Spray coagulation reduces the use of hemostatic forceps for intraoperative bleeding in gastric endoscopic submucosal dissection.

Aims: During intraoperative bleeding in endoscopic submucosal dissection (ESD), switching to spray coagulation may be beneficial compared with the continuous use of swift coagulation and can reduce the need for hemostatic forceps. We retrospectively assessed the effectiveness of spray modes on intraoperative bleeding during gastric ESD. Methods and Results: A total of 316 bleeding events (156 in the Swift group and 160 in the Spray group) were consecutively recorded. In the Swift group, hemostasis was performed using the swift mode with a retracted tip of the needle-type knife, followed by the hemostatic forceps. In the Spray group, bleeding was treated in a stepwise manner: the swift mode, the spray mode, and the hemostatic forceps. All bleeding events were assigned to one of two groups by an endoscopist who retrospectively reviewed the videos. We compared the use of hemostatic forceps, the total hemostatic time, and the cumulative hemostasis rate between the two groups.The use of hemostatic forceps was significantly lower in the Spray group than in the Swift group (32.7% vs. 13.8%, P < 0.001). There was no significant difference in the total hemostatic time (Swift group, 20 s.; Spray group, 16 s.; P = 0.42), whereas the cumulative hemostasis rate with the knife was significantly higher in the Spray group (P = 0.007). Conclusion: The results suggested that spray coagulation from the tip of the needle-type knife could reduce the use of hemostatic forceps. In gastric ESD, spray coagulation may facilitate the hemostasis of intraoperative bleeding.

Early gastric cancer with RhoGAP fusion is linked to frequent nodal metastasis and a part of microtubular-mucocellular histology.

INTRODUCTION: Gastric cancer with fusion genes involving the Rho GTPase-activating protein domain (RhoGAP-GC) is mainly included in the genomically stable type of The Cancer Genome Atlas classification. Clinical implications and histological characteristics of RhoGAP-GC in the early phase remain unclear. METHODS: We analyzed 878 consecutive pT1b GCs for RhoGAP and its partner genes using fluorescence in situ hybridization assay. RESULTS: RhoGAP fusion was detected in 57 (6.5%) GCs. Univariate analysis revealed that female sex, middle-lower third tumor location, advanced macroscopic type, tumor diameter > 2 cm, pT1b2, lymphatic invasion, venous invasion, negative EBER-ISH, and RhoGAP fusion were significantly associated with lymph node metastasis (LNM). Multivariate analysis presented RhoGAP fusion, lymphatic invasion, tumor diameter > 2 cm, advanced macroscopic type, venous invasion, and middle-lower third tumor location as independent risk factors for LNM. Notably, RhoGAP fusion had the highest odds ratio (3.92) for LNM among analyzed parameters (95% CI 2.12-7.27; p < 0.001). Compared to non-RhoGAP-GCs, RhoGAP-GCs were significantly frequent in younger females and showed the highest incidence of lymphatic invasion (56.2%) and LNM (49.1%) (p < 0.001). Histologically, microtubular architecture with pseudo-trabecular interconnection and small aggregations of tumor cells with a varied amount of cytoplasmic mucin, named "microtubular-mucocellular (MTMC) histology," was found in 93.0% (53 of 57) of RhoGAP-GCs in the intramucosal area. MTMC histology showed high sensitivity and negative predictive value (93.0% and 99.4%, respectively) for RhoGAP fusion, albeit positive predictive value is low (34.9%). CONCLUSION: RhoGAP-GC is linked to a characteristic MTMC histology and a high incidence of LNM.

Potential for expanded application of endoscopic hand suturing: A pilot study of 15 cases.

