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: 01 May 2018  
 
Reviewer: Ulrich Peitz  
 
Revi ewer's report:  
Mayor general points  
 
This study addresses a clinically important issue: Risk factor for post -ERCP cholesystis. Its 
strength is the high number of cases. One of its weaknesses is the retrospective analysis.  
Another problem is:  
It is not clear why endoscopic sphincterotomy, sphincteroplasty, mechanical lithotripsy, laser 
lithotripsy, the type of self -expandable biliary metal stents (uncovered vs. covered) or 
cholecystolithiasis are not considered as risk factors. Based on pathoph ysiology and previous 
data, these factors are supposed to be risk factors.  
The relevance of the conclusion is limited, as the five identified risk factors for PEC (i.e. chronic 
cholecystitis, history of pancreatitis, gallbladder, opacification, leucocyte and biliary metallic 
duct stent) are difficult to avoid, because they are mostly inherent in the disease that is indication 
for ERCP and sphincterotomy  
The elaborated statistics with ROC and nanogram, for me, are difficult to follow and use in 
clinical pra ctice.  
 
Minor points.  
Page 4, line 18  
"ALT, AST, AKP, γ -GT, TB, DB"  Please, spell out  
Page 5, line 40 -45 
"A total of 4238 patients underwent the first ERCP procedure in our hospital was collected in 
Department of Gastroenterology, Nanjing Drum Tower  Hospital Affiliated to Nanjing University 
Medical School from January 1, 2012 to December 31, 2016" Please, consider sentence structure  
Page 6, line 27 -36 
A ROC analysis is used to find a threshold. I do not understand for which parameters you 
determine a threshold.  
Discussion  
 
Page 7, line 4  
"occurrence PEC". occurrence of PEC?  
 
Page 7, line 8  
"The diameter of biliary duct metallic stent was greater than that of the plastic stent, so metallic 
stent placement during ERCP greatly increased duodenal biliar y reflux, which further increased 
the possibility of PEC." Obstruction of the cystic duct by the stent as one cause of acute 
cholecystitis may be discussed.  
 
Page 7, line 16  
"was predispose to PEC." were predisposes to PEC?  
 
Page 7, line 38  
"Our observation time is within two weeks after ERCP and PEC incidence is 1.35%." This is an 
unnecessary redundancy.  
 
Page 7, line 41 -52 
Sorry, I am not able to understand how to use the nomogram  
 
Table 1  
"Acute pancreatitis" Does this mean history of , o r indication for ERCP, or post -ERCP acute 
pancreatitis? It is mentioned in the main text, but please, specify here.  
 
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.  
Unable to assess  
Are the conclusions drawn adequa tely 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 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 recommend additional statistical review  
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 no competing interests'  
 
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