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Per-oral endoscopic myotomy( POEM) is an endoscopic treatment of achalasia. Since the world's first case was performed in Japan in 2008, over 15 years have passed. More than 3,200 cases have been performed at Showa University alone, and over 6,000 cases have been performed throughout Japan. The success rate in Japan exceeds 97%. Internationally, the efficacy of POEM has been demonstrated to be equal to or better than surgical treatment in randomized controlled trials( RCTs) with Heller-Dor surgery [The New England Journal of Medicine (NEJM) 2019]. Additionally, the superiority of POEM over balloon dilation therapy was proven in another RCT (NEJM 2011). Based on the results of these two RCTs, POEM has become the standard treatment for achalasia and the first choice of treatment. Furthermore, when compared to Heller-Dor surgery, POEM has the decisive advantage of easily extending the myotomy on the esophageal side without leaving any external scars. Especially for type Ⅲ in the Chicago classification, POEM is particularly the first choice. Technically, the double scope technique allows for a 2 cm myotomy on the gastric side, preventing both incomplete myotomy and post-POEM gastroesophageal reflux disease( GERD).

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., (© 2023 Japan Gastroenterological Endoscopy Society.)

Background: Achalasia is an esophageal motility disorder with an unknown etiology. We aimed to determine the pathogenesis of achalasia by studying alterations in esophageal smooth muscle contraction and the associated inflammatory response, and evaluate the role of esophageal microbiota in achalasia development., Methods: We analyzed esophageal mucosa and lower esophageal sphincter (LES) samples, obtained from patients with type II achalasia who underwent peroral endoscopic myotomy. Esophageal conditioned media obtained from patients were transferred into the mouse esophagus to determine whether the esophageal intraluminal environment is associated with achalasia., Results: Approximately 30% of 20-kDa myosin light chains (LC 20 ) was phosphorylated in LES from the control group under resting and stimulated conditions, whereas less than 10% of LC 20 phosphorylation was detected in achalasia under all conditions. The hypophosphorylation of LC 20 in achalasia was associated with the downregulation of the myosin phosphatase-inhibitor protein CPI-17. Th17-related cytokines, including IL-17A, IL-17F, IL-22, and IL-23A, were significantly upregulated in achalasia. α-Diversity index of esophageal microbiota and the proportion of several microbes, including Actinomyces and Dialister, increased in achalasia. Actinomyces levels positively correlated with IL-23A levels, whereas Dialister levels were positively associated with IL-17A, IL-17F, and IL-22 levels. Esophageal IL-17F levels increased in mice after oral administration of the conditioned media., Conclusions: In LES of patients with achalasia, hypophosphorylation of LC 20 , a possible cause of impaired contractility, was associated with CPI-17 downregulation and an increased Th17-related immune response. The esophageal intraluminal environment, represented by the esophageal microbiota, could be associated with the development and exacerbation of achalasia., (© 2024. Japanese Society of Gastroenterology.)

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., (© 2022 Japan Gastroenterological Endoscopy Society.)

Objectives: Patients with esophageal motility disorders (EMDs) including achalasia after gastric surgery have not been thoroughly characterized. Furthermore, the efficacy of peroral endoscopic myotomy (POEM) in this population should be clarified., Methods: In this retrospective multicenter study of 3707 patients with EMDs, 31 patients (0.8%) had a history of gastric surgery. Patient characteristics and POEM efficacy were compared between patients with and without previous gastric surgery., Results: In patients with EMD after gastric surgery, age at EMD diagnosis was higher (72.0 years), male sex was predominant (90.3%), and the American Society of Anesthesiologists physical status score was higher (≥II, 48.4%). High-resolution manometry (HRM) findings did not reveal significant differences. In patients who underwent gastric surgery, atrophic gastritis was common (80.6%), and gastric cancer was the primary surgical indication (32.3%). Distal gastrectomy was performed in 28 patients (90.3%). POEM was effective (3.3% adverse events; 100% treatment success). The incidence rates of reflux esophagitis (RE) and symptomatic gastroesophageal reflux disease (GERD) were 60.0% and 16.7%, respectively, without significant intergroup differences, and severe RE was not observed in the long-term follow-up. Extended gastric myotomy was a risk factor for RE., Conclusion: Patients with gastric surgery often present severe disease manifestations; the surgical indication is mainly gastric cancer. HRM findings can be similarly used for diagnosis in patients with and without gastric surgery. POEM maintains safety and efficacy with acceptable RE and symptomatic GERD rates. To prevent RE, extended myotomy should be avoided., (© 2022 Japan Gastroenterological Endoscopy Society.)

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., (Copyright © 2021 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.)

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., (© 2020 Japan Gastroenterological Endoscopy Society.)