Endoscopic hand suturing (EHS) was first developed to firmly close a mucosal defect following endoscopic submucosal dissection and has the potential for expanded applications. This study aimed to investigate the feasibility and safety of EHS in various clinical settings. In this single-center pilot study, 15 patients who had diseases with potential indications for EHS were prospectively recruited. Technical success, clinical success after the procedure, and severe EHS-related adverse events (AEs) were evaluated. EHS was applied for defect closure after gastric subepithelial lesion removal under laparoscopic observation (n = 9), defect closure after rectal endoscopic full-thickness resection (EFTR) (n = 2), defect closure after thoracoscopy-assisted esophageal EFTR (n = 1), mucosal closure for gastric ulcer bleeding (n = 1), mucosal closure after peroral endoscopic myotomy (POEM) (n = 1), and postoperative anastomotic leak (n = 1). EHS was completed without severe AEs and the clinical courses were also favorable in 13 patients (87%). The median suturing time was 61 minutes. In patients with POEM and anastomotic leak, EHS was discontinued because of the narrow lumen. In conclusion, EHS appears feasible and safe in situations.

Tumor size discrepancy between endoscopic and pathological evaluations in colorectal endoscopic submucosal dissection.

BACKGROUND: Tumor size impacts the technical difficulty and histological curability of colorectal endoscopic submucosal dissection (ESD); however, the preoperative evaluation of tumor size is often different from histological assessment. Analyzing influential factors on failure to obtain an accurate tumor size evaluation could help prepare optimal conditions for safer and more reliable ESD. AIM: To investigate the tumor size discrepancy between endoscopic and pathological evaluations and the influencing factors. METHODS: This was a retrospective study conducted at a single institution. A total of 377 lesions removed by colorectal ESD at our hospital between April 2018 and March 2022 were collected. We first assessed the difference in size with an absolute percentage of the scaling discrepancy. Subsequently, we compared the clinicopathological characteristics of the correct scaling group (> -33% and < 33%) with that of the incorrect scaling group (< -33% or > 33%), which was further subdivided into the underscaling group (-33% or less of the discrepancy) and overscaling group (33% or more of the discrepancy), respectively. As secondary outcome measures, parameters on size estimation were compared between the underscaling and correct scaling groups, as well as between the overscaling and correct scaling groups. Finally, multivariate analysis was performed in terms of the following relevant parameters on size estimation: Pathological size, location, and possible influential factors (P < 0.1) in the univariate analysis. RESULTS: The mean of absolute percentage in the scaling discordance was 21%, and 91 lesions were considered to be incorrectly estimated in size. The incorrect scaling was significantly remarkable in larger lesions (40 mm vs 28 mm; P < 0.001) and less experience (P < 0.001), and these two factors were influential on the underscaling (75 lesions; P < 0.001). Conversely, compared with the correct scaling group, 16 lesions in the overscaling group were significantly small (20 mm vs 28 mm; P < 0.001), and the small lesion size was influential on the overscaling (P = 0.002). CONCLUSION: Lesions indicated for colorectal ESD tended to be underestimated in large tumors, but overestimated in small ones. This discrepancy appears worth understanding for optimal procedural preparation.

Correction: Potential for expanded application of endoscopic hand suturing: A pilot study of 15 cases.

[This corrects the article DOI: 10.1055/a-2284-9492.].

Potential of Direct Oral Anticoagulant in Bleeding After Gastric Endoscopic Submucosal Dissection: A Systematic Review and Meta-Analysis.

BACKGROUND AND AIMS: An increasing number of patients are undergoing gastric endoscopic submucosal dissection (ESD) with active prescriptions of direct oral anticoagulants (DOACs). Only a few reports have described the effects of DOAC intake on postoperative bleeding. We aimed to investigate the bleeding risk associated with DOACs after gastric ESD. METHODS: Clinical studies published up to April 2022 showing bleeding rates after gastric ESD in patients taking DOACs were identified using electronic searches. The primary outcome was the rate of bleeding after gastric ESD in patients receiving DOACs compared to those not receiving antithrombotic therapy. In this meta-analysis, odds ratios (ORs) were calculated and pooled using a random effects model. The secondary outcome was the difference in the bleeding rate between patients treated with DOACs and those treated with warfarin and antiplatelet drugs. RESULTS: Seven studies were included in this meta-analysis. The pooled analysis showed that DOACs had a higher bleeding rate than non-thrombotic therapy (17.0% vs. 3.4%; OR 5.72; 95% confidence interval [CI], 4.33-7.54; I2 = 0%). The bleeding risk associated with DOAC administration was similar to that associated with warfarin (17.0% vs. 20.0%; OR 0.83; 95% CI 0.59-1.18; I2 = 0%), whereas it was higher than that associated with antiplatelet administration (16.9% vs. 11.0%; OR 1.63; 95% CI 1.14-2.34; I2 = 8%). CONCLUSIONS: This meta-analysis reveals that the bleeding risk of DOACs is higher than that of non-antithrombotics and antiplatelets, whereas it is comparable to that of warfarin. Gastric ESD in patients on anticoagulants requires careful postoperative management.

