Review for 10.1186/s12876-020-01325-9 (2020)

Reviewer ’s report  
 
Title: A newly designed uncovered biliary stent for palliation of mali gnant obstruction: results of 
a prospective study  
 
Version: 4 Date: 05 Jan 2020  
 
Reviewer's report:  
 
This is a multicenter study of a newly developed biliary stent. There are several points to be  
supplemented  in this manuscript.  
 
1. Please attach the photos of the used stent and delivery system.  
 
2. You classified jaundice and stricture tortuosity as mild, moderate or severe. What are the 
specific criteria for this classification?  
 
3. In this study, ten patients  presented with symptoms of recurrent biliary obstruction. However, 
in adverse/other events section, you commented that biliary obstruction developed in two cases. 
Please explain why this difference has occurred.  
 
4. In discussion, you compared the results with that of a meta -analysis by Sawas, which showed 
long term stent occlusion rate of 27%. How long was the median follow -up duration of your 
study?  
 
5. In your study, obstruction occurred distal or proximal to the stent (e.g. tumor overgrowth) was 
not cons idered as clinical failure. However, tumor overgrowth was considered as recurrent 
obstruction and stent failure in many previous studies, so it seems that comparison between 
previous studies and the current study is not fair. Why did you exclude obstructio n occurred 
distal or proximal to the stent in clinical failure? And how about including obstruction occurred 
distal or proximal to the stent in clinical failure for head -to-head comparison with other studies?     
 
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.  
 
Yes 
 
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 t he 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 quality 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, f ees, funding, or salary 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 that may in any way gai n 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 salar y 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 answe r 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 understan d that m y 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 websi te along with the authors' 
responses. I agree for my report to be made available under an Open Access 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 name d report can be in cluded as confidential comments 
to the editors, which will not be published.  
 
I agree to the open peer review policy of the journal