Gastric Intestinal Metaplasia: Real Culprit or Innocent Bystander as a Precancerous Condition for Gastric Cancer?

Gastric intestinal metaplasia (GIM), which denotes conversion of gastric mucosa into an intestinal phenotype, can occur in all regions of the stomach, including cardiac, fundic, and pyloric mucosa. Since the earliest description of GIM, its association with gastric cancer of the differentiated (intestinal) type has been a well-recognized concern. Many epidemiologic studies have confirmed GIM to be significantly associated with subsequent gastric cancer development. Helicobacter pylori, the principal etiologic factor for gastric cancer, plays the most important role in predisposing to GIM. Although the role of GIM in the stepwise progression model of gastric carcinogenesis (the so-called "Correa cascade") has come into question recently, we review the scientific evidence that strongly supports this long-standing model and propose a new progression model that builds on the Correa cascade. Eradication of H pylori is the most important method for preventing gastric cancer globally, but the effect of eradication on established GIM, is limited, if any. Endoscopic surveillance for GIM may, therefore, be necessary, especially when there is extensive corpus GIM. Recent advances in image-enhanced endoscopy with integrated artificial intelligence have facilitated the identification of GIM and neoplastic lesions, which will impact preventive strategies in the near future.

Diagnosis by combination of endoscopic findings helps differentiate non-Helicobacter pylori Helicobacter-infected gastritis from Helicobacter pylori-infected gastritis.

BACKGROUND: The characteristic endoscopic findings of non-Helicobacter pylori Helicobacter (NHPH) gastritis, including white marbled appearance and crack-like mucosa, have been reported. However, these findings can also manifest in H. pylori (HP)-infected gastritis. This study compared NHPH gastritis and mild atrophic HP gastritis to identify features that may enhance NHPH diagnosis. MATERIALS AND METHODS: A total of 2087 patients underwent upper gastrointestinal endoscopy and were histologically evaluated by multiple gastric mucosal biopsies according to the updated Sydney System (USS) at Shinshu University Hospital between 2005 and 2023. Among them, nine patients were classified into the NHPH group and 134 patients with HP infection and mild atrophy were classified into the HP group for retrospective comparisons of endoscopic findings and clinicopathological characteristics. RESULTS: All nine patients in the NHPH group (eight males [89%], median ± standard deviation [SD] age: 49 ± 13.0 years) were infected with H. suis. The 134 patients in the HP group contained 70 men (52%) and had a median ± SD age of 35 ± 19.9 years. Endoscopic findings were statistically comparable for white marbled appearance (three patients [33%] in the NHPH group and 37 patients [31%] in the HP group) and crack-like mucosa (three patients [33%] and 27 patients [20%], respectively). Diffuse redness was significantly less frequent in the NHPH group (one patient [14%] vs. 97 patients [72%], p < 0.001). White marbled appearance or crack-like mucosa without diffuse redness was significantly more common in the NHPH group (56% vs. 13%, p = 0.004), with a sensitivity and specificity of 56% and 87%, respectively. Mean USS neutrophil infiltration and Helicobacter density scores were significantly higher in the HP group (both p < 0.01), which might have influenced the endoscopic findings of diffuse redness. CONCLUSIONS: When endoscopic findings of white marbled appearance or cracked-like mucosa are present, evaluation for diffuse redness may contribute to a more accurate diagnosis of NHPH gastritis.

Association between colonic adenoma size and proliferative zone in the crypt.

BACKGROUND: We previously reported unusual adenomas with proliferative zones confined to the lower two-thirds of the crypt. The proliferative zones of colorectal adenomas have three patterns: 'lower,' 'superficial' and 'entire'. This study aimed to clarify the characteristics of each adenoma pattern. METHODS: We investigated 2925 consecutive patients who underwent colonoscopy at our institute. All polyps that were removed were histologically examined using hematoxylin and eosin staining. The location of the proliferative zone was assessed for adenomas. Data were compared using Dunn's and Kruskal-Wallis tests. RESULTS: Colorectal adenomas with 'lower' proliferative zone often appeared similar to hyperplastic polyps (42.8%), and the frequency was significantly higher than that of adenomas with 'superficial' and 'entire' proliferative zones (p < 0.001). The mean sizes of adenomas were 2.4, 3.0 and 3.9 mm for 'lower,' 'superficial' and 'entire' proliferative zones, respectively. A significant gradual increase was observed. Regarding morphology, the proportion of type 0-I in adenomas with an 'entire' proliferative zone was significantly higher than that in adenomas with 'superficial' proliferative zone (p < 0.001). CONCLUSION: While colorectal adenomas develop and increase in size, the proliferative zone appears to shift upward and become scattered.

