Analysis of the learning curve for peroral endoscopic myotomy for esophageal achalasia: Single-center, two-operator experience

Impedance planimetry during per-oral endoscopic myotomy is associated with decreased inadvertent capnoperitoneum

BACKGROUND

Per-oral endoscopic myotomy (POEM) has become an accepted minimally invasive alternative to Heller myotomy for the treatment of achalasia and other disorders of esophageal dysmotility. One associated adverse event is the inadvertent creation of capnoperitoneum. A proposed mechanism is that extension of the submucosal tunnel below the esophageal hiatus and onto the gastric wall leads to transmural perforation. We hypothesized that the use of impedance planimetry with the endoscopic functional luminal imaging probe (EndoFLIP) more accurately identifies the esophagogastric junction and helps to better define the myotomy's ideal limits, thus lowering the incidence of inadvertent capnoperitoneum.

METHODS

This is a single-center, retrospective review of consecutive POEM cases from 06/11/2011 to 08/08/2022, with EndoFLIP introduced in 2017. Patient and procedural characteristics, including the incidence of clinically significant capnoperitoneum and decompression, were analyzed using univariate and multivariable linear regression statistics.

RESULTS

There were 140 POEM cases identified, 74 (52.9%) of which used EndoFLIP. Clinically significant capnoperitoneum was encountered in 26 (18.6%) cases, with no differences in patient characteristics between those who had capnoperitoneum and those who did not. There was a decreased incidence of capnoperitoneum in cases using EndoFLIP compared to those without (n = 6, 23% vs n = 20, 77%, p = 0.001), with zero instances in the final 56 cases. After adjusting for potentially confounding factors, EndoFLIP use was associated with a - 15.93% (95% confidence interval - 30.68%, - 1.18%) decrease in procedure duration.

CONCLUSIONS

The routine use of EndoFLIP during POEM was associated with decreased incidence of clinically significant capnoperitoneum, potentially due to improved myotomy tailoring and decreased duration of insufflation with shorter procedure times.

[Therapy of esophageal motility disorders]

Esophageal motility disorders are diseases in which there are malfunctions of the act of swallowing due to a change in neuromuscular structures. The main symptom is therefore dysphagia for solid and/or liquid foods, often accompanied by symptoms such as chest pain, regurgitation, heartburn, and weight loss. Esophageal manometry is the gold standard in diagnostics. Endoscopy and radiology serve to exclude inflammatory or malignant changes. With the introduction of high-resolution esophageal manometry (HRM), the diagnosis of esophageal motility disorders has improved and led to a new classification with the Chicago Classification, which has been modified several times in the last decade, most recently in 2020 with the Chicago Classification v4.0. Compared to the previous version 3.0, there are some important changes that are presented based on the most important esophageal motility disorders in everyday clinical practice.

What role does the submucosa play in the pathophysiology and treatment of achalasia? An analysis of impedance planimetry during POEM

BACKGROUND

It is thought the therapeutic benefit of per-oral endoscopic myotomy (POEM) in the treatment of esophageal dysmotility disorders is from longitudinal myotomy creation, but it is unknown if the submucosa contributes to the pathophysiology. This study investigates if submucosal tunnel (SMT) dissection alone contributes to POEM's luminal changes as measured by EndoFLIP.

METHODS

A single-center, retrospective review of consecutive POEM cases from June 1, 2011 to September 1, 2022 with intraoperative luminal diameter and distensibility index (DI) data as measured by EndoFLIP. Patients with diagnoses of achalasia or esophagogastric junction outflow obstruction were grouped by those with pre-SMT and post-myotomy measurements (Group 1) and those with a third measurement post-SMT dissection (Group 2). Outcomes and EndoFLIP data were analyzed using descriptive and univariate statistics.

