Toshifumi Mitani

Primary Levofloxacin Resistance and gyrA/B Mutations Among Helicobacter pylori in Japan

Background:  Recent years have witnessed a decrease in the rate of Helicobacter pylori eradication due to antimicrobial resistance, clarithromycin or metronidazole resistance in particular. As one of the alternatives to the standard regimens, levofloxacin‐containing therapy has been considered a promising regimen. Nevertheless, there is a little information concerning the prevalence of levofloxacin resistance and this resistance mechanism.

Endoscopic submucosal dissection for residual/locally recurrent lesions after endoscopic therapy for colorectal tumors.

Background and Study Aim:  Residual or locally recurrent lesions may occur after endoscopic therapy for epithelial colorectal tumors. Additional endoscopic mucosal resection is difficult for large lesions. Endoscopic submucosal dissection may be useful for such lesions, but may be more technically difficult for residual/locally recurrent lesions than for primary lesions. This study evaluated the efficacy of endoscopic submucosal dissection for residual/locally recurrent lesions in comparison with primary lesions.

Endoscopic submucosal dissection for nonampullary large superficial adenocarcinoma/adenoma of the duodenum: feasibility and long-term outcomes.

Background and study aims: The clinical benefit of endoscopic submucosal dissection (ESD) for superficial duodenal neoplasias has not yet been verified. The aims of this study were to validate the feasibility and long-term outcomes of ESD for nonampullary superficial duodenal neoplasias, larger than 20 mm. Patients and methods: 41 patients, with 41 nonampullary large superficial duodenal neoplasias, who underwent ESD between April 2005 to March 2013 were included in the study. The short- and long-term outcomes were retrospectively evaluated, related to tumor size, resection size, histological type, invasion depth, complete resection rate, operation time, perforation rate, delayed bleeding rate, local recurrence rate, distant metastasis, and survival rate. Results: ESD was successfully completed in 38 of 41 patients (92.7 %). The median sizes of tumors and resected specimens were, respectively, 26 mm (range 20 – 70 mm) and 36.5 mm (range 23 – 80 mm). Histopathological findings showed 13 adenocarcinomas (12 mucosal, 1 submucosal) and 28 adenomas (26 high grade dysplasia, 2 low grade dysplasia). The complete resection rate was 89.5 % (34 /38 tumors). The mean operation time was 128.3minutes. Perforation during ESD occurred in 39 % and delayed bleeding occurred in 18.4 %. The median observation period was 48 months (range 3.2 – 94.1 months), and no local recurrence or distant metastasis was seen during this time, representing a disease-free survival rate of 100 %. Conclusions: ESD for nonampullary large superficial duodenal adenocarcinoma/adenoma is feasible with favorable long-term outcomes. However, because of the high complication rate due to its technical difficulty, experience and skill of the operator, along with adequate perioperative management, are essential.

Feasibility and safety of laparoscopic and endoscopic cooperative surgery for gastric submucosal tumors, including esophagogastric junction tumors.

Recently, the use of endoscopic submucosal dissection (ESD) for gastric submucosal tumor (gSMT) and the development of laparoscopic and endoscopic cooperative surgery (LECS) have enabled either preservation of the stomach or minimization of the extent of partial resection. In the present study, the outcomes following the recent introduction of LECS for gSMT are presented. The aim of this retrospective study was to evaluate the feasibility and safety of LECS for gSMT, including esophagogastric junction (EGJ) SMT.

Clinicopathological Outcomes of Patients with Early Gastric Cancer after Non-Curative Endoscopic Submucosal Dissection.

Background: Endoscopic submucosal dissection (ESD) was developed to resect early gastric cancer (EGC), which could not be resected by conventional endoscopic mucosal resection, and the indications for ESD are expanding to include more types of EGCs. Favorable long-term outcomes of ESD for EGCs that meet the expanded curability criteria have been reported. However, the outcomes of non-curative ESD are not known in detail. Summary: We analyzed the outcomes of 165 EGCs in 165 patients after non-curative ESD, as well as the clinical course. Of these patients, 109 underwent additional surgical resection (group S) and 56 patients were followed up without additional surgery (group F). The complete resection rate was 90.7% (39/43) for intramucosal cancer (M), 97.3% (36/37) for minimally submucosal invasive cancer (SM1), and 74.1% (63/85) for deep submucosal invasive cancer (SM2). The lymph node metastasis rate was 0% for M, 5.4% for SM1, and 10.6% for SM2 cancers. Regarding long-term survival, although the number of patients who died of another disease was significantly higher in group F than in group S, there was no significant difference in overall survival between the groups. Key Message: The resectability of ESD for ECGs with an invasion depth of M to SM1 after non-curative ESD was excellent, and lesions without lymphovascular invasion did not metastasize or recur, resulting in a favorable prognosis. Our data may help in deciding whether additional surgery should be performed for borderline lesions after non-curative ESD. Furthermore, we suggest the possibility of further expanding the indications for ESD.