Evaluating the usefulness of considering the size and morphological type of type B2 vessel area based on Japan Esophageal Society classification in estimating tumor invasion depth in superficial esophageal squamous cell carcinomas: study protocol for a prospective observational study (Japan BEES study).

BACKGROUND: Accurate evaluation of tumor invasion depth is essential to determine the appropriate treatment strategy for patients with superficial esophageal cancer. The pretreatment tumor depth diagnosis currently relies on the magnifying endoscopic classification established by the Japan Esophageal Society (JES). However, the diagnostic accuracy of tumors involving the muscularis mucosa (MM) or those invading the upper third of the submucosal layer (SM1), which correspond to Type B2 vessels in the JES classification, remains insufficient. Previous retrospective studies have reported improved accuracy by considering additional findings, such as the size and macroscopic type of the Type B2 vessel area, in evaluating tumor invasion depth. Therefore, this study aimed to investigate whether incorporating the size and/or macroscopic type of the Type B2 vessel area improves the diagnostic accuracy of preoperative tumor invasion depth prediction based on the JES classification. METHODS: This multicenter prospective observational study will include patients diagnosed with MM/SM1 esophageal squamous cell carcinoma based on the Type B2 vessels of the JES classification. The tumor invasion depth will be evaluated using both the standard JES classification (standard-depth evaluation) and the JES classification with additional findings (hypothetical-depth evaluation) for the same set of patients. Data from both endoscopic depth evaluations will be electronically collected and stored in a cloud-based database before endoscopic resection or esophagectomy. This study's primary endpoint is accuracy, defined as the proportion of cases in which the preoperative depth diagnosis matched the histological depth diagnosis after resection. Outcomes of standard- and hypothetical-depth evaluation will be compared. DISCUSSION: Collecting reliable prospective data on the JES classification, explicitly concerning the B2 vessel category, has the potential to provide valuable insights. Incorporating additional findings into the in-depth evaluation process may guide clinical decision-making and promote evidence-based medicine practices in managing superficial esophageal cancer. TRIAL REGISTRATION: This trial was registered in the Clinical Trials Registry of the University Hospital Medical Information Network (UMIN-CTR) under the identifier UMIN000051145, registered on 23/5/2023.

Impact of peroral endoscopic myotomy on the endoscopic pressure study integrated system.

OBJECTIVES: The endoscopic pressure study integrated system (EPSIS) is an endoscopic diagnostic system utilized for evaluation of lower esophageal sphincter function. Although previous studies have determined that EPSIS was effective as a tool for the diagnosis of achalasia, it remains uncertain if EPSIS can detect significant changes before and after peroral endoscopic myotomy (POEM), which is the premier treatment for achalasia. This study aimed to evaluate the effectiveness of EPSIS as an objective diagnostic tool for assessing the clinical effect of POEM. METHODS: We conducted a retrospective analysis of patients who underwent POEM from January 2022 to December 2023. The patients underwent EPSIS preoperatively and 2 months postoperatively. Intragastric pressure (IGP) parameters, including the maximum IGP, IGP difference, and waveform gradient were compared pre- and post-POEM. These parameters also were compared between two groups: the postoperative gastroesophageal reflux disease (GERD) group and the non-GERD group. RESULTS: A total of 50 patients were analyzed. The mean maximum IGP was significantly lower postoperatively than preoperatively (15.0 mmHg vs. 19.8 mmHg, P < 0.001). The mean IGP difference and waveform gradient were also significantly lower postoperatively than preoperatively (8.0 mmHg vs. 12.2 mmHg, P < 0.001; and 0.26 mmHg/s vs. 0.43 mmHg/s, P < 0.001, respectively). The mean postoperative waveform gradient was significantly lower in the GERD group (17 patients, 34%) than in the non-GERD group (33 patients, 66%) (0.207 mmHg vs. 0.291 mmHg, P = 0.034). CONCLUSION: The results supported the use of EPSIS as an effective diagnostic tool for assessing the effect of POEM.

