Review for 10.1186/s12876-020-01265-4 (2020)

Reviewer ’s report  
 
Title: Efficacy of gastric decompression after  pancreatic surgery: a systematic review and meta -
analysis  
 
Version: 0 Date: 13 Feb 2020  
 
Reviewer: Salvatore Paiella  
 
Reviewer's report:  
 
In this manuscript, Gao et al. from a Chinese Institution a imed at assessing the role of routine 
gastric decompression after pancreatic surgery through a systematic review and metanalysis of 
previously published data. The authors selected 6 retrospective studies, including 940 patients 
overall. The analysis reveal ed no differences in terms of overall complications and POPF, while 
a higher incidence of clinically relevant delayed gastric emptying, higher rate of mortality and 
longer hospital stay were found among RGD patients.   
 
Despite the small number of selecte d studies, this is technically plenty to perform a metanalysis. 
Statistics seem adequate; however, several major concerns are to be pointed out:  
 
1) The first concern regards the main goal of the study, which is to assess the utility of 
RGD in pancreatic surgery.  I agree that it is crucial to augment the evidence regarding the 
routine use of NGT in pancreatic resections, but it is even more interestin g to address how 
should surgeons behave with the different types of resection ( i.e. PD -Whipple, PPPD, DP, TP), 
and with the different types of reconstruction (i.e PJ, PG). The authors do not report this aspect 
nor do the data they elicit from the included  studies.  
 
2) The introduction should be more focused on the topic. It is important to stress that 
ERAS recommendations discourage the routine use of postoperative NGT following pancreatic 
surgery though the level of evidence is still improvable, which is correctly stated in the 
"discussion".  
 
3) In the "methods" the authors state that "the search terms were divided into two groups: 
the "pancreatic resection" terms, and the "Gastric decompression" terms (. The search strategy 
was adapted to the databases ac cordingly.". Can the authors better explain this peculiar 
methodology?  
 
4) The third exclusion criteria for the study selection is not clear.  
 
5) The measures of outcomes include overall complications, major complications and 
some of the most common pancre atic surgery complications such as POPF and DGE.  
-What do the authors mean "major complications? "  
-Are pancreatic surgery related complications defined and graded according to the ISGPS 
classification? As for the DGE, this is reported only in the "result s". Which edition was used to 
define POPF?  
-Why do the authors consider the secondary gastric decompression as a separate outcome despite 
this is included in the ISPGS definition of DGE?  
 
6) Being the secondary gastric decompression a separate outcome, it is diffult to 
understand why the authors excluded one study with the reason reported as following:"In 
addition, one studies were excluded because some patients in the no -routine decompression 
group underwent NGT"  
 
7) In the "conclusion", the authors state t hat RGD does not have any effect on the 
postoperative outcome, which is more likely to be a speculation than a reliable transcription of 
what the results describe.  
 
8) Finally, despite understandable, the manuscript contains some typo inaccuracies as well 
as some major syntactical errors. The English form is definitely improvable.  
 
 
Other comments:  
 
1) What do the author mean when they state : "Two studies were conducted in the USA, 
two in Korea, one in Korea and one in Norway". Is it two in the USA, 3 in  Korea and 1 in 
Norway?  
 
 
 
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 c omments to the authors.  
 
No 
 
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 qual ity 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 recei ved 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  
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 sa lary 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 an swer 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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