Review for 10.1186/s12876-025-03973-1 (2025)

Title: Clinical outcomes of endoscopic retrograde cholangiopancreatography after Billroth II
anastomosis: A comparison of gastroscope and duodenoscope
Version: 1 Date: 05 Apr 2025
Reviewer:  Anwar Ashraf Abouelnasr
Reviewer's report:
Dear Authors, please address the following points below
-The study is retrospective, which introduces the potential for selection bias and confounding
variables. Prospective randomized controlled trials (RCTs) would provide more robust evidence,
as they can control for confounding factors more effectively.
-The study is conducted at a single institution, which may limit the generalizability of the results.
A multicenter study would provide a broader and more diverse patient population, helping to
confirm the findings across different settings and institutions.
-Although patients were grouped based on the technique used (gastroscope or duodenoscope),
there is no mention of randomization. This could introduce selection bias, as patients may have
been assigned to one group based on factors that are not controlled for. Randomization would
be a better way to reduce bias and confounding.
-The study does not mention whether long-term outcomes were assessed. Complications such
as post-ERCP pancreatitis and delayed bleeding may manifest after the short-term follow-
up period. A longer follow-up could provide a more complete picture of the outcomes and
complications associated with both techniques.
-While the study mentions that experienced endoscopists performed all procedures, it does not
provide information about the specific level of experience or whether the operators had prior
experience with one technique over the other. The learning curve associated with both the
duodenoscope and gastroscope could impact the outcomes, and it would be valuable to assess
if operator experience played a role in the success rates.
-There could be other confounding factors not accounted for in the study, such as variations
in patient comorbidities, previous abdominal surgeries, or the presence of additional anatomic
alterations. These factors could influence the procedural difficulty and outcomes.
-The use of different guidewires (0.035-inch and 0.025-inch) depending on procedural
requirements might introduce variability in the technique. While this is likely standard practice,
the decision-making process for choosing one guidewire over another is not elaborated on, and
this could potentially influence outcomes.
-The use of fluoroscopy during the procedures is mentioned, but it is not clear whether there were
any differences between the groups in terms of fluoroscopic guidance or fluoroscopy time. This
could influence the cannulation success rates and procedural duration, and it might be valuable
to assess if the fluoroscopy usage differed between the two groups.
-The discussion notes that the procedure duration was significantly shorter in their study
compared to previous studies (10.7 minutes vs. 37.7 minutes). However, while they suggest this
might be due to the availability of immediate interventional radiology support at their center, it is
unclear why this would result in an overall shorter duration. More details on how this impacted
the procedural approach (e.g., whether certain cases were discontinued earlier than they would
have been in other centers) could be helpful for understanding this result.
-Although the discussion mentions that malignant obstruction may influence ALP levels in the
SBC failure group, this relationship is not explored in depth. Given the small sample size and
the lack of statistical significance, more emphasis could be placed on how this finding might
influence future studies, especially with regard to using ALP as a potential marker for predicting
SBC success or failure.
-Although the study acknowledges that procedures were carried out by experienced
endoscopists, the discussion could further explore the potential role of the operator's experience
and how it could have influenced procedural outcomes. For instance, variability in endoscopists'
familiarity with either the duodenoscope or gastroscope might have affected cannulation success
rates or procedure times, which should be addressed more directly.
-The study mentions that procedural decisions were made at the endoscopist's discretion,
including when to discontinue ERCP. However, the discussion does not fully explain how these
decisions were made and how they might have impacted the results. For example, were there
clear guidelines followed, or was it based solely on the endoscopist's assessment? Understanding
this decision-making process more thoroughly could shed light on why certain cases were
discontinued early, which may have influenced the outcomes.
-The discussion does not address the cost implications of using a cap-assisted gastroscope versus
a duodenoscope. In clinical practice, procedural costs may influence decision-making, especially
if one technique is more cost-effective or efficient than the other. Including a brief mention of
cost considerations could offer a more comprehensive perspective on the decision to use either
instrument.