Endoscopic pressure study integrated system using an ultrathin gastroscope for the functional assessment of the lower esophageal sphincter.

OBJECTIVES: The endoscopic pressure study integrated system (EPSIS) represents an innovative approach for evaluating lower esophageal sphincter function by monitoring intragastric pressure using diagnostic gastroscopes. This study aimed to assess the feasibility and validity of employing ultrathin gastroscopes for EPSIS. METHODS: A retrospective analysis was conducted on a database of consecutive patients who underwent EPSIS using both ultrathin and regular gastroscopes between September 2021 and October 2023. The study compared EPSIS parameters between the two gastroscope types to evaluate the correlation of key metrics. RESULTS: Thirty patients underwent EPSIS with both ultrathin and regular gastroscopes. Significant positive correlations were observed in the pressure waveform: maximum intragastric pressure (mmHg) (ρ = 0.82, P < 0.001) and intragastric pressure gradient (mmHg/s) (ρ = 0.80, P < 0.001) when comparing the two gastroscopes. Maximum intragastric pressure (15.5 [5.3-20.3] vs. 18.5 [3.4-21.6], P < 0.001) and pressure gradient (0.16 [0.013-0.41] vs. 0.24 [0.0039-1.13], P < 0.001), (median [range]) were significantly lower with ultrathin gastroscopes. CONCLUSIONS: This study establishes that EPSIS parameters obtained with an ultrathin gastroscope exhibit a significant correlation with those obtained using a regular gastroscope, with each EPSIS parameter consistently lower. These findings support the viability of EPSIS for ultrathin gastroscopy and highlight its potential as a diagnostic tool for assessing lower esophageal sphincter function.

Long-term Risks of Recurrence After Hospital Discharge for Acute Lower Gastrointestinal Bleeding: A Large Nationwide Cohort Study.

BACKGROUND & AIMS: Currently, large, nationwide, long-term follow-up data on acute lower gastrointestinal bleeding (ALGIB) are scarce. We investigated long-term risks of recurrence after hospital discharge for ALGIB using a large multicenter dataset. METHODS: We retrospectively analyzed 5048 patients who were urgently hospitalized for ALGIB at 49 hospitals across Japan (CODE BLUE-J study). Risk factors for the long-term recurrence of ALGIB were analyzed by using competing risk analysis, treating death without rebleeding as a competing risk. RESULTS: Rebleeding occurred in 1304 patients (25.8%) during a mean follow-up period of 31 months. The cumulative incidences of rebleeding at 1 and 5 years were 15.1% and 25.1%, respectively. The mortality risk was significantly higher in patients with out-of-hospital rebleeding episodes than in those without (hazard ratio, 1.42). Of the 30 factors, multivariate analysis showed that shock index ≥1 (subdistribution hazard ratio [SHR], 1.25), blood transfusion (SHR, 1.26), in-hospital rebleeding (SHR, 1.26), colonic diverticular bleeding (SHR, 2.38), and thienopyridine use (SHR, 1.24) were significantly associated with increased rebleeding risk. Multivariate analysis of colonic diverticular bleeding patients showed that blood transfusion (SHR, 1.20), in-hospital rebleeding (SHR, 1.30), and thienopyridine use (SHR, 1.32) were significantly associated with increased rebleeding risk, whereas endoscopic hemostasis (SHR, 0.83) significantly decreased the risk. CONCLUSIONS: These large, nationwide follow-up data highlighted the importance of endoscopic diagnosis and treatment during hospitalization and the assessment of the need for ongoing thienopyridine use to reduce the risk of out-of-hospital rebleeding. This information also aids in the identification of patients at high risk of rebleeding.

Endoscopic pressure study integrated system for the diagnosis of achalasia.

