Review for 10.1186/s12876-018-0880-1 (2018)

Reviewer ’s report  
 
Title:  Feasibility of a 20 -gauge ProCore needle in EUS -guided subepithelial tumor sampling: a 
prospective multicenter study  
 
Version: 0 Date: 30 May 2018 
 
Reviewer:  Hiroyuki  Matsubayashi  
 
Reviewer’s report:  
 
General comments  
 
Current study focused on the diagnostic yield of 20G Procore needle for the histological 
diagnosis of gastrointestinal subepithelial tumors (SET), with size ≥2 cm. So far, EUS -FNA have 
been done by 22G - or 25G - fine needle, so that the specimens obtained f rom gastrointestinal 
SETs tended to be small fragments of tissues. In this sense, current needle demonstrated a higher 
frequency of core samples and could reduce the number of passes for accurate pathological 
diagnosis.  
 
 
Major comments  
 
1) The limitation of  this study is the size of SET, and only tumors with ≥2 cm in size were 
analyzed. You should describe the reasons for it in Materials and Methods and discuss it? Is that 
because biological behavior is good when SET is <2 cm? Or, is that because diagnostic yield of 
EUS -FNA is stable and high?  
 
 
2) You should mention the characteristic of needle construction of Procore 20.  
 
This needle has a side hole at some mm from the tip. This may help good sampling, but may 
hinder when tumor size is small and stroke length  is not enough.  
 
 
Minor comments  
 
1) Page 7, L133. Did you use rapid on -site evaluation (ROSE) and determined only by 
macroscopic view? Even if not using ROSE, you should add the description.  
 
2) Discussion, P11, L231 -232. The sentences written in above are  about histological adequacy 
(89.5%) and diagnostic accuracy (86.0%, 81.8% -86.0%). However, your following sentences on 
current result were mention by optimal macroscopic and histological core sample rate (97.2%). 
This is not logical. If you compare with t he previous papers, you should state in the same 
measurements.   
 
3) I recommend to add one photo (Figure) showing a low -power view of typical sample to 
demonstrate the size of acquired tissue.  
 
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 manuscript or would you recommend an 
additional statistical review?  
If an additional statistical review is r ecommended, please specify what aspects require further 
assessment in your comments to the editors.  
 
Not relevant to this manusc ript 
 
Quality of written English  
Please indicate the quality of language in the manuscript:  
 
Acceptable  
 
Declaration of competing interests  
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