Review for 10.1186/s12876-025-04010-x (2025)

Title: Comparative Efficacy of Gelatin Sponge, Microcoils, and NBCA in Arterial
Gastrointestinal Bleeding: A Retrospective Study
Version: 1 Date: 28 Mar 2025
Reviewer:  Anwar Ashraf Abouelnasr
Reviewer's report:
Dear Authors, please address the following points below
-While retrospective studies are valuable, they are inherently subject to biases such as selection
bias and recall bias. The study does not appear to control for potential confounding factors that
could affect the outcomes. For instance, patient comorbidities or the timing of the intervention
could influence results but are not explicitly addressed.
-The study design lacks randomization, meaning that patient selection into the different
embolization groups was not randomized. This could introduce confounding variables, as
patients in each group may have differed in important baseline characteristics, such as the
severity or location of bleeding. A randomized controlled trial (RCT) would have been more
powerful in providing unbiased comparisons between the groups.
-The study focuses on short-term outcomes (30-day clinical success and rebleeding rates).
However, it would be valuable to assess longer-term outcomes, such as mortality beyond 30
days, chronic complications, or the need for further treatments after discharge.
-The study was conducted at a single institution, and the outcomes may not be generalizable to
other hospitals or healthcare settings with different patient populations, procedural practices, or
embolization techniques. A multi-center study could strengthen the findings and enhance their
applicability to a wider population.
-While postoperative outcomes are assessed within 30 days, there may be issues related to
follow-up duration. If follow-up data is incomplete or not standardized, it could affect the
reliability of the results. Additionally, the study does not mention how the follow-up was
performed (e.g., through clinic visits, telephone, or medical records), which could impact
consistency in data collection.
-The description of the embolization techniques for gelatin sponge and micro coils is quite
detailed, but there is less information about the procedure used for NBCA. Given that NBCA
offers rapid polymerization, further detail about how the agent is introduced and controlled
during the procedure would be valuable for clinicians unfamiliar with the material.
-The claim of a "100% clinical success rate" for the gelatin sponge + NBCA combination, while
promising, may be somewhat overstated, especially considering the study's retrospective nature.
A 100% success rate is highly unusual in clinical settings, and there could be some variability in
outcomes that are not fully captured in the data presented. This claim could benefit from more
cautious language, such as “near 100%” or “extremely high success rate,” to avoid overstating
the results.
-While the study highlights the benefits of combination therapies, the discussion lacks a thorough
exploration of potential complications or downsides associated with the use of micro coils or
NBCA. For example, the risk of vascular injury with micro coils or the potential for NBCA
embolization to non-target areas could be addressed in more detail to provide a balanced
perspective.
-Although the study emphasizes the superior outcomes of combination therapies, it could have
gone a step further by discussing any possible subgroup differences. For instance, were there
any differences in outcomes based on factors like the location of bleeding, comorbidities, or
hemodynamic status? A more granular analysis could provide insights into how embolization
strategies might be optimized for specific patient populations.