OBJECTIVES: The endoscopic pressure study integrated system (EPSIS) is a novel diagnostic tool used to evaluate lower esophageal sphincter (LES) function. EPSIS allows the measurement of intragastric pressure (IGP) during gastric insufflation through esophagogastroduodenoscopy (EGD) and records its pressure waveform. This study aimed to assess the usefulness and applicability of EPSIS as an adjunct diagnostic modality for achalasia. METHODS: This case-control study was conducted using a database of patients who underwent EGD, barium swallow (BS), high-resolution manometry (HRM), and EPSIS between January 2022 and December 2022. The achalasia (experimental) group (n = 35) consisted of patients with a definitive diagnosis of achalasia. The control group (n = 34) consisted of patients with no abnormalities in EGD, BS, or HRM and no abnormal acid reflux confirmed with 24-h pH-impedance monitoring. EPSIS findings were compared between the two groups and characterized by the waveform pattern (uphill or flat), maximum IGP (IGP-Max), pressure difference, and the gradient of the waveform. RESULTS: All patients in the achalasia group showed an uphill pattern, in contrast to 21 patients (61.8%) in the control group. IGP-Max demonstrated the best diagnostic accuracy for achalasia, with a cut-off value of 15.8 mmHg (100% sensitivity, 58.8% specificity, and area under the curve [AUC] 0.78). The pressure gradient also demonstrated good diagnostic accuracy, with a cut-off value of 0.40 mmHg/s (80% sensitivity, 61.8% specificity, and AUC 0.76). CONCLUSION: This study demonstrated that EPSIS can be applied as a diagnostic modality in patients with achalasia.

Current status and perspectives for endoscopic diagnosis of superficial nonampullary duodenal epithelial tumors.

In recent years, there have been significant advances in the endoscopic resection (ER) procedures of superficial nonampullary duodenal epithelial tumors (SNADETs). A preoperative endoscopic diagnosis is thus deemed necessary in determining the indication for subsequent ER. For the histologic and endoscopic diagnosis of SNADETs, understanding the mucin phenotype is inevitable. Recently, two diagnostic algorithms for the differential diagnosis of SNADETs from nonneoplastic lesions under magnifying endoscopy with narrow-band imaging have been proposed. In addition, various endoscopic approaches have been proposed to differentiate low- and high-grade adenomas/carcinomas, including white light endoscopy, magnifying image-enhanced endoscopy, and endocytoscopy. These methods, however, have not been standardized with respect to the classification of their findings and the validation of their diagnostic accuracy. Moreover, there are still concerns with respect to the histologic criteria required to establish a SNADETs diagnosis. Standardization in the histologic and endoscopic diagnosis of SNADETs is needed.

Towards automatic recognition of pure and mixed stones using intra-operative endoscopic digital images.

OBJECTIVE: To assess automatic computer-aided in situ recognition of the morphological features of pure and mixed urinary stones using intra-operative digital endoscopic images acquired in a clinical setting. MATERIALS AND METHODS: In this single-centre study, a urologist with 20 years' experience intra-operatively and prospectively examined the surface and section of all kidney stones encountered. Calcium oxalate monohydrate (COM) or Ia, calcium oxalate dihydrate (COD) or IIb, and uric acid (UA) or IIIb morphological criteria were collected and classified to generate annotated datasets. A deep convolutional neural network (CNN) was trained to predict the composition of both pure and mixed stones. To explain the predictions of the deep neural network model, coarse localization heat-maps were plotted to pinpoint key areas identified by the network. RESULTS: This study included 347 and 236 observations of stone surface and stone section, respectively; approximately 80% of all stones exhibited only one morphological type and approximately 20% displayed two. A highest sensitivity of 98% was obtained for the type 'pure IIIb/UA' using surface images. The most frequently encountered morphology was that of the type 'pure Ia/COM'; it was correctly predicted in 91% and 94% of cases using surface and section images, respectively. Of the mixed type 'Ia/COM + IIb/COD', Ia/COM was predicted in 84% of cases using surface images, IIb/COD in 70% of cases, and both in 65% of cases. With regard to mixed Ia/COM + IIIb/UA stones, Ia/COM was predicted in 91% of cases using section images, IIIb/UA in 69% of cases, and both in 74% of cases. CONCLUSIONS: This preliminary study demonstrates that deep CNNs are a promising method by which to identify kidney stone composition from endoscopic images acquired intra-operatively. Both pure and mixed stone composition could be discriminated. Collected in a clinical setting, surface and section images analysed by a deep CNN provide valuable information about stone morphology for computer-aided diagnosis.

