Review for 10.1186/s12876-019-0940-1 (2019)

Reviewer ’s report  
 
Title: Endoscopic Injection Sclerotherapy versus N -butyl -2 cyanoacrylate injection in the 
Management of Actively Bleeding Esophageal Varices: A Randomized Control Trial  
 
Version: 4 Date: 02 Apr 2018  
 
Reviewer: Raymond Tang  
 
Reviewer's report:  
 
Please include all comments for the authors in this box rather than uploading your report as an 
attachment. Please only upload as attachments annotated versions of manuscripts, graphs, 
supporting materials or other aspects of your report which cannot be in cluded in a text format.  
 
Please overwrite this text when adding your comments to the authors.  
The authors conducted a randomized prospective study comparing sclerotherapy with 
ethanolamine to glue injection for treatment of bleeding esophageal varices. Wh ile the research 
topic is an important one, there are some key weaknesses in this study that need to be addressed:  
1) Sample size calculation: The study was presented as a randomized controlled trial, but there's 
no description of sample size calculation in the statistics / methods sessions. Based on the 
current form of the manuscript, we are not sure whether the sample size of 113 patients have 
enough statistical power to draw valid conclusions for the desired primary endpoint. As such, 
the current conclu sion of glue injection being superior to sclerotherapy may not be fully 
substantiated.  
 
2) While the authors claimed that injection therapies such as sclerosant or glue injection may be 
easier to perform in the setting of active esophageal variceal bleedi ng, this claim may not 
always be true. For example, a safe / effective glue injection needs to be intravariceal and if 
the endoscopic view is poor, this may not be achieved easily. If glue is injected in a para -
esophageal fashion, the chance of post glue i njection ulcer formation is high and is not 
desirable. In addition, current major society guidelines have supported banding ligation as 1st 
line therapy for bleeding esophageal varices, therefore the above assumption may not be well 
substantiated.  
 
3) The major study outcomes (eg, rate of initial bleeding control, rebleeding rate) were not 
clearly presented in the abstract. It would be helpful for the authors to present this in the 
abstract for readers to better interpret the study results.     
 
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 whic h 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.  
 
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:  
 
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 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  
financi ally 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 organiz ation 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 th e 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 autho rs 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'  
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 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