Endoscopy 2020; 52(01): 77
DOI: 10.1055/a-1026-6136
Letter to the editor
© Georg Thieme Verlag KG Stuttgart · New York

Reply to Murakami et al.

Yosuke Kataoka
 1  Department of Gastroenterology, Sanraku Hospital, Tokyo, Japan
,
Yosuke Tsuji
 2  Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
,
Kingo Hirasawa
 3  Division of Endoscopy, Yokohama City University Medical Center, Kanagawa, Japan
,
Kengo Takimoto
 4  Department of Gastroenterology, National Hospital Organization Kyoto Medical Center, Kyoto, Japan
,
Tomonori Wada
 1  Department of Gastroenterology, Sanraku Hospital, Tokyo, Japan
,
Satoshi Mochizuki
 5  Shinagawa Gut Clinic, Tokyo, Japan
,
Ken Ohata
 6  Department of Gastroenterology, NTT Medical Center Tokyo, Tokyo, Japan
,
Yoshiki Sakaguchi
 2  Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
,
Keiko Niimi
 2  Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
 7  Center for Epidemiology and Preventive Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
,
Satoshi Ono
 8  Department of Gastroenterology, Chiba-Nishi General Hospital, Matsudo, Japan
,
Shinya Kodashima
 9  Department of Gastroenterology, Teikyo University School of Medicine, Tokyo, Japan
,
Nobutake Yamamichi
 2  Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
 7  Center for Epidemiology and Preventive Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
,
Mitsuhiro Fujishiro
10  Department of Gastroenterology and Hepatology, Graduate School of Medicine, Nagoya University, Nagoya, Japan
,
Kazuhiko Koike
 2  Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
› Author Affiliations
Further Information

Publication History

Publication Date:
18 December 2019 (online)

We appreciate the comments from Murakami et al. regarding our study [1], and are grateful for the opportunity to address their points.

As the authors point out, it remains unclear how the polyglycolic acid (PGA) shielding method works on endoscopic submucosal dissection (ESD)-induced ulcers. Our study could not assess the mechanism because it was a clinical study to investigate the efficacy of the PGA shielding method for preventing post-ESD bleeding.

To date, only two studies have investigated the mechanism of PGA shielding for ESD-induced ulcers in an animal model [2] [3]. Takao et al. reported that histological examination of ESD-induced ulcers on which PGA sheets with fibrin glue were applied revealed no excessive inflammation, necrosis or infection in a porcine model [2]. Tsujimoto et al. reported that the fibrin glue used in the PGA shielding method has a protective effect against gastric juice and reduces tissue damage, and that the scaffold function of PGA fabric induces better granulation formation at an earlier phase, resulting in excellent long-term tissue repair in a canine model [3]. These two studies demonstrated the protective effect of PGA shielding, but in both studies histological examinations were performed at least 3 days after ESD. Therefore, whether acute inflammation occurs in early phases, as Murakami et al. suggest, was not assessed. Inflammatory reaction against PGA sheets immediately after shielding might lead to early-phase bleeding after ESD, but post-ESD bleeding occurs most frequently within 24 hours after ESD procedures [4]. In this regard, it is questionable whether PGA shielding truly aggravates early-phase bleeding. More investigations would be essential.

At present there are several types of biodegradable materials available, and we totally agree with the authors that we should deepen our understanding of those materials and their mechanisms in order to apply them more effectively in endoscopic fields.