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.

Advancements in minimally invasive endoscopic treatment: Navigating deeper layers for upper gastrointestinal lesion.

The field of minimally invasive endoscopic treatment has seen a continual progression, marked by significant advancements in treatment devices and the refinement of endoscopic techniques. While endoscopic resection has become the standard for treating superficial gastrointestinal neoplasms, a proactive approach becomes imperative when dealing with lesions that extend beyond the submucosal layer and deeper into the muscularis propria. The ongoing evolution of endoscopic closure techniques has facilitated the introduction of advanced procedures such as endoscopic muscularis dissection, endoscopic subserosal dissection, and endoscopic full-thickness resection. This evolution is achieved by the commitment to improve the efficacy and precision in treating challenging lesions. Nevertheless, there is currently a lack of definitive guidelines or consensus regarding the specifics of deeper layer dissection. Drawing from prior research and clinical insights, this review discusses indications, techniques, clinical outcomes, and future perspectives of deeper layer dissection.

Functional Endoscopy.

BACKGROUND: Functional endoscopy signifies a significant advancement in gastrointestinal examination, integrating motor function assessments alongside routine endoscopy findings. Traditional gastrointestinal endoscopy primarily focuses on the detection of early-stage cancer by identifying morphological changes within the gastrointestinal tract. These alterations include modifications in lumen structure, color tone, and surface patterns, which can be diagnosed using endoscopic images that assess these morphological changes. In contrast, functional endoscopy aims to dynamically evaluate the peristaltic movements of the digestive tract and the presence or movement of reflux of digestive fluids during the endoscopic procedure. It also seeks to identify morphological changes such as hiatal hernias, as observed in conventional endoscopy. Consequently, relying solely on endoscopic images proves inadequate for diagnosis, necessitating continuous observation of these dynamic movements. SUMMARY: The endoscopic pressure study integrated system (EPSIS) serves as an exemplar of functional endoscopy. It incorporates a stress test to assess the functionality of the lower esophageal sphincter (LES) through intragastric insufflation. A crucial element of EPSIS evaluation is the identification of the scope holding sign (SHS), which signifies LES contraction. EPSIS also encompasses the observation of esophageal peristaltic waves and the auditory detection of burping, providing a comprehensive diagnostic approach while observing the sphincter from a retroflex view on the stomach side. By integrating these dynamic findings, functional endoscopy offers an efficient method for diagnosing functional gastrointestinal diseases, such as gastroesophageal reflux disease (GERD). KEY MESSAGES: Functional endoscopy combines motor function assessments with traditional endoscopy, enhancing the diagnostic capabilities of gastrointestinal examinations. Traditional endoscopy focuses on identifying morphological changes, while functional endoscopy evaluates dynamic movements, reflux, and sphincter functionality. EPSIS exemplifies functional endoscopy, featuring a stress test and the SHS for LES contraction assessment. EPSIS provides a comprehensive approach to diagnose GERD by integrating dynamic observations.

Clinical outcomes of anti-reflux mucosal ablation for gastroesophageal reflux disease: An international bi-institutional study.

BACKGROUND AND AIM: Anti-reflux mucosal ablation (ARMA) is an emerging endoscopic treatment aimed at enhancing the gastroesophageal junction flap valve. This study aimed to evaluate its feasibility, effectiveness, and safety. METHODS: Between May 2018 and December 2022, patients with gastroesophageal reflux disease (GERD) symptoms refractory to acid suppression medications or those dependent on such medications were enrolled for ARMA. This retrospective analysis utilized prospectively collected data from an international bi-center study. GERD questionnaire, upper endoscopy, and 24-h pH monitoring were conducted at 2-6 months and 12 months post-ARMA. Clinical success was defined as a > 50% reduction in a validated GERD questionnaire. RESULTS: A total of 68 patients underwent ARMA. Definitive GERD was diagnosed in 44 (64.7%) patients, while 24 (35.3%) exhibited reflux hypersensitivity. Clinical success rates at 2-6 months and 1 year post-ARMA were 60% (39/65) and 70% (21/30), respectively. The median GERD-health-related quality of life score significantly improved from 26 to 11 at 2-6 months (P < 0.001). Among the 51 patients (71.8%) who underwent 24-h pH monitoring, the median acid exposure time decreased from 5.3% to 0.7% (P = 0.003), accompanied by a significant reduction in esophagitis rates (P < 0.001). Multivariate analysis did not identify predictors of short-term success. Nine (13.2%) patients experienced transient stenosis requiring balloon dilation. CONCLUSIONS: ARMA demonstrates both technical feasibility and reproducibility as a safe procedure that effectively ameliorates GERD symptoms in approximately two-thirds of patients during short-term follow up. Both reflux hypersensitivity and confirmed GERD patients, regardless of their response to acid suppression medication, may be suitable candidates.

