Review for 10.1186/s12876-025-04225-y (2025)

Title: A Real-world Study of Balloon dilation vs. Self-Expandable Metal Stents for Benign
Gastric Outlet Obstruction
Version: 0 Date: 23 Jul 2025
Reviewer's report:
Major comments
1. Study design and reporting
• Retrospective design and group allocation.  The authors label this work a “real#world study”;
however, the manuscript is essentially a single#centre retrospective cohort.  Patient inclusion/
exclusion criteria and group allocation are not described in sufficient detail.  It is unclear
why patients were assigned to balloon dilation or stenting – the groups differ in etiology
(postoperative vs. non-postoperative strictures), which introduces confounding.  Please describe
how treatment allocation decisions were made, whether there were baseline differences in
stricture severity or comorbidities, and whether any measures were taken to minimise selection
bias.  Consider using multivariable regression or propensity#score methods to adjust for baseline
differences.
• Inconsistent description of groups.  The Methods section divides patients into three groups, yet
parts of the Results refer to “four groups” and some tables list three groups, but the text refers to
“three groups … from GOOSS 1 to GOOSS 3”.  This inconsistency makes it difficult to follow
the results.  Please harmonise the number of study groups throughout the manuscript.
• Definition of endpoints.  “Technical success”, “clinical success” and “clinical cure” are used
without clear, reproducible definitions.  For example, the primary end#point is described as
“clinical success” defined as a significant increase in stricture diameter that allows passage of
an endoscope with symptom resolution; Table 3 reports “Cured”, “Improved” and “Ineffective”
without explaining how these categories were assigned.  Please define each endpoint a priori
and describe which outcomes were used for statistical testing.
• Sample size and statistical power.  The study includes 70 patients divided among three groups;
some sub#analyses involve very small numbers (e.g., complications in Group A).  No sample
size calculation or power analysis is provided.  Please discuss the possibility of type II error and
justify that the study is sufficiently powered to detect differences in complications or recurrence
rates.
2. Statistical analysis
• Appropriateness of tests.  The GOOSS is an ordinal scale (scores 1–3), yet one#way ANOVA
was used to compare post#procedure scores.  Ordinal data are more appropriately analysed with
non#parametric tests (e.g., Kruskal–Wallis) unless normality can be demonstrated.  Similarly,
“technical success” and complication rates are proportions; #² tests are acceptable, but logistic
regression would permit adjustment for covariates.  Please reconsider the statistical methods and
ensure that assumptions are met.  Provide measures of central tendency and spread (mean ± SD
or median [IQR]) for continuous variables and report exact p values rather than simply stating
“< 0.05”.
• Survival analysis.  A “5#year survival rate” is reported despite a median follow#up of
19.7 months, and Kaplan–Meier curves are mentioned but not shown.  Please clarify how
survival was analysed, provide a Kaplan–Meier plot if applicable and explain how a 5#year
survival estimate was obtained when the follow#up appears to be shorter.
• Multiple comparisons.  Many variables are compared across groups, increasing the risk of
type I error.  Please describe whether adjustments (e.g., Bonferroni correction) were made for
multiple testing.
3. Ethics and transparency
• Ethics approval and consent.  The manuscript states that the study was approved by the ethics
committee and that informed consent was waived.  However, the Declarations section later states
that written informed consent for publication was obtained.  This is contradictory.  Please clarify
the ethical approvals obtained and ensure that information about ethics approval, consent to
participate and consent for publication is presented under separate subheadings, as required by
BMC Gastroenterology #.
• Data availability.  BMC Gastroenterology strongly encourages authors to make the datasets on
which conclusions are based available to readers #.  The current statement “For further details,
the corresponding author can be contacted” does not meet this expectation.  Please provide a
data availability statement indicating where the de#identified dataset can be accessed or justify
why data cannot be shared.
4. Clarity and structure
• Running head and category.  The running head states “Treatments for benign colorectal
stricture”, which does not match the topic of gastric outlet obstruction.  This should be corrected.
In addition, the manuscript is classified as an “original article”; please confirm that it meets the
criteria for a research article (original primary research) #.