Current status of endoscopic detection, characterization and staging of superficial esophageal squamous cell carcinoma.

BACKGROUND: This review focuses on the current status of endoscopic detection, characterization and tumour category staging of oesophagealsquamous cell carcinoma. DETECTION: The diagnostic yield of white-light imaging is limited and narrow-band imaging has demonstrated a better performance for detecting oesophageal cancer. Narrow-band imaging has also shown similar sensitivity and superior specificity to iodine staining. CHARACTERIZATION: Accurate differentiation between cancerous and non-cancerous lesions can be achieved by magnifying narrow-band imaging or iodine staining with confirmation of a pink-colour sign. A per-patient analysis of a randomized study showed similar sensitivities, specificities and overall accuracies of magnifying narrow-band imaging and iodine staining of 82.2%, 95.1% and 91.2%, and 80.5%, 94.3% and 90.5%, respectively. TUMOUR-STAGING: The diagnostic capability of endoscopic ultrasonography after conventional and narrow-band imaging in terms of tumour depth was evaluated in a multicentre prospective study. Endoscopic ultrasonography did not significantly improve the accuracy for distinguishing between mucosal or submucosal microinvasive cancer and deeper cancers from 72.9 to 74.0%, suggesting that additional endoscopic ultrasonography did not improve the diagnostic accuracy. In addition, endoscopic ultrasonography increased the incidence of overdiagnosis, defined as a diagnosis of cancer depth greater than the actual depth, by 6.6%. The risk of overdiagnosis by endoscopic ultrasonography was reconfirmed in two systematic reviews. CONCLUSIONS: Narrow-band imaging is currently considered as the standard modality for the detection and characterization of oesophageal cancer. The risk of overdiagnosis should be considered when applying endoscopic ultrasonography for the evaluation of tumour invasion depth of superficial oesophageal squamous cell carcinoma.

Toward improved endoscopic examination of urinary stones: a concordance study between endoscopic digital pictures vs microscopy.

OBJECTIVE: To improve endoscopic recognition of the most frequently encountered urinary stone morphologies for a better aetiological approach in lithiasis by urologists. MATERIALS AND METHODS: An expert urologist intraoperatively and prospectively (between June 2015 and June 2018) examined the surface, the section, and the nucleus of all encountered kidney stones. Fragmented stones were subsequently analysed by a biologist based on both microscopic morphological (i.e. binocular magnifying glass) and infrared (i.e. Fourier transform-infrared spectroscopy) examinations (microscopists were blinded to the endoscopic data). Morphological criteria were collected and classified for the endoscopic and microscopic studies. The Wilcoxon-Mann-Whitney test was used to detect differences between the endoscopic and microscopic diagnoses. A diagnosis for a given urinary stone was considered 'confirmed' for a non-statistically significant difference. RESULTS: A total of 399 urinary stones were included in this study: 51.4% of the stones had only one morphological type, while 48.6% were mixed stones (41% had at least two morphologies and 7.6% had three morphologies). The overall matching rate was 81.6%. Diagnostics were confirmed for the following morphologies: whewellite (Ia or Ib), weddellite (IIa or IIb), uric acid (IIIa or IIIb), carbapatite-struvite association (IVb), and brushite (IVd). CONCLUSIONS: Our preliminary study demonstrates the feasibility of using endoscopic morphology for the most frequently encountered urinary stones and didactic boards of confirmed endoscopic images are provided. The present study constitutes the first step toward endoscopic stone recognition, which is essential in lithiasis. We provide didactic boards of confirmed endoscopic images that pave the way for automatic computer-aided in situ recognition.

Current status of endoscopic diagnosis and treatment for superficial non-ampullary duodenal epithelial tumors.

Though superficial non-ampullary duodenal epithelial tumors (SNADETs) have been traditionally considered rare, there is a growing detection under the development and widespread of endoscopic techniques in recent times. Many case studies have revealed early manifestations of lesions through advanced endoscopic technology, however, because of the low incidence of duodenal tumors and challenges in diagnosing, the preoperative diagnosis criteria have not been established so far. In spite of this, recently the increasing detection rate of early duodenal epithelial lesions enhances the demand for minimally invasive treatment as well. The most suitable therapeutic endoscopic modality to remove duodenal lesions should be selected according to the size, location and histological invasive depth of duodenal lesions. Nevertheless, due to the special anatomical structure of the duodenum, the incidence of complications is much higher than in any other part of the digestive tract. To prevent these adverse events prophylactically, a few novel strategies have been applied effectively after resection. This review describes the current status of preoperative endoscopic diagnosis and endoscopic resection approaches, as well as countermeasures for avoiding procedure-related complications.