Prophylactic use of steroids for a mucosal defect with a circumference of less than three-fourths prevents both symptomatic and asymptomatic stricture after esophageal endoscopic submucosal dissection.

BACKGROUND: Subclinical stricture after esophageal endoscopic submucosal dissection (ESD) makes the detection and re-ESD of metachronous lesions difficult. This study aimed to investigate the effectiveness of prophylactic steroid use after esophageal ESD for mucosal defects with a circumference less than 75% for the prevention of symptomatic and asymptomatic stricture. METHODS: In 80 retrospectively enrolled patients, we collected paired endoscopic images of a mucosal defects immediately after resection and a scar thereafter. After calculating circumference by image analysis software, all patients were classified into three groups in reference to mucosal defect circumference (MDC; ≤ 50%, 50-75%, ≥ 75%). Frequency of steroid use and symptomatic stricture were compared, and in < 75% MDC patients, a degree of asymptomatic stricture with or without steroid was compared by calculating a scar contraction rate (SCR). RESULTS: In the ≤ 50% (43 patients), 50-75% (27 patients) and ≥ 75% (10 patients) MDC groups, steroids were used in 12%, 59% and 100%, respectively, and symptomatic stricture occurred in 0%, 7% and 40%, respectively. In < 75% MDC patients, SCR in the steroid cohort was significantly lower than that in the nonsteroid cohort (42% vs. 65%, p = 0.002). No steroid-related adverse events occurred. CONCLUSION: Steroid use even for mucosal defects with < 75% circumference appears effective for the reduction of the risk on both symptomatic and asymptomatic stricture after esophageal ESD.

Chronological Changes in Mucosal Deformity by Endoscopic Suturing after Gastric Endoscopic Submucosal Dissection: A Multicenter Retrospective Analysis.

INTRODUCTION: Endoscopic suturing of a mucosal defect is expected to prevent postoperative bleeding after endoscopic submucosal dissection (ESD). Endoscopic suturing causes mucosal deformity, which may interfere with endoscopic surveillance thereafter. We retrospectively investigated long-term chronological changes in mucosal suturing by endoscopic suturing. METHODS: Forty-three patients who underwent endoscopic hand suturing (EHS) after gastric ESD at three institutions were enrolled. First, our hypothesis that the suturing sites healed via inflammation, disappearance of mucosal inversion, and flattening was validated. Subsequently, the duration required to reach each healing step was evaluated. RESULTS: A total of 137 follow-up endoscopies were assessed, in which all cases showed the hypothesized chronological course on the suturing sites. The 95th percentiles of the duration when showing the disappearance of the inflammatory change and the inverted change were 63 days and 15.5 months after the procedure, respectively. DISCUSSION/CONCLUSION: The data show that the mucosal deformity induced by EHS disappeared within 16 months. Endoscopic suturing is thus considered to have a negligible effect on endoscopic surveillance following the procedure.

Combination of high-density cholesterol level, elastic score, and severity of exocrine pancreatic dysfunction may be useful for a predictive factor for patients with early chronic pancreatitis.

