Review for 10.1186/s12876-020-01506-6 (2020)

Reviewer’s report
Title: 
Vertical distance from navel as a risk factor for bowel obstruction
associated with feeding jejunostomy after esophagectomy : a retrospective
cohort study
Version: 
1 
Date: 
16 Aug 2020
Reviewer's report:
The authors present a retrospective review of 70 patients who underwent
'thoracoscopic' esophagectomy between March 2013 and December 2019 of
whom 6 patients developed bowel obstruction after feeding jejunostomy tube
placement (BOFJ). They found that the vertical distance between the umbilicus
and the j-tube site was the only significant factor that predicted BOFJ. I have
several questions and concerns about this manuscript.
1.) I am worried that you have a significant variable that you do not seem to
have taken into account--this is the fact that you changed the type of abdominal
mobilization you were using after the first two years--going from hand-assisted
to a more complete laparoscopic approach for the final 4 years. In doing this, you
changed the location of your incision to one in the upper abdomen to one closer
to the umbilicus. It seems pretty clear to this reader that in doing so you have
naturally changed the location of where the j-tube would most naturally lie--
lower in the latter half of your experience. So, please tell us how many patients
were in each group (HALS vs. laparoscopic) and the BOFJ--did these all occur
in the patients undergoing HALS? This may be difficult to evaluate statistically
because there are so few patients with bowel obstruction. 
2.) I think you need to better define your terminology for esophagectomy. You
state it is a thoracoscopic esophagectomy but this is only part of the procedure
you describe in your methods. It is really what we would call a 3-hole
esophagectomy with an abdominal component and an anastomosis in the neck.
3.) You had 3 patients that had 3 or more episodes (I think) of BOFJ--one
wonders why these obstructions were not treated more aggressively with FJ
removal after one or two bouts.
4.) Why did your patients undergo neoadjuvant chemotherapy as opposed to
chemoradiation which is standard of care based on CROSS trial results.
5.) All of your patients appear to have had an abdominal CT scan performed
within one month after the primary operation by which you measured the
vertical distance--Is this CT scan part of your normal routine? Why a 30 day CT
scan--is it part of some sort of protocol?
Minor issues:
There is a sentence in the results section of the abstract that does not make
sense--"Conducting univariate analysis, logistic regression analysis showed...." Is
is logistic regression or univariate analysis?
Your paragraphs should be indented to signify a new paragraph
In your methods section on page 4, you have several one sentence paragraphs--
these should all be combined.
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