RESULTS

There were 66 patients identified, of whom 57 (86.4%) had achalasia, 32 (48.5%) were female, and median pre-POEM Eckardt score was 7 [IQR: 6-9]. There were 42 (64%) patients in Group 1, and 24 (36%) patients in Group 2, with no differences in baseline characteristics. In Group 2, SMT dissection changed luminal diameter by 2.15 [IQR: 1.75-3.28]cm, which comprised 38% of the median 5.6 [IQR: 4.25-6.3]cm diameter of complete POEM change. Similarly, the median post-SMT change in DI of 1 [IQR: 0.5-1.2]units comprised 30% of the median 3.35 [2.4-3.98]units overall change in DI. Post-SMT diameters and DI were both significantly lower than the full POEM.

CONCLUSIONS

Esophageal diameter and DI are significantly affected by SMT dissection alone, though not equaling the magnitude of diameter or DI changes from full POEM. This suggests that the submucosa does play a role in achalasia, presenting a future target for refining POEM and developing alternative treatment strategies.

The learning curve for gasless transaxillary posterior endoscopic thyroidectomy for thyroid cancer: a cumulative sum analysis

Gasless transaxillary posterior endoscopic thyroidectomy (GTPET) is a new approach for thyroid cancer. It allows en bloc resection of the thyroid and central lymph nodes. Few studies have reported on the learning curve for GTPET.We examined the learning curve of GTPET for thyroid cancer by cumulative sum (CUSUM) analysis by retrospectively analyzing patients who underwent hemithyroidectomy with ipsilateral central neck dissection between December 2020 and September 2021 at a tertiary medical center, including the first patient. Moving average analysis and sequential time-block analysis were used for validation. Data on the clinical factors between the two periods were compared. In the overall cohort, the average time for GTPET for thyroid cancer was 113.25 min to harvest an average of 6.4 central lymph nodes. The CUSUM curve of the operative time indicated an inflection point after 38 patients. Moving average analysis and sequential time-block analysis validated the number of procedures needed for GTPET proficiency. (124.05 min vs. 107.63 min for the unproficient period vs. proficient period, respectively; P < 0.001) The number of retrieved lymph nodes was not associated with a certain level of proficiency per the learning curve. The main complication during the surgeon's unproficient period was transient hoarseness (3/38), which was similar to that in their proficient period (2/73, p = 0.336). Proficiency in GTPET is associated with performing more than 38 procedures. Standard course training and instruction on careful management are required prior to introducing the procedure.

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.

Successful Design and Implementation of a POEM Program for Achalasia in an Integrated Healthcare System

BACKGROUND

Per Oral Endoscopic Myotomy (POEM) is a minimally invasive treatment for achalasia with results comparable to laparoscopic Heller myotomy (LHM). Studies have described the development of proficiency for endoscopists learning to perform POEM, and societies have defined educational and technical objectives for advanced endoscopy fellows in training. However, there is limited guidance on the organizational strategy and educational plan necessary to develop an achalasia service with POEM expertise.

AIMS

We aim to outline the steps for design and implementation of a successful POEM program.

METHODS

We reported our experience developing a multi-disciplinary clinical program for POEM and the steps taken to achieve procedural proficiency. We also reported our technical success (successful tunneling into the gastric cardia and myotomy of LES muscle fibers) and clinical success (post-procedure Eckardt score ≤ 3) at 3-6 months and 12 months post-procedure. Adverse events were classified per the ASGE lexicon for endoscopic adverse events.

RESULTS

After creating a multi-disciplinary clinical program for achalasia and completing procedural proficiency for POEM, our technical success rate was 100% and clinical success rate 90% for the first 41 patients. One adverse event (2.4%) occurred, moderate in severity per the American Society of Gastrointestinal Endoscopy (ASGE) lexicon for adverse endoscopic events.

CONCLUSION

In this study, we outlined the steps involved to establish a POEM service in a large integrated healthcare system. Prior competency in interventional endoscopy, procedural training models, POEM observation and education, proctorship, and interdisciplinary patient care are recommended.

[Therapy of esophageal motility disorders]

Esophageal motility disorders are diseases in which there are malfunctions of the act of swallowing due to a change in neuromuscular structures. The main symptom is therefore dysphagia for solid and/or liquid foods, often accompanied by symptoms such as chest pain, regurgitation, heartburn, and weight loss. Esophageal manometry is the gold standard in diagnostics. Endoscopy and radiology serve to exclude inflammatory or malignant changes. With the introduction of high-resolution esophageal manometry (HRM), the diagnosis of esophageal motility disorders has improved and led to a new classification with the Chicago Classification, which has been modified several times in the last decade, most recently in 2020 with the Chicago Classification v4.0. Compared to the previous version 3.0, there are some important changes that are presented based on the most important esophageal motility disorders in everyday clinical practice.

