Effect of Real-Time Computer-Aided Polyp Detection System (ENDO-AID) on Adenoma Detection in Endoscopists-in-Training: A Randomized Trial.

BACKGROUND: The effect of computer-aided polyp detection (CADe) on adenoma detection rate (ADR) among endoscopists-in-training remains unknown. METHODS: We performed a single-blind, parallel-group, randomized controlled trial in Hong Kong between April 2021 and July 2022 (NCT04838951). Eligible subjects undergoing screening/surveillance/diagnostic colonoscopies were randomized 1:1 to receive colonoscopies with CADe (ENDO-AID[OIP-1]) or not (control) during withdrawal. Procedures were performed by endoscopists-in-training with <500 procedures and <3 years' experience. Randomization was stratified by patient age, sex, and endoscopist experience (beginner vs intermediate level, <200 vs 200-500 procedures). Image enhancement and distal attachment devices were disallowed. Subjects with incomplete colonoscopies or inadequate bowel preparation were excluded. Treatment allocation was blinded to outcome assessors. The primary outcome was ADR. Secondary outcomes were ADR for different adenoma sizes and locations, mean number of adenomas, and non-neoplastic resection rate. RESULTS: A total of 386 and 380 subjects were randomized to CADe and control groups, respectively. The overall ADR was significantly higher in the CADe group than in the control group (57.5% vs 44.5%; adjusted relative risk, 1.41; 95% CI, 1.17-1.72; P < .001). The ADRs for <5 mm (40.4% vs 25.0%) and 5- to 10-mm adenomas (36.8% vs 29.2%) were higher in the CADe group. The ADRs were higher in the CADe group in both the right colon (42.0% vs 30.8%) and left colon (34.5% vs 27.6%), but there was no significant difference in advanced ADR. The ADRs were higher in the CADe group among beginner (60.0% vs 41.9%) and intermediate-level (56.5% vs 45.5%) endoscopists. Mean number of adenomas (1.48 vs 0.86) and non-neoplastic resection rate (52.1% vs 35.0%) were higher in the CADe group. CONCLUSIONS: Among endoscopists-in-training, the use of CADe during colonoscopies was associated with increased overall ADR. (ClinicalTrials.gov, Number: NCT04838951).

Asia-Pacific survey on green endoscopy.

BACKGROUND AND AIM: Greenhouse gas emissions are the fundamental cause of global warming, with CO2 being the most contributive. Carbon reduction has been widely advocated to mitigate the climate crisis. The endoscopy unit is the third highest waste-generating department in a hospital. The awareness and acceptance of the practice of green endoscopy among healthcare workers is unclear. METHOD: An online survey was conducted over a 5-week period from July to August 2023 in the Asia-Pacific region, which targeted endoscopists, nurses, and other healthcare professionals of the endoscopy unit. The primary outcome was the agreement to adopt green endoscopy. The secondary outcomes included views on sustainable practices, factors associated with increased acceptance of green endoscopy, the acceptance of different carbon reduction measures, and the perceived barriers to implementation. RESULTS: A total of 259 valid responses were received. Overall, 79.5% of participants agreed to incorporate green endoscopy into their practice. Nevertheless, existing green policies were only reported by 12.7% of respondents. The level of understanding of green endoscopy is the only significant factor associated with its acceptance (odds ratio 3.10, P < 0.007). Potential barriers to implementation include healthcare cost increment, infection risk, inadequate awareness, and lack of policy and industrial support. CONCLUSION: Green endoscopy is well accepted among healthcare workers but not widely implemented. The level of understanding is highly associated with its acceptance, highlighting the importance of education. A reliable assessment tool is needed to quantify the environmental impact of endoscopy. Further studies are needed to ascertain its benefit and cost effectiveness.

Gastro-esophageal diagnostic workup before bariatric surgery or endoscopic treatment for obesity: position statement of the International Society of Diseases of the Esophagus.

