Review for 10.1186/s12876-015-0234-1 (2015)

Reviewer's report
Title:Cap assisted colonoscopy for the detection of serrated polyps
Version:3Date:11 July 2014
Reviewer: Joep IJspeert
Reviewer's report:
In this article the authors evaluated the detection rate of serrated polyps (SPs)
with cap-assisted colonoscopy (CAC) compared to standard colonoscopy (SC).
CAC detected a higher total number of significant serrated polyps as well as a
higher number of patients with significant serrated polyps compared to SC.
The outcome of this article is interesting considering the fact that SPs are easily
missed during colonoscopy due their subtle morphology and appearance in the
proximal colon. Recent literature showed that a substantial amount of proximal
colonic interval carcinomas probably arise from serrated polyp precursor lesions.
I do have a couple of major and minor revisions that should receive attention
before this manuscript is suitable for publication
Major Compulsory Revisions:
1. The authors have stated that the diagnosis of SPs was made according to the
2010 criteria of the WHO. It is however not mentioned which pathologists have
assessed the polyp histology. Because of a high inter-observer variability
between pathologists regarding the discrimination of SSA/P and HP, it is
essential that the assessment of the sections is performed by an expert
GI-pathologist and/or is revised by one. Clarification is needed in the manuscript.
2. The primary outcome of this study was the comparison of CAC and SD in
significant serrated polyp detection. Significant serrated polyps were defined as:
sessile serrated adenoma/polyp, traditional serrated adenoma, proximal
hyperplastic polyps and large (# 1 cm) hyperplastic polyp]. It would be more
reasonable to evaluate the detection of proximal serrated polyps as the primary
outcome, because of the following reasons: 1) As mentioned above the
histopathologic differentiation between SP subtypes is difficult. Inclusion of all
SSA/Ps and TSA, but only the proximal and large HP could lead to biased
results; 2) It is stated in the article that the main issue in practice is the limited
protection of colonoscopy against right-sided colon cancer due to missed SPs in
the proximal colon. It therefore seems logical to compare the detection of
proximal SPs rather than polyps spread throughout the entire colorectum.
The assessment of proximal SP detection should at least be taken into account
in this study.
Minor Essential Revisions
1. Conclusion of abstract: The study have shown an increased detection of
“significant” serrated polyps with CAC. In the conclusion of the abstract the
authors have stated that CAC offers a higher detection rate of serrated polyps in
general when compared to standard colonoscopy. This should be rephrased.
2. Introduction third paragraph: It is stated that CAC has not been studied
specifically for the detection of serrated polyps in earlier research. However this
is not entirely true since the detection rate of SSA’s and HP using CAC is already
described by de Wijkerslooth et al(Gut 2012;61:1426–1434.
doi:10.1136/gutjnl-2011-301327). This sentence should therefore be rephrased.
3. Results first paragraph: The baseline characteristics of both groups are
compared in this study. Since both groups have been originated based on
randomization, this comparison is superfluous. This sentence can therefore be
removed from the manuscript
4. Results second paragraph: SSA/SSP should be changed into SSA/P
5. Discussion third paragraph: change enod-scopist into endoscopist
6. Discussion fourth paragraph: “We found that CAC showed a significantly
higher detection rates for significant serrated polyps”. Remove the word a or
change rates into rate.
7. Discussion fifth paragraph: It should be mentioned that other inexpensive and
safe technologies exist to examine behind folds; e.g. the endocuff.
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 have no competing interests to declare.