Learning curve for esophageal peroral endoscopic myotomy: a systematic review and meta-analysis

BACKGROUND AND STUDY AIMS : Peroral endoscopic myotomy (POEM) is a minimally invasive endoscopic procedure for the treatment of achalasia and certain spastic esophageal motility disorders, delivering excellent results in experienced hands. However, this complex and technically challenging procedure requires advanced endoscopic skills. The aim of this study was to conduct a systematic review and meta-analysis of current data to evaluate the learning curve for POEM in new adopters of this technique. METHODS : Electronic databases (PubMed, Embase, and Cochrane Library) from inception to November 2021 were searched for publications addressing the learning curve in POEM. Pooling was conducted by both fixed- and random-effects models. Secondary outcomes reviewed were clinical success defined by Eckardt score ≤ 3 when available and adverse events. RESULTS : Eight studies involving 1904 patients met the inclusion criteria. In the pooled analysis, new adopters of POEM attained proficiency at a mean of 24.67 procedures (95 %CI 23.93 to 25.41). Once proficiency was achieved, the pooled total procedure time plateaued at a mean of 85.38 minutes (95 %CI 81.48 to 89.28), the pooled mean procedure time per centimeter of myotomy was 6.25 minutes (95 %CI 5.69 to 6.82), and the pooled mean length of myotomy was 11.49 cm (95 %CI 10.90 to 12.08). CONCLUSIONS : Our analysis showed that new adopters of POEM with previous advanced endoscopy experience required about 25 procedures to attain proficiency. The average time for each procedure once proficiency was attained was about 85 minutes.

New Applications for Submucosal Tunneling in Third Space Endoscopy: A Comprehensive Review

Third space endoscopy (TSE), a type of natural orifice transluminal endoscopic surgery, was first introduced a decade ago, and since then, has revolutionized the field of therapeutic endoscopy. TSE involves tunneling into the submucosal space between the intestinal mucosa and the muscularis propria. By accessing this "third space," endoscopists can perform minimally invasive myotomies, resections, and dissections while maintaining the mucosa and preventing full-thickness perforation. TSE procedures can be used to treat motility disorders as well as neoplasms throughout the gastrointestinal tract, which were traditionally conditions that would require open or laparoscopic surgery. The main TSE procedures include peroral endoscopic myotomy, gastric peroral endoscopic myotomy, Zenker peroral endoscopic myotomy, submucosal tunneling for endoscopic resection, endoscopic submucosal tunnel dissection, peroral endoscopic tunneling for restoration of the esophagus, and per-rectal endoscopic myotomy. Some of those procedures have now been accepted as viable alternative to surgical techniques due to their limited invasiveness, safety and cost. This review will explore the different techniques recently added to our arsenal while describing their potential efficacy and limitations.

Pilot prospective study on formal training in per-oral endoscopic myotomy (POEM) during advanced endoscopy fellowship

Background and study aims  Gastroenterology societies have recently proposed core curricula for training in per-oral endoscopic myotomy (POEM) based on expert opinion with limited data on its applicability for advanced endoscopy fellowship (AEF) trainees. We prospectively evaluated the feasibility of a structured POEM training curriculum during a dedicated AEF and the trainee's performance during independent practice. Methods  This was a single-center prospective study evaluating a trainee's performance of POEM using a structured assessment tool (POEMAT) to assess core cognitive and technical skills. The trainee's performance was then prospectively assessed during the first 12 months of independent practice. Results  The trainee, who had not prior background in submucosal endoscopy, first observed 22 POEM cases followed by 35 hands-on procedures during his advanced endoscopy fellowship. Based on the POEMAT, submucosal entry and mucosal incision closure were the most challenging technical aspects, while cognitive skills were uniformly attained early in training. Overall, the trainee was able to cross the threshold for competence in his POEMAT performance score in 15 of his last 18 cases (83.3 %). The trainee performed 16 POEMs (baseline mean Eckardt 7.2) in his first 12 months of independent practice. Mean procedural time was 79.8 minutes (interquartile range: 67-94 minutes minutes) with no adverse events. Clinical success (Eckardt score < 3) was achieved in 100 % of the cases at a median follow-up of 20 weeks. Conclusions  Results from this pilot study support the adoptability of the recently proposed core curricula for POEM training within the context of a dedicated AEF and provide a potential blueprint for future studies of performance in POEM among trainees.

