Shuntaro Yoshida

The diagnosis of submucosal tumors of the stomach by endoscopic ultrasonography

The clinical value of endoscopic ultrasonography (EUS) in the diagnosis of submucosal tumors (SMTs) of the stomach was examined. We used echo endoscopes with a 7.5 or 10.0 MHz radial-scan transducer made by Olympus Co. Ltd. EUS was carried out on 80 patients with SMTs of the stomach including 54 cases confirmed histologically (24 cases of leiomyoma, 3 of leiomyosarcoma, 12 of cysts, 7 of aberrant pancreas, 4 of lipoma, 2 of carcinoid, and 3 of other diseases). Fifty-nine patients with extraluminal compression were detected by endoscopy and/or x-ray examination. We examined the effectiveness of EUS based on our analysis of the gastrointestinal tract wall seen in the EUS image as a five-layered structure corresponding with that of the histological layers. As a result, SMTs and extragastric compression were easily distinguishable in the EUS images of the lesions. The size, location, and origin of the SMTs could be detected. From the location of the SMT in the five-layered structure seen in the EUS image we could predict its histological nature. Thus, EUS was a most valuable method not only in the diagnosis of intramural and extramural SMTs but also in the detection of extragastric compressive lesions and organs.

Endoscopic submucosal dissection is an effective and safe therapy for early gastric neoplasms: a multicenter feasible study.

Background and Aim: The technique of endoscopic submucosal dissection (ESD) was introduced to obtain en bloc specimens of large early gastrointestinal neoplasms. The drawback of ESD is its technical difficulty and, consequently, its higher rate of complication. In this multicenter study, we investigated the therapeutic outcomes of ESD in consecutive patients. Methods: From January 2002 to December 2008, 485 early gastric neoplasms in 418 patients were consecutively treated by using ESD procedure performed by 6 endoscopists in 4 institutions in Tokyo. Demorgraphics, tumor location, therapeutic outcomes, and complication rates were analyzed. Results: The rates of en bloc resection, complete en bloc resection, submucosal invasion, and piecemeal resection were 93.6%, 85.4%, 10.9%, and 5.4%, respectively. In multivariate analysis, the en bloc resection rate was independently lower in lesions in upper portion than in lower portion (P<0.01), lower in larger lesions (>30 mm, P<0.05; 20 to 30 mm, P<0.05), and lower in lesions with a scar (P<0.01). Delayed bleeding occurrence was independently high in larger lesions (>30 mm, P<0.01; 20 to 29 mm, P<0.01) than in small lesions (<20 mm). Institution and endoscopists were not risk factors of en bloc resection and complications Conclusions: ESD is an effective and safe therapy in the management of early gastric neoplasms when performed by well-trained endoscopists. Endoscopists should recognize the difficulty to perform ESD for en bloc resection of upper lesion, and the risk of delayed bleeding in cases of lesions >2 cm in size.

Distribution of intestinal metaplasia as a predictor of gastric cancer development

Helicobacter pylori, gastritis, and intestinal metaplasia (IM) are known risk factors for gastric cancer. In the present study, we conducted a cohort study to evaluate the predictive value of the distribution of IM for gastric cancer development.

Sitafloxacin resistance in Helicobacter pylori isolates and sitafloxacin-based triple therapy as a third-line regimen in Japan

The third-line treatment regimen for Helicobacter pylori after failure of clarithromycin- and metronidazole-based therapies is not yet established. Sitafloxacin (STX) is a quinolone that possesses potent in vitro activity against H. pylori. In this study, the susceptibility of H. pylori isolates to STX was examined and the efficacy of STX-based triple therapy as a third-line regimen was evaluated. STX showed minimum inhibitory concentrations (MICs) of ≤1 μg/mL against all 100 H. pylori isolates, and the MIC(90) (MIC for 90% of the organisms) of STX was 5 log(2) dilutions lower than that of levofloxacin (LVX). The MIC(50) (MIC for 50% of the organisms) of STX against gyrA mutants was 0.12 μg/mL and was significantly lower than that of LVX (8 μg/mL). The activity of STX at pH 5.5 was significantly less than that at pH 7.0. In the clinical trial, 28 patients with two eradication failures were treated with STX-based triple therapy [rabeprazole 10 mg twice daily (b.i.d.), amoxicillin 750 mg b.i.d. and STX 100mg b.i.d. for 7 days]. The eradication rate was 75% using intention-to-treat analysis and 80% using per-protocol analysis. Two gyrA mutant strains were eradicated. Amongst participants, a low pepsinogen I/II ratio was associated with successful eradication. These results suggest that STX could be active against most clinical H. pylori isolates and that STX-based triple therapy is a promising and safe third-line therapy.

Endoscopic management of colonic diverticular bleeding

Colonic diverticular bleeding is the most common cause of lower gastrointestinal bleeding. Colonoscopy can be used for both diagnosis and treatment of colonic diverticular bleeding. Identification of the stigmata of recent hemorrhage allows for various endoscopic hemostasis methods. Clipping, endoscopic band ligation, injection therapy, and thermal contact are available methods for endoscopic hemostasis. However, the optimal technique remains to be determined. Herein, we review the techniques and clinical outcomes of endoscopic hemostasis for colonic diverticular bleeding.

A Japanese prospective multicenter study of self-expandable metal stent placement for malignant colorectal obstruction: short-term safety and efficacy within 7 days of stent procedure in 513 cases.