Background and Aims: Peroral endoscopic myotomy (POEM) is an available treatment modalities for achalasia. The reported efficacy of POEM in the only prospective multicenter study was 82%; however, a retrospective multicenter study in Japan reported a higher efficacy rate of 95%. The aim of this study was to prospectively verify treatment outcomes after POEM at multiple facilities in Japan., Methods: This was a prospective single-arm trial of POEM for achalasia at 8 facilities in Japan between April 2016 and March 2018 to evaluate its safety and efficacy. Patients were re-evaluated at 3 months and up to 1 year after POEM., Results: Among the 233 patients with achalasia who underwent POEM, procedure-related adverse events occurred in 24 patients (10.3%), none of whom required surgical intervention. In the 207 patients satisfying the inclusion criteria, the efficacy rate of POEM, defined by an Eckardt score ≤3 at 1 year, was 97.4% (95% CI, 95.3%-99.7%). The Eckardt score decreased significantly from 6.6 ± 2.0 preoperatively to 1.1 ± 1.1, 1 year after POEM. Postoperative reflux esophagitis, severe reflux esophagitis, and symptomatic GERD were reported in 54.2%, 5.6%, and 14.7%, respectively, and proton pump inhibitors were administered in 21.1%., Conclusions: Our prospective multicenter study in Japan showed greater efficacy of POEM for achalasia compared with the results of a previous prospective multicenter study. POEM is safe and highly effective for at least 1 year. (Clinical trial registration number: UMIN 000021550.)., (Copyright © 2020 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.)

Background: Peroral endoscopic myotomy (POEM) is a novel, minimally invasive treatment for esophageal achalasia. We retrospectively examined and evaluated the results following POEM to verify the technique's efficacy and safety., Methods: We retrospectively analyzed data for patients who underwent POEM at eight Japanese facilities between September 2008 and October 2015. Pre- and postoperative assessments 3 months and 1 year after POEM included patient interviews, endoscopy, and manometry., Results: A total of 1346 patients underwent POEM during the study period. Achalasia was the straight type in 1105 patients (82%) and the sigmoid type in 241 patients (18%). The average patient age was 47.2 years (range 3-95 years); 617 patients (46%) were men and 729 (54%) were women. Previous treatment included balloon dilatation in 381 patients (28%) and Heller-Dor operation in 43 patients (3%). The average operation time was 99.6 min. The mean length of the myotomy in the esophageal body was 10.8 cm, and the myotomy extended into the stomach a mean of 2.8 cm. The response rate (Eckardt score ≤ 3) was 95.1% 3 months postoperatively and 94.7% 1 year postoperatively. We noted 50 adverse events (3.7%) of Clavien-Dindo classification grade ≤ IIIa, and all resolved with conservative treatment. There were no Clavien-Dindo classification grade ≥ IIIb adverse events. After POEM, erosive esophagitis according to the Los Angeles classification was absent in 37% of the patients, grade A in 33%, B in 24%, C in 6%, and D in 0.2%. Symptomatic gastroesophageal reflux disease after POEM was confirmed in 14.8% of the patients; both erosive esophagitis and symptomatic gastroesophageal reflux disease responded to treatment with a proton-pump inhibitor., Conclusion: Our results confirmed the safety and efficacy of POEM in a large patient series and support POEM as the first-line and standard treatment for esophageal achalasia.

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.

Background: Peroral endoscopic myotomy (POEM) for achalasia is technically challenging to carry out in patients with type III, multiple prior treatments, prior myotomy, and sigmoid type. Herein, we present a series of consecutive patients with complex achalasia and introduce the POEM difficulty score (PDS)., Aim: To demonstrate the application and discuss the utility of PDS and present the feasibility, safety, and efficacy of POEM in complex achalasia patients., Methods: Forty consecutive POEM were carried out with 28 meeting the criteria for complex achalasia. Primary outcome was clinical success (Eckardt score ≤3) at a minimum of 3 months follow-up. Secondary outcomes included adverse events, procedural velocity and PDS., Results: Twenty-eight complex and 12 non-complex POEM procedures were carried out with 100% and 92% clinical success, respectively, without any major adverse events with a median follow up of 15 months (complex) and 8 months (non-complex). Mean velocities for non-complex, type III, prior myotomy, ≥4 procedures and sigmoid type were as follows: 4.4 ± 1.6, 4.8 ± 1.5, 5.9 ± 2.2, 6.9 ± 2.2 and 8.2 ± 3.2 min/cm, respectively. Median PDS for non-complex, type III, prior myotomy, ≥4 treatments and sigmoid type were 1 (0-3), 2 (0-4), 2.5 (1-6), 3 (2-6) and 3.5 (1-6), respectively. PDS was shown to correlate well with procedural velocity with a correlation coefficient of 0.772 (Spearman's P < 0.001)., Conclusions: PDS identifies the factors that contribute to challenging POEM procedures and correlates well with procedural velocity. The order of increasing difficulty of POEM in complex achalasia appears to be type III, prior myotomy, ≥4 treatments and sigmoid type., (© 2018 Japan Gastroenterological Endoscopy Society.)