Obesity is a chronic and multifactorial condition characterized by abnormal weight gain due to excessive adipose tissue accumulation that represents a growing worldwide challenge for public health. In addition, obese patients have an increased risk of hiatal hernia, esophageal, and gastric dysfunction, as well as gastroesophageal reflux disease, which has a prevalence over 40% in those seeking endoscopic or surgical intervention. Surgery has been demonstrated to be the most effective treatment for severe obesity in terms of long-term weight loss, comorbidities, and quality of life improvements and overall mortality decrease. The recent emergence of bariatric endoscopic techniques promises less invasive, more cost-effective, and reproducible approaches to the treatment of obesity. With the endorsement of the International Society for Diseases of the Esophagus, we started a Delphi process to develop consensus statements on the most appropriate diagnostic workup to preoperatively assess gastroesophageal function before bariatric surgical or endoscopic interventions. The Consensus Working Group comprised 11 international experts from five countries. The group consisted of gastroenterologists and surgeons with a large expertise with regard to gastroesophageal reflux disease, bariatric surgery and endoscopy, and physiology. Ten statements were selected, on the basis of the agreement level and clinical relevance, which represent an evidence and experience-based consensus of the International Society for Diseases of the Esophagus.

International consensus on the management of large (≥20 mm) colorectal laterally spreading tumors: World Endoscopy Organization Delphi study.

OBJECTIVES: There have been significant advances in the management of large (≥20 mm) laterally spreading tumors (LSTs) or nonpedunculated colorectal polyps; however, there is a lack of clear consensus on the management of these lesions with significant geographic variability especially between Eastern and Western paradigms. We aimed to provide an international consensus to better guide management and attempt to homogenize practices. METHODS: Two experts in interventional endoscopy spearheaded an evidence-based Delphi study on behalf of the World Endoscopy Organization Colorectal Cancer Screening Committee. A steering committee comprising six members devised 51 statements, and 43 experts from 18 countries on six continents participated in a three-round voting process. The Grading of Recommendations, Assessment, Development and Evaluations tool was used to assess evidence quality and recommendation strength. Consensus was defined as ≥80% agreement (strongly agree or agree) on a 5-point Likert scale. RESULTS: Forty-two statements reached consensus after three rounds of voting. Recommendations included: three statements on training and competency; 10 statements on preresection evaluation, including optical diagnosis, classification, and staging of LSTs; 14 statements on endoscopic resection indications and technique, including statements on en bloc and piecemeal resection decision-making; seven statements on postresection evaluation; and eight statements on postresection care. CONCLUSIONS: An international expert consensus based on the current available evidence has been developed to guide the evaluation, resection, and follow-up of LSTs. This may provide guiding principles for the global management of these lesions and standardize current practices.

Evaluation of oropharyngeal deglutitive pressure dynamics in patients with Parkinson's disease.

In Parkinson's disease (PD), oropharyngeal dysphagia is common and clinically relevant. The neurophysiology of dysphagia in PD is complex and incompletely understood. The aim of the study was to determine the changes in oropharyngeal deglutitive pressure dynamics in PD and to correlate these with clinical characteristics including dysphagia and PD severity. In prospective consecutive series of 64 patients with PD [mean age: 66.9 ± 8.3 (SD)], we evaluated dysphagia severity clinically as well as with Sydney Swallow Questionnaire (SSQ) and Swallow Quality-of-Life Questionnaire (SWAL-QOL). PD severity was assessed with Movement Disorder Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS). We used high-resolution pharyngeal impedance manometry (HRPIM) to objectively evaluate swallow function and compared data from 23 age-matched healthy controls [mean age 62.3 ± 9.1 (SD)]. Metrics assessed were upper esophageal sphincter (UES), integrated relaxation pressure (IRP), relaxation time (RT), maximum opening (MaxAdm), and pharyngeal intrabolus pressure (IBP) and pharyngeal contractility (PhCI). Mean MDS-UPDRS score was positively associated with dysphagia severity on SSQ and SWAL-QOL. HRPIM in PD compared with controls showed impaired UES relaxation parameters, with shorter RT, and elevated IRP and IBP. MaxAdm was not affected. The overall pharyngeal contractility was significantly higher in PD. Only the IBP and IRP were associated with PD severity and only IBP was significantly associated with dysphagia severity. UES dysfunction leading to increased flow resistance is common in patients with PD and correlates with dysphagia severity. Increased flow resistance may suggest impaired UES relaxation and/or impaired neuromodulation to bolus volume.NEW & NOTEWORTHY In Parkinson's disease, objective assessment of swallow function with high-resolution impedance manometry identifies upper esophageal sphincter dysfunction leading to increased flow resistance.

Worldwide Techniques and Outcomes in Robot-assisted Minimally Invasive Esophagectomy (RAMIE): Results From the Multicenter International Registry.

