Unified Magnifying Endoscopic Classification (UMEC) of Gastrointestinal Lesions: A North American Validation Study.

Background and study aim: Magnifying endoscopy enables the diagnosis of advanced neoplasia throughout the gastrointestinal tract. The unified magnifying endoscopic classification (UMEC) framework unifies optical diagnosis criteria in the esophagus, stomach, and colon, dividing lesions into three categories: non-neoplastic, intramucosal neoplasia, and deep submucosal invasive cancer. This study aims to ascertain the performance of North American endoscopists when using the UMEC. Methods: In this retrospective cohort study, five North American endoscopists without prior training in magnifying endoscopy independently diagnosed images of gastrointestinal tract lesions using UMEC. All endoscopists were blinded to endoscopic findings and histopathological diagnosis. Using histopathology as the gold standard, the endoscopists' diagnostic performances using UMEC were evaluated. Results: A total of 299 lesions (77 esophagus, 92 stomach, and 130 colon) were assessed. For esophageal squamous cell carcinoma, the sensitivity, specificity, and accuracy ranged from 65.2% (95%CI: 50.9-77.9) to 87.0% (95%CI: 75.3-94.6), 77.4% (95%CI: 60.9-89.6) to 96.8% (95%CI: 86.8-99.8), and 75.3% to 87.0%, respectively. For gastric adenocarcinoma, the sensitivity, specificity, and accuracy ranged from 94.9% (95%CI: 85.0-99.1) to 100%, 52.9% (95%CI: 39.4-66.2) to 92.2% (95%CI: 82.7-97.5), and 73.3% to 93.3%. For colorectal adenocarcinoma, the sensitivity, specificity, and accuracy ranged from 76.2% (95%CI: 62.0-87.3) to 83.3% (95%CI: 70.3-92.5), 89.7% (95%CI: 82.1-94.9) to 97.7% (95%CI: 93.1-99.6), and 86.8% to 90.7%. Intraclass correlation coefficients indicated good to excellent reliability. Conclusion: UMEC is a simple classification that may be used to introduce endoscopists to magnifying narrow-band imaging and optical diagnosis, yielding satisfactory diagnostic accuracy.

Comparison of Endoscopic Mucosal Resection versus Endoscopic Submucosal Dissection for Barrett's Neoplasia and Esophageal Adenocarcinoma: A Systematic Review and Meta-Analysis.

BACKGROUND AND AIMS: Endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) are both accepted resection strategies for Barrett's esophagus-related neoplasia and esophageal adenocarcinoma (EAC). However, a lack of consensus exists regarding which technique offers superior outcomes. This study aims to systematically review the evidence comparing EMR versus ESD in treating Barrett's neoplasia and EAC. METHODS: We searched three databases (Embase, MEDLINE, Cochrane Central) until October 2023. We included studies comparing the efficacy of EMR and ESD for Barrett's neoplasia and EAC. Primary outcomes include en bloc, R0, and curative resection, complete remission of dysplasia (CRD), and local recurrence. Secondary outcomes encompass adverse events. RESULTS: Our search identified 905 records. Eleven studies were included in the final analyses. Data showed significantly higher en bloc resection rates with ESD [odds ratio(OR)=27.36 (95% confidence intervals(CI):7.12-105.21), p<0.01, 6 studies]. R0 resection rates were significantly higher with ESD [OR=5.73 (95%CI:2.32-14.16), p<0.01, 7 studies]. Curative resection rates tended to be higher with ESD [OR=3.49 (95%CI:0.86-14.14), p=0.080, 4 studies]. There was no significant difference in CRD rates [OR=0.92 (95%CI:0.37-2.26),p=0.86, 3 studies]. Local recurrence rates tended to be lower with ESD [OR=0.35 (95%CI: 0.11-1.04), p=0.058, 10 studies]. As for adverse events, there was no significant difference in bleeding, perforation, and postoperative stricture rates. CONCLUSIONS: This systematic review and meta-analysis demonstrates that ESD achieves higher en bloc, R0 and curative resection rates, with a tendency toward lower recurrence rates. These results suggest that ESD may be a more effective option for managing Barrett's neoplasia and EAC.

Establishment of Standards for the Referral of Large Non-Pedunculated Colorectal Polyps: An International Expert Consensus Using a Modified Delphi Process.

