Review for 10.1186/s12876-019-0953-9 (2019)

Reviewer ’s report  
 
Title: ERCP -guided cholangiopancreatoscopy using a single -opera tor system. An appraisal of its 
clinical value based on an extensiv e single institution experience  
 
Version: 1 Date: 01 Aug 2018  
 
Reviewer: Ken Kawabe  
 
Reviewer' s report:  
 
This original article, titled "ERCP -guided cholangiopancreatoscopy using a single -operator 
system. An appraisal of its clinical value based on an extensive single institution experience "is 
discussed the diagnostic and therapeutic usefulness of single -operator, per -oral 
cholangiopancreatoscopy (SOPCP).  For evaluating the usefulness of SOPCP, it should be noted 
that the authors are trying to make as objective judgment as possible by defining the new gradin g 
system. However, the new grading system defined this time is a result from a single institution 
and may contain a lot of bias, I think that it is not difficult to show the usefulness of SOPCP only 
with these presented data. Reviewer would like the author s to answer some questions below.  
 
 
 
(Major)  
 
1. In what kind of case, could it be is possible that information (equivalent to Grade 3 - 4 
defined by the authors) that clinically important decision -make is obtained by performing 
SOPCP compared with convention al image examinations? Please discuss some concrete 
cases.  
 
 
2. How much academic significance does the graph of the annual transition of the number 
of ERCP and SOPCP procedures in the institution of the authors shown in Fig. 1 have in 
this article? In acad emic papers, how far is there a need to show private data such as 
facility report? Please reconsider.  
 
 
3. In Table 2, it has been shown that SOPCP is indicated for cases of indeterminate 
strictures of the bile duct, but the ratio of cases of Grade 1 - 2 and Grade 3 - 4 was no 
significant differences as shown in Table 4. For these cases (indeterminate strict ures), 
despite the high degree of necessity of SOPCP, it is advisable to fully discuss the fact that 
important information has not been obtained as a result.  
 
 
4. Please indicate the contents of "ASA 1 -4" shown in Table 1 in the text.  
 
 
Are the methods appropriate and well described?  
If not, please specify what is required in your comments to the authors.  
 
Yes 
 
Does the work include the necessary controls?  
If not, please specify which controls are required in your comments  to the authors.  
 
Unable to assess  
 
Are the conclusions drawn 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 manus cript or would you recommend an 
additional statistical review?  
If an additional statistical review is recommended, please speci fy 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 qua lity of language in the manuscript:  
 
Acceptable  
 
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 salar y from an 
organisation that may in any way gain or lose financial ly from the publication of this 
manuscript, either now or in the future?  
 
2. Do you hold any stocks or shares in an organisation t hat may in any way gain or lose 
financially from the publicati on 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 competing interests in relation to this paper?  
If you can answer no to all of the above, write 'I decla re that I have  no competing interests' 
below . If your reply is yes to any, please give details below.  
 
I dec lare that I have no competing interests.  
 
I agree to the open peer review policy of the journal. I understan d that my name will be included 
on my report to the authors and, if the manuscript is accepted f or publication, my named report 
including any attachments I upload will be posted on the website along with the authors' 
responses. I agree for my report to be made available under a n Open Acc ess Creative Commons 
CC-BY license ( http://creativecommons.org/licenses/by/4.0/ ). I understand that any comments 
which I do not wish to be included in my named report can be in cluded as confidential comments 
to the editor s, which will not be published.  
 
I agree to the open peer review policy of the journal