Background and Aims: The optimal orientation of the myotomy during peroral endoscopic myotomy (POEM) is unknown. This meta-analysis aims to compare anterior and posterior myotomy regarding clinical success and safety., Methods: PubMed, Embase, Cochrane Library, WOK, and clinicaltrials.gov were searched to identify randomized clinical trials (RCTs) comparing anterior and posterior myotomy during POEM for the treatment of achalasia. The primary outcome was clinical success. Secondary outcomes included postprocedural gastroesophageal reflux disease (GERD), adverse events (AEs), manometric findings, and procedure-related parameters. Random-effects models were used for the primary analysis., Results: Four RCTs enrolling 488 patients were included. Overall clinical success 3-12 months after POEM was 97% (95% confidence interval [CI] 93-100%) and did not differ between anterior and posterior myotomy (Relative risk [RR] 0.98, 95%CI: 0.96-1.01; I2: 0%). Incidence of GERD after POEM based on 24-hour pH monitoring (RR 0.98, 95%CI: 0.75-1.28), endoscopy (RR 1.04, 95%CI: 0.78-1.38), and symptoms (RR 0.89, 95%CI: 0.55-1.42) was similar. Posterior myotomy was associated with fewer AEs (RR 0.63, 95%CI: 0.42-0.94), lower risk of mucosotomy (RR 0.42, 95%CI: 0.27-0.66) and shorter incision closure time (mean difference: -2.28 minutes, 95%CI: -3.46 to -1.10). Anterior myotomy was associated with a shorter length of hospitalization (mean difference: 0.31 days, 95%CI: 0.05-0.57), although the clinical relevance of this finding is negligible. No significant differences were found regarding manometric outcomes, total operation and myotomy time., Conclusions: Anterior and posterior myotomy are equally effective for the treatment of achalasia, without significant differences in postprocedural GERD. Posterior POEM was associated with fewer AEs and a shorter incision closure time.

Background: Peroral endoscopic myotomy (POEM) has become the minimally invasive endoscopic treatment for achalasia; however, gastroesophageal reflux (GER) post-POEM has been reported. A pilot study was conducted in which an endoscopic fundoplication was added to the standard POEM (POEM + F) procedure to overcome this issue. We report the technical details of POEM + F and short-term safety results., Methods: POEM + F was performed in 21 patients. After completing myotomy, the endoscope was advanced from the submucosal tunnel into the peritoneal cavity. A partial mechanical barrier was created by retracting the anterior gastric wall at the esophagogastric junction with the use of endoclips and an endoloop., Results: POEM + F was technically feasible in all cases and created a visually recognizable fundoplication. The clinical course after POEM + F was uneventful. No immediate or delayed complications occurred., Conclusion: POEM + F may help mitigate the post-POEM incidence of GER and serve as a minimally invasive endoscopic alternative to a laparoscopic Heller-Dor procedure. This is the largest case series of peroral natural orifice transluminal endoscopic surgery without laparoscopic assistance in the human foregut., Competing Interests: Dr. Inoue is an advisor for Olympus Corporation and Top Corporation. He has also received educational grants from Olympus Corp. and Takeda Pharmaceutical Co., (© Georg Thieme Verlag KG Stuttgart · New York.)

Background and Aims: Per-oral endoscopic myotomy (POEM) for achalasia is particularly appealing in the elderly because it is minimally invasive. However, data in patients aged ≥80 years are scarce. The aim of this study was to assess the clinical outcome of POEM in octogenarians., Methods: This was a multicenter retrospective study at 8 centers. Consecutive octogenarians with achalasia who underwent POEM between 2010 and 2016 were included. Rates of technical success (completion of myotomy), clinical response (Eckardt score ≤3), and adverse events (severity graded as per American Society for Gastrointestinal Endoscopy lexicon) were assessed., Results: A total of 76 patients (47.4% female, mean age 84 years) underwent POEM for treatment of achalasia: type I, 17.1%; type II, 35.5%; type III, 17.1%; and unspecified, 30.3%. Overall, 41.1% were treatment naïve, whereas others had previous botulinum toxin injection and/or pneumatic dilation. The mean (± standard deviation [SD]) age-adjusted Charlson comorbidity index score was 6.2 ± 2.4, with the majority of patients having American Society of Anesthesiologists Physical Status Classification System (ASA) scores of II/III. Technical success was 93.4%, with a median follow-up of 256 days. Fourteen adverse events occurred in 11 patients (14.5%). There were 3 inadvertent mucosotomies, 6 cases of symptomatic capnoperitoneum and/or capnomediastinum, 2 esophageal leaks, 1 cardiac arrhythmia, and 2 other). The severities of these adverse events were mild (78.6%), moderate (14.3%), and severe (7.1%). Clinical success was achieved in 90.8% of patients, with a mean (± SD) Eckardt score reduction from 7.0 ± 2.3 to 0.8 ± 0.1 (P < .001), a median follow-up of 256 days, and interquartile range of 66 to 547., Conclusion: Although the rate of technical success may be somewhat lower and the rate of adverse events slightly higher than previously reported, our data suggest that POEM in octogenarians is safe and effective, supporting its role as a primary modality for achalasia in this patient population., (Copyright © 2018 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.)

