atsushi Fujimoto,Kana Oomoto,and Yoshitaka Kadowaki at Kumamoto City Hospital;and Yuki Iwagoi,Hajime Iwasaki,and Hibiki Ootani at Kumamoto Chuo Hospital;Satoshi Yamabe at Saiseikai Kumamoto Hospital.

Saito H,Kadono Y,Shono T,Kamikawa K,Urata A,Nasu J,Imamura H,Matsushita I,and Tada S have been equally involved and have read and approved the final manuscript;Saito H,Kadono Y,Shono T,Kamikawa K,Urata A,Nasu J,Imamura H,Matsushita I,and Tada S meet the criteria for authorship established by the International Committee of Medical Journal Editors and verify the validity of the reported results.

The institutional review boards of the participating institutions approved this study.

All study participants or their legal guardian provided informed written consent about personal and medical data collection prior to study enrolment.

When the saint saw that the prince was not to be moved, he said: Learn and know, O youth! that Waq of Qaf is in the Caucasus and is a dependency of it

The authors declare that there are no conflicts of interest in relation to this article.

No additional data are available.

All the authors have read the STROBE Statement—checklist of items,and the manuscript was prepared and revised according to the STROBE Statement—checklist of items.

This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers.It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BYNC 4.0) license,which permits others to distribute,remix,adapt,build upon this work non-commercially,and license their derivative works on different terms,provided the original work is properly cited and the use is noncommercial.See:https://creativecommons.org/Licenses/by-nc/4.0/

Japan

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Hirokazu Saito 0000-0001-8729-9604;Yoshihiro Kadono 0000-0003-2358-120X;Takashi Shono 0000-0002-7577-2991;Kentaro Kamikawa 0000-0002-7783-7584;Atsushi Urata 0000-0001-8232-0988;Jiro Nasu 0000-0001-8555-7454;Haruo Imamura 0000-0001-6825-3758;Ikuo Matsushita 0000-0001-5160-8823;Tatsuyuki Kakuma 0000-0002-3713-3099;Shuji Tada 0000-0001-9087-5457.

The reasons and theories behind three s popularity are numerous and diverse. The number has been considered powerful across history in different cultures and religions, but not all of them. Christians have the Trinity, the Chinese have the Great Triad (man, heaven, earth), and the Buddhists have the Triple Jewel (Buddha, Dharma, Sanga). The Greeks had the Three Fates. Pythagoras considered three to be the perfect number because it represented everything: the beginning, middle, and end. Some cultures have different powerful numbers, often favoring seven, four and twelve.Return to place in story.

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1 Oken MM,Creech RH,Tormey DC,Horton J,Davis TE,McFadden ET,Carbone PP.Toxicity and response criteria of the Eastern Cooperative Oncology Group.

1982;

649-655 [PMID:7165009]

2 Katsinelos P,Paroutoglou G,Kountouras J,Zavos C,Beltsis A,Tzovaras G.Efficacy and safety of therapeutic ERCP in patients 90 years of age and older.

2006;63:417-423 [PMID:16500389 DOI:10.1016/j.gie.2005.09.051]

3 Fritz E,Kirchgatterer A,Hubner D,Aschl G,Hinterreiter M,Stadler B,Knoflach P.ERCP is safe and effective in patients 80 years of age and older compared with younger patients.

2006;64:899-905 [PMID:17140895 DOI:10.1016/j.gie.2006.05.010]

4 Yun DY,Han J,Oh JS,Park KW,Shin IH,Kim HG.Is endoscopic retrograde cholangiopancreatography safe in patients 90 years of age and older?

2014;8:552-556 [PMID:25228977 DOI:10.5009/gnl13310]

5 Han SJ,Lee TH,Kang BI,Choi HJ,Lee YN,Cha SW,Moon JH,Cho YD,Park SH,Kim SJ.Efficacy and Safety of Therapeutic Endoscopic Retrograde Cholangiopancreatography in the Elderly Over 80 Years.

2016;61:2094-2101 [PMID:26873537 DOI:10.1007/s10620-016-4064-y]

6 Saito H,Koga T,Sakaguchi M,Kadono Y,Kamikawa K,Urata A,Imamura H,Tada S,Kakuma T,Matsushita I.Safety and Efficacy of Endoscopic Removal of Common Bile Duct Stones in Elderly Patients ≥90 Years of Age.