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.

Determination of esophageal squamous cell carcinoma and gastric adenocarcinoma on raw tissue using Raman spectroscopy.

BACKGROUND: Cancer detection is a global research focus, and novel, rapid, and label-free techniques are being developed for routine clinical practice. This has led to the development of new tools and techniques from the bench side to routine clinical practice. In this study, we present a method that uses Raman spectroscopy (RS) to detect cancer in unstained formalin-fixed, resected specimens of the esophagus and stomach. Our method can record a clear Raman-scattered light spectrum in these specimens, confirming that the Raman-scattered light spectrum changes because of the histological differences in the mucosal tissue. AIM: To evaluate the use of Raman-scattered light spectrum for detecting endoscop-ically resected specimens of esophageal squamous cell carcinoma (SCC) and gastric adenocarcinoma (AC). METHODS: We created a Raman device that is suitable for observing living tissues, and attempted to acquire Raman-scattered light spectra in endoscopically resected specimens of six esophageal tissues and 12 gastric tissues. We evaluated formalin-fixed tissues using this technique and captured shifts at multiple locations based on feasibility, ranging from six to 19 locations 200 microns apart in the vertical and horizontal directions. Furthermore, a correlation between the obtained Raman scattered light spectra and histopathological diagnosis was performed. RESULTS: We successfully obtained Raman scattered light spectra from all six esophageal and 12 gastric specimens. After data capture, the tissue specimens were sent for histopathological analysis for further processing because RS is a label-free methodology that does not cause tissue destruction or alterations. Based on data analysis of molecular-level substrates, we established cut-off values for the diagnosis of esophageal SCC and gastric AC. By analyzing specific Raman shifts, we developed an algorithm to identify the range of esophageal SCC and gastric AC with an accuracy close to that of histopathological diagnoses. CONCLUSION: Our technique provides qualitative information for real-time morphological diagnosis. However, further in vivo evaluations require an excitation light source with low human toxicity and large amounts of data for validation.

Risk scoring system for the preprocedural prediction of the clinical failure of peroral endoscopic myotomy: a multicenter case-control study.

BACKGROUND: Peroral endoscopic myotomy (POEM) is effective for the management of achalasia and its variants; however, it can be ineffective in some patients. We aimed to develop and validate a risk scoring system to predict the clinical failure of POEM preoperatively. METHODS: Consecutive patients who underwent POEM in 14 high volume centers between 2010 and 2020 were enrolled in this study. Clinical failure was defined as an Eckardt score of ≥ 4 or retreatment. A risk scoring system to predict the short-term clinical failure of POEM was developed using multivariable logistic regression and internally validated using bootstrapping and decision curve analysis. RESULTS: Of the 2740 study patients, 112 (4.1 %) experienced clinical failure 6 months after POEM. Risk scores were assigned for three preoperative factors as follows: preoperative Eckardt score (1 point), manometric diagnosis (-4 points for type II achalasia), and a history of prior treatments (1 point for pneumatic dilation or 12 points for surgical/endoscopic myotomy). The discriminative capacity (concordance statistics 0.68, 95 %CI 0.62-0.72) and calibration (slope 1.15, 95 %CI 0.87-1.40) were shown. Decision curve analysis demonstrated its clinical usefulness. Patients were categorized into low (0-8 points; estimated risk of clinical failure < 5 %) and high risk (9-22 points; ≥ 5 %) groups. The proportions of clinical failure for the categories were stratified according to the mid-term outcomes (log-rank test, P < 0.001). CONCLUSIONS: This risk scoring system can predict the clinical failure of POEM preoperatively and provide useful information when making treatment decisions.

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.

The Journey from Endoscopic Submucosal Dissection to Third Space Endoscopy.

