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: 10 Mar 2020  
 
Reviewer's report:  
 
PEER REVIEWER A SSESSMENTS:  
 
OBJECTIVE - Full research articles: is there a clear objective that addresses a testable research 
question(s) (brief or other article types: is there a clear objective)?  
No - there are minor issues  
 
DESIGN - Is the current approach (including  controls and analysis protocols) appropriate for the 
objective?  
No - there are major issues  
 
EXECUTION - Are the experiments and analyses performed with technical rigor to allow 
confidence in the results?  
No - there are major issues  
 
STATISTICS - Is the use of statistics in the manuscript appropriate?  
No - there are issues with the statistics in the study  
 
INTERPRETATION - Is the current interpretation/discussion of the results reasonable and not 
overstated?  
No - there are major issues  
 
OVERALL MANUSCRIPT POTENTIAL - Is the current version of this work technically 
sound? If not, can revisions be made to make the work technically sound?  
No - manuscript has some fundamental flaw(s)  
 
PEER REVIEWER COMMENTS:  
 
GENERAL COMMENTS:  
I would rec ommend the authors amend the title. The study is essentially an observational study 
on the use of uncovered SEMS with apparently new design features.  
I personally found the paper difficult to read and unclear.  
 
REQUESTED REVISIONS:  
State clearly the desig n of the study, i.e., a pilot study looking at safety and efficacy of a new 
device?  
The authors need to clearly state their primary and secondary objectives.  
Marketing aspects about the stent need to be removed from the Abstract.  In Methodology, they 
can say which company supplied the stent. Also, the authors need to make clear that the 6/12 
patency is in n=48.  
 
Design of the study: the authors need to state more clearly how patients were selected for SEMS. 
I must admit I am not used to SEMS being deployed if the patient then goes on and has surgical 
resection in the next month.  
 
The authors need to describe their cohort more clearly --were all cases biopsy -confirmed cancer? 
local/metastatic disease? What was the aim of deployment? --purely palliation or to fac ilitate 
treatment, i.e., chemo+/ -surgery, etc.  
 
It would be useful to document patient performance status, problems with sepsis beforehand, 
how long plastic stents had been in situ before SEMS, procedural times, etc.  
From the authors description, I didn't r eally gain any insight into how the design of the SEMS 
they were evaluating was advancing the technology/field forward.  
In the Discussion, the authors could highlight more clearly the technical issues of concern in 
palliating malignant strictures and sten t design considerations.  
No discussion about limitations of the study.  
No discussion about each participating unit endoscopic performance in general.  
    
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 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.  
 
This reviewer has been recruited by a partner organization, Research Square. Reviewers with 
declared  or apparent competing interests are not utilized for t hese reviews. This reviewer has 
agreed to publication of their comments online under a Creat ive Commons Attribution License 
attributed to Research Square and was paid a small honorarium f or completing the review within 
a specified timeframe. Honoraria for reviews such as this are paid regardless of the reviewer  
recommendation.  
 
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on my report to the authors and, if the manuscript is accepted f or publication, my named report 
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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