OBJECTIVE: This international multicenter study by the Upper GI International Robotic Association aimed to gain insight in current techniques and outcomes of RAMIE worldwide. BACKGROUND: Current evidence for RAMIE originates from single-center studies, which may not be generalizable to the international multicenter experience. METHODS: Twenty centers from Europe, Asia, North-America, and South-America participated from 2016 to 2019. Main endpoints included the surgical techniques, clinical outcomes, and early oncological results of ramie. RESULTS: A total of 856 patients undergoing transthoracic RAMIE were included. Robotic surgery was applied for both the thoracic and abdominal phase (45%), only the thoracic phase (49%), or only the abdominal phase (6%). In most cases, the mediastinal lymphadenectomy included the low paraesophageal nodes (n=815, 95%), subcarinal nodes (n = 774, 90%), and paratracheal nodes (n = 537, 63%). When paratracheal lymphadenectomy was performed during an Ivor Lewis or a McKeown RAMIE procedure, recurrent laryngeal nerve injury occurred in 3% and 11% of patients, respectively. Circular stapled (52%), hand-sewn (30%), and linear stapled (18%) anastomotic techniques were used. In Ivor Lewis RAMIE, robot-assisted hand-sewing showed the highest anastomotic leakage rate (33%), while lower rates were observed with circular stapling (17%) and linear stapling (15%). In McKeown RAMIE, a hand-sewn anastomotic technique showed the highest leakage rate (27%), followed by linear stapling (18%) and circular stapling (6%). CONCLUSION: This study is the first to provide an overview of the current techniques and outcomes of transthoracic RAMIE worldwide. Although these results indicate high quality of the procedure, the optimal approach should be further defined.

COVID-19 and endoscopic management of superficial gastrointestinal neoplastic lesions: a multinational cross-sectional survey.

INTRODUCTION: We aimed to report the impact of the pandemic lockdown period on the treatment and prognosis of superficial gastrointestinal neoplastic lesions. METHODS: A survey was completed by 11 centers from four continents regarding postponements during the early lockdown period of the pandemic, and the same period in 2019. RESULTS: In 2020, 55 % of the scheduled procedures were deferred, which was 11 times higher than in 2019; the main reasons were directly related to COVID-19. In countries that were highly affected, this proportion rose to 76 % vs. 26 % in those where there was less impact. Despite the absolute reduction, the relative distribution in 2019 vs. 2020 was similar, the only exception being duodenal lesions (affected by a 92 % reduction in mucosectomies). Although it is expected that the majority of postponements will not affect the stage (based on the results from biopsies and/or endoscopic appearance), 3 % of delayed procedures will probably require surgery. CONCLUSIONS: The lockdown period caused by the SARS-CoV-2 pandemic led to a substantial reduction in the number of endoscopic resections for neoplastic lesions. Nevertheless, based on clinical judgment, the planned median delay will not worsen the prognosis of the affected patients.

Prevention of recurrent idiopathic gastroduodenal ulcer bleeding: a double-blind, randomised trial.

OBJECTIVE: Patients with a history of Helicobacter pylori-negative idiopathic bleeding ulcers have a considerable risk of recurrent ulcer complications. We hypothesised that a proton pump inhibitor (lansoprazole) is superior to a histamine 2 receptor antagonist (famotidine) for the prevention of recurrent ulcer bleeding in such patients. DESIGN: In this industry-independent, double-blind, randomised trial, we recruited patients with a history of idiopathic bleeding ulcers. After ulcer healing, we randomly assigned (1:1) patients to receive oral lansoprazole 30 mg or famotidine 40 mg daily for 24 months. The primary endpoint was recurrent upper GI bleeding within 24 months, analysed in the intention-to-treat population as determined by an independent adjudication committee. RESULTS: Between 2010 and 2018, we enrolled 228 patients (114 patients in each study group). Recurrent upper GI bleeding occurred in one patient receiving lansoprazole (duodenal ulcer) and three receiving famotidine (two gastric ulcers and one duodenal ulcer). The cumulative incidence of recurrent upper GI bleeding in 24 months was 0.88% (95% CI 0.08% to 4.37%) in the lansoprazole arm and 2.63% (95% CI 0.71% to 6.91%) in the famotidine arm (p=0.313; crude HR 0.33, 95% CI 0.03 to 3.16, p=0.336). None of the patients who rebled used aspirin, non-steroidal anti-inflammatory drugs or other antithrombotic drugs. CONCLUSION: This 2-year, double-blind randomised trial showed that among patients with a history of H. pylori-negative idiopathic ulcer bleeding, recurrent bleeding rates were comparable between users of lansoprazole and famotidine, although a small difference in efficacy cannot be excluded. TRIAL REGISTRATION NUMBER: NCT01180179; Results.

