Kei Terasaki

Background: Accurate diagnosis of the demarcation line (DL) of gastric tumors is essential for curative complete resection by endoscopic submucosal dissection (ESD). It is controversial to perform only magnifying endoscopy for diagnosing the DL of gastric tumors prior to ESD. This study aimed to evaluate the diagnostic accuracy for the DL of gastric adenomas and well-differentiated adenocarcinomas using only magnifying blue laser imaging (M-BLI) compared with that using both M-BLI and biopsy confirmation. Methods: In this prospective, single-center study, 96 well-differentiated adenocarcinomas and 32 gastric adenomas were enrolled between July 2015 and December 2016. A total of 122 lesions with a clear DL on M-BLI were randomly allocated to undergo M-BLI only (the M-BLI group) or M-BLI with biopsy confirmation (the M-BLI-BC group), performed as biopsies in 4 directions from noncancerous tissues ≈ 5 mm outside the lesion before ESD. The primary end point was to clarify the noninferiority of M-BLI without biopsy confirmation compared with that with biopsy confirmation, in terms of the diagnostic accuracy and complete resection. Results: There were no significant differences in sex, median age, color, circumference, macroscopic type, biopsy-based diagnosis, and Helicobacter pylori infection between the 2 groups. The diagnostic accuracy for the DL was 100 and 95.0% and the complete resection was 100 and 100% in the M-BLI and M-BLI-BC groups, respectively. Conclusion: The diagnostic ability of M-BLI is excellent in diagnosing the demarcation of gastric adenoma and well-differentiated adenocarcinoma. Biopsy confirmation is not needed for these lesions with a clear DL by M-BLI.

Introduction: An innovative endoscopic system using 4-color light-emitting diodes (LED) was released between 2016 and 2017 in locations that had not approved laser endoscopes for use, including the United States and Europe. Objective: This study compared the diagnostic efficacy between magnifying blue light imaging with an LED light source (LED-BLI) and magnifying blue laser imaging with a laser light source (Laser-BLI) for early gastric cancer (EGC). Methods: In this prospective, single-center, noninferiority study, 80 gastric lesions were evaluated between January 2017 and July 2017. The magnifying findings of gastric lesions – including the demarcation line (DL), microvascular pattern (MVP), and microsurface pattern (MSP) – were evaluated using Laser-BLI and LED-BLI according to the vessel plus surface classification system (VSCS). The primary end point was to determine whether the diagnostic accuracy of LED-BLI for EGC was noninferior to that of conventional Laser-BLI. Results: Overall, we evaluated 79 gastric lesions histopathologically diagnosed as adenocarcinomas from the specimens obtained via endoscopic submucosal dissection. A DL was observed by Laser-BLI and LED-BLI in 98.7% (78/79) and 96.2% (76/79) of EGCs, respectively. The MVP observed using Laser-BLI and LED-BLI was irregular in 92.4% (73/79) and 89.9% (71/79), respectively. The MSP observed using Laser-BLI and LED-BLI was irregular in 83.5% (66/79) and 82.2% (65/79), respectively. According to the VSCS, diagnosable cancers were found in 94.9% (75/79) and 93.7% (74/79) of cases when using Laser-BLI and LED-BLI, respectively (p = 0.73; difference ratio, 1.2%; 95% CI –8.5 to 6.0%). Conclusions: LED-BLI could accurately visualize the DL, MVP, and MSP of EGCs and was not inferior to Laser-BLI. Therefore, LED-BLI can be used to diagnose EGC accurately according to the VSCS-based diagnosis criteria.

