Many clinical studies on narrow‐band imaging (NBI) magnifying endoscopy classifications advocated so far in Japan (Sano, Hiroshima, Showa, and Jikei classifications) have reported the usefulness of NBI magnifying endoscopy for qualitative and quantitative diagnosis of colorectal lesions. However, discussions at professional meetings have raised issues such as: (i) the presence of multiple terms for the same or similar findings; (ii) the necessity of including surface patterns in magnifying endoscopic classifications; and (iii) differences in the NBI findings in elevated and superficial lesions. To resolve these problems, the Japan NBI Expert Team (JNET) was constituted with the aim of establishing a universal NBI magnifying endoscopic classification for colorectal tumors (JNET classification) in 2011. Consensus was reached on this classification using the modified Delphi method, and this classification was proposed in June 2014. The JNET classification consists of four categories of vessel and surface pattern (i.e. Types 1, 2A, 2B, and 3). Types 1, 2A, 2B, and 3 are correlated with the histopathological findings of hyperplastic polyp/sessile serrated polyp (SSP), low‐grade intramucosal neoplasia, high‐grade intramucosal neoplasia/shallow submucosal invasive cancer, and deep submucosal invasive cancer, respectively.

Sedation in gastroenterological endoscopy has become an important medical option in routine clinical care. Here, the Japan Gastroenterological Endoscopy Society and the Japanese Society of Anesthesiologists together provide the revised “Guidelines for sedation in gastroenterological endoscopy” as a second edition to address on‐site clinical questions and issues raised for safe examination and treatment using sedated endoscopy. Twenty clinical questions were determined and the strength of recommendation and evidence quality (strength) were expressed according to the “MINDS Manual for Guideline Development 2017.” We were able to release up‐to‐date statements related to clinical questions and current issues relevant to sedation in gastroenterological endoscopy (henceforth, “endoscopy”). There are few reports from Japan in this field (e.g., meta‐analyses), and many aspects have been based only on a specialist consensus. In the current scenario, benzodiazepine drugs primarily used for sedation during gastroenterological endoscopy are not approved by national health insurance in Japan, and investigations regarding expense‐related disadvantages have not been conducted. Furthermore, including the perspective of beneficiaries (i.e., patients and citizens) during the creation of clinical guidelines should be considered. These guidelines are standardized based on up‐to‐date evidence quality (strength) and supports on‐site clinical decision‐making by patients and medical staff. Therefore, these guidelines need to be flexible with regard to the wishes, age, complications, and social conditions of the patient, as well as the conditions of the facility and discretion of the physician.

Background and study aim: Endoscopic submucosal dissection (ESD) for colorectal tumors is not generally recommended because of the technical difficulties and complications, including perforation. These aspects of ESD are thoroughly analyzed in our retrospective study. Patients and methods: We studied 105 colorectal tumors, from 100 patients, that were treated by ESD at the Kyoto Prefectural University of Medicine or Nara City Hospital between 2005 and 2008. We analyzed tumor size, operation time, rate of en bloc resection, and complications. In addition, we thoroughly investigated the cases of perforation. Results: The average tumor size was 30.4 mm; average operation time, 102 min; and rate of en bloc resection, 88.5 %. Perforation occurred in 10.4 % of the ESD procedures. Of the 11 perforations, 8 were detected during ESD and treated by clip closure during endoscopy, while 3 were evident only on subsequent routine computed tomography (CT); these were also managed conservatively. A case of postoperative hemorrhage was also observed. Conclusions: ESD effectively achieved a high rate of en bloc resection. However, the perforation rate was substantial; hence, improvement in the ESD method is required. The outcomes of ESD, especially for early colorectal malignancies, need to be assessed further.

Safe procedure in endoscopic submucosal dissection for colorectal tumors focused on preventing complications