The Learning Curve for Peroral Endoscopic Myotomy in Latin America: A Slide to the Right?

Background/Aims

Per oral endoscopic myotomy (POEM) has been increasingly used for achalasia in Latin America, where Chagas disease is prevalent, and this makes POEM more challenging. The aim of this study was to determine the learning curve for POEM in Latin America.

Methods

Patients undergoing POEM in Latin America with a single operator were included from a prospective registry over 4 years. Non-linear regression and cumulative sum control chart (CUSUM) analyses were conducted for the learning curve.

Results

A total of 125 patients were included (52% male; mean age, 59 years), of which 80 had type II achalasia (64%), and 38 had Chagas disease (30%). The average pre-procedure and post-procedure Eckardt scores were 6.79 and 1.87, respectively. Technical success was achieved in 93.5% of patients, and clinical success was achieved in 88.8%. Adverse events occurred in 27 patients (22%) and included bleeding (4 patients), pneumothorax (4 patients), mucosal perforation (13 patients), mediastinitis (2 patients), and leakage (4 patients). The CUSUM chart showed a median procedure time of 97 min (range, 45-196 min), which was achieved at the 61st procedure. Procedure duration progressively decreased, with the last 10 procedures under 50 min approaching a plateau (p-value <0.01).

Conclusions

Mastering POEM in Latin America requires approximately 61 procedures for both POEM efficiency and to accomplish the procedure within 97 minutes.

Assessment of the learning curve for EUS-guided gastroenterostomy for a single operator

BACKGROUND AND AIMS

EUS-guided gastroenterostomy (EUS-GE) is increasingly used as an alternative to surgery and enteral stent placement to manage gastric outlet obstruction (GOO). However, no data are available on the learning curve (LC) for EUS-GE. Defining the LC is necessary to create adequate subspecialty training programs and quality assurance.

METHODS

This study is a retrospective analysis of a prospectively maintained dataset of patients who underwent EUS-GE at 1 tertiary referral center. Primary outcome was the LC for EUS-GE defined by the number of cases needed to achieve proficiency and mastery using cumulative sum (CUSUM) analysis. Moving average graphs and sequential time-block analysis were also performed to assess procedural time. Secondary outcomes included efficacy and safety of EUS-GE.

RESULTS

Eighty-seven consecutive patients underwent EUS-GE, mostly for malignant GOO. For consistency, 14 patients were excluded from analysis (noncautery-assisted EUS-GE, 11; surgical anatomy, 3). The same endoscopist performed all procedures using the same freehand technique. Technical success was achieved in 68 of 73 patients (93%). Immediate adverse events occurred in 4 patients (5.5%), whereas late adverse events occurred only in 1 patient (1%), all managed conservatively or endoscopically. All immediate adverse events occurred during the first 39 cases. Clinical success (defined as resuming at least an oral liquid diet within a week) was achieved in 97% of patients. The mean procedural time was 36 minutes (standard deviation, 24). Evaluation of the CUSUM curve revealed that 25 cases were needed to achieve proficiency and 40 cases to achieve mastery. These results were confirmed with the average moving curve and sequential time-block analysis.

CONCLUSIONS

We report, for the first time, data on the LC for EUS-GE. About 25 procedures can be considered as the threshold to achieve proficiency and about 40 cases are needed to reach mastery of the technique.