Background & Aims: In patients with persistent symptoms after Heller myotomy (HM), treatment options include repeat HM, pneumatic dilation, or peroral endoscopic myotomy (POEM). We evaluated the efficacy and safety of POEM in patients with achalasia with prior HM vs without prior HM., Methods: We conducted a retrospective cohort study of 180 patients with achalasia who underwent POEM at 13 tertiary centers worldwide, from December 2009 through September 2015. Patients were divided into 2 groups: those with prior HM (HM group, exposure; n = 90) and those without prior HM (non-HM group; n = 90). Clinical response was defined by a decrease in Eckardt scores to 3 or less. Adverse events were graded according to criteria set by the American Society for Gastrointestinal Endoscopy. Technical success, clinical success, and rates of adverse events were compared between groups. Patients were followed up for a median of 8.5 months., Results: POEM was technically successful in 98% of patients in the HM group and in 100% of patients in the non-HM group (P = .49). A significantly lower proportion of patients in the HM group had a clinical response to POEM (81%) than in the non-HM group (94%; P = .01). There were no significant differences in rates of adverse events between the groups (8% in the HM group vs 13% in the non-HM group; P = .23). Symptomatic reflux and reflux esophagitis after POEM were comparable between groups., Conclusions: POEM is safe and effective for patients with achalasia who were not treated successfully by prior HM. Although the rate of clinical success in patients with prior HM is lower than in those without prior HM, the safety profile of POEM is comparable between groups., (Copyright © 2017 AGA Institute. Published by Elsevier Inc. All rights reserved.)

Objectives: The safety of peroral endoscopic myotomy (POEM) is still debated since comprehensive analysis of adverse events (AEs) associated with the procedure in large multicenter cohort studies has not been performed. To study (1) the prevalence of AEs and (2) factors associated with occurrence of AEs in patients undergoing POEM., Methods: Patients who underwent POEM at 12 tertiary-care centers between 2009 and 2015 were included in this case-control study. Cases were defined by the occurrence of any AE related to the POEM procedure. Control patients were selected for each AE case by matching for age, gender, and disease classification (achalasia type I and II vs. type III/spastic esophageal disorders)., Results: A total of 1,826 patients underwent POEM. Overall, 156 AEs occurred in 137 patients (7.5%). A total of 51 (2.8%) inadvertent mucosotomies occurred. Mild, moderate, and severe AEs had a frequency of 116 (6.4%), 31 (1.7%), and 9 (0.5%), respectively. Multivariate analysis demonstrated that sigmoid-type esophagus (odds ratio (OR) 2.28, P=0.05), endoscopist experience <20 cases (OR 1.98, P=0.04), use of a triangular tip knife (OR 3.22, P=0.05), and use of an electrosurgical current different than spray coagulation (OR 3.09, P=0.02) were significantly associated with the occurrence of AEs., Conclusions: This large study comprehensively assessed the safety of POEM and highly suggests POEM as a relatively safe procedure when performed by experts at tertiary centers with an overall 7.5% prevalence of AEs. Severe AEs are rare. Sigmoid-type esophagus, endoscopist experience, type of knife, and current used can be considered as predictive factors of AE occurrence.