BACKGROUND AND AIMS: Resection of colorectal polyps has been shown to decrease the incidence and mortality of colorectal cancer. Large non-pedunculated colorectal polyps are often referred to expert centres for endoscopic resection, which requires relevant information to be conveyed to the therapeutic endoscopist to allow for triage and planning of resection technique. The primary objective of our study was to establish minimum expected standards for the referral of LNPCP for potential ER. METHODS: A Delphi methodology was employed to establish consensus on minimum expected standards for the referral of large colorectal polyps among a panel of international endoscopy experts. The expert panel was recruited through purposive sampling, and three rounds of surveys were conducted to achieve consensus, with quantitative and qualitative data analysed for each round. RESULTS: A total of 24 international experts from diverse continents participated in the Delphi study, resulting in consensus on 19 statements related to the referral of large colorectal polyps. The identified factors, including patient demographics, relevant medications, lesion factors, photodocumentation and the presence of a tattoo, were deemed important for conveying the necessary information to therapeutic endoscopists. The mean scores for the statements ranged from 7.04 to 9.29 out of 10, with high percentages of experts considering most statements as a very high priority. Subgroup analysis by continent revealed some variations in consensus rates among experts from different regions. CONCLUSION: The identified consensus statements can aid in improving the triage and planning of resection techniques for large colorectal polyps, ultimately contributing to the reduction of colorectal cancer incidence and mortality.

How to make cost-effective polyp simulators for high-fidelity simulation-based training in postpolypectomy bleeding management and EMR.

Video 1Demonstration of manufacturing instructions and features of the postpolypectomy bleeding and conventional and underwater EMR simulators.

Impact of Residing in Below Median Household Income Districts on Outcomes in Patients with Advanced Barrett's Esophagus.

Background: Barrett's esophagus (BE) is a premalignant condition to esophageal adenocarcinoma (EAC). Low socioeconomic (SES) status adversely impacts care and outcomes in patients with EAC, but this has not been evaluated in BE. As the treatment of BE is similarly intensive, we aimed to evaluate the effect of SES on achieving complete eradication of intestinal metaplasia (CE-IM), dysplasia (CE-D) and development of invasive EAC. Methods: Our study was a retrospective cohort study. Consecutive patients between January 1, 2010, to December 31, 2018, referred for BE-associated high-grade dysplasia or intramucosal adenocarcinoma were included. Pre, intra and post-procedural data were collected. Household income data was collected from the 2016 census based on postal code region. Patients were divided into income groups relative to the 2016 median household income in Ontario. Multivariate regression was performed for outcomes of interest. Results: Four hundred and fifty-nine patients were included. Rate of CE-IM was similar between income groups. Fifty-five per cent (n = 144/264) versus 65% (n = 48/264) in the below and above-income groups achieved CE-D, respectively, P = 0.02. Eighteen per cent (n = 48/264) versus 11% (n = 22/195) were found to have invasive EAC during their treatment course in below and above-income groups, respectively, P = 0.04. Residing in a below-median-income district was associated with developing invasive EAC (Odds Ratio, [OR] 1.84, 95% confidence interval [CI] 1.01 to 3.35) and failure to achieve CE-D (OR 0.64, 95% CI 0.42 to 0.97). Conclusions: Residing in low-income districts is associated with worse outcomes in patients with advanced BE. Further research is needed to guide future initiatives to address the potential impact of SES barriers in the optimal care of BE.

Endoscopic carbon dioxide insufflation tolerance test on the anal sphincter for anorectal hypofunction: a pilot and feasibility study.