Peroral endoscopic myotomy: techniques and outcomes

Achalasia is progressive neurodegenerative disorder of the esophagus, resulting in uncoordinated esophageal motility and failure of lower esophageal sphincter relaxation, leading to impaired swallowing. Surgical myotomy of the lower esophageal sphincter, either open or minimally invasive, has been a standard of care for the past several decades. Recently, new procedure-peroral endoscopic myotomy (POEM) has been introduced into clinical practice. This procedure accomplishes the same objective of controlled myotomy only via endoscopic approach. In the current chapter authors review the present state, clinical applications, outcomes and future directions of the POEM procedure.

Impact of Focused Hands-on Training Course on Practice Adoption of Advanced Endoscopic Techniques and Per-Oral Endoscopic Myotomy

Background: Per-oral endoscopic myotomy (POEM) is a valuable tool for the treatment of foregut motility disorders. Hands-on courses are often utilized at the initial means of training in POEM. Whether such training is sufficient to allow individuals to launch an independent practice in POEM is unknown. The purpose of this study was to evaluate the successes and barriers of implementing a POEM practice after attending a hands-on course. Methods: We evaluated participants of a 2-day focused POEM training course. All participants of the course were sent a survey to assess their endoscopic practice before and after the course, concentrating on their ability to implement POEM after returning to their home institution. Results: Between 2012 and 2017, 11 POEM courses were held at our institution, with a total of 102 trainees. Fifty-five individuals responded to our survey (53.9%), most of whom were general surgeons who were already doing some therapeutic endoscopy but had not previously performed POEM. More than half (58.2%) were able to institute a POEM practice at their home institution after the course. Those that were successful in starting a POEM practice were more often those with previous advanced endoscopic experience (90.3%). Success was assisted by high rates of additional explant laboratories (43.6%) and in-person proctoring (52.4%) after completing the course. Those that did not start a POEM practice sited lack of institutional support as the main barrier, followed by problems with insurance approval, and lack of referral volume. Conclusion: Despite the complexity of the POEM procedure, a focused hands-on POEM training course is associated with a high rate of implementation of an independent POEM practice, particularly in individuals with previous advanced endoscopic experience. The largest barriers to POEM adoption are not technical factors, but rather are related to institutional and insurance factors.

Per-oral Endoscopic Myotomy and Other Applications of Third Space Endoscopy: Current Status and Future Perspectives

INTRODUCTION

The modification of NOTES (natural orifice transluminal endoscopic surgery) by mucosal safety flap has introduced us to the world of third space endoscopy (TSE). POEM (per-oral endoscopic myotomy) for achalasia cardia being its first vista, the realm expanded so that we can now remove en bloc a subepithelial/intramural tumor by POET (per-oral endoscopic tumor resection), perform G-POEM (gastric per-oral endoscopic myotomy) for refractory gastroparesis, restore esophageal continuity in complete obstruction by performing POETRE (per-oral endoscopic tunneling for the restoration of the esophagus), divide the septum in Zenker diverticulum completely with negligible risk of perforation by Z-POEM (Zenker per-oral endoscopic myotomy) and relieve constipation in Hirschsprung disease by PREM (per-rectal endoscopic myotomy). However, the real potential of TSE became evident with the introduction of POEM with fundoplication. TSE has opened the gates of the peritoneal cavity. Improved expertise and equipment will make the role of endoscopist complimentary to the surgeon with the dawn of a new field in therapeutic endoscopy.

AREAS COVERED

This review intends to comprehensively discuss the various aspects of POEM for achalasia studied so far followed by a brief discussion about other applications of TSE and the future perspectives in this exciting field.

The Modern Age of POEM: the Past, Present and Future of Per-Oral Endoscopic Myotomy

BACKGROUND

Per-oral endoscopic myotomy (POEM) has gained widespread enthusiasm amongst foregut specialists since its introduction in the mid 2000s as an effective and less invasive treatment option for achalasia. As more than 6000 POEM procedures have been performed to date throughout the world, we aim to summarize the history and current state of POEM in the treatment of esophageal motility disorders.

METHODS

We performed a comprehensive review of the published literature focusing on the history and development of the POEM procedure, and its most current applications and outcomes.

