Background/Aims: Mucosal cutting biopsy (MCB) is useful for the histopathological diagnosis of gastric subepithelial tumors (SETs). However, there is little information on cases in which MCB did not establish a diagnosis. In the current study, we aimed to investigate the characteristics of cases in which MCB was unsuccessful. Methods: Cases in which MCB was used to histopathologically diagnose gastric SETs at Kobe University Hospital between August 2012 and October 2018 were retrospectively reviewed. Results: Forty-five cases in which MCB was used to diagnose 43 gastric SETs in 43 patients were analyzed. The median tumor size was 20 mm (range, 8–50 mm). Pathological examinations resulted in definitive and suspected diagnoses and no diagnosis in 29 (gastrointestinal stromal tumor: n=17, leiomyoma: n=7, aberrant pancreas: n=3, others: n=2), 6, and 10 cases, respectively. Failure to expose the tumor according to retrospective examinations of endoscopic images was significantly associated with no diagnosis. Other possible explanations included a less elevated tumor, biopsy of the surrounding field instead of the tumor due to the mobility, and poor endoscope maneuverability due to the tumor being close to the cardia. Conclusions Clear exposure of gastric SETs during MCB may improve the diagnostic rate of such examinations.

Background/Aims: Application of polyglycolic acid (PGA) sheets using fibrin glue in post-endoscopic submucosal dissection (ESD) ulcers to prevent bleeding has been reported to be difficult with the conventional delivery method because of gravity. This study assessed the usefulness of the envelope-based delivery system with and against gravity in living pigs. Methods: PGA sheets were applied on post-ESD ulcers with and against gravity six times each using the conventional and envelope methods, respectively. The PGA sheet delivery time and the endoscopic and histological findings of the treated ulcer floors were compared. Results: With gravity, the median PGA sheet application time was 1.00 (0.68–1.30) min/cm2 and 0.32 (0.18–0.52) min/cm2 with the conventional and envelope techniques (p=0.002), respectively, and against gravity, it was 1.20 (1.13–1.63) min/cm2 and 0.50 (0.39–0.58) min/cm2 (p=0.002), respectively. Against gravity, the endoscopic and histological findings revealed that the conventional group had insufficient fixation of the PGA sheets, but the envelope groups had sufficient fixation. The results with gravity were similar between the groups. Conclusions The envelope method makes it possible to deliver PGA sheets to the stomach quickly and cover ulcers appropriately both with and against gravity in living pigs.

Background/Aims: The anastomotic site after distal gastrectomy is the area most affected by duodenogastric reflux. Different reconstruction methods may affect the lesion characteristics and treatment outcomes of remnant gastric cancers at the anastomotic site. We retrospectively investigated the clinicopathologic and endoscopic submucosal dissection outcomes of remnant gastric cancers at the anastomotic site. Methods: We recruited 34 consecutive patients who underwent endoscopic submucosal dissection for remnant gastric cancer at the anastomotic site after distal gastrectomy. Clinicopathology and treatment outcomes were compared between the Billroth II and non-Billroth II groups. Results: The tumor size in the Billroth II group was significantly larger than that in the non-Billroth II group (22 vs. 19 mm; p=0.048). More severe gastritis was detected endoscopically in the Billroth II group (2 vs. 1.33; p=0.0075). Moreover, operation time was longer (238 vs. 121 min; p=0.004) and the frequency of bleeding episodes was higher (7.5 vs. 3.1; p=0.014) in the Billroth II group. Conclusions Compared to remnant gastric cancers in non-Billroth II patients, those in the Billroth II group had larger lesions with a background of severe remnant gastritis. Endoscopic submucosal dissection for remnant gastric cancers in Billroth II patients involved longer operative times and more frequent bleeding episodes than that in patients without Billroth II.