Background: Anorectal function deteriorates with age. The diagnostic performance of the endoscopic pressure study integrated system (EPSIS), an endoscopic carbon dioxide (CO2) insufflation stress test of the lower esophageal sphincter has been previously evaluated as a diagnostic tool for gastroesophageal reflux disease. We aimed to evaluate the applicability of EPSIS in improving anorectal function. We hypothesized that EPSIS can be applied to the diagnosis of lower gastrointestinal tract disorders. Methods: This was a pilot, single-center, retrospective study using prospectively collected data between December 2021 and March 2022. It was designed to evaluate the differences in EPSIS rectal pressure measurements between older (≥80 years) and younger (<80 years) patients. At the end of the screening colonoscopy, the colonoscope was fixed in a retroflex position. When bowel movement was observed, CO2 was insufflated to the point where gas leakage occurred through the anus. The measured maximum pressure was defined as EPSIS-rectal pressure max (EPSIS-RP max) and compared between the groups. Results: Overall, 30 patients were included and examined. The median ages of the <80 and ≥80 years' groups were 53 (range: 27-79) and 82 (range: 80-94) years, respectively, with corresponding median measured EPSIS-RP max of 18.7 (range: 8.5-30.2) and 9.8 (range: 5.4-22.3) mmHg (P<0.001). Conclusions: Measurement of maximum rectal pressure illustrates the age-related decline in physiological anorectal function. Future studies should consider a loading test using EPSIS to quantify the decline in anorectal function and use it as a routine tool for screening and adjunctive diagnosis of anorectal hypofunction.

The third space for endoscopic treatment of motility disorders of the gastrointestinal tract.

Over the last few decades, we have seen the further advancement and progress of the field of interventional and therapeutic endoscopy, bringing us to undiscovered areas of the gut's lumen. The development of peroral endoscopic myotomy (POEM) created a breakthrough in the field of therapeutic endoscopy by bringing us to the so-called "third space," which is an artificially created space in the submucosal layer. The rise of third space endoscopy brought us novel and fundamental aspects into therapeutic endoscopy by paving the way to interventions throughout the gastrointestinal (GI) tract. With the success of POEM, the same third space principles have become the foundation for the development of other third space endoscopic techniques for the management of motility disorders of the GI tract, giving rise to a number of POEM offshoots. Since motility disorders of the GI tract are commonly encountered in clinical practice, the development of third space endoscopic interventions to address these disorders was seemingly timely, providing patients optimal care. In this chapter, we would like to offer a closer look and provide the readers a general overview of POEM and other POEM-based techniques which have been developed for the management of motility disorders of the GI tract.

Evolving field of third-space endoscopy: Derivatives of peroral endoscopic myotomy.

Third-space endoscopy, also known as submucosal endoscopy, allows for a wide range of therapeutic interventions within the submucosal layer and even into the muscular or subserosal layers of the gastrointestinal lumen. The technical development of peroral endoscopic myotomy (POEM) for achalasia has revolutionized the field of therapeutic endoscopy and the method has been continuously refined and modified. Although POEM has been applied to treat primary achalasia, it shows a favorable clinical response in other esophageal motility disorders and as a salvage treatment after previously failed intervention. Gastroesophageal reflux after POEM has drawn considerable attention and there have been major advancements in its prevention and management. POEM has led to advantageous derivatives such as peroral endoscopic tumor resection or submucosal tunneling endoscopic resection for resection of subepithelial lesions, Zenker POEM for hypopharyngeal diverticula, diverticular POEM for epiphrenic esophageal diverticula, and gastric POEM for refractory gastroparesis. These techniques have a similar concept, which constitutes submucosal tunneling with a mucosal flap valve and secure mucosal incision closure. The submucosal tunneling technique is widely accepted and continues to evolve. This study aimed to review in detail the indications, outcomes, and technical variations in POEM and explore several emerging submucosal tunneling procedures. This review will benefit future studies by providing a summary of recent developments in this field.

Learning curve for peroral endoscopic myotomy in therapeutic endoscopy experts and nonexperts: Large single-center experience.

OBJECTIVES: Reports on learning curve for peroral endoscopic myotomy (POEM) in therapeutic endoscopy nonexperts are limited. We aimed to assess the number of cases required to achieve POEM proficiency for endoscopic submucosal dissection (ESD) experts and nonexperts. METHODS: This is a retrospective study at the largest POEM referral center in Japan. POEM between April 2014 and December 2020 were included. Nonexperts and ESD experts were divided by training phases: A, 1-20; B, 21-40; C, 41-60; D, 61-80; and E, 81-100 cases. Primary outcome was operation time, and the phase to reach target time (83 min) was investigated. Secondary outcomes were clinical success rate, adverse events, and post-POEM gastroesophageal reflux disease (GERD). RESULTS: Five hundred and sixty-six cases were performed by 14 nonexperts, and 555 cases by 15 ESD experts. As the primary outcome, operation time in nonexperts was: A, 95 (79-115.8); B, 86.5 (71-105); C, 80 (70-100); D, 73 (64.5-100.5); and E, 73.5 (57.8-88.8) min, while in ESD experts: A, 90 (74-128); B, 77 (70-92); and C, 77 (70-93.5) min (median [interquartile range]). Operation time decreased significantly as experience increased in both groups (P < 0.001), and nonexperts required 41-60 cases to achieve proficiency, while experts required 21-40 cases. As secondary outcomes, in nonexperts, clinical success was 96.9-100%, adverse events were 5.0-9.2%, symptomatic GERD was 11.8-26.5%, and proton pump inhibitor (PPI) intake was 11.5-18.7% in each phase. While in experts, clinical success was 96.2-100%, adverse events were 3.0-5.8%, symptomatic GERD was 14.6-22.0%, and PPI intake was 12.6-17.9%. There were no significant differences among training phases. CONCLUSIONS: Non-ESD experts require more cases to achieve proficiency in POEM. These results are useful for establishing POEM training programs and institutional implementation of the procedure.

