Review for 10.1186/s12876-020-01393-x (2020)

Reviewer ’s report  
 
Title: Comparison of End -to-Side Hand -Sewn an d Side -to-Side Stapled Cervical Esophagogastric 
Anastomosis in Patients with Lower Thoracic Esophagea l Cancer Undergoing Transhiatal 
Esophagectomy: An Iranian Retrospective Cohort Study  
 
Version: 1 Date: 24 Apr 2020  
 
Reviewer: C Gutschow  
 
Reviewer's report:  
 
Rasihashemi SZ et al.: Comparison of Hand -sewn and Modified Mechanical Anastomosis in 
Esophageal Cancer Patients Undergoing Transhiatal Esophagectomy: An Iranian Retrospective 
Cohort Study  
 
In this retrospective single -center study, the authors report resu lts of 409 patients that underwent 
transhiatal esophagectomy with gastric pull -up and cervical esophago -gastrostomy over a 6 -year 
period. Two distinct anastomotic techniques were compared; a stapled side -to-side (MMS) and a 
double -layer hand -sewn end -to-side technique (HS). The main outcome parameters were 
anastomotic leakage anastomotic stenosis/stricture, and need for dilation and symptoms at FU. 
Leak and stenosis rate were significantly lower after MMS, and the authors conclude that the 
stapled side -to-side technique may be preferred for this type of procedure.   
 
Style and structure of the manuscript seem acceptable, the discussion covers most important 
aspects, and conclusions are in line with most relevant publications on this topic. On the other 
hand,  there are various retrospective cohort studies in the literature covering this topic and the 
message provided here is certainly not breathtakingly new; however, given that this study looks at 
an interesting technical aspect of esophagectomy, it may be a v aluable contribution. Nevertheless, 
I have a few remarks:  
 
General remarks:  
 
* Some parts of the manuscript are difficult to understand and sometimes misleading. 
Therefore, I recommend proof reading by an English native speaker.  
 
Abstract:  
 
* The descripti on of the stapled technique "modified mechanical stapled (MMS) 
anastomosis (double stapled technique)" is confusing for the reader, because  the term "double 
stapling" usually delineates a circular stapling technique, where the circular stapler is fired ac ross 
a linear stapler line that was used for previous transsection of a tubular structure. The technique 
described here is very similar to Collard's stapled side -to-side cervical esophago -gastrostomy 
technique with the exception that the anterior aspect of  the anastomosis is not closed with sutures, 
but with another stapler cartridge. Therefore I suggest changing to "stapled side -to-side esophago -
gastrostomy" and "hand -sewn end -to-side esophago -gastrostomy" throughout the manuscript.  
 
Introduction:  
 
* "Durin g the last two decades, stapled techniques have been introduced in order to 
decrease the risk of anastomotic leakage…"  As far as I am informed, stapled esophago -
gastrostomy was introduced more than 40 years ago.  
 
*  Page 3,line 12: Please change "Collared»  to «Collard».  
 
* Page 3, line 13: Whether the Orringer technique is superior remains a matter of debate.  
Methods:  
 
* The authors excluded patients who died or did not attend FU after 12 months. I suggest 
to include those patients for analysis of perioperat ive outcomes (OR time, anastomotic leakage, 
perioperative morbidity and mortality).  
 
* Did you include all consecutive cases over the whole study period? Please indicate all 
exclusion criteria for this study.  
 
* In addition, I recommend to include more perio perative outcome parameters: 
reoperation, ICU stay, overall morbidity, etc.  
 
* How many patients had a jejunal feeding catheter inserted during esophagectomy and 
subsequently received enteral nutrition?  
 
* Please state the exact definition of anastomotic le akage. How many patients had opening 
of the cervical wound? Where other diagnostic means for detection of leakage used (CT -scan, 
endoscopy, clinical aspect)?  
 
Results:  
 
* For better readability, I suggest to subdivide the "Results" section into separate 
paragraphs regarding the main outcome parameters: A) perioperative morbidity and anastomotic 
leakage, and B) anastomotic stricture, need for anastomotic dilation and symptoms at FU.  
 
* Please state in -hospital, 30 -day- and 90 day mortality. What about other c omplications 
(pulmonary, cardiac etc.)? Where deaths statistically related to anastomotic leakage?  
 
* Please add information about the median FU, the number of patients undergoing 
postoperative endoscopy at which FU.  
 
* Regurgitation (of already ingested fo od) is ususally a sign of delayed gastric emptying 
and not of anastomotic stenosis. Any ideas why regurgitation was less in the MMS cohort? Did 
you systematically assess dysphagia, aspiration, weight loss / malnourishment as main symptoms 
of anastomotic st enosis?  
 
* How many patients had local/distant recurrence of cancer? How did you make sure that 
anastomotic stricture was not caused by local recurrence?  
 
* Page 6, line 30: «Despite HS anastomosis patients, anastomotic stricture symptoms 
significantly reso lved in patients with linear stapled anastomosis (PV= 0.004).» I do not understand 
this sentence.  
 
* Page 6, line 35: «Patients with HS anastomosis had significantly required dilatation 
compared with MMS group at the end of the follow up period (PV= 0.04), and also compared with 
patients underwent MMS technique, the rate of anastomotic stricture dilatation was significantly 
higher in the patients underwent HS technique during one year of follow up (PV= 0.021).» This 
sentence is very confusing, too.  
 
 
Discussion/Conclusion:  
 
* According to the literature, the leak rate of cervical esophago -gastrostomy can reach 
&gt;30% even in experienced centers - depending on the definition used for anastomotic leak.  
 
* In my view, the conclusion does not reflect the r esults presented, as in the "Results" 
section it was stated that need for dilation was higher in the HS group after 12 months.  
 
Tables:  
 
* Table 1: Percentages seem not correct for female / male distribution and tumor types. 
Please check.  
 
In summary, the m anuscript needs major revision but may be suitable for publication in the BMC 
Gastroenterology.  
 
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.  
 
Yes 
 
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 statisti cs in the manus cript or would you recommend an additional 
statistical review?  
If an additional statistical review is recommended, please speci fy what aspects require further 
assessment in your comments to the editors.  
 
I recommend additional statistical rev iew 
 
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 any 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 recei ved 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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