Endoscopic Submucosal Dissection and Endoscopic Mucosal Resection for Non-Ampullary Superficial Duodenal Tumor

Background: Endoscopic submucosal resection (ESD) and endoscopic mucosal resection (EMR) are well established as curable and safety procedures for treating superficial tumors of the stomach, esophagus and colon. However, a majority of endoscopic resection strategies for non-ampullary superficial duodenal tumors (NASDTs) remains undefined. The aim of this study was to clarify which was the right method for NASDT treatment - EMR or ESD. Summary: We analyzed 129 consecutive endoscopic resection (74 ESD and 55 EMR) procedures performed with NADSTs and divided the ESD group into 49 large ESD groups (more than 20 mm in diameter) and 25 small ESD groups (less than 20 mm in diameter). With respect to the technical outcomes of EMR/ESD for small size NASDTs, EMR was safer than ESD, but its nature of curability was inferior to that of ESD. The rates of complication such as perforation or delayed bleeding were significantly higher in both ESD groups than in the EMR group. However, the prophylactic endoscopic closure of large mucosal defects after ESD was useful for resolving those complications. The limitations of our study were involvement of a single-center, limited sample size, short follow-up duration and the retrospective design, which may have introduced selection bias. However, the present findings suggest that adequate endoscopic treatment strategy for NASDTs can lead to favorable outcomes and an excellent prognosis. Key Message: It is necessary to select EMR or ESD adequately for R0 resection of small NASDTs, according to their size and location. For large NASDTs, duodenal ESD with essential management is feasible and useful as a therapeutic procedure.

Endocytoscopy is a promising modality with high diagnostic accuracy for gastric cancer.

BACKGROUND AND STUDY AIM Endocytoscopy (ECS) enables in vivo microscopic imaging, which allows analysis of mucosal structures at the cellular level; however, limited data are available on the validity of ECS in the stomach. The aim of this study was to evaluate the feasibility of ECS in the diagnosis of early gastric cancer. PATIENTS AND METHODS Gastric lesions that were the targets of histopathological diagnosis by endoscopic submucosal dissection or biopsy specimen were prospectively enrolled and evaluated using a single charge-coupled device-integrated endocytoscope, following double staining with crystal violet and methylene blue. High grade ECS atypia was defined according to specific irregularities in gland structure and cell nuclei. The primary end point was the accuracy of ECS diagnosis for gastric cancer, using histopathological diagnosis as the gold standard. RESULTS A total of 82 lesions were investigated, including 23 early gastric cancers, 10 gastric adenomas, and 49 non-neoplastic lesions. Ten lesions could not be clearly observed by ECS because of poor staining due to viscous mucus or plaque; thus, assessability rates with ECS were 88 % in total and 91 % for gastric cancer. High grade ECS atypia was observed in 86 % of assessable gastric cancers, but not in any cases of gastric adenomas or non-neoplastic lesions. The sensitivity, specificity, positive and negative predictive values of high grade ECS atypia as the criterion for the diagnosis of gastric cancer were 86 %, 100 %, 100 %, and 94 %, respectively. No serious complications occurred during or after the examinations. CONCLUSION ECS is a clinically feasible modality to obtain in vivo histology, with high diagnostic accuracy in gastric cancer.

Delayed bleeding after endoscopic submucosal dissection for non-ampullary superficial duodenal neoplasias might be prevented by prophylactic endoscopic closure: Analysis of risk factors

Duodenal endoscopic submucosal dissection (ESD) is technically challenging because of anatomical specificities and, to date, has not been validated concerning the high rate of complications such as perforation and delayed bleeding. In the present study, the risk factors for delayed bleeding after duodenal ESD are presented with the goal of establishing preventive measures.

Safety and Efficacy of Secondary Endoscopic Submucosal Dissection for Residual Gastric Carcinoma after Primary Endoscopic Submucosal Dissection

Background/Aims: In endoscopic submucosal dissection (ESD), misdiagnosis of the tumor margin may lead to residual carcinoma, which we treat by secondary ESD (sESD) for local control. Methods: 1,458 lesions of early gastric carcinoma were treated by ESD between July 2006 and November 2011. 33 lesions were resected with positive lateral margins. Among them, 13 patients were treated by surgery, 12 patients were followed up, and 8 patients were treated by sESD. sESD was defined as resection of residual carcinoma surrounding the ulcer of primary ESD (pESD). Safety and efficacy of sESD were retrospectively evaluated. Results: Mean interval between two ESDs was 8.4 days. The mean specimen area was 14.9 cm2 in pESD and 23.9 cm2 in sESD. The mean procedure time was 107.3 and 193.0 min, and mean dissection area was 15.9 and 11.6 mm2/min, respectively. There were no significant differences and no serious complications occurred during sESD. There was no local recurrence after a mean follow-up period of 896 days. Meanwhile, 4 cases of local recurrence were detected after ESD with a positive lateral margin. Conclusion: The results suggest that sESD may be technically feasible and favorable for local control of residual gastric carcinoma.

Role of metallothionein in Helicobacter pylori-positive gastric mucosa with or without early gastric cancer and the effect on its expression after eradication therapy

Background and Aim:  Metallothionein (MT) has a proven relationship with various kinds of cancer and reduces tissue damage. Helicobacter pylori (H. pylori) infection is associated with the alteration of gastric epithelial cell cycle events, a condition implicated in the initiation and development of gastric cancer. This study investigates the role of MT in H. pylori‐induced gastritis with or without early gastric cancer (ECG) and evaluates the effect on MT expression after eradication therapy.