Review for 10.1186/1471-230X-9-1 (2009)

Reviewer's report
Title:Usefulness and safety of 0.4 percent sodium hyaluronate solution as a
submucosal fluid cushion for endoscopic resection of colorectal mucosal
neoplasms: A prospective multi-center open-label trial
Version: 1Date:27 April 2008
Reviewer: alessandro A repici
Reviewer's report:
This a prospective, multicenter study evaluating the usefulness of 0.4% HA
submucosal injection before EMR of colonic lesions.
The study was conducted between 2003 and 2004 in 6 japanese centers which
have enrolled 40 patients with colonic lesions between 5 and 20 mm suitable for
endoscopic resection.
1)The study has a number of substantial limitations which may significantly
reduce the scientific and technical value of the overall investigation conducted by
the japanese collegues.
2)The first limitation regards the size of the sample size. The authors considered
that “the reported rate of en bloc complete resection with normal saline as the
submucosal injection solution is 72.9-85%. Hence, when the rateof en bloc
complete resection for the 0.4% SH was set at 90%,of 35 patients was required
in order to bound the hypothesized rate ofresection with 95% confidence
interval”.For this statement the authors cited references 16-18 which are very old
and really not fitting the topic of the rate of en-bloc resection. It's very easy to find
more recent data with higher rate of en-bloc resection for lesions smaller than 20
mm. This means that the sample size should be calculated on different basis
which may require much higher number of patients.
3)The second crucial point is the size of the lesions. The authors have included
lesions between 5 and 20 mm which normally are very easily removed en-bloc
with the technique of standard polypectomy. For these lesions injection of HA is
not really required at all and the rate of en-bloc resection is not influenced by the
injected substance rather than the small size. This bias prevent the correct
evaluation of one of the major outcome of the study: the en-bloc resection.
4)Despite the large number of involved centers and small size of the lesions
different technique of mucosal resection and dissection have been used by the
authors. This limits again the statistical analysis making impossible correlations
between the HA injection and the different subgroups of patients selected for the
specific mucosal resection technique adopted.
5)The criteria adopted to evaluate the usefulness of HA injection are quite
subjective and not in line with previous studies conducted to evaluate the
usefulness of different solutions for submucosal injection.
6)The lesion morphology is not specified by the authors. This should be clearly
indicated.
7)Despite the small size of the lesion, the rate of complication is high as
compared with previous series of EMR for colonic lesions. This should
commented by the authors who should also discuss the role of HA in preventing
complications.
8)The conclusions of the study are not supported by the study design,
methodology and results.
9) Economic impact of the use of HA for colonic EMR should be discussed
Level of interest: An article of insufficient interest to warrant publication in a
scientific/medical journal
Quality of written English: Acceptable
Statistical review: No, the manuscript does not need to be seen by a
statistician.
Declaration of competing interests:
I declare that I have no competing interests