Review for 10.1186/s12876-025-03591-x (2025)

Title: Evaluation of Double-Balloon Enteroscopy in the Management of Type 1 Small Bowel
Vascular Lesions (angioectasia): A Retrospective Cohort Study
Version: 3 Date: 23 Nov 2024
Reviewer:  Daniel Wild
Reviewer's report:
Dolu and colleagues present a retrospective review the adds to the existing literature
investigating rates of re-bleeding from SBVL and the factors that influence these rates.
Overall, their study is well-conducted and posses no glaring methodological flaws but some of
their results vary significantly from the literature I am familiar and my experience of managing
these patients and performing DBE in the US for many years.  In particular, the following stand
out as particularly unexpected:
1) Of the 740 DBE's performed over their 15 year study period, only 42% were performed for
bleeding.  This stands in contrast to most prior studies in which bleeding is the indication for
DBE closer to 75% of the time.
2) It is also unexpected that they report finding a source for the bleeding in a high number of
patients (80%) whereas rates in other studies are more typically around 50% and despite this
high diagnostic rate, only 67 of the pts (21% of the bleeding cohort, 9% of their entire cohort who
underwent DBE) had SBVL whereas these are most typically the dominant source of bleeding
in pts reported in other studies.
3) It is surprising that in the entire cohort which spans hundreds of DBE's over a 15 year period,
only 5 patients had active small bowel bleeding at the time of their DBE.  Without knowing
more about Turkey's health system and their hospital in particular, it is hard to make sense of
how low this number is as at our US referral center, we typical find at least 5 active small bowel
bleeds on DBE in a month.
4) As the author's acknowledge in their Discussion, their re-bleeding rates are also surprisingly
low at 16.1% over their median 25 months of follow-up and 11.3% within the first year.  These
numbers are much lower than the 40-50% re-bleeding rates described in most other similar
studies.
5) It is unexpected that over a 15 year span, not a single patient required embolization, surgery
or medical therapy for management of their bleeding as embolization and medical therapy are
commonly employed in the management of these patients in the US at least.
Though there is nothing presented by the authors that makes me question their results, the
differences in their findings when compared to other literature and my considerable anecdotal
experience makes me question the generalizability of their findings as their cohort of patients
seems to be quite different from those cared for elsewhere.
Their paper would be further strengthened by clarifying, extrapolating on the following:
1) When describing their approach to DBE in the Methods section, it is written as though their
was a prospective protocol  on how DBE was performed but this is a retrospective study.  They
wrote that they "insisted" that the ileum was reached on antegrade exams but I find it difficult
to believe that they 1) could always reliably discern when they reached the ileum and 2) that
they were always able to reach the ileum, especially when the mean time for their exams was
only 60 minutes.  What if they found the clear source of bleeding in the proximal jejunum, did
they still go to the ileum?  What if there was a patient with a fixed / tethered small bowel that
prevented deep insertion?
2) As their ability to calculate rates of re-bleeding is contingent on patient's following up in their
health center, they should state how many patients in the cohort died or were lost to follow-up.
3) They should state what the mean / median number of additional DBE's and the mean /median
time between exams was in the cohort of patients that required "multiple" DBE's.
4) In their Results, the authors state that rebleeding occured in 16.1% over the entire study and
11.3% in the first year but then seem to sum these 2 rates in their Discussion when stating that
their overall rebleeding rate was 27.4%.  I don't think this is valid as I'm assuming that the 11.3%
of patients that re-bled in the first year are included in the 16.1% that re-bled overall.  If not,
these results need to be clarified.