Review for 10.1186/s12876-020-01323-x (2020)

Reviewer ’s report  
 
Title: Comparison between transpancreatic sphincterotomy and needle -knife fistulotomy in  
difficulty biliary access, a retrospective study in Taiwan  
 
Version: 3 Date: 19 Feb 2020  
 
Revi ewer's report:  
 
Thanks for the answer to my questions. However, I have further concerns:  
 
1. I'm sorry but you didn't answer my question N.1. You refer to a paper published in 2017 
regarding the definition of "difficult biliary cannulation". How can you use this definition, which 
is a very restrictive definition, in a retrospective study that includes patients from 2015 to 2017?  
 
2. My question N. 4 was: Why the 18 patients with failed cannulation didn't undergo NKF or 
TPS attempt? Of course, they underwent other procedures, but I don't understand why, after a 
failed standard cannulation, NKF or TPS attempt was not performed if you usually did it after "5 
contacts with the papilla or mor e than 10 minutes of cannulation".  
 
3. Table 2: What is the difference between EPBD: endoscopic papillary balloon dilatation and 
EPLBD: endoscopic papillary large balloon dilatation? What ERBD mean?  
 
4. Table 4: if you use 1 or 2 for patient gender to guar antee the anonymity of the patient (as 
suggested by the Editor), to me, you should not use a caption explaining what is 1 and what is 2 
(i.e., 1=male and 2= female). Moreover, patient number 8 has still M.  
 
 
 
 
Are the methods appropriate and well described?  
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.  
 
No 
 
Are the conclusions drawn adequately supported by the data shown?  
If not, please explain in your comments to the authors.  
 
No 
 
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:  
 
Needs some langu age corrections before being published  
 
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  
organisation 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 manuscript, 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 patents relating to the content of the manuscript?  
 
5. Do you have any other financial competing interests?  
 
6. Do you have any non -financial com peting interests in relation to this paper?  
 
If you can answer no to all of the above, write 'I declare that I have no competing interests' 
below.  If your reply is yes to any, please give details below.  
 
I declare that I have no competing interests  
 
I agree to the open peer review policy of the journal. I understand that my name will be included  
on my report to the authors and, if the manuscript is accepted for publication, my named report  
including any attachments I upload will be posted on the website along  with the authors'  
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which I do not wish to be included in my named report  can be included as confidential comments  
to the editors, which will not be published.  
 
I agree to the open peer review policy of the journal