Background and Aims: Per-oral endoscopic myotomy (POEM) has shown promising safety and efficacy in short-term studies. However, long-term follow-up data are very limited. The aims of this study were to assess (1) clinical outcome of patients with a minimum post-POEM follow-up of 2 years and (2) factors associated with long-term clinical failure after POEM., Methods: A retrospective chart review was performed that included all consecutive patients with achalasia who underwent POEM with a minimum follow-up of 2 years at 10 tertiary-care centers. Clinical response was defined by a decrease in Eckardt score to 3 or lower., Results: A total of 205 patients (45.8% men; mean age, 49 years) were followed for a median of 31 months (interquartile range, 26-38 months). Of these, 81 patients (39.5%) had received previous treatment for achalasia before POEM. Clinical success was achieved in 98% (185/189), 98% (142/144), and 91% (187/205) of patients with follow-up within 6 months, at 12 months, and ≥24 months, respectively. Of 185 patients with clinical response at 6 months, 11 (6%) experienced recurrent symptoms at 2 years. History of previous pneumatic dilation was associated with long-term treatment failure (odds ratio, 3.41; 95% confidence interval, 1.25-9.23). Procedure-related adverse events occurred in 8.2% of patients and only 1 patient required surgical intervention. Abnormal esophageal acid exposure and reflux esophagitis were documented in 37.5% and 18% of patients, respectively. However, these rates are simply a reference number among a very selective group of patients., Conclusions: POEM is safe and provides high initial clinical success and excellent long-term outcomes. Among patients with confirmed clinical response within 6 months, 6% had recurrent symptoms by 2 years., (Copyright © 2017 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.)

Background and Aims: Spastic esophageal disorders (SEDs) include spastic achalasia (type III), diffuse esophageal spasm (DES), and nutcracker/jackhammer esophagus (JH). Per-oral endoscopic myotomy (POEM) has demonstrated efficacy and safety in the treatment of achalasia. Recently, POEM has been indicated for the treatment of SEDs. We conducted a systematic review and meta-analysis to determine the clinical success and safety of POEM in SEDs., Methods: We searched several databases from 01/01/2007 to 01/10/2016 to identify studies (with five or more patients) on POEM for the treatment of SEDs. Weighted pooled rates (WPRs) for clinical success and adverse events (AEs) were calculated for all SEDs. Clinical success was defined as Eckardt scores of ≤3 and/or improvement in severity of dysphagia based on achalasia disease-specific health-related quality of life questionnaire. The WPRs for clinical success and AEs were analyzed using fixed- or random-effects model based on heterogeneity. The proportionate difference in clinical success and post-procedure adverse event rates among individual types of SEDs was also calculated., Results: A total of eight observational studies with 179 patients were included in the final analysis. Two studies were of good quality and six were of fair quality based on the National Institutes of Health quality assessment tool. The WPR with 95% confidence interval (CI) for cumulative clinical success of POEM in all SEDs was 87% (78, 93%), I 2  = 37%. The total number of patients for individual disorders, i.e., type III achalasia, JH, and DES, was 116, 37, and 18, respectively. The WPRs for clinical success of POEM for type III achalasia, DES, and JH were 92, 88, and 72%, respectively. Proportion difference of WPR for clinical success was significantly higher for type III achalasia in comparison with JH (20%, P = 0.01). The WPR with 95% CI for AEs of POEM in all SEDs was 14% (9, 20%), I 2  = 0%. The WPRs for post-procedure adverse events for type III achalasia, DES, and JH were 11, 14, and 16%, respectively. There was no difference in safety of POEM among individual SEDs., Conclusion: POEM is an effective and safe therapeutic modality for the treatment of spastic esophageal disorders.

Background and Aim: Endoscopy, barium esophagram and manometry are used in the diagnosis of achalasia. In the case of early achalasia, characteristic endoscopic findings are difficult to recognize. As a result, the diagnosis of achalasia is often made several years after symptom onset. Therefore, we examined the endoscopic findings of the cardiac orifice in achalasia and propose a new classification., Methods: A total of 400 patients with spastic esophageal motility disorders who underwent peroral endoscopic myotomy (POEM) at our hospital between March 2014 and August 2015 were screened for this study. Champagne glass sign (CG) was defined as when the distal end of the lower esophageal sphincter relaxation failure (LESRF) was proximal to the squamocolumnar junction (SCJ) and the SCJ was dilated in the retroflex view. Specifically, CG-1 was defined as a distance from the SCJ to the lower end of LESRF of <1 cm, and CG-2 was defined as a distance ≥1 cm., Results: CG-0 was seen in 73 patients (28.0%), whereas the CG sign was seen in 186 patients (71.3%), of whom 170 (65.1%) were CG-1 and 16 (6.1%) were CG-2., Conclusions: The CG sign is often observed in esophageal achalasia patients. CG-0 (equal to Maki-tsuki) was observed in 28.0% of achalasia patients only. Its absence with dilated SCJ cannot be used to rule out achalasia. Barium esophagram and manometry should be done if esophageal achalasia is strongly suspected., (© 2016 Japan Gastroenterological Endoscopy Society.)

