Review for 10.1186/s12876-017-0631-8 (2017)

Reviewer ’s report  
Title: Optimal timing of cholecystectomy after percutaneous gallbladder drainage for severe  
cholecystitis  
 
Version: 0 Date: 13 Mar 2017  
 
Revie wer: M Minagawa  
 
Reviewer's report:  
The Inoue's paper gives us beneficial information for timing of surgery for severe cholecystitis.  
I think that this paper is worth of publication on the journal. However, there are several of 
questions to clarify as follo wing;  
 
The 1st paragraph of Result, and Table 4.  
 
There are no criteria in terms of making a preoperative decision of open surgery, though the 
authors mentioned this limitation in discussion. Recent digestive surgeons usually need to decide 
open surgery p reoperatively, for the purpose of reducing the difficulty of surgical approach.  
Table 4 shows that the rate of open surgery is higher in non -difficult cholecystectomy group 
(Group B) than the difficult cholecystectomy group (Group A) even though there is no statistical 
difference. This may confuse the journal readers. I think a criteria or reasons for selecting open 
surgery should be mentioned specifically, or cases undergone open surgery should be excluded.  
 
The third paragraph of Discussion ． 
 
The authors say that their data indicate "at least" 216 hours waiting after PTGBD is 
recommended. One question will occur, does waiting for longer time lead safer   
cholecystectomy?  To consider the "optimal" timing, we need to know if longer than 216 hour s 
waiting have an effect on difficulty in cholecystectomy. It is difficult to lead the answer from the 
ROC curve. Please show the understandable data and the authors' view of this question, if 
possible.  
 
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 supporte d 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 recommended, please spec ify 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:  
Accept able 
Declaration of competing interests  
Please comple te 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 thi s 
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  
financially from the publication of this manuscript, either now or in the future?  
3. Do you hold or are you currently applyin g 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 financ ial 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 d eclare 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.  
 
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