BACKGROUND Endoscopic self-expandable metal stent placement has been used as an alternative to surgery for malignant colorectal obstruction; however, factors affecting its clinical outcome are unclear. OBJECTIVE To clarify the short-term safety and efficacy of endoscopic self-expandable metal stent placement for malignant colorectal obstruction and to identify factors associated with its clinical and technical failure. DESIGN Prospective clinical cohort study. SETTING Fourteen academic centers and 32 community hospitals. PATIENTS A total of 513 consecutive patients with malignant colorectal obstruction. INTERVENTION Endoscopic self-expandable metal stent placement, sharing of stent placement methods among participating facilities. MAIN OUTCOME MEASUREMENTS The primary endpoint was clinical success, defined as symptom and radiological finding resolution within 24 hours. Secondary endpoints were technical success and adverse events. The follow-up period was 7 days. RESULTS The clinical and technical success rates were 95.5% and 97.9%, respectively. Major adverse events included perforation (2.1%), stent migration (1.0%), and stent occlusion (0.8%). The main causes of perforation were the procedure itself (0.8%) and comorbidities (obstructive colitis and impending perforation) not apparent before stent placement (0.6%). Extrinsic tumor origin was independently associated with the clinical failure after stent placement (odds ratio 4.23; 95% confidence interval, 1.21-14.79; P = .02). Stricture marking trended toward a negative association with technical failure (P = .09). LIMITATIONS Noncomparative study. CONCLUSION Strict inclusion criteria and stricture marking may improve the technical and clinical success of stent placement.

Feasibility of a new self-expandable metallic stent for patients with malignant colorectal obstruction

Stent migration due to peristalsis of the colon is one of the unresolved complications of colonic self‐expandable metallic stent (SEMS) placement. Axial force (AF), a recovery force of the stent to a straight position after bending, has been considered a factor influencing the conformability of the digestive tract. An uncovered SEMS (Niti‐S Enteral Colonic Uncovered Stent, D‐type; Taewoong, Inc., Gimpo, South Korea) with improved conformability is considered to decrease migration.

Irsogladine improves small-intestinal injuries in regular users of nonsteroidal anti-inflammatory drugs.

BACKGROUND Nonsteroidal anti-inflammatory drugs (NSAIDs) cause a high frequency of mucosal injuries in the small intestine. However, no reliable intervention, other than cessation of NSAIDs, has been established. OBJECTIVE To evaluate whether irsogladine maleate reduces these injuries while continuing NSAID therapy. DESIGN Prospective, interventional, endoscopist-blinded, randomized, controlled trial (RCT). SETTING University hospital. PATIENTS Patients regularly taking conventional NSAIDs for more than 4 weeks. INTERVENTIONS We initially examined small-intestinal mucosal injuries by capsule endoscopy (CE) and screened participants for the RCT. In the RCT, patients with any mucosal injury were randomly assigned to the irsogladine group (4 mg/day) or the control group. MAIN OUTCOME MEASUREMENTS The primary endpoint was the rate of mucosal injury improvement after 4 weeks of treatment monitored with a second CE. RESULTS Sixty-one patients were evaluated with the first CE. Small intestine mucosal injuries were found in 41 patients (67.2%) and erosive or ulcerative lesions in 21 patients (34.4%). The injury prevalence was not different with gastroprotective drug treatment. Of 41 patients enrolled, 39 (19 patients in the irsogladine group and 20 in the control group) completed the study. The improvement rate was significantly higher in the irsogladine group (16/19 patients; 84.2%) than in the control group (9/20 patients; 45.0%; P = .02). LIMITATIONS Asymptomatic lesions, single-institution data, and single-blind setting. CONCLUSION Irsogladine maleate was effective for reducing NSAID-induced small-intestinal mucosal injury. (University Hospital Medical Information Network Clinical Trials Registry number UMIN000001507.).

Effects of patient age and choice of antisecretory agent on success of eradication therapy for Helicobacter pylori infection

The effects of patient age on the efficacy of eradication treatment for Helicobacter pylori (H. pylori) remain unclear. The present study aimed to determine whether age affects eradication therapy involving vonoprazan, a novel potassium-competitive acid blocker (PCAB). We reviewed the cases of 3,261 patients who were administered first-line and second-line H. pylori eradication therapy at Toyoshima Endoscopy Clinic. The first-line treatment was clarithromycin and amoxicillin combined with a proton pump inhibitor (PPI) or a PCAB. The second-line treatment was metronidazole and amoxicillin combined with a PPI or PCAB. The patients were divided into a young to middle-aged group (age ≤50 years) and an older group (age >50 years) as well as into PPI and PCAB groups. The PPI-clarithromycin-amoxicillin regimen demonstrated a significantly lower H. pylori eradication rate than the PCAB-clarithromycin-amoxicillin regimen (p<0.001). With the PPI-clarithromycin-amoxicillin regimen, the eradication rate in the young to middle-aged group was significantly lower than that in the older group (p<0.001). Lastly, age had no impact on the eradication rate of PCAB-based therapy or metronidazole-based therapy. In conclusion, with clarithromycin-based triple therapy, PCAB is a better choice of antisecretory agent compared to PPIs, especially in young to middle-aged patients.

New predictive model of rebleeding during follow-up of patents with obscure gastrointestinal bleeding: A multicenter cohort study.

The long‐term recurrence rate of patients with obscure gastrointestinal bleeding (OGIB) who underwent video capsule endoscopy (VCE) remains unknown. Our study aimed to identify the cumulative incidence of rebleeding, develop a predictive model of rebleeding, and evaluate whether the model can be applied in other outcomes among patients with OGIB.