Review for 10.1186/s12876-020-01415-8 (2020)

Reviewer’ s report
Title: Comparison of surgical outcomes between isolated pancreaticojejunostomy, isolated
gastrojejunostomy, and conventional pancreaticojejunostomy after pancreaticoduodenectomy: Asystematic review and meta-analysis
Version: 0Date: 25 Apr 2020
Reviewer's report:
This manuscript was written about comparison of surgical outcomes between isolated
pancreaticojejunostomy, isolated gastrojejunostomy, and conventional pancreaticojejunostomyafter pancreaticoduodenectomy. This manuscript states some important issues regardingpostoperative complications in isolated pancreaticojejunostomy. However further analysis anddiscussion would be required to confirm this conclusion. Therefore, authors would clarify severalmatters that mentioned below to confirm these conclusions.
1.The concept of reconstruction between isolated pancreaticojejunostomy and isolated gastro-
jejunostomy is completely different. Isolated pancreaticojejunostomy was created to preventpancreatic fistula by separating pancreatic juice from bile juice after pancreaticoduodenectomy. Onthe other hand, isolated gastrojejunostomy was created to prevent delayed gastric emptying afterpancreaticoduodenectomy. Therefore, comparison between isolated pancreaticojejunostomy,isolated gastrojejunostomy, and conventional pancreaticojejunostomy seems to confuse someissues. Authors had better focus on comparison between isolated pancreaticojejunostomy andconventional pancreaticojejunostomy to clearly evaluate the benefit of isolated pancreaticojeju-nostomy.
2.Authors concluded that isolated pancreaticojejunostomy was associated with fewer major
complications. However, the definition of major complications is ambiguous. If the definition ofcomplications among several studies is not unified in a systematic review and meta-analysis, thisconclusion in comparison between isolated pancreaticojejunostomy and conventional pancreati-cojejunostomy might mislead in the wrong way. Authors could clarify the definition of majorcomplications. If impossible, the factor of major complications should be excluded from this meta-analysis.
3.This study reported that isolated pancreaticojejunostomy was not associated with reduction of
pancreatic fistula, clinically-relevant postoperative pancreaticfistula, delayed gastric emptying,clinically-relevant delayed gastric emptying, bile leakage, hemorrhage, or length of postoperativehospital stay. However, isolated pancreaticojejunostomy was associated with fewer majorcomplications. Pancreatic fistula, clinically-relevant postoperative pancreatic fistula, delayedgastric emptying, clinically-relevant delayed gastric emptying, bile leakage, or hemorrhage afterpancreaticoduodenectomy are major complications. There seems to be a discrepancy betweenthese results. What complications does major complications include?
4.I would like to know the reason why isolated pancreaticojejunostomy was associated with a
lower reoperation rate. Authors could discus about the reason by interpreting results of reoperationin each study.
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.
YesAre the conclusions drawn adequately supported by the data shown?
If not, please explain in your comments to the authors.
NoAre 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 furtherassessment 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:
AcceptableDeclaration of competing interests
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