With the advent of endoscopic submucosal dissection, a variety of endoscopic devices including knives and high-frequency electrosurgical unit have become available. In addition, the concept of natural orifice transluminal endoscopic surgery pushed flexible endoscopic surgery ahead. In this review, the birth of peroral endoscopic myotomy and its expansion into the field of submucosal endoscopy are reviewed.

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.

Impact of peroral endoscopic myotomy on high-resolution manometry findings and their association with the procedure's outcomes.

BACKGROUND AND AIMS: Peroral endoscopic myotomy (POEM) is conducted for patients with esophageal motility disorders based on high-resolution manometry (HRM) findings. However, the impact of POEM on HRM findings and the associations between post-POEM HRM and outcomes have not been clarified. METHODS: In a multicenter, observational, cohort study, patients with achalasia treated by POEM received follow-up HRM. Associations between patient characteristics, POEM procedures, and post-POEM HRM findings, including integrated relaxation pressure (IRP) and distal contractile integral (DCI), were investigated. Furthermore, POEM procedure outcomes were compared with post-POEM HRM findings. RESULTS: Of 2171 patients, 151 (7.0%) showed residual high post-POEM IRP (≥26 mm Hg; Starlet [Starmedical Ltd, Tokyo, Japan]). In a multivariate analysis, high pre-POEM IRPs (odds ratio [OR], 24.3) and gastric myotomy >2 cm (OR, .22) were found to be positive and negative predictive factors of high post-POEM IRPs, respectively. Peristalsis recovery (DCI ≥500 mm Hg/cm/s, at least 1 swallow; Starlet) was visible in 121 of 618 patients (19.6%) who had type II to III achalasia. High pre-POEM IRP (OR, 2.65) and DCI ≥500 (OR, 2.98) predicted peristalsis recovery, whereas esophageal dilation (OR, .42) predicted a risk of no recovery. Extended myotomy did not reveal a significant impact on peristalsis recovery. High or low post-POEM IRP and DCI did not increase the incidence of clinical failure, reflux esophagitis, or symptomatic GERD. CONCLUSIONS: Extended gastric myotomy decreased IRP values, whereas peristalsis recovery depended on the characteristics of achalasia. A residual high post-POEM IRP does not necessarily mean clinical failure. Routine HRM follow-up is not recommended after POEM.

Successful endoscopic full-thickness resection of an exophytic subepithelial lesion with double scope traction technique.

Video 1Video demonstrating the endoscopic full-thickness resection of an exophytic subepithelial lesion with "double scope traction" technique.

Risk factors and long-term course of gastroesophageal reflux disease after peroral endoscopic myotomy: A large-scale multicenter cohort study in Japan.

BACKGROUND : Gastroesophageal reflux disease (GERD) and reflux esophagitis remain problems after peroral endoscopic myotomy (POEM). This study aimed to elucidate the risk factors and long-term course of reflux esophagitis and symptomatic GERD after POEM. METHODS : This multicenter cohort study involved 14 high volume centers. Overall, 2905 patients with achalasia-related esophageal motility disorders treated with POEM were analyzed for reflux esophagitis, severe reflux esophagitis (Los Angeles classification C or D), and symptomatic GERD. RESULTS : Reflux esophagitis was diagnosed in 1886 patients (64.9 %). Age ≥ 65 years (risk ratio [RR] 0.85), male sex (RR 1.11), posterior myotomy (RR 1.12), esophageal myotomy > 10 cm (RR 1.12), and gastric myotomy > 2 cm (RR 1.17) were independently associated with reflux esophagitis. Severe reflux esophagitis was diagnosed in 219 patients (7.5 %). Age ≥ 65 years (RR 1.72), previous treatments (RR 2.21), Eckardt score ≥ 7 (RR 0.68), sigmoid-type achalasia (RR 1.40), and esophageal myotomy > 10 cm (RR 1.59) were factors associated with severe reflux esophagitis. Proton pump inhibitors (PPIs) were more effective for reflux esophagitis at 5-year follow-up (P = 0.03) than after 1 year (P = 0.08). Symptomatic GERD was present in 458 patients (15.9 %). Symptom duration ≥ 10 years (RR 1.28), achalasia diagnosis (RR 0.68), integrated relaxation pressure ≥ 26 (RR 0.60), and posterior myotomy (RR 0.80) were associated with symptomatic GERD. The incidence of symptomatic GERD was lower at 5-year follow-up compared with that after 1 year (P = 0.04), particularly in PPI users (P < 0.001). CONCLUSIONS : The incidence of severe reflux esophagitis was low after POEM, but excessive myotomy for older patients with previous treatments should be avoided. Early phase symptomatic GERD is non-acid reflux dependent and the natural course is favorable, basically supporting conservative treatment.