Background/Aims: Visualization of palisade vessels (PVs) in Barrett’s esophagus is crucial for proper assessment. This study aimed to determine whether red dichromatic imaging (RDI) improves PV visibility compared with white-light imaging (WLI) and narrow-band imaging (NBI). Methods: Five expert and trainee endoscopists evaluated the PV visibility in Barrett’s esophagus using WLI, NBI, and RDI on 66 images from 22 patients. Visibility was rated on a 4-point scale: 4, excellent; 3, good; 2, fair; and 1, poor. The color difference between the most recognizable PV spots and surrounding areas with undetectable blood vessels was also analyzed. Results: Mean visibility scores were 2.6±0.7, 2.3±0.6, and 3.4±0.4 for WLI, NBI, and RDI, respectively. The RDI scores were significantly higher than the WLI (p<0.001) and NBI (p<0.001) scores. These differences were recognized by trainees and expert endoscopists. Color differences in PVs were 7.74±4.96 (WLI), 10.43±5.09 (NBI), and 15.1±6.54 (RDI). The difference in RDI was significantly higher than that in WLI (p<0.001) and NBI (p=0.006). Conclusions RDI significantly improved PV visibility compared to WLI and NBI based on objective and subjective measures.

Background/Aims: Visualization of palisade vessels (PVs) in Barrett’s esophagus is crucial for proper assessment. This study aimed to determine whether red dichromatic imaging (RDI) improves PV visibility compared with white-light imaging (WLI) and narrow-band imaging (NBI). Methods: Five expert and trainee endoscopists evaluated the PV visibility in Barrett’s esophagus using WLI, NBI, and RDI on 66 images from 22 patients. Visibility was rated on a 4-point scale: 4, excellent; 3, good; 2, fair; and 1, poor. The color difference between the most recognizable PV spots and surrounding areas with undetectable blood vessels was also analyzed. Results: Mean visibility scores were 2.6±0.7, 2.3±0.6, and 3.4±0.4 for WLI, NBI, and RDI, respectively. The RDI scores were significantly higher than the WLI (p<0.001) and NBI (p<0.001) scores. These differences were recognized by trainees and expert endoscopists. Color differences in PVs were 7.74±4.96 (WLI), 10.43±5.09 (NBI), and 15.1±6.54 (RDI). The difference in RDI was significantly higher than that in WLI (p<0.001) and NBI (p=0.006). Conclusions RDI significantly improved PV visibility compared to WLI and NBI based on objective and subjective measures.

Background/Aims: Visualization of palisade vessels (PVs) in Barrett’s esophagus is crucial for proper assessment. This study aimed to determine whether red dichromatic imaging (RDI) improves PV visibility compared with white-light imaging (WLI) and narrow-band imaging (NBI). Methods: Five expert and trainee endoscopists evaluated the PV visibility in Barrett’s esophagus using WLI, NBI, and RDI on 66 images from 22 patients. Visibility was rated on a 4-point scale: 4, excellent; 3, good; 2, fair; and 1, poor. The color difference between the most recognizable PV spots and surrounding areas with undetectable blood vessels was also analyzed. Results: Mean visibility scores were 2.6±0.7, 2.3±0.6, and 3.4±0.4 for WLI, NBI, and RDI, respectively. The RDI scores were significantly higher than the WLI (p<0.001) and NBI (p<0.001) scores. These differences were recognized by trainees and expert endoscopists. Color differences in PVs were 7.74±4.96 (WLI), 10.43±5.09 (NBI), and 15.1±6.54 (RDI). The difference in RDI was significantly higher than that in WLI (p<0.001) and NBI (p=0.006). Conclusions RDI significantly improved PV visibility compared to WLI and NBI based on objective and subjective measures.

Background/Aims: Endoscopic submucosal dissection (ESD) for diverticulum-associated colorectal lesions is generally contraindicated because of the high risk of perforation. Several studies on patients with such lesions treated with ESD have been reported recently. However, the feasibility and safety of ESD for lesions in proximity to a colonic diverticulum (D-ESD) have not been fully clarified. The aim of this study was to evaluate the feasibility and safety of D-ESD. Methods: D-ESD was defined as ESD for lesions within approximately 3 mm of a diverticulum. Twenty-six consecutive patients who underwent D-ESD were included. Two strategic approaches were used depending on whether submucosal dissection of the diverticulum-related part was required (strategy B) or not (strategy A). Treatment outcomes and adverse events associated with each strategy were analyzed. Results: The en bloc resection rate was 96.2%. The rates of R0 and curative resection in strategies A and B were 80.8%, 73.1%, 84.6%, and 70.6%, respectively. Two cases of intraoperative perforation and one case of delayed perforation occurred. The delayed perforation case required emergency surgery, but the other cases were managed conservatively. Conclusions D-ESD may be a feasible treatment option. However, it should be performed in a high-volume center by expert hands because it requires highly skilled endoscopic techniques.