Background and Aims: Eight years have passed since the introduction of the per-oral endoscopy myotomy (POEM) procedure. POEM was initially received as an investigational procedure, but since the revelation of promising safety and efficacy data, it is becoming the preferred treatment for achalasia. With the recent completion of our 1000th POEM procedure, we share our experience and knowledge through the discussion of clinical pearls, pitfalls, and practical considerations., Methods: The various aspects of the procedure and conditions that warrant special attention are discussed from our perspective, with a focus on areas in which there is currently limited evidence., Results: The key points on patient position, submucosal tunneling, myotomy, closure, intraprocedural bleeding, and advanced sigmoid achalasia are presented., Conclusions: The dissemination of this information serves as a foundation for new POEM operators and as a catalyst for more-experienced operators to further refine and advance their POEM skills and stimulate international discourse and collaboration., (Copyright © 2016 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.)

Background: Since its introduction in 2010, per oral endoscopic myotomy (POEM) has offered an alternative to laparoscopic Heller myotomy for the treatment of achalasia. A gastric myotomy length of 3 cm has been recommended; however, it can be difficult to ensure that adequate submucosal dissection has been performed during the procedure. Commonly accepted endoscopic markers of the gastric side can be inaccurate, particularly in patients with prior endoscopic treatments, such as balloon dilation or Botox injection of the lower esophageal sphincter. We hypothesized that the use of a second endoscope would result in a more complete gastric myotomy., Methods: One hundred consecutive achalasia patients were randomized into single- and double-scope POEM groups. In the treatment group, a second endoscope was used to obtain a retroflexed view of the gastric cardia, while the dissecting scope transilluminated from the end of the submucosal tunnel. Prospectively collected data were analyzed, including myotomy lengths, procedure times, adverse events, and clinical outcomes., Results: POEM was completed with high rates of technical (98-100%) and clinical success (93-97%) in both groups, with a low rate of serious adverse events (2%). The second endoscope resulted in a 17 min increase in procedure time (94 vs. 77 min), myotomy extension in 34% of cases, and an increase in the average gastric myotomy length from 2.6 to 3.2 cm (p = 0.01)., Conclusion: A second endoscope is useful for ensuring a complete gastric myotomy during POEM. With minimal increase in procedure time and no increase in morbidity, it may be particularly useful in cases of sigmoid esophagus or otherwise altered anatomy that makes identification of the gastroesophageal junction difficult.

Background: After the first case of per-oral endoscopic myotomy (POEM) at our institution in 2008, the procedure was quickly accepted as an alternative to surgical myotomy and is now established as an excellent treatment option for achalasia. This study aimed to examine the safety and outcomes of POEM at our institution., Study Design: Per-oral endoscopic myotomy was performed on 500 consecutive achalasia patients at our institution between September 2008 and November 2013. A review of prospectively collected data was conducted, including procedure time, myotomy location and length, adverse events, and patient data with short- (2 months) and long-term (1 and 3 years) follow-up., Results: Per-oral endoscopic myotomy was successfully completed in all patients, with adverse events observed in 3.2%. Two months post-POEM, significant reductions in symptom scores (Eckardt score 6.0 ± 3.0 vs 1.0 ± 2.0, p < 0.0001) and lower esophageal sphincter (LES) pressures (25.4 ± 17.1 vs 13.4 ± 5.9 mmHg, p < 0.0001) were achieved, and this persisted at 3 years post-POEM. Gastroesophageal reflux was seen in 16.8% of patients at 2 months and 21.3% at 3-year follow-up., Conclusions: Per-oral endoscopic myotomy was successfully completed in all cases, even when extended indications (extremes of age, previous interventions, or sigmoid esophagus) were used. Adverse events were rare (3.2%), and there were no mortalities. Significant improvements in Eckardt scores and LES pressures were seen at 2 months, 1 year, and 3 years post-POEM. Based on our large series, POEM is a safe and effective treatment for achalasia; there are relatively few contraindications, and the procedure may be used as either first- or second-line therapy., (Copyright © 2015. Published by Elsevier Inc.)

Background: Limited data exist on the use of peroral endoscopic myotomy (POEM) for therapy of spastic esophageal disorders (SEDs)., Objective: To study the efficacy and safety of POEM for the treatment of patients with diffuse esophageal spasm, jackhammer esophagus, or type III (spastic) achalasia., Design: Retrospective study., Setting: International, multicenter, academic institutions., Patients: All patients who underwent POEM for treatment of SEDs refractory to medical therapy at 11 centers were included., Interventions: POEM., Main Outcome Measurements: Eckardt score and adverse events., Results: A total of 73 patients underwent POEM for treatment of SEDs (diffuse esophageal spasm 9, jackhammer esophagus 10, spastic achalasia 54). POEM was successfully completed in all patients, with a mean procedural time of 118 minutes. The mean length of the submucosal tunnel was 19 cm, and the mean myotomy length was 16 cm. A total of 8 adverse events (11%) occurred, with 5 rated as mild, 3 moderate, and 0 severe. The mean length of hospital stay was 3.4 days. There was a significant decrease in Eckardt scores after POEM (6.71 vs 1.13; P = .0001). Overall, clinical response was observed in 93% of patients during a mean follow-up of 234 days. Chest pain significantly improved in 87% of patients who reported chest pain before POEM. Repeat manometry after POEM was available in 44 patients and showed resolution of initial manometric abnormalities in all cases., Limitations: Retrospective design and selection bias., Conclusion: POEM offers a logical therapeutic modality for patients with SEDs refractory to medical therapy. Results from this international study suggest POEM as an effective and safe platform for these patients., (Copyright © 2015 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.)

