Review for 10.1186/s12876-022-02607-0 (2022)

Title: Value of abdominal ultrasonography in predicting intestinal resection for premature
infants with necrotizing enterocolitis
Version: 3 Date: 24 Oct 2022
Reviewer's report:
Brief Summary
This is a retrospective study evaluating the use of abdominal ultrasound in infants with NEC to
predict need for intestinal resection. There is a need to earlier identify and predict the severity of
NEC and need for additional interventions, where the author proposes abdominal US to have a
role. The revised manuscript provides better clarity, especially in the methods and results section,
and the discussion has been enhanced. Some minor points for additional clarity and organization
have been suggested for consideration below.
Major Comments: None
Minor Comments
I appreciate the expansion of the methods section to include more details, including more about
timing of the imaging studies. Can you clarify if these babies in your study are inborn (born at
the included hospitals and therefore day of admission is newborn day) or are they outborn and
admission day is day of transfer/day of suspected diagnosis of NEC?
Broadly, would recommend reviewing the tense used in the methods section as there are some
discrepancies. For example, line 104, AUS “was” performed at admission. Similar comments
for line 107, line 121 (The most important goal “was”), and some additional areas throughout
the methods section.
Line 165 – Use of “odds ratios” rather than “risk ratios” were calculated
Line 226: I agree that the differences in indications for surgical intervention may account for
some of the difference, though likely other factors also contribute between the difference in data
between other centers.
Line 228: I appreciate the addition of some long term discussion of complications of intestinal
resection. Consider adding “adverse”: …”predispose infants to adverse long term nutritional
and developmental outcomes” for clarity.
Lines 229-230: Suggest clarifying the end of this sentence, or perhaps create a second sentence
here (rather than continuation of lines 227-228) to better transition into your last sentence of
this paragraph.
Line 240 – Suggest clarifying which parameters – is this from the meta-analysis or the AUS
parameters from your study? It would be great to discuss which AUS parameters were significant
from this metaanalysis and how it compares to your study. Lines 241-247: Is this information
also from the meta-analysis? Suggest clarifying or moving these lines to another section as it
doesn’t seem to be related to the parameters associated with resection/surgery, etc. which were
previously being discussed.
Line 259: abdominal XR are still widely used, especially when AUS is not as readily available. I
would suggest saying “not as suitable” to focus on the comparison with AUS and the advantages
you mention.
Line 279: Is this because of the use of AUS serially rather than AXR?
Line 299-300: I appreciate this discussion, however, I do think it will vary based on many factors
and your data can be useful for older patient populations elsewhere. Consider stating that “The
median gestational age of infants with NEC is higher than  many other cohorts so could be
difficult to generalize to younger populations” or something similar.