BACKGROUND: This study aimed to clarify whether any risk factors including clinical characteristics, endosonographic features, and exocrine pancreatic dysfunction may be useful for a predictive factor for patients with early chronic pancreatitis. METHODS: A total of 163 consecutive patients that presented with functional dyspepsia with pancreatic enzyme abnormalities (FD-P) (n = 46), early chronic pancreatitis (ECP) (n = 47), and asymptomatic patients with pancreatic enzyme abnormalities (AP-P) (n = 70) based on the Rome III classification and the Japan Pancreatic Association were included in this study. The enrolled patients were evaluated using endosonography (EUS) and EUS elastography. The levels of the five pancreatic enzymes were measured. Pancreatic exocrine function was analyzed using N-benzoyl-l-tyrosyl-p-aminobenzoic acid (BT-PABA). RESULTS: There were no significant differences in clinical characteristics such as age, gender, body mass index, alcohol consumption, and smoking among patients with AP-P, FD-P, and ECP. The ratio of BT-PABA test less than 35% in patients with ECP was significantly (P = 0.043) higher than in AP-P patients. Elastic score was a useful tool to differentiate the FD-P group from the ECP group. The high-density cholesterol levels in patients with ECP were significantly lower than those in AP-P. In addition, the combination of total and high-density cholesterol levels, BT-PABA test, and elastic score has a higher area under the curve value (0.708) of patients with ECP than in the other groups. CONCLUSIONS: The combination of high-density cholesterol levels, elastic score, and severity of exocrine pancreatic dysfunction may be useful for a predictive factor for patients with ECP.

Esophageal Submucosal Hematoma after Transesophageal Echocardiography under General Anesthesia.

Esophageal submucosal hematoma is a rare disease mainly caused by mechanical stimulation to the esophageal wall. We reported a case of esophageal submucosal hematoma after transesophageal echocardiography (TEE) which was performed during cardiovascular surgery. The stimuli of TEE insertion under general anesthesia and the perioperative use of multiple antithrombotic agents were considered as a possible cause. This is the first report of esophageal submucosal hematoma related to TEE, and endoscopic ultrasonography should be carefully performed in patients, particularly at bleeding tendency and without consciousness.

Convolutional neural network-based system for endocytoscopic diagnosis of early gastric cancer.

BACKGROUND: Endocytoscopy (ECS) aids early gastric cancer (EGC) diagnosis by visualization of cells. However, it is difficult for non-experts to accurately diagnose EGC using ECS. In this study, we developed and evaluated a convolutional neural network (CNN)-based system for ECS-aided EGC diagnosis. METHODS: We constructed a CNN based on a residual neural network with a training dataset comprising 906 images from 61 EGC cases and 717 images from 65 noncancerous gastric mucosa (NGM) cases. To evaluate diagnostic ability, we used an independent test dataset comprising 313 images from 39 EGC cases and 235 images from 33 NGM cases. The test dataset was further evaluated by three endoscopists, and their findings were compared with CNN-based results. RESULTS: The trained CNN required 7.0 s to analyze the test dataset. The area under the curve of the total ECS images was 0.93. The CNN produced 18 false positives from 7 NGM lesions and 74 false negatives from 28 EGC lesions. In the per-image analysis, the accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were 83.2%, 76.4%, 92.3%, 93.0%, and 74.6%, respectively, with the CNN and 76.8%, 73.4%, 81.3%, 83.9%, and 69.6%, respectively, for the endoscopist-derived values. The CNN-based findings had significantly higher specificity than the findings determined by all endoscopists. In the per-lesion analysis, the accuracy, sensitivity, specificity, PPV, and NPV of the CNN-based findings were 86.1%, 82.1%, 90.9%, 91.4%, and 81.1%, respectively, and those of the results calculated by the endoscopists were 82.4%, 79.5%, 85.9%, 86.9%, and 78.0%, respectively. CONCLUSIONS: Compared with three endoscopists, our CNN for ECS demonstrated higher specificity for EGC diagnosis. Using the CNN in ECS-based EGC diagnosis may improve the diagnostic performance of endoscopists.

Bilateral Risk Assessments of Surgery and Nonsurgery Contribute to Providing Optimal Management in Early Gastric Cancers after Noncurative Endoscopic Submucosal Dissection: A Multicenter Retrospective Study of 485 Patients.