Background: Management of antithrombotic agents during endoscopic treatment changed after the publishing of ­Japan Gastroenterological Endoscopy Society guidelines for gastroenterological endoscopy in antithrombotic drug users (GL-2012). Objectives: We aimed to evaluate the effect of implementing antithrombotic agent management guidelines (GL-2012) on postoperative bleeding after endoscopic submucosal dissection (ESD) for early gastric cancer (EGC) and on the prevention of thromboembolic events. Methods: A total of 1,264 patients who underwent ESD for EGC at Kyoto Prefectural University Hospital between June 2002 and March 2017 were enrolled and divided into 2 groups: 621 patients before the publication of GL-2012 (Pre-GL group) and 643 patients after (Post-GL group). Relationships between postoperative bleeding and various clinicopathological factors in each group were investigated through propensity score-matching analysis. Results: In the Pre-GL group, antihypertensive agent use (p < 0.01) and upper third of the stomach (p < 0.01) were significantly related to postoperative bleeding in univariate analysis. Antihypertensive agent use (OR 4.6, 95% CI 1.6–12.8) and upper third of the stomach (OR 4.9, 95% CI 1.8–13.4) were significantly related to postoperative bleeding in multivariate analysis. In the Post-GL group, antihypertensive agent use (p < 0.01), dual antiplatelet agents use (p < 0.01), anticoagulant agents use (p < 0.01), and heparin replacement therapy (p < 0.01) were significantly related to postoperative bleeding in univariate analysis. Antihypertensive agent use (OR 3.4, 95% CI 1.1–9.6), dual antiplatelet agents (OR 12.3, 95% CI 2.4–63.0), and heparin replacement therapy (OR 10.2, 95% CI 2.5–41.5) were significantly related to postoperative bleeding in multivariate analysis. Conclusions: The adherence to GL-2012 might reduce risk of thromboembolic events. On the other hand, dual antiplatelet agents therapy and heparin replacement therapy were the new independent risk factors for ESD postoperative bleeding in EGC after GL-2012. Especially as for heparin replacement therapy, uninterrupted warfarin or a temporary short interruption of direct oral anticoagulants without heparin replacement therapy might be recommended rather than heparin replacement therapy.

Background/Aims: The purpose of this study was to evaluate the safety and efficacy of gastric endoscopic submucosal dissection (ESD) using the Clutch Cutter (CC), a scissor-type knife, compared with those of procedures using conventional devices. Methods: This single-center retrospective study evaluated 237 patients with early gastric cancer: 83 who underwent ESD using the CC group and 154 who underwent ESD using the insulated-tip knife 2 (IT2 group). Clinicopathological features and technical outcomes were compared between the 2 groups using a propensity score-matched analysis. Results: In 61 pairs of matched patients, there was no significant difference in R0 resection, perforation, or postoperative bleeding between the CC and IT2 groups. Comparisons between the 2 groups showed similar treatment outcomes for an expert endoscopist. Nevertheless, there were significant differences between the 2 groups for nonexperts in terms of self-completion (61.7 and 24.5%, respectively, p < 0.001), mean procedure times (45 and 61 min, respectively, p = 0.002), and mean numbers of intraoperative bleeding points and bleeding points requiring hemostatic forceps (3 and 0 vs. 8 and 3, respectively, p < 0.001). Conclusion: Better self-completion rates and shorter procedure times were noted for gastric ESD using the CC by nonexperts than for that using IT2, probably due to hemostatic efficacy.

Background/Aims: The aim of this study was to evaluate the diagnostic accuracy of magnifying narrow-band imaging (M-NBI) with histopathological confirmation in identifying the demarcation line (DL) of early gastric cancer (EGC). Methods: EGCs resected by endoscopic submucosal dissection after identifying the DL using M-NBI following histopathological confirmation were included. After determining the DL for the entire EGC lesion using M-NBI, at least 4 biopsies were taken from non-cancerous tissues outside the EGC lesion for histopathological confirmation. Results: A total of 330 EGCs were analyzed in this study. The rate of biopsy-negative and negative horizontal margin were 96.7% (319/330) and 97.9% (323/330) in EGC respectively. Tumors larger than 20 mm showed a higher risk for showing remnant cancer cells on biopsies taken outside the DL. Risk factors for a positive horizontal resection margin were tumor size > 20 mm and moderately or poorly differentiated adenocarcinomas. Conclusion: The assessment of demarcation of EGC using M-NBI was excellent in well-differentiated (WD) adenocarcinoma and lesions below 20 mm in size. However, histopathological confirmation is needed to assess the demarcation of non-WD adenocarcinomas and EGC over 20 mm in size.