Overview of guidance for endoscopy during the coronavirus disease 2019 pandemic.

From its beginning in December 2019, the coronavirus disease 2019 outbreak has spread globally from Wuhan and is now declared a pandemic by the World Health Organization. The sheer scale and severity of this pandemic is unprecedented in the modern era. Although primarily a respiratory tract infection transmitted by direct contact and droplets, during aerosol-generating procedures, there is a possibility of airborne transmission. In addition, emerging evidence suggests possible fecal-oral spread of the virus. Clinical departments that perform endoscopy are faced with daunting challenges during this pandemic. To date, multiple position statements and guidelines have been issued by various professional organizations to recommend practices in endoscopic procedures. This article aims to summarize and discuss available evidence for these practices, to provide guidance for endoscopy to enhance patient safety, avoid nosocomial outbreaks, protect healthcare personnel, and ensure rational use of personal protective equipment. Responses adapted to national recommendations and local infection control guidelines and tailored to the availability of medical resources are imminently needed to fight the coronavirus disease 2019 pandemic.

ELSA recommendations for minimally invasive surgery during a community spread pandemic: a centered approach in Asia from widespread to recovery phases.

BACKGROUND: The COVID-19 pandemic has resulted in significant changes to surgical practice across the worlds. Some countries are seeing a tailing down of cases, while others are still having persistent and sustained community spread. These evolving disease patterns call for a customized and dynamic approach to the selection, screening, planning, and for the conduct of surgery for these patients. METHODS: The current literature and various international society guidelines were reviewed and a set of recommendations were drafted. These were circulated to the Governors of the Endoscopic and Laparoscopic Surgeons of Asia (ELSA) for expert comments and discussion. The results of these were compiled and are presented in this paper. RESULTS: The recommendations include guidance for selection and screening of patients in times of active community spread, limited community spread, during times of sporadic cases or recovery and the transition between phases. Personal protective equipment requirements are also reviewed for each phase as minimum requirements. Capability management for the re-opening of services is also discussed. The choice between open and laparoscopic surgery is patient based, and the relative advantages of laparoscopic surgery with regard to complications, and respiratory recovery after major surgery has to be weighed against the lack of safety data for laparoscopic surgery in COVID-19 positive patients. We provide recommendations on the operating room set up and conduct of general surgery. If laparoscopic surgery is to be performed, we describe circuit modifications to assist in reducing plume generation and aerosolization. CONCLUSION: The COVID-19 pandemic requires every surgical unit to have clear guidelines to ensure both patient and staff safety. These guidelines may assist in providing guidance to units developing their own protocols. A judicious approach must be adopted as surgical units look to re-open services as the pandemic evolves.

Statement for gastroesophageal reflux disease after peroral endoscopic myotomy from an international multicenter experience.

It has been 10 years since peroral endoscopic myotomy (POEM) was reported for the first time, and POEM has currently become the standard treatment for achalasia and related disorders globally because it is less invasive and has a higher curative effect than conventional therapeutic methods. However, there are limited studies comparing the long-term outcomes of POEM with those of conventional therapeutic methods, particularly in the occurrence of gastroesophageal reflux disease (GERD) after therapy. With this background, we held a consensus meeting to discuss the pathophysiology and management of GERD after POEM based on published papers and experiences of each expert and to discuss the prevention of GERD and dealing with anti-acid drug refractory GERD. This meeting was held on April 27, 2018 in Tokyo to establish statements and finalize the recommendations using the modified Delphi method. This manuscript presents eight statements regarding GERD after POEM.

Transcervical minimally invasive esophagectomy using da Vinci® SP™ Surgical System: a feasibility study in cadaveric model.

