Endoscopy 2023; 55(11): 1056
DOI: 10.1055/a-2106-7613
Letter to the editor

Reply to Drs. Hamo and Samo

1   Department of Gastroenterology and Hepatology, Sint Antonius Hospital, Nieuwegein, The Netherlands
2   Department of Gastroenterology and Hepatology, Amsterdam UMC location Boelelaan, Amsterdam, The Netherlands
3   Department of Gastroenterology and Hepatology, KU Leuven, Leuven, Belgium
› Author Affiliations

We would like to thank Drs. Hamo and Samo for their interest in, and knowledgeable comments on, our study. They addressed two concerns that might potentially have biased our outcomes; however, neither concern would change the direction of our findings. In contrast, both concerns would most likely further strengthen our conclusion that there is no difference in dysplasia detection between random biopsies and WATS3 D.

First, the authors question whether biopsies at 1-cm intervals, instead of 2-cm intervals, could have increased the yield of dysplasia for random biopsies. Logically, when the number of biopsies is increased, dysplasia detection would be expected to rise concordantly. In our study, we chose to use the 2-cm protocol, because this was used in the EURO-II and SURF trials, on which the power calculation of our study was based. In addition, adherence to the Seattle protocol is low and specifically, in the presence of dysplasia, many experts only take 2-cm random biopsies and look instead for visible lesions and perform targeted biopsies (which was also the case for the EURO-II and SURF trials). In addition, WATS will most likely be used in a population of nondysplastic Barrett’s patients undergoing endoscopic surveillance, where 2-cm Seattle biopsies are recommended. Furthermore, and more importantly, we found that WATS did not detect more dysplasia compared with random biopsies. If random biopsies are performed at 1-cm intervals, the statistically nonsignificant gap between biopsies and WATS, as found in our study, will most likely become smaller, which further confirms the findings of our study.

Second, the authors question whether WATS could affect the mucosal architecture of the tissue and, as a result, affect the yield of dysplasia found in the “WATS first, followed by biopsy” group. In order to compensate for the effects of procedure order, we randomized patient allocation to one of the two study groups (i. e. WATS followed by biopsies, or biopsies followed by WATS). We did not find significantly different outcomes for the two groups. Furthermore, if WATS were to affect the mucosal structure, this could lead to a falsely lowered dysplasia detection rate for random biopsies; the “true” dysplasia detection rate in random biopsies would therefore be higher. Again, the nonsignificant gap between dysplasia in random biopsies and WATS that we found in our study would then in fact be even smaller, further strengthening the findings of our study.

Publication History

Article published online:
26 October 2023

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