BACKGROUND AND AIMS: Surgery is recommended in early gastric cancer (EGC) after noncurative endoscopic submucosal dissection (ESD), although observation can be an alternative. We aimed to develop a tailor-made treatment strategy for noncurative EGCs by comparing the lymph node metastasis risk (LNMR) and the surgical risk. METHODS: We retrospectively identified 485 patients with differentiated-type, noncurative EGCs removed by ESD and classified them into two groups: a surgery-preferable group and an observation-preferable group, according to the clinical courses. Subsequently, LNMR and surgery-related death risk were assessed using a published scoring system and a risk calculator for gastrectomy, respectively. Finally, we investigated the optimal cutoff value of the risk difference (LNMR minus surgery-related death risk) to efficiently allocate these cases into either of two groups, surgery-preferable or observation-preferable. RESULTS: In 485 patients (surgery in 322, observation in 163), 57 and 428 patients were classified into the surgery-preferable group and the observation-preferable group, respectively. The optimal cutoff value of the risk difference (LNMR minus surgery-related death risk) to allocate the cases to the two preferable groups was 7.85 with the highest area under the curve (0.689). When cases with >7.85 LNMR over the surgery-related death risk were allocated into the surgery-preferable group and vice versa, the discriminability was 73.2%, which was sufficiently higher than that in the clinical decision (44.5%). CONCLUSION: Personalized comparison of LNMR and surgery-related death risk is helpful to provide a favorable treatment option for each patient with EGCs after noncurative ESD.

Circularity Is a Potential Noninvasive Diagnostic Indicator to Differentiate Gastric Submucosal Tumors.

BACKGROUND AND AIMS: Noninvasive, imaging diagnosis of gastrointestinal mesenchymal tumors (GIMTs) is still difficult. This study aimed to develop a novel diagnostic method of GIMTs via endoscopic ultrasonography (EUS) using circularity. METHODS: In a derivation series, we retrospectively collected 50 GIMTs 2-5 cm in diameter of two institutions. After selecting one EUS still image showing the maximal area per lesion, two endoscopists who were blind to the histological diagnosis assessed circularity, a surrogate indicator of roundness (range, 0-1; 1 = a true circle), with an image-analyzing software. Median circularity of three types of GIMT was compared, and the cutoff value to differentiate a group from other groups was presented by drawing a receiver operating characteristic curve. Subsequently, we assessed the diagnostic ability of circularity in 91 GIMTs which were retrospectively collected from the other two institutions by using the optimal cutoff value presented in the derivation series. RESULTS: The circularity in leiomyomas indicated 0.70 and was significantly lower than that of gastrointestinal stromal tumors (0.89), schwannomas (0.90), and their combined group. When leiomyomas were diagnosed as the circularity of <0.8305, which was presented as the optimal cutoff value, the diagnostic accuracy, sensitivity, and specificity in the validation series were 73.6%, 80.0%, and 72.4%, respectively. CONCLUSION: The data demonstrated that leiomyomas significantly exhibited more distortion than other GIMTs. That implies that the difference in shape, which is objectively determined as circularity, is useful to noninvasively discriminate leiomyomas from other GIMTs.

Prophylactic clip closure for mucosal defects is associated with reduced adverse events after colorectal endoscopic submucosal dissection: a propensity-score matching analysis.

BACKGROUND: It is unclear whether prophylactic endoscopic closure after colorectal endoscopic submucosal dissection (ESD) reduces the risk of postoperative adverse events due to variability in lesion characteristics. Therefore, we conducted a retrospective study using propensity score matching to evaluate the efficacy of prophylactic clip closure in preventing postoperative adverse events after colorectal ESD. METHODS: This single-center retrospective cohort study included 219 colorectal neoplasms which were removed by ESD. The patients were allocated into the closure and non-closure groups, which were compared before and after propensity-score matching. Post-ESD adverse events including major and minor bleeding and delayed perforation were compared between the two groups. RESULTS: In this present study, 97 and 122 lesions were allocated to the closure and non-closure groups, respectively, and propensity score matching created 61 matched pairs. The rate of adverse events was significantly lower in the closure group than in the non-closure group (8% vs. 28%, P = 0.008). Delayed perforation occurred in two patients in the non-closure group, whereas no patient in the closure group developed delayed perforation. In contrast, there were no significant differences in other postoperative events including the rate of abdominal pain; fever, white blood cell count, and C-reactive protein; and appetite loss between the two groups. CONCLUSIONS: Propensity score matching analysis demonstrated that prophylactic closure was associated with a significantly reduced rate of adverse events after colorectal ESD. When technically feasible, mucosal defect closure after colorectal ESD may result in a favorable postoperative course.