BACKGROUND: This is a preclinical cadaveric study to investigate the feasibility of transcervical esophagectomy using a novel single-port robotic surgical system. METHODS: A 40-mm cervical incision was created over left supraclavicular fossa. The novel da Vinci® SP™ Surgical System was introduced through a wound retraction port. The mobilization of esophagus was performed using da Vinci SP from cervical, thoracic to abdominal segments. Lymph nodes were dissected en bloc with esophagus. RESULTS: The transcervical esophagectomy with complete mobilization of the cervical, thoracic, and abdominal esophagus was completed in 60 min. The procedure was completed using the novel da Vinci SP Surgical System, which was introduced via the cranial side over the left cervical incision. No additional port was used for retraction and dissection, and the esophageal hiatus could be reached after complete transcervical dissection. CONCLUSION: This preclinical study demonstrated that transcervical esophagectomy is technically feasible and can be completed with the novel da Vinci SP Surgical System without additional ports or assistance. This will serve as an important step to the performance of robotic transcervical esophagectomy without the necessity of one-lung ventilation.

How I do it: Flexible 3-D endoscope for endoscopic submucosal dissection.

Endoscopic submucosal dissection (ESD) is technically challenging as a result of a lack of depth perception. The present article investigated the 3-D endoscope for carrying out ESD and translated the technique from bench to clinical use. In a preclinical porcine experiment, ESD using a 3-D endoscope was compared between an experienced and a novice endoscopist. All ESD were completed without perforation. Median operative time per surface area was significantly lower for the experienced endoscopist than for the novice (197.9 s/cm2 vs 434.7 s/cm2 ; P = 0.05). The second part was a prospective clinical experience to evaluate use of the 3-D endoscope for carrying out ESD. Ten patients received ESD using the 3-D endoscope. Four patients had gastric ESD, two had duodenal ESD and four had sigmoid and rectal ESD. There were no complications, whereas ESD failed in one patient who had gastric neoplasia at anastomosis. Mean operative time was 99.4 min, and operative time per surface area resection was 391 s/cm2 . The operating endoscopist did not complain of motion sickness, whereas the assistants had some dizziness upon prolonged ESD procedure. This study showed that carrying out ESD was safe and effective using a 3-D endoscope with an excellent 3-D view enhancing depth perception. Future study should be conducted to compare 3-D against 2-D endoscopes for ESD.

Effect of Peroral Endoscopic Myotomy vs Pneumatic Dilation on Symptom Severity and Treatment Outcomes Among Treatment-Naive Patients With Achalasia: A Randomized Clinical Trial.

Importance: Case series suggest favorable results of peroral endoscopic myotomy (POEM) for treatment of patients with achalasia. Data comparing POEM with pneumatic dilation, the standard treatment for patients with achalasia, are lacking. Objective: To compare the effects of POEM vs pneumatic dilation as initial treatment of treatment-naive patients with achalasia. Design, Setting, and Participants: This randomized multicenter clinical trial was conducted at 6 hospitals in the Netherlands, Germany, Italy, Hong Kong, and the United States. Adult patients with newly diagnosed achalasia and an Eckardt score greater than 3 who had not undergone previous treatment were included. The study was conducted between September 2012 and July 2015, the duration of follow-up was 2 years after the initial treatment, and the final date of follow-up was November 22, 2017. Interventions: Randomization to receive POEM (n = 67) or pneumatic dilation with a 30-mm and a 35-mm balloon (n = 66), with stratification according to hospital. Main Outcomes and Measures: The primary outcome was treatment success (defined as an Eckardt score ≤3 and the absence of severe complications or re-treatment) at the 2-year follow-up. A total of 14 secondary end points were examined among patients without treatment failure, including integrated relaxation pressure of the lower esophageal sphincter via high-resolution manometry, barium column height on timed barium esophagogram, and presence of reflux esophagitis. Results: Of the 133 randomized patients, 130 (mean age, 48.6 years; 73 [56%] men) underwent treatment (64 in the POEM group and 66 in the pneumatic dilation group) and 126 (95%) completed the study. The primary outcome of treatment success occurred in 58 of 63 patients (92%) in the POEM group vs 34 of 63 (54%) in the pneumatic dilation group, a difference of 38% ([95% CI, 22%-52%]; P < .001). Of the 14 prespecified secondary end points, no significant difference between groups was demonstrated in 10 end points. There was no significant between-group difference in median integrated relaxation pressure (9.9 mm Hg in the POEM group vs 12.6 mm Hg in the pneumatic dilation group; difference, 2.7 mm Hg [95% CI, -2.1 to 7.5]; P = .07) or median barium column height (2.3 cm in the POEM group vs 0 cm in the pneumatic dilation group; difference, 2.3 cm [95% CI, 1.0-3.6]; P = .05). Reflux esophagitis occurred more often in the POEM group than in the pneumatic dilation group (22 of 54 [41%] vs 2 of 29 [7%]; difference, 34% [95% CI, 12%-49%]; P = .002). Two serious adverse events, including 1 perforation, occurred after pneumatic dilation, while no serious adverse events occurred after POEM. Conclusions and Relevance: Among treatment-naive patients with achalasia, treatment with POEM compared with pneumatic dilation resulted in a significantly higher treatment success rate at 2 years. These findings support consideration of POEM as an initial treatment option for patients with achalasia. Trial Registration: Netherlands Trial Register number: NTR3593.