Effect of educational lecture on the diagnostic accuracy of Japan NBI Expert Team classification for colorectal lesions.

BACKGROUND: An educational and training program is required for generalization of Japan NBI Expert Team (JNET) classification. However, there is no detailed report on the learning curve of the diagnostic accuracy of endoscopists using JNET classification. We examined the effect of an educational lecture on beginners and less experienced endoscopists for improving their diagnostic accuracy of colorectal lesions by JNET classification. METHODS: Seven beginners with no endoscopy experience (NEE group), 7 less experienced endoscopists (LEE group), and 3 highly experienced endoscopists (HEE group) performed diagnosis using JNET classification for randomized NBI images of colorectal lesions from 180 cases (Type 1: 22 cases, Type 2A: 105 cases, Type 2B: 33 cases, and Type 3: 20 cases). Next, the NEE and LEE groups received a lecture on JNET classification, and all 3 groups repeated the diagnostic process. We compared the correct diagnosis rate and interobserver agreement before and after the lecture comprehensively and for each JNET type. RESULTS: In the HEE group, the correct diagnosis rate was more than 90% with good interobserver agreements (kappa value: 0.78-0.85). In the NEE and LEE groups, the correct diagnosis rate (NEE: 60.2 → 68.0%, P < 0.01; LEE: 66.4 → 86.7%, P < 0.01), high-confidence correct diagnosis rate (NEE: 19.6 → 37.2%, P < 0.01; LEE: 43.6 → 61.1%, P < 0.01), and interobserver agreement (kappa value, NEE: 0.32 → 0.43; LEE: 0.39 → 0.75) improved after the lecture. In the examination by each JNET type, the specificity and positive predictive value in the NEE and LEE groups generally improved after the lecture. CONCLUSION: After conducting an appropriate lecture, the diagnostic ability using JNET classification was improved in beginners or endoscopists with less experience in NBI magnifying endoscopy.

Clue of Diagnosis for Autoimmune Gastritis.

BACKGROUND: The diagnostic clues for autoimmune gastritis (AIG) can be classified into 2 categories: endoscopic findings and pathological diagnosis. We believe that research on the AIG detection rate by endoscopists could provide a better understanding of the diagnosis of AIG. This study aimed to clarify the ratio of the endoscopic and the pathological diagnoses of AIG. METHODS: We retrospectively reviewed consecutive patients who underwent esophagogastroduodenoscopy (EGD). During their first EGD, the gastric mucosa with C2 atrophy or more was biopsied for pathological evaluation based on the updated Sydney system. A gastric biopsy was also performed after Helicobacter pylori eradication, obtaining specimens from at least 2 sites, the greater curvature of the corpus and the antrum. We enrolled patients who were positive for the anti-parietal cell antibody and were diagnosed with AIG, histologically and/or endoscopically. The detection rates of AIG were compared between endoscopic diagnosis and pathological diagnosis. RESULTS: A total of 10,822 patients underwent EGD during the study period. Finally, 41 patients with AIG were enrolled, leading to an AIG prevalence of 0.38% in this study. As for the clue leading to AIG detection, 31.7% (13/41) were diagnosed through endoscopy (proximal-predominant atrophy), and 68.3% (28/41) were diagnosed pathologically. The AIG detection rate by endoscopists in the posteradication group was significantly lower than in the H. pylori-negative group (p < 0.05). CONCLUSION: Endoscopists frequently overlooked AIG, especially in posteradication cases. Pathological assessment using the updated Sydney system after H. pylori eradication might be a promising strategy to detect AIG better.

Effectiveness of L-Menthol Spray Application on Lesions for the Endoscopic Clarification of Early Gastric Cancer: Evaluation by the Color Difference.

