除菌後胃粘膜に出現する発赤陥凹性病変の臨床的意義

内容の要旨, 審査の要旨広島大学(Hiroshima University)博士(医学)Doctor of Philosophy in Medical Sciencedoctora

Analysis of Delayed Bleeding after Endoscopic Submucosal Dissection for Gastric Epithelial Neoplasms

Aim. Delayed bleeding after endoscopic submucosal dissection (ESD) for gastric epithelial neoplasms is a major complication. We investigated factors related to post-ESD bleeding to identify preventive measures. Methods. The study included 161 gastric epithelial neoplasms in 142 patients from June 2007 to September 2010. Post-ESD bleeding was defined as an ulcer with active bleeding or apparent exposed vessels diagnosed by an emergency endoscopy or a planned follow-up endoscopy. We analyzed associations between bleeding and the following factors: age, sex, morphology, pathology, tumor depth, ulcer presence/absence, location, size of the resected lesion, duration of the procedure, the number of times bleeding occurred during ESD, and the use of anticoagulants and/or antiplatelet drugs. Subsequently, we examined characteristics of bleeding cases. Results. Post-ESD bleeding occurred in 21 lesions. Univariate analysis of these cases showed that ulcer presence/absence (P < 0.001), middle or lower third lesions (P = 0.036), circumference (P = 0.014), and a post-ESD ulcer with an extended lesser curve (P = 0.009) were significant predictors of bleeding. Multivariate analysis showed that ulcer presence/absence (OR 9.73, 95% CI 2.28–41.53) was the only significant predictor. Conclusion. Ulcer presence/absence was considered the most significant predictor of post-ESD bleeding

Clinical Usefulness of Dual Red Imaging in Gastric Endoscopic Submucosal Dissection: A Pilot Study

Background/Aims Dual red imaging (DRI) is a new, image-enhanced endoscopy technique. There are few reports about the usefulness of DRI during gastric endoscopic submucosal dissection (ESD). We aimed to examine the usefulness of DRI in endoscopic hemostasis during gastric ESD. Methods We enrolled a total of 20 consecutive patients who underwent gastric ESD. Five endoscopists compared DRI with white light imaging (WLI) for the visibility of blood vessels and bleeding points while performing endoscopic hemostasis. Results The visibility of blood vessels was increased in 56% (19/34) of the cases, and the visibility of bleeding points was improved in 55% (11/20) of the cases with the use of DRI compared with the use of WLI. Conclusions DRI improved the visibility of blood vessels and bleeding points in cases with oozing bleeding, blood pooling around the bleeding points, and multiple bleeding points

Genomic landscape of epithelium with low-grade atypia on gastric cancer after Helicobacter pylori eradiation therapy

Background Gastric cancer may develop after successful eradication of Helicobacter pylori, although the incidence is lower than in non-eradicated individuals. We previously reported the appearance of characteristic epithelium with low-grade atypia (ELA) on the surface of gastric cancer after H. pylori eradication. However, whether ELA originates from cancer after re-differentiation or from the non-cancerous surrounding mucosa is unknown. Methods We isolated ELA regions from 10 early gastric cancer patients and analyzed the nucleotide sequences for 90 oncogenes and 35 fusion oncogenes, comparing them with counterpart cancer tissue, normal gastric mucosa, and blood cell-derived DNA. Somatic mutations in each tissue were identified by comparing them with the sequences from whole blood-derived DNA. Result Gene alterations were observed in nine of the ten patients, and up to 42 and 70 somatic mutations were seen in cancer and ELA samples, respectively. Common mutations shared between cancer and ELA tissues were found in eight of these nine patients. In contrast, common mutations between non-cancer mucosa and ELA were only detected in one patient, who also had common mutation between cancer and ELA. ELA-specific nucleotide substitutions were seen in seven patients. In contrast, cancer-specific substitutions were only found in two patients. 18 out of 19 amino acid substitutions present in cancer tissue were also identified in ELA. These results suggest that ELA originated from cancer tissue and accumulated further nucleotide substitutions. Conclusions Differential diagnosis of ELA and normal mucosa should be carefully performed to prevent misdiagnosis of ELA as normal mucosa with atypia.This study was supported by grants from the Japan Society for the Promotion of Science (JSPS KAKENHI GrantNumber: 16K19379; https://www.jsps.go.jp/j-grantsinaid/)

Efficacy of the specialized scissor-type knife for gastric endoscopic submucosal dissection: a propensity score matched retrospective study

Background and study aims Prevention of bleeding and perforation during gastric endoscopic submucosal dissection (ESD) is important. Scissor-type knives can accurately grasp and incise the targeted tissue using electrosurgical currents, thereby eliminating unexpected incisions. The SB Knife GX, a scissor-type knife specialized for gastric ESD, was released in June 2016 in Japan. The aim of the present study was to evaluate the efficacy and safety of gastric ESD using the SB Knife GX. Patients and methods A total of 716 patients who underwent gastric ESD at Hiroshima University Hospital between July 2016 and December 2020 were retrospectively reviewed. From these, 671 patients underwent ESD using the IT Knife 2 (IT-2 group), while 45 underwent ESD using an SB Knife GX (SB-GX group). After propensity score matching, the procedure time, specimen size, en bloc and complete resection rates, and intraoperative bleeding, delayed bleeding, and perforation rates were evaluated. Results No significant differences were observed in mean procedure time (SB-GX group: 115 ± 165 min; IT-2 group: 95 ± 61 min; P  = 0.82) and en bloc and complete resection rates between the two groups. Intraoperative bleeding rates were significantly lower in the SB-GX group than in the IT-2 group (18 % vs. 40 %; P  = 0.01), and there were no differences in delayed bleeding (4 % vs. 4 %) or perforation (0 % vs. 4 %) between the two groups. Conclusions The SB Knife GX was proven to be useful for control of intraoperative bleeding during gastric ESD, although the procedure time tended to be longer

Additional file 1 of Predictive factors for esophageal stenosis in patients receiving prophylactic steroid therapy after endoscopic submucosal dissection for esophageal squamous cell carcinoma

Additional file 1: Supplementary Table 1. Comparison of clinicopathological factors between the groups in patients administered TrA injection only