2019;58:2125-2132 [PMID:30996182 DOI:10.2169/internalmedicine.2546-18]

7 Tohda G,Ohtani M,Dochin M.Efficacy and safety of emergency endoscopic retrograde cholangiopancreatography for acute cholangitis in the elderly.

2016;22:8382-8388 [PMID:27729744 DOI:10.3748/wjg.v22.i37.8382]

8 Obana T,Fujita N,Noda Y,Kobayashi G,Ito K,Horaguchi J,Koshita S,Kanno Y,Yamashita Y,Kato Y,Ogawa T.Efficacy and safety of therapeutic ERCP for the elderly with choledocholithiasis:comparison with younger patients.

2010;49:1935-1941 [PMID:20847495 DOI:10.2169/internalmedicine.49.3660]

9 Iida T,Kaneto H,Wagatsuma K,Sasaki H,Naganawa Y,Nakagaki S,Satoh S,Shimizu H,Nakase H.Efficacy and safety of endoscopic procedures for common bile duct stones in patients aged 85 years or older:A retrospective study.

2018;13:e0190665 [PMID:29298346 DOI:10.1371/journal.pone.0190665]

10 Kanamori A,Kiriyama S,Tanikawa M,Hisanaga Y,Toyoda H,Tada T,Kitabatake S,Kaneoka Y,Maeda A,Kumada T.Long- and short-term outcomes of ERCP for bile duct stones in patients over 80 years old compared to younger patients:a propensity score analysis.

2016;4:E83-E90 [PMID:26793790 DOI:10.1055/s-0041-108194]

11 Kitano R,Inoue T,Ibusuki M,Kobayashi Y,Ohashi T,Sumida Y,Nakade Y,Ito K,Yoneda M.Safety and Efficacy of Endoscopic Retrograde Cholangiopancreatography in Patients with Performance Status 4.

2021;66:1291-1296[PMID:32440744 DOI:10.1007/s10620-020-06339-7]

12 Takahashi K,Nihei T,Aoki Y,Nakagawa M,Konno N,Munakata A,Okawara K,Kashimura H.Efficacy and safety of therapeutic endoscopic retrograde cholangiopancreatography in patients with native papillae with a performance status score of 3 or 4:A single-center retrospective study.

2019;14:226-230 [PMID:31788147 DOI:10.2185/jrm.19-3007]

13 Cotton PB,Eisen GM,Aabakken L,Baron TH,Hutter MM,Jacobson BC,Mergener K,Nemcek A Jr,Petersen BT,Petrini JL,Pike IM,Rabeneck L,Romagnuolo J,Vargo JJ.A lexicon for endoscopic adverse events:report of an ASGE workshop.

2010;71:446-454 [PMID:20189503 DOI:10.1016/j.gie.2009.10.027]

14 Kanda Y.Investigation of the freely available easy-to-use software 'EZR' for medical statistics.

2013;48:452-458 [PMID:23208313 DOI:10.1038/bmt.2012.244]

15 Park TY,Choi JS,Oh HC,Kim JW,Do JH,Jung YH.Assessment of safety of non-anesthesiologist-assisted endoscopic retrograde cholangiopancreatography based on performance status in elderly patients.

2014;29:1943-1948 [PMID:24730577 DOI:10.1111/jgh.12608]

16 Dumonceau JM,Kapral C,Aabakken L,Papanikolaou IS,Tringali A,Vanbiervliet G,Beyna T,Dinis-Ribeiro M,Hritz I,Mariani A,Paspatis G,Radaelli F,Lakhtakia S,Veitch AM,van Hooft JE.ERCP-related adverse events:European Society of Gastrointestinal Endoscopy (ESGE) Guideline.

2020;52:127-149 [PMID:31863440 DOI:10.1055/a-1075-4080]

17 Chopra KB,Peters RA,O'Toole PA,Williams SG,Gimson AE,Lombard MG,Westaby D.Randomised study of endoscopic biliary endoprosthesis

duct clearance for bileduct stones in high-risk patients.

1996;348:791-793[PMID:8813987 DOI:10.1016/S0140-6736(96)06316-7]

18 Akazawa Y,Ohtani M,Nosaka T,Saito Y,Takahashi K,Naito T,Ofuji K,Matsuda H,Hiramatsu K,Nemoto T,Nakamoto Y.Long-term prognosis after biliary stenting for common bile duct stones in high-risk elderly patients.

2018;19:626-634 [PMID:30117280 DOI:10.1111/1751-2980.12656]