INTRODUCTION: Although L-menthol spray application on lesions has been shown to be effective for the endoscopic clarification of early gastric cancer (EGC), the currently available data are all based on subjective evaluations. OBJECTIVES: This study was aimed to objectively evaluate the effectiveness of L-menthol spray for the endoscopic classification of EGC. METHODS: Patients with EGC treated by endoscopic submucosal dissection were included. Images taken by white light imaging (WLI) and narrow band imaging (NBI) before and after spraying L-menthol directly on a lesion were saved. The primary endpoint was a change in the color difference between the EGC lesion and surrounding mucosa (ΔExy) before and after L-menthol spray application. The secondary endpoints were patient factors related to the change in ΔExy after L-menthol spray application and the pathological findings. RESULTS: Fifty cases of EGC were included in the analysis. The median ΔExy was significantly larger after L-menthol spray application than before, as assessed by either WLI (p <0.001) or NBI (p < 0.001). An increased ΔExy after L-menthol spray application was noted in 76 and 92% of patients by WLI and NBI, respectively. The percentage of patients with a ΔExy ≥5 (a level distinguishable by human eyes) was significantly larger after L-menthol spray application either by WLI (p <0.001) or NBI (p < 0.001). Pathologically, mucosal vasodilatation and stromal edema were noted after L-menthol spray application in the evaluated 2 cases. CONCLUSIONS: These results objectively demonstrate that L-menthol provides benefits in the endoscopic clarification of EGC.

Characterization of intragastric pressure waveform in endoscopic pressure study integrated system: Novel diagnostic device for gastroesophageal reflux disease.

OBJECTIVES: Endoscopic pressure study integrated system (EPSIS) is a novel diagnostic tool for gastroesophageal reflux disease (GERD). EPSIS has been developed to evaluate lower esophageal sphincter function by monitoring the intragastric pressure (IGP) while insufflating the stomach during gastroscopy. Based on previous data, EPSIS could diagnose GERD with good accuracy by assessing IGP waveform pattern. This study aimed to further characterize the waveform to improve the diagnostic yield of EPSIS. METHODS: We conducted a retrospective analysis of patients with typical GERD symptoms who underwent both EPSIS and 24-h impedance-pH monitoring (MII-pH) at a single tertiary referral center from October 2018 to May 2020. EPSIS was performed by using a through-the-scope catheter connected to the pressure measuring system (TR-W550, TR-TeH08, AP-C35; Keyence, Osaka, Japan) to monitor IGP. Abnormal acid reflux was defined as acid exposure time (AET) over 6.0%. Pressure waveform was characterized as follows: (i) Basal IGP, (ii) Maximum IGP, (iii) Pressure difference, (iv) Gradient of the waveform. RESULTS: A total of 57 patients with GERD symptoms were analyzed. Twenty-one patients presented abnormal AET on MII-pH. Among EPSIS parameters, pressure difference during insufflation correlated with AET (ρ = -0.66, P < 0.01) and showed the best diagnostic accuracy for AET with the cutoff value of 4.7 mmHg (area under the curve [AUC], 0.87). The gradient of EPSIS waveform also revealed good diagnostic accuracy for abnormal AET with the cutoff value of 0.07 mmHg/s (AUC, 0.81). CONCLUSIONS: Endoscopic pressure study integrated system waveform parameters, especially pressure difference, presented high diagnostic accuracy for the presence of abnormal acid reflux.

Simplified endoscopic pressure study integrated system for the diagnosis of gastroesophageal reflux disease.

Endoscopic pressure study integrated system (EPSIS) is a novel tool for the diagnosis of gastroesophageal reflux disease. It enables the evaluation of the function of the lower esophageal sphincter by monitoring intragastric pressure (IGP) while insufflating the stomach during esophagogastroduodenoscopy. EPSIS can predict abnormal acid reflux with high accuracy based on previous studies. IGP was measured by inserting through the working channel of the scope an intragastric catheter connected to a pressure measuring device. Herein, we assess the feasibility of an updated EPSIS system, which can be performed just by connecting a flush tube to the working channel. This method does not require inserting foreign objects in the stomach and spares catheter insertion in order to simplify the procedure and reduce costs. A single-center pilot study was conducted to evaluate the association between catheter-based EPSIS and the updated EPSIS. The results of EPSIS in 20 patients who underwent both methods were assessed. In all cases, the waveform pattern of IGP measured by catheter-based EPSIS and updated EPSIS was consistent with 15 uphill pattern and five flat pattern. Intraobserver agreement of waveform pattern was perfect between two examiners with kappa value = 1. Intraclass correlation coefficient (ICC) for intraobserver reliability for maximum IGP was excellent with 0.91 (95% confidence interval [CI] of 0.77 < ICC < 0.96) and for pressure gradient was also good with 0.89 (95% CI of 0.71 < ICC < 0.95). In conclusion, our study suggests that the updated EPSIS can be performed without the use of a catheter.