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.

Per-oral endoscopic myotomy in patients with antithrombotic agents: A large-scale multicenter study in Japan.

BACKGROUND AND AIM: The perioperative management and clinical course of per-oral endoscopic myotomy for patients receiving antithrombotic therapy remains unknown. This study aimed to clarify the status of antithrombotic therapy in per-oral endoscopic myotomy and to determine its safety and efficacy. METHODS: Patients treated with per-oral endoscopic myotomy from 2010 to 2019 in seven high-volume centers in Japan were retrospectively investigated. The patients' characteristics and antithrombotic agent management were analyzed; clinical outcomes were compared with those without antithrombotic agents. RESULTS: Of 2752 patients who underwent per-oral endoscopic myotomy, 120 patients on antithrombotic therapy (mean age 71.0 years, American Society of Anesthesiologists class II-IV [67.5%]) were identified. Antiplatelet, anticoagulant, and a combination of antithrombotic agents were used in 82, 30, and 8 patients, respectively. The perioperative management adhered to the therapeutic endoscopy guidelines published by the Japanese Society of Gastroenterological Endoscopy in most patients (88.3%). A poorer clinical baseline status (American Society of Anesthesiologists class II-IV; 67.0% vs 24.3%) and the sigmoid type (40.7% vs 22.3%) were more frequently observed in patients with achalasia on antithrombotic therapy. However, the clinical success (Eckardt score ≤ 3; 97.6% vs 94.6) and adverse event rates, such as bleeding and thromboembolic events (5.5% vs 4.7%), did not show inferiority. CONCLUSIONS: Per-oral endoscopic myotomy on antithrombotic therapy is safe and effective. However, caution is required as patients on antithrombotic therapy tend to have poorer baseline health and achalasia statuses. Our experience should help establish perioperative management with antithrombotic therapy.

Predictors of recurrence of dysplasia or cancer in patients with dysplastic Barrett's esophagus following complete eradication of dysplasia: a single-center retrospective cohort study.

BACKGROUND AND AIMS: Endoscopic mucosal resection (EMR) and radiofrequency ablation (RFA) for Barrett's esophagus (BE)-related high-grade dysplasia (HGD) and early esophageal adenocarcinoma (EAC) are considered effective treatments for eradication of BE. Little is known about the impact of achieving complete eradication of intestinal metaplasia (CE-IM) following the complete eradication of neoplasia (CE-N), specifically if CE-IM reduces the risk of recurrent dysplasia. METHODS: Retrospective cohort study of consecutive patients with BE and HGD or intramucosal cancer (IMC)-treated endoscopically at a tertiary referral center between 2001 and 2019. Association between CE-IM and recurrent dysplasia after CE-N was evaluated. RESULTS: A total of 433 patients treated with EMR and/or RFA were included. Of these, 381 (88%) achieved CE-N, of which 345 (80%) had adequate follow-up for inclusion in the analysis. A total of 266 (77%) patients achieved CE-IM; with a median follow-up since initial treatment for HGD/IMC of 45.9 months (IQR 25.9, 93.1); 20 patients (5.8%) had recurrent dysplasia after achieving CE-N. Kaplan Meier survival curves revealed that time free of recurrence in those who achieved CE-IM was significantly higher (p = 0.002). In the multivariable analysis, CE-IM was associated with a significant lower hazard of recurrence (HR 0.2, 95% CI 0.1, 0.6), whereas the number of endoscopic treatments to achieve CE-N was associated with a significant higher hazard of recurrence (HR 1.1, 95% CI 1.0, 1.2). CONCLUSION: Achieving CE-IM following CE-N reduces the risk of recurrent dysplasia and should be considered a treatment target among patients with BE undergoing endoscopic therapies for HGD or EAC.

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.