Risks of refractory chest pain after peroral endoscopic myotomy in achalasia-related esophageal motility disorders: short-term results from a multicenter study in Japan.

BACKGROUND AND AIMS: The etiology of chest pain in achalasia-related esophageal motility disorders and the frequency and risk factors of persistent chest pain after peroral endoscopic myotomy (POEM) remain unclear. METHODS: A multicenter cohort study including 14 hospitals was conducted to elucidate the characteristics of patients with chest pain and the efficacy of POEM. RESULTS: Consecutive cases of achalasia-related esophageal motility disorders included 2294 (64.2%) and 1280 (35.8%) patients with and without chest pain, respectively. Among the 2107 patients with chest pain who underwent POEM, we observed complete remission in 1464 patients (69.5%) and nonremission in 643 patients (30.5%), including a partial response in 619 patients (29.4%) and resistance in 24 patients (1.1%). Multivariate analysis revealed that advanced age (odds ratio [OR], .28), male sex (OR, .70), prior treatment (OR, 1.39), and sigmoid type (OR, .65) were related to the prevalence of chest pain. Long disease duration (OR, .69) and esophageal dilation (OR, .79) were related to decreased severity. POEM improved patients' quality of life that was hindered by chest pain. Early onset (OR, 1.45), advanced age (OR, .58), male sex (OR, .79), prior treatment (OR, 1.37), and posterior myotomy (OR, 1.42) were associated with nonremission after POEM; high-resolution manometry (HRM) findings and myotomy length showed no statistical significance on pain etiology and persistence after POEM. CONCLUSIONS: The prevalence and severity of chest pain were dependent on age, sex, disease duration, prior treatment, and esophageal morphology rather than HRM findings. The efficacy of POEM is satisfactory; however, residual pain was often observed. Excessively long myotomy can be avoided, and anterior myotomy may be recommended.

A novel endoscopic purse-string suture technique, "loop 9", for gastrointestinal defect closure: a pilot study.

BACKGROUND : This study aimed to assess the feasibility and efficacy of the novel loop 9 method of gastrointestinal (GI) defect closure. METHODS : 20 patients underwent a GI procedure that required defect closure. Loop 9 can be delivered through a single instrument channel (3.2 mm) and released at the defect site. After it has been anchored by two clips positioned on opposite sides of the defect edge, the loop 9 is tightened by pulling the end of the suture intraluminally using biopsy forceps. Additional clips are placed to achieve complete closure. The primary outcome was complete closure rate. The secondary outcomes were closure time, sustained closure rate, and adverse events. RESULTS : Complete closure was achieved in 100 % of cases. The mean size of the mucosal defects was 17.5 mm (range 10-55 mm). The median closure time was 14 minutes. The sustained closure rate was 90 %. No adverse events were noted. CONCLUSIONS : The loop 9 technique is feasible and effective in achieving complete and sustained closure of therapeutic endoscopy-related GI defects.

Impact of the COVID-19 pandemic on high-resolution manometry and peroral endoscopic myotomy for esophageal motility disorder in Japan.