Early results of a safety and feasibility clinical trial of a novel single-port flexible robot for transoral robotic surgery.

The aim of this study was to describe the early results of a phase 1 safety and feasibility clinical trial of the first clinical use of a novel robot for transoral robotic surgery (TORS)-the da Vinci SP (Intuitive Surgical Inc., Sunnyvale, CA, USA). Study design of this study is prospective clinical trial. The methods used in this study are prospective innovation, development, exploration, assessment, and long-term study phase 1 clinical trial. Early results of six patients underwent TORS with the da Vinci SP (Intuitive Surgical Inc., Sunnyvale, CA, USA) demonstrate access the nasopharynx, oropharynx, larynx, and hypopharynx. There were no conversions of the robotic surgical system. There were no serious adverse events or adverse events related to the use of the robot at 30-day follow-up for all six patients. The early results of this safety and feasibility trial of the da Vinci SP (Intuitive Surgical Inc., Sunnyvale, CA, USA) clearly demonstrate that the device is safe and that it is feasible in performing TORS to access the nasopharynx, oropharynx, larynx, and hypopharynx.

MDGA2 is a novel tumour suppressor cooperating with DMAP1 in gastric cancer and is associated with disease outcome.

BACKGROUND: Using the promoter methylation assay, we have shown that MDGA2 (MAM domain containing glycosylphosphatidylinositol anchor 2) is preferentially methylated in gastric cancer. We analysed its biological effects and prognostic significance in gastric cancer. METHODS: MDGA2 methylation status was evaluated by combined bisulfite restriction analysis and bisulfite genomic sequencing. The effects of MDGA2 re-expression or knockdown on cell proliferation, apoptosis and the cell cycle were determined. MDGA2 interacting protein was identified by mass spectrometry and MDGA2-related cancer pathways by reporter activity and PCR array analyses. The clinical impact of MDGA2 was assessed in 218 patients with gastric cancer. RESULTS: MDGA2 was commonly silenced in gastric cancer cells (10/11) and primary gastric cancers due to promoter hypermethylation. MDGA2 significantly inhibited cell proliferation by causing G1-S cell cycle arrest and inducing cell apoptosis in vitro, and suppressed xenograft tumour growth in both subcutaneous and orthotopic xenograft mouse models (both p<0.001). The anti-tumorigenic effect of MDGA2 was mediated through direct stabilising of DNA methyltransferase 1 associated protein 1 (DMAP1), which played a tumour suppressive role in gastric cancer. This interaction activated their downstream key elements of p53/p21 signalling cascades. Moreover, promoter methylation of MDGA2 was detected in 62.4% (136/218) of gastric cancers. Multivariate analysis showed that patients with MDGA2 hypermethylation had a significantly decreased survival (p=0.005). Kaplan-Meier survival curves showed that MDGA2 hypermethylation was significantly associated with shortened survival in patients with early gastric cancer. CONCLUSIONS: MDGA2 is a critical tumour suppressor in gastric carcinogenesis; its hypermethylation is an independent prognostic factor in patients with gastric cancer.

From POEM to POET: Applications and perspectives for submucosal tunnel endoscopy.

Recent advances in submucosal endoscopy have unlocked a new horizon for potential development in diagnostic and therapeutic endoscopy. Increasing evidence has demonstrated that peroral endoscopic myotomy (POEM) is not only clinically feasible and safe, but also has excellent results in symptomatic relief of achalasia. The success of submucosal endoscopy in performance of tumor resection has confirmed the potential of this new area in diagnostic and therapeutic endoscopy. This article reviews the current applications and evidence, from POEM to peroral endoscopic tunnel resection (POET), while exploring the possible future clinical applications in this field.