Background: Per-oral endoscopic myotomy (POEM) for achalasia with esophagocardiomyotomy in the lesser curvature (LC myotomy) is now established and accepted widely. However, in some cases LC myotomy is precluded by previous procedures, such as Heller myotomy, or by other anatomic considerations that obscure the normal dissection planes. It may also be difficult to identify the esophagogastric junction (EGJ), which can result in an incomplete gastric myotomy and poor rates of symptom relief. On the other hand, the angle of His is always located in the greater curvature of the stomach and serves as a consistent, definite landmark of the gastric side., Objective: To evaluate esophagocardiomyotomy in the greater curvature (GC myotomy) as an alternative POEM technique in cases where a prior LC myotomy or supervening anatomic constraints make identification of the EGJ technically challenging., Design: Prospective., Setting: Single-center study., Patients: Twenty-one achalasia patients who received POEM with GC myotomy., Interventions: POEM., Main Outcome Measurements: Efficacy and safety of GC myotomy measured in terms of reduction in lower esophageal sphincter (LES) pressures, improvement in Eckardt scores, and development of intraoperative or postoperative adverse events., Results: Identification of the EGJ was achieved in all cases, resulting in a mean gastric myotomy length of 2.6±1.1 cm. Mean LES pressure and Eckardt symptom scores decreased significantly (21.2±7.3 vs 10.5±2.7 mm Hg, 5 [2-8] vs 1 [0-5], respectively) (P<.01). Endoscopic evidence of gastroesophageal reflux was identified in 52% of patients (11/21) postmyotomy; however, only 9.5% (2/11) were symptomatic, and these patients were successfully controlled with proton pump inhibitors. No severe adverse events were encountered., Limitations: Single center., Conclusions: GC myotomy is a promising, safe modification of the POEM technique and may be especially useful in cases of redo POEM, POEM post-Heller myotomy, or when the EGJ is difficult to recognize because of supervening anatomic constraints., (Copyright © 2015 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.)

Peroral endoscopic myotomy (POEM) is an evolving minimally invasive endoscopic surgical procedure, with no skin incision, intended for long-term recovery from symptoms of esophageal achalasia. POEM was developed based on both the already established surgical principles of esophageal myotomy and the advanced techniques of endoscopic submucosal dissection. This article relates how POEM was developed, and its use in practice is reported and discussed. As an extension of the POEM technique, submucosal endoscopic tumor resection is introduced., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Background: Surgical Heller myotomy has high rates of successful long-term results, but failed cases still remain. Moreover, the treatment strategy in patients with surgical myotomy failure is controversial. Recently, peroral endscopic myotomy (POEM) was reported to be efficient and safe in primary treatment of achalasia. In this study, we aimed to evaluate the efficacy and safety of POEM for surgical myotomy failure as a rescue second-line treatment, and we discuss the treatment options adapted in achalasia recurrence., Study Design: A total of 315 consecutive achalasia patients received POEM from September 2008 to December 2012 in our hospital. Eleven (3.5%) patients who had persistent or recurrent achalasia and had received surgical myotomy as a first-line treatment from other hospitals were included in this study. Patient background, barium swallow studies, esophagogastroduodenoscopy (EGD), manometry, and symptom scores were prospectively evaluated. In principle, all patients in whom surgical myotomy failed received pneumatic balloon dilatation (PBD) as the first line "rescue" treatment, and only if PBD failed were patients considered for rescue POEM., Results: The PBD alone was effective in 1 patient, and in the remaining 10 patients, rescue POEM was performed successfully without complications. Three months after rescue POEM, significant reduction in lower esophageal sphincter (LES) resting pressures (22.1 ± 6.6 mmHg vs 10.9 ± 4.5 mmHg, p < 0.01) and Eckardt symptom scores (6.5 ± 1.3 vs 1.1 ± 1.3, p < 0.001) were observed., Conclusions: Short-term results of POEM for failed surgical myotomy were excellent. Long-term results are awaited., (Copyright © 2013 American College of Surgeons. Published by Elsevier Inc. All rights reserved.)