AIM: To elucidate the impact of the coronavirus disease 2019 (COVID-19) on the practice of high-resolution manometry (HRM) and peroral endoscopic myotomy (POEM) in Japan. METHODS: We utilized a large-scale database involving 14 high-volume centers in Japan to investigate changes in the numbers of HRM and POEM procedures performed and outcomes of POEM between 2019 and 2020. A questionnaire survey was also conducted to analyze pandemic-associated changes in the HRM and POEM protocols. RESULTS: Compared to that in 2019, the number of HRM and POEM procedures decreased by 17.2% (1587-1314) and 20.9% (630-498), respectively. These declines were prominent during the state of emergency from April to May 2020, particularly in pandemic areas. HRM and POEM in nonpandemic areas were relatively unaffected. From 2019 to 2020, there was a 0.4% (254-248) decrease in POEM cases within the prefecture, but the number outside the prefecture decreased by 33.6% (372-247). During the pandemic, the safety and efficacy of POEM were maintained. The implementation of personal protective equipment (PPE) measures varied among facilities, and PPE for POEM was relatively insufficient compared to that for HRM. CONCLUSION: The COVID-19 pandemic influenced HRM and POEM practices in Japan. It is necessary to establish a sufficient system for HRM and POEM in each hospital as well as countrywide to overcome the effects of the pandemic.

Unified magnifying endoscopic classification for esophageal, gastric and colonic lesions: a feasibility pilot study.

Background and study aims Image-enhanced magnifying endoscopy allows optimization of the detection and diagnosis of lesions found in the gastrointestinal tract. Current organ-specific classifications are well-accepted by specialized endoscopists but may pose confusion for general gastroenterologists. To address this, our group proposed the Unified Magnifying Endoscopic Classification (UMEC) which can be applied either in esophagus, stomach, or colon. The aim of this study was to evaluate the diagnostic performance and clinical applicability of UMEC. Patients and methods A single-center, feasibility pilot study was conducted. Two endoscopists with experience in magnifying narrow band imaging (NBI), blinded to white-light and non-magnifying NBI findings as well as histopathological diagnosis, independently reviewed and diagnosed all images based on UMEC. In brief, UMEC is divided into three categories: non-neoplasia, intramucosal neoplasia, and deep submucosal invasive cancer. The diagnostic performance of UMEC was assessed while using the gold standard histopathology as a reference. Results A total of 303 gastrointestinal lesions (88 esophageal squamous lesions, 90 gastric lesions, 125 colonic lesions) were assessed. The overall accuracy for both endoscopists in the diagnosis of esophageal squamous cell cancer, gastric cancer, and colorectal cancer were 84.7 %, 89.5 %, and 83.2 %, respectively. The interobserver agreement for each organ, Kappa statistics of 0.51, 0.73, and 0.63, was good. Conclusions UMEC appears to be a simple and practically acceptable classification, particularly to general gastroenterologists, due to its good diagnostic accuracy, and deserves further evaluation in future studies.

Diagnostic yield of fourth-generation endocytoscopy for esophageal squamous lesions using a modified endocytoscopic classification.

OBJECTIVES: Endocytoscopy (EC) is an ultra-high magnification endoscopy designed to provide in vivo histologic assessment. This study aimed to evaluate the diagnostic yield of the newly developed fourth-generation EC for esophageal squamous lesions by using a modified EC classification. METHODS: A total of 2548 EC images of 57 esophageal targeted areas between June 2015 and October 2017 were retrospectively collected. Two lesions with low-quality images were excluded. Only EC images were independently reviewed by two expert and two non-expert endoscopists. The lesions were classified according to a three-tier modified EC classification. We used a multilevel logistic regression to analyze the data. RESULTS: The sensitivity and specificity of diagnosing non-squamous cell cancer (SCC) vs SCC were 82.5% and 83.0% by the experts; 90.1% and 75.0% by non-experts. The interobserver agreement among the four raters was good (kappa statistic 0.59). The diagnostic accuracy of experts and non-experts was similar (P = 0.16 for specificity and P = 0.20 for sensitivity). The sensitivity and specificity of EC for non-neoplasia vs neoplasia were 88.7% and 74.6% by experts; 90.3 and 52.1% by non-experts. The interobserver agreement among the four raters was moderate (kappa statistic 0.44). The specificity of experts was higher compared to non-experts, although the difference did not reach statistical significance (P = 0.08 for specificity and P = 0.93 for sensitivity). CONCLUSIONS: Fourth-generation EC offers acceptable diagnostic accuracy and reliability in both experts and non-experts, especially when diagnosing SCC lesions.