• Organisation.  The manuscript does not fully follow the recommended structure for research
articles.  For instance, the Background section could better summarise existing literature and
clearly state the study’s rationale #.  The Methods section includes two separate headings
labelled “Patients” without clear distinctions.  The Results section intermingles narrative text
and statistical results without always providing corresponding tables or figure references.
Please reorganise the manuscript so that each required section (Background, Methods, Results,
Discussion, Conclusions) is clearly delineated #.
• Language and grammar.  Several sentences contain grammatical errors or unclear phrasing
(e.g., “patients were admitted for benign GOO and entered into the study”, “Balloon dilation
may have short#term benefits in many cases… and the stricture tends to recur”).  The authors
are encouraged to have the manuscript edited by a native English speaker or professional editing
service.
5. Interpretation and context
• Use of uncovered stents.  Uncovered SEMSs are generally recommended for malignant GOO
and not for benign GOO because tissue ingrowth prevents removal #.  The study reports the use
of uncovered stents in some patients with benign obstruction without justification.  Please clarify
why uncovered SEMSs were chosen, discuss their appropriateness, and consider focusing on
fully covered stents which are designed to be retrievable.  Note that new techniques such as
endoscopic ultrasound#guided gastrojejunostomy (EUS#GJ) are increasingly used for benign
GOO #; the Discussion should place the current findings in the context of these emerging
treatments.
• Conclusions exceeding data.  The conclusion that SEMSs “are not recommended as first choice
for the management of benign GOO compared to balloon dilation” may be premature given the
non#randomised design and heterogeneity among groups.  Please moderate the conclusion by
acknowledging that balloon dilation appears to have fewer complications and lower cost in this
cohort but that prospective randomised studies are needed.
6. Figures and tables
• Figure presentation.  Figures should be numbered in the order first mentioned and each figure
should be accompanied by a concise title and legend in the manuscript #.  The composite figures
(Figs 1 and 2) illustrate cases of balloon dilation and stenting; however, the legends are lengthy
and contain patient identifiers such as “a middle#aged man” and “an elderly man”.  Please
remove unnecessary demographic descriptors, use consistent labelling (a–f, a–i) and ensure that
arrows or scale bars are visible in the images.  The legend should briefly describe what each
panel shows without repeating data that belong in the Results.
• Table formatting and content.  The tables provided separately summarise patient
characteristics, technical outcomes and complications.  There are misalignments and
typographical errors in the headings (e.g., “Others’ discomfort”, “Clinical symptoms” appears
as a blank row) and some rows mix units (e.g., “Hospitalization cost, ×10# ¥”).  Ensure that each
table has a clear title and footnotes defining all abbreviations.  Check consistency of decimal
places and that the numbers in the tables agree with the text.  The statistical test used for each
comparison should be indicated.
Minor comments
• Abstract length and structure.  BMC Gastroenterology limits abstracts to 350 words and expects
the abstract to be structured with Background, Methods, Results, and Conclusions sub#headings
#.  The current abstract is 168 words but uses “Background”, “Purpose”, “Methods”, “Results”
and “Conclusions”.  Please change “Purpose” to “Methods” and ensure that no references are
cited in the abstract #.
• Keywords.  Provide 3–10 keywords that describe the main content of the article #.  At present,
six keywords are listed; ensure they are separated by semicolons and follow the journal’s
formatting.
• Acronyms.  Define all abbreviations at first use in the text and provide a list of abbreviations
after the Conclusions #.  For example, GOOSS, IQR, and SEMS should be defined.  In the
manuscript, “course of disease, months” is ambiguous; specify whether it refers to the duration
of obstruction symptoms.
• References.  Reference formatting should follow the Vancouver style; ensure that all citations
are numbered sequentially in the order they appear in the text and that journal names are
abbreviated according to PubMed.  Some citations are missing spaces (e.g., “et al.2018”) and
one citation is split across lines (“Kochhar S. Endoscopic balloon dilation … 2010;2(1):29-35.”).
Double#check that all references are accurate and complete.
• Date range.  The study period extends to March 2025, only four months before the current date
(24 July 2025).  Please confirm that all follow#up data were available at the time of analysis
and specify the cut#off date for data collection.