Feasibility of endoscopic hand suturing on rectal anastomoses in ex vivo porcine models.

Prevention of postoperative anastomotic leakage in rectal surgery is still required. This study investigated the feasibility of endoscopic hand suturing (EHS) on rectal anastomosis ex vivo. By using isolated porcine colon, we prepared ten anastomoses 6-10 cm from the virtual anus. Then, we sutured anastomoses intraluminally by EHS, which involved a continuous suturing method in 5 cases and a nodule suturing method with extra corporeal ligation in 5 cases. Completeness of suturing, number of stitches, procedure time and presence of stenosis were investigated. Furthermore, the degree of stenosis was compared between the two suturing methods. In all cases, EHS were successfully completed. The median number of stitches and procedure time was 8 and 5.8 min, respectively. Stenosis was created in all continuous suturing cases whereas none was seen in nodule suturing cases. The shortening rate was significantly greater in the continuous suturing method than in the nodule suturing method. Intraluminal reinforcement of rectal anastomosis by EHS using nodule suturing with extra corporeal ligation is feasible without stenosis, which may be helpful as a countermeasure against possible postoperative anastomotic leakage in rectal surgery.

Novel Method of Sampling the Gastrointestinal Muscle Layer: Feasibility of Endoscopic Muscular Resection with a Ligation Device in an in Vivo Porcine Model.

BACKGROUND: Gastrointestinal muscular sampling is useful in the histological assessment of functional gastrointestinal disorders. We devised a new sampling method to obtain a large volume of muscle tissues and then investigated the feasibility and safety of endoscopic muscular resection with a ligation device in an in vivo porcine model. METHODS: After establishing a submucosal tunnel, a rubber band was placed on the muscle tissue by sucking the exposed muscle layer. Thereafter, the established pseudopolyp was removed using an electrocautery snare, and the entry site of the submucosal tunnel was closed endoscopically. This procedure was performed at three sites in the esophagus and stomach of two pigs. The technical success, histology, and survival rate on postoperative day 7 were examined postoperatively. RESULTS: We successfully completed the mentioned procedure in 11 of the 12 sites (92%), without the occurrence of severe adverse events. The median diameters of obtained tissues from the esophagus and stomach, respectively, were 5 mm and 10 mm. Histologically, both the inner and outer muscle layers were included in all specimens. The postprocedural course was found uneventful in both pigs during the observatory period. CONCLUSIONS: Endoscopic muscular resection using a ligation device enabled us to obtain large and thick muscle tissue samples. This approach may facilitate more precise histological assessments of functional gastrointestinal disorders.

Three-dimensional visualization improves the endoscopic diagnosis of superficial gastric neoplasia.