Differentiation between duodenal neoplasms and non-neoplasms using magnifying narrow-band imaging - Do we still need biopsies for duodenal lesions?

OBJECTIVES: Endoscopic biopsies for nonampullary duodenal epithelial neoplasms (NADENs) can induce submucosal fibrosis, making endoscopic resection difficult. However, no biopsy-free method exists to distinguish between NADENs and non-neoplasms. We developed a diagnostic algorithm for duodenal neoplasms based on magnifying endoscopy findings and evaluated the model's diagnostic ability. METHODS: Magnified endoscopic images and duodenal lesion histology were collected consecutively between January 2015 and April 2016. Diagnosticians classified the surface patterns as pit, groove or absent. In cases of nonvisible surface patterns, the vascular pattern was evaluated to determine regularity or irregularity. The correlation between our algorithm (pit-type or absent with irregular vascular pattern) and the lesion histology were evaluated. Four evaluators, who were blinded to the histology, also classified the endoscopic findings and evaluated the diagnostic performance and interobserver agreement. RESULTS: Endoscopic images of 114 lesions were evaluated (70 NADENs and 44 non-neoplasms, 31 in the superior and 83 in the descending and horizontal duodenum). Of the NADEN surface patterns, 88% (62/70) were pit-type, while 79% (35/44) of the non-neoplasm surface patterns were groove-type. Our diagnostic algorithm for differentiating NADENs from non-neoplasms was high (sensitivity 96%, specificity 95%) in the descending and horizontal duodenum. The evaluators' diagnostic performances were also high, and interobserver agreement for the algorithm was good between each diagnostician and evaluator (κ = 0.60-0.76). CONCLUSION: Diagnostic performance of our algorithm sufficiently enabled eliminating endoscopic biopsies for diagnosing the descending and horizontal duodenum.

The sub-classification of type B2 vessels according to the magnifying endoscopic classification of the Japan Esophageal Society.

OBJECTIVES: Guidelines for magnified endoscopic diagnosis of esophageal squamous cell carcinoma (SCC) have been proposed by the Japan Esophageal Society. Type B1, B2, and B3 reflect increasing tumor invasion depths (within mucosal epithelium or into lamina propria mucosa [T1a-EP/LPM], into muscularis mucosa or superficial invasion into submucosa [T1a-MM/T1b-SM1], and into submucosa [T1b-SM2], respectively). The diagnostic accuracy of type B1 and B3 is high, but accuracy of type B2 is low. We aimed to improve the diagnostic accuracy of type B2. METHODS: We retrospectively reviewed 248 SCC lesions treated with endoscopic submucosal dissection between January 2012 and July 2018 and identified the B2 lesions. The maximum diameter of the area presenting B2 was measured and evaluated in relation to tumor invasion, for which receiver-operating characteristic (ROC) curves were generated. The optimal area size for distinguishing T1a-EP/LPM from T1a-MM or deeper invasion was determined. RESULTS: There were 78 lesions with B2, of which 26 (33%) were T1a-MM or T1b-SM1 SCCs. ROC curve analysis indicated that the optimal cut-off for the target area showing B2 was 4 mm. The invasion depth (EP/LPM: MM/SM1: SM2) of B2 observed in an area with a diameter <4 mm (B2-Narrow) and those with diameter ≥4 mm (B2-Broad) was 46:11:1 and 1:15:4, respectively. To predict T1a-MM or deeper invasion, B2-Broad had a sensitivity, specificity, positive predictive value, and negative predictive value of 61%, 98%, 95%, and 79%, respectively. CONCLUSION: The diagnostic accuracy of type B2 was improved by evaluating the area of type B2.