Review for 10.1186/s12876-018-0854-3 (2018)

Reviewer ’s report  
Title: Risk Factors for Post -ERCP Cholecystitis ：A single -Center Retrospective Study  
 
Version: 0 Date: 03 May 2018  
 
Reviewer: Stephan Haas  
 
Reviewer's report:  
Jun Cao and co -workers analyzed in a large retrospe ctive study more than 4000 patients who 
underwent ERCP and identified 36 patients who developed post -ERCP cholecystitis. The authors 
identified key risk factors and developed a prognostic nomogram which deserves future 
application and confirmation in prosp ective studies.  
In contrast to post -ERCP pancreatitis, data on post -ERCP cholecystitis is limited. Therefore, this 
study is of clear interest.  
 
Some suggestions may be made:  
* The title should be changed and the term post -ERCP cholecystitis should be used . 
Cholecystitis is only possible in the presence of a gallbladder - therefore "gallbladder in 
situ" can be omitted.  
* Abstract: Uni -and multivariate analysis was performed and should be both noted.  
* Unfortunately, the indications for ERCP are vaguely ment ioned and a more detailed 
presentation of the indications would be favorable.  
* Freeman et al (NEJM 1996) identified gallstones as the only risk factor for cholecystitis post 
sphincterotomy. Unfortunately, no information regarding the prevalence of gallsto nes is 
presented in the present study. It should be feasable to determine the rate of gallstones in the 
36 patients who developed post -ERCP cholecystitis (if not in the rest of patients).  
* Chronic cholecystitis is one of the main risk factors for post -ERCP cholecystitis suggesting 
that gallstones (as the main risk factor for chronic cholecystitis) have a prominent role in 
post-ERCP cholecystitis even in the present study.  
* The term opacification should be briefly defined as not all readers may be familia r with this 
term. Has the term "gallbladder development" in Figure 4 the same meaning? In this case 
the term could be changed to opacification.  
* Number of patients in brackets should be noted as e.g. (n=182).  
* TB, DB should be noted as total bilirubin an d direct bilirubin  
* Endoscopic gallbladder drainage is discussed as a possible prophylactic intervention in high 
risk patients. This procedure should be explained very briefly.  
* The relationship of white blood cell count before ERCP and PEC was depicted by a binned 
scatterplot diagram (Figure 3). The discussion should point out that the association was 
shown to have a rather low odds ratio (OR=1.1)  
* The authors could discuss the possibility that a number of patients with a past "idiopathic" 
acute pancrea titis might have suffered from an acute pancreatitis due to microlithiasis and 
sludge referring to published EUS studies.  
* Abbreviations of lab parameters should be explained in Table 1.  
* The manuscript should be "polished" by an English native speaker.   
 
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 adequa tely 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 manus cript or would you recommend an 
additional statistical review?  
If an additional statistical review is recommende d, 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:  
Needs some language corrections before being  published  
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 a ny 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 t hat 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 applying 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 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 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 not competing interests.  
 
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