BACKGROUND: Three-dimensional (3D) technology has been used in many fields, including flexible endoscopy. We evaluated the usefulness of 3D visualization for endoscopically diagnosing superficial gastric neoplasia. METHODS: Twelve participants (4 novices, 4 trainees and 4 experts) evaluated two-dimensional (2D) and 3D endoscopic still images of 28 gastric neoplasias, obtained before ESD with white-light imaging (WLI) and narrow-band imaging (NBI). Assessments of the delineation accuracy of tumor extent and tumor morphology under 2D and 3D visualization were based on the histopathological diagnosis of ESD specimens. Participants answered visual analog scale (VAS) questionnaires (0-10, worst to best) concerning the (a) ease of recognition of lesion morphology, (b) lesion extent and (c) comprehensive endoscopic cognition under 2D and 3D visualization. The endpoints were the accuracy of tumor extent and morphology type and the degree of confidence in assessing (a)-(c). RESULTS: The delineation accuracy of lesion extent [mean (95% confidence interval)] with WLI under 3D visualization [60.2% (56.1-64.3%)] was significantly higher than that under 2D visualization [52.3% (48.2-56.4%)] (P < 0.001). The accuracy with NBI under 3D visualization [70.3% (66.8-73.7%)] was also significantly higher than that under 2D visualization [64.2% (60.7-67.4%)] (P < 0.001). The accuracy of the morphology type with NBI under 3D visualization was significantly higher than that under 2D visualization (P = 0.004). The VAS for all aspects of endoscopic recognition under 3D visualization was significantly better than that under 2D visualization (P < 0.01). CONCLUSIONS: Three-dimensional visualization can enhance the diagnostic quality for superficial gastric tumors.

Cutting-Edge Technologies for Gastrointestinal Therapeutic Endoscopy.

With advancements in the development of flexible endoscopes and endoscopic devices and the increased demand for minimally invasive treatments, the indications of therapeutic endoscopy have been expanded. Methods of endoscopic treatment used for tissue removal, hemostasis, and dilatation are as follows. Endoscopic submucosal dissection (ESD) is considered the gold standard curative method for removal of gastrointestinal node-negative neoplasms, regardless of their size or the presence of ulcer formation. Laparoscopic endoscopic cooperative surgery (LECS), which incorporates ESD, was introduced for removal of lesions in deeper layers. Another technique is endoscopic full-thickness resection, which is challenging without the assistance of laparoscopy. In terms of hemostasis, management of iatrogenic bleeding after endoscopic treatment is an important issue. Shielding methods and suturing techniques have been introduced for large mucosal defects after ESD, and their efficacy has been investigated clinically. Peroral endoscopic myotomy (POEM) is a new alternative surgical approach for minimally invasive treatment of esophageal achalasia. Furthermore, endoscopic fundoplication after POEM was devised to prevent post-POEM gastroesophageal reflux disease. Many endoscopic treatments, including ESD, LECS, and POEM, have been introduced in Japan. With the aging of the population, more attention will be directed toward therapeutic endoscopy for elderly patients, because it is less invasive. Development of endoscopic treatments with expanded indications is expected.

Characteristics of non-neoplastic epithelium that appears within gastric cancer with and without Helicobacter pylori eradication: A retrospective study.

A non-neoplastic epithelium (NE) often appears in gastric cancer (GC). We explored the histological features of NE in comparison between HP-eradicated and HP-infected GCs. We enrolled 40 HP-eradicated and 40 HP-infected GCs matched by size, macroscopic and histological type. NE was classified into full gland type and surface type; the former was a non-neoplastic gland isolated within cancer, and the latter was NE on the surface of the cancer. Surface type was additionally divided into NE at the cancer margin (marginal surface type) and NE inside cancer (internal surface type). The primary endpoints were the frequency and the length ratio (the ratio to cancer length) of NE. The secondary endpoints were the relationships between NE and clinicopathological factors, including endoscopic findings of a gastritis-like appearance (GLA), reddish depressed lesion (RDL), and white nodular mucosa (WNM). The frequency and length ratio of the internal surface type in HP-eradicated GCs were significantly higher (82.5% vs 50%, P = 0.005) and larger (11.6 ± 10.6 vs 4.2 ± 9.9, P < 0.001) than those in HP-infected GCs, and the increase was more significant according to the passage of time since HP eradication. The frequency and length ratio of marginal surface type and full gland type were not significantly different between the two groups, but the coexistence of internal surface and full gland types was statistically significant (p < 0.001). The frequencies of GLA, RDLs, and WNM in HP-eradicated GCs were significantly higher than those in HP-infected GCs. GLA-positive GCs were covered more widely by internal surface type than GLA-negative GCs (13.3% vs. 6.6%, P = 0.003). Various types of NE were noted in gastric cancer, and the internal surface type of NE was shown to be significantly linked to HP-eradicated cancer and GLA.