Review for 10.1186/s12876-019-1017-x (2019)

Reviewer ’s report  
 
Title: The efficacy of limited endoscopic sphincterotomy plus endoscopic papillary large balloon 
dilation for removal of large bile duct stones  
 
Version: 1 Date: 17 Jan 2019  
 
Reviewer: Ioannis S. Papanikolaou  
 
Reviewer's report:  
 
The study by Kuo et al is a retrospective analysis regarding the efficacy of limited endos copic 
sphincterotomy plus endoscopic papillary large balloon dilation for the removal of large bile duct 
stones. It is an interesting topic and there is still «room» in the literature for studies regarding 
such comparisons but the paper has some limitation s that should be addressed before publication 
is possible.  
The main limittaion of the study derives from its retrospective design. Hence, the groups are not 
defined, nor are they completely balanced, at least in terms of numbers.  
 
Major remarks:  
Page 9, lines 94 -98: Groups are not balanced in terms of numbers and they are not defined. How 
were the patients included in each of the groups? By arbitrary choice of the examiners? By test 
and error? Did every examiner try all three techniques or did each examin er do just on method? 
If so the results could reflect a difference in the examiners' abilities. This needs clarification in 
the "patients" section, as well as in the discussion.  
Page 9, line 101: exclusion criteria, regarding stones > than 15mm?  
Page 10, line 112: was the sedation of the whole ERCP just 30 -50mg meperidine? If meperidine 
is chosen as sedation, this would be a surprisingly low dose to perform a 25 -30 min ERCP.  
Page 10, line 115: was the cannulation technique used exclusively the ERCP cathete r? Not the 
sphincterotome/ guidewire? Could this affect the results? What is the percentage of successful 
cannulation of the study population? I did not see it written somewhere and this could lead to 
bias in terms of group selection (e.g. large impacted s tones not being include in the study or 
affecting the allocation of the patient to one of three groups). Also please make a remark in the 
discussion.  
Page 11, lines 132 -133: The authors state: "When stones were not extracted completely, a plastic 
biliary s tent was inserted and the residual stones were removed after 3 to 7 days without 
repeating EST or EPLBD". Were these patients excluded, counted as one case, as 2 cases? Also 
please make a remark in the discussion.  
Page 17, lines 229 -230: The study is inter esting but has a plethora of limitations. These should be 
highlighted better than in merely two lines in the closing paragraph of the paper.  
 
Major remarks:  
English should be improved throughout the text.  
Are the methods appropriate and well des cribed?  
If not, please specify what is required in your comments to the authors.  
 
No 
 
Does the work include the necessary controls?  
If not, please specify which controls are required in your comments to the authors.  
 
Yes 
 
Are the conclusions dr awn adequately supported by the data shown?  
If not, please explain in your comments to the authors.  
 
Yes 
 
Are you able to assess any statistics in the manuscript or would you recommend an  
additional statistical review?  
If an additional statistical review is recommended, please specify what aspects require further  
assessment in your comments to the editors.  
 
I am able to assess the statistics  
 
Quality of written English  
Please indicate the quality of language in the manuscript:  
 
Not suitable for publication unless extensively edited  
 
Declaration of competing interests  
Please complete a declaration of competing interests, considering the following questions:  
 
1. Have you in the past five years received reimbursements, fees, funding, or salary from an  
organisat ion that may in any way gain or lose financially from the publication of this  
manuscript, either now or in the future?  
 
2. Do you hold any stocks or shares in an organisation that may in any way gain or lose  
financially from the publication of this manuscri pt, either now or in the future?  
 
3. Do you hold or are you currently applying for any patents relating to the content of the  
manuscript?  
 
4. Have you received reimbursements, fees, funding, or salary from an organization that 
holds  or has applied for patent s relating to the content of the manuscript?  
 
5. Do you have any other financial competing interests?  
 
6. Do you have any non -financial competing interests in relation to this paper?  
 
If you can answer no to all of the above, write 'I declare that I have no c ompeting interests' 
below.  If your reply is yes to any, please give details below.  
 
I declare that I have no competing interests.  
 
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