Importance of second-look endoscopy after per-oral endoscopic myotomy for safe postoperative management.

OBJECTIVES: Per-oral endoscopic myotomy (POEM) is a safe and effective treatment for achalasia and esophageal motility disorders. The role of second-look endoscopy (SE) on postoperative day 1 has not been examined. This study aimed to evaluate the findings and need of SE after POEM. METHODS: This is a single-center, retrospective study. All consecutive patients who underwent POEM and SE on postoperative day 1 between December 2017 and September 2019 were included. The primary endpoint was the rate of newly-detected adverse events (nAE) during SE that required endoscopic intervention or deviation from the normal postoperative course. Multivariate logistic regression was used to identify predictors of nAE. RESULTS: Four-hundred-ninety-seven patients (mean age, 50.3 years; female, 49.9%) were included. SE identified abnormal findings in a total of 71 patients (14.3%). nAE which required endoscopic intervention or deviation from the normal postoperative course were identified in 12 patients (2.4%): eight (1.6%) entry site dehiscence; two (0.4%) submucosal hemorrhage or hematoma; and two (0.4%) dehiscence of an intraoperative perforation site after endoclip closure. Other findings such as mucosal thermal damage without perforation and small submucosal hematoma were found in 54 patients (10.9%) and five patients (1.0%), respectively. Multivariate analysis showed that longer operation time and intraoperative adverse events (AE) were associated with clinically significant nAE during SE. CONCLUSIONS: Second-look endoscopy can detect and treat nAE that may lead to severe AE. Thus, SE should be highly considered before starting oral ingestion in all cases, and especially in those who present an intraoperative AE and longer operation time.

Safety and effectiveness of peroral endoscopic myotomy in patients on antiplatelet or anticoagulant therapy: an international multicenter case-control study.

BACKGROUND AND AIMS: The risk of bleeding and thromboembolic events in patients undergoing peroral endoscopic myotomy (POEM) who are receiving antithrombotic therapy is unknown. Our primary aim was to assess the safety of POEM in this patient subset. Secondary outcomes were rates of clinical success, GERD, and procedure-related outcomes. METHODS: This was an international, 1:1, case-control study performed at 10 centers using prospectively maintained databases. All consecutive patients who underwent POEM before November 2019 were considered for inclusion. Cases were patients on antiplatelet and/or anticoagulant therapy. Controls not receiving antithrombotics were matched for age and esophageal motility disorder. Primary outcomes were major bleeding and thromboembolic events on postprocedural day 30. RESULTS: Of 2895 patients who underwent POEM, 126 cases (103 on antiplatelets, 35 anticoagulants, 12 both) and 126 controls were enrolled. The rate of major bleeding was higher for the antithrombotics users (5.6% vs 0.8%, P = .03). Anticoagulants and clopidogrel were temporarily interrupted in all cases. Aspirin was continued in 40.5% of users without increasing the bleeding risk. One thromboembolic event occurred in each group (0.79%; P = 1.00). No POEM-related deaths were noted. Rates of clinical success (91.7% vs 96% in controls, P = .20), postprocedural GERD, and technical-related outcomes were similar in both groups. Antithrombotic management was heterogeneous, and guidelines were not adhered to in 23.8% of cases. CONCLUSIONS: POEM is safe and effective in patients receiving antithrombotic therapy although it is associated with a greater risk of major bleeding.

Endoscopic Classifications of Early Gastric Cancer: A Literature Review.

Endoscopic technologies have been continuously advancing throughout the years to facilitate improvement in the detection and diagnosis of gastric lesions. With the development of different endoscopic diagnostic modalities for EGC, several classifications have been advocated for the evaluation of gastric lesions, aiming for an early detection and diagnosis. Sufficient knowledge on the appearance of EGC on white light endoscopy is fundamental for early detection and management. On the other hand, those superficial EGC with subtle morphological changes that are challenging to be detected with white light endoscopy may now be clearly defined by means of image-enhanced endoscopy (IEE). By combining magnifying endoscopy and IEE, irregularities in the surface structures can be evaluated and highlighted, leading to improvements in EGC diagnostic accuracy. The main scope of this review article is to offer a closer look at the different classifications of EGC based on several endoscopic diagnostic modalities, as well as to introduce readers to newer and novel classifications, specifically developed for the stomach, for the assessment and diagnosis of gastric lesions.

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.