Peroral endoscopic myotomy (POEM) has been developed as an incisionless, minimally invasive endoscopic treatment intending a permanent cure for esophageal achalasia. The concept of endoscopic myotomy was first reported about 3 decades ago, but the direct incision method through the mucosal layer was not considered to be a safe and reliable approach. A novel method of endoscopic myotomy was developed and established by the authors. In this article, the current techniques, applications, and clinical results of POEM are described., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Endoscopic balloon dilatation is an established treatment for benign gastrointestinal strictures. In order to dilatate safely, it is necessary to dilatate gradually and preferably under direct endoscopic visualization. However, it is currently difficult to achieve dilatation widths of 20–30 mm with commercial products and of over 30‐mm with endoscopic visualization. Therefore, a safe and innovative application technique is needed for patients who need these 20‐mm or greater dilatation widths. We have developed two methods that enable more than 20‐mm dilatation under direct visualization. (i) Single‐barrel method: an endoscopic balloon dilatation catheter was fixed with grasping forceps at the tip of the endoscope and carried into the stomach. The balloon catheter was released from the endoscope to create a retroflexed view. The endoscope and balloon were positioned adjacent to each other at the gastric cardia. The balloon was inflated gradually and the esophagogastric junction was dilatated under direct visualization. (ii) Double‐barrel method: the same procedure was repeated with two balloons. Theoretically, we achieved a dilatation of >30‐mm in diameter. These modified methods may be helpful for esophagogastric junction strictures, such as esophageal achalasia (serving as an initial endoscopic balloon dilatation prior to using a 30‐mm achalasia balloon), or for functional strictures after Nissen fundoplication. In conclusion, our simple, modified method enables safe and gradual dilatation under direct endoscopic visualization. Additionally, combination of the sizes of one or two balloons can achieve various widths of dilatation. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Peroral endoscopic myotomy (POEM) is a novel clinical technique developed in Japan used to treat esophageal achalasia and esophageal motility disorders. This technique has been rapidly accepted and widely disseminated throughout our clinical practice because of its low invasiveness, technical novelty, and high efficacy. Since the advent of POEM, there have been no clinical guidelines that clearly indicated its standard of care, and these guidelines have been anticipated both nationally and internationally by clinicians who engage in POEM practice. In 2017, to meet these needs, the Japan Gastroenterological Endoscopy Society (JGES) launched the guideline committee for POEM. Based on the guideline development process proposed by the Medical Information Network Distribution Service (MINDS), the guideline committee initially created research questions on POEM and conducted a systematic review and meta‐analysis on each topic. The clinical research extracted from databases for these clinical questions and the systematic review mainly comprised a few retrospective studies with a small number of participants and short trial periods; hence, the strength of the evidence and recommendations derived from these results was low. Throughout this process, the guideline committee met thrice: once on May 13, 2017, and again on September 17, 2017, to formulate the draft. A consensus meeting was then held on January 14, 2018, in Tokyo to establish the guideline statements and finalize the recommendations using the modified Delphi method. This manuscript presents clinical guidelines regarding current standards of practice and recommendations in terms of the nine chief topics in POEM. [ABSTRACT FROM AUTHOR]

Peroral endoscopic myotomy (POEM) has been developed in the context of natural orifice transluminal endoscopic surgery (NOTES) as a minimally invasive endoscopic treatment for symptomatic esophageal achalasia, which is a chronic progressive benign disease with severe morbidity and difficult management. Since September 2008, POEM has been successfully performed in more than 200 consecutive patients with symptomatic achalasia at the Digestive Disease Center of Showa University, Northern Yokohama Hospital, Yokohama, Japan, with excellent short- and long-term results and absence of serious complications. International experience of POEM within clinical studies is also promising. According to these results, POEM is considered as a safe procedure that can be applied to all achalasia patients. However, the low incidence of achalasia (0.3%-1% per 100,000 population), in combination with the potential serious complications related to the technically demanding POEM procedure, has made training difficult. There is therefore an urgent need for an animal model for training to decrease the learning curve. Further, there are other ethical and training issues to address. The pig is the most appropriate animal model for training in POEM due to its anatomy being similar to that of humans. The porcine esophagus has the advantage of easy mobilization due to absence of tight junctions to surrounding organs. A non-survival porcine model would be a simple, inexpensive, and reproducible animal model for training in POEM, without the need for concern about complications. A possible training process might first involve observation of POEM performed by specialists, then training on non-survival and survival porcine models, followed by training in humans under specialist guidance and finally, performance of POEM in humans. [ABSTRACT FROM AUTHOR]

Objectives Methods Results Conclusion 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.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.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).The results supported the use of EPSIS as an effective diagnostic tool for assessing the effect of POEM. [ABSTRACT FROM AUTHOR]