Review for 10.1186/1471-230X-13-15 (2013)

Reviewer's report
Title:Endoscopic large-balloon dilation alone versus endoscopic sphincterotomy
plus large-balloon dilation for the treatment of large bile duct stones
Version: 1Date:2 December 2012
Reviewer: Evangelos Kalaitzakis
Reviewer's report:
The authors have performed a retrospective study comparing two consecutive
cohorts of patients with large common bile ducts stones: one in which patients
underwent endoscopic sphincterotomy (EST) combined with large-balloon
dilatation (LBD) and another in which patients underwent LBD only without EST.
The two groups were comparable in terms of demographics, the size and number
of bile duct stones, the size of the bile duct, or the presence of a periampullary
diverticulum. Compared with regard to the therapeutic outcome (stone removal
with/without mechanical lithotripsy) and complications, the two techniques did not
differ significantly in terms of any of the outcome variables. The authors
concluded that LBD might be a simple, safe, and effective alternative to
EST+LBD.
This is an interesting study in view of the lack of comparative data in the field,
since, as the authors point out, there have been initial concerns of a possibly
increased rate of pancreatitis in patients undergoing balloon sphincteroplasty.
The authors correctly point out in the Discussion the need for a randomized trial
to fully clarify the issue.
Major concerns
1. An issue to be clarified is patient selection. Although the data and comparisons
presented appear to be sound, it is somewhat unclear, at least for this reviewer,
whether the patients included from each period of time were treated according to
a standard protocol. For example, can there have been patients with stones
>12mm who were treated with EST only? or can there have been patients in
LBD-only period who had LBD+EST but were not included in the study? (for
instance upon realizing that an initial EST would not be enough for stone
removal, i.e. in the event of a change of plan during the procedure). It seems
probable that choice of treatment method was at the discretion of the
endoscopist and this would be a limitation inherent to the retrospective nature of
the study. Although the authors mention the need for a randomized study in the
Discussion, they could consider elaborating a little on limitations inherent to the
retrospective nature of the study that may limit the generalizability of their
findings.
2. Conversely, can there have been patients with stones <12mm treated with
LBD (with/without prior EST)?
3. Patients with "distal extrahepatic bile duct stenosis" were excluded. Although it
is understandable that the investigators may have wanted to exclude patients
with strictures, especially in the suspicion of malignancy, it is not uncommon to
perform LBD in patients with a relative narrowing of the distal CBD. Do the
authors feel that further clarification of this exclusion criterion would help
re-assure the reader that an important group of patients who are actually thought
to usually benefit from LBD were not excluded from the analyses?
Minor essential revisions
1. The authors could consider numbering tables that appear in the manuscript
consecutively and define any supplementary tables/material as such.
Discretionary revisions
1. The authors could consider omitting reported data in the Discussion (for
example in the second last paragraph), which could facilitate reading.
Level of interest: An article whose findings are important to those with closely
related research interests
Quality of written English: Acceptable
Statistical review: No, the manuscript does not need to be seen by a
statistician.
Declaration of competing interests:
I do not have any conflicts of interests to declare