RESULTS

Multiple favorable long-term studies have been published advocating for the use of POEM as a valid and perhaps the most valid treatment option for achalasia. The procedure is also increasingly being applied to a wider spectrum of esophageal motility disorders including type III achalasia, spastic esophageal disease or isolated lower esophageal sphincter (LES) dysfunction, as well as new endoluminal procedures such as submucosal tumor endoscopic resection (STER), endoscopic fundoplications (POEM-F) and peroral pyloromyotomy (POP or G-POEM).

CONCLUSIONS

While POEM is a proved and valid procedure, its further adoption is being threatened by external factors: challenges related to teaching, institutional support (politics) and insurance reimbursement. While this technique has come an incredible distance in its relatively short lifespan, the future of POEM in the USA will depend on the support from surgical societies to validate it as a valuable tool in the esophageal specialist's armamentarium, and to encourage a commitment to training in endoluminal surgery.

Per-oral endoscopic myotomy (POEM) training and skills evaluation tool: a pilot study

Background and study aims  Hands-on training for per-oral endoscopic myotomy (POEM) in the United States is limited and without a structured curriculum or assessment tool. Training to competency in POEM is critical and POEM trainees must acquire multiple cognitive and technical skills to achieve proficiency. The aim of this study was to develop a POEM training and skills evaluation tool. Patients and methods  The training protocol included initial explant porcine models followed by live human cases, proctored by a single endoscopist experienced in POEM who prospectively graded trainees for each step ("skill") of the procedure on a 5-point scale. Procedural skills were divided into cognitive and technical skills. Acceptable passing level was considered a score ≥ 4 for each skill. Results  Three trainees completed a total of 18 cases (8 cases on animal explant models and 10 human cases). Overall, cognitive skills were acquired early in training with scores of ≥ 4 achieved by ≤ 3 cases. Technical skills required more cases and direction with scores ≥ 4 in technical skills achieved by three porcine and eight human cases. Entry of the endoscope into the submucosal space and submucosal tunneling were the most challenging steps followed by myotomy. Conclusion  This pilot study introduces a POEM training and skills evaluation tool for training to competency. Submucosal entry, tunneling, and myotomy were the most challenging to learn while cognitive skills were learned early in training. Evaluation of more trainees at multiple sites will be necessary to further validate the utility of this tool.

Techniques and devices for the endoscopic treatment of gastroparesis (with video)

BACKGROUND AND AIMS

Gastroparesis is a symptomatic chronic disorder of the stomach characterized by delayed gastric emptying in the absence of mechanical obstruction. Several endoscopic treatment modalities have been described that aim to improve gastric emptying and/or symptoms associated with gastroparesis refractory to dietary and pharmacologic management.

METHODS

In this report we review devices and techniques for endoscopic treatment of gastroparesis, the evidence regarding their efficacy and safety, and the financial considerations for their use.

RESULTS

Endoscopic modalities for treatment of gastroparesis can be broadly categorized into pyloric, nonpyloric, and nutritional therapies. Pyloric therapies such as botulinum toxin injection, stent placement, pyloroplasty, and pyloromyotomy specifically focus on pylorospasm as a therapeutic target. These interventions aim to reduce the pressure gradient across the pyloric sphincter, with a resultant improvement in gastric emptying. Nonpyloric therapies, such as venting gastrostomy and gastric electrical stimulation, are intended to improve symptoms. Nutritional therapies, such as feeding tube placement, aim to provide nutritional support.

CONCLUSIONS

Several endoscopic interventions have shown utility in improving the quality of life and symptoms of select patients with refractory gastroparesis. Methods to identify which patients are best suited for a specific treatment are not well established. Endoscopic pyloromyotomy is a relatively recent development that may prove to be the preferred pyloric-directed intervention, although additional and longer-term outcomes are needed.

ASGE guideline on the management of achalasia

Achalasia is a primary esophageal motor disorder of unknown etiology characterized by degeneration of the myenteric plexus, which results in impaired relaxation of the esophagogastric junction (EGJ), along with the loss of organized peristalsis in the esophageal body. The criterion standard for diagnosing achalasia is high-resolution esophageal manometry showing incomplete relaxation of the EGJ coupled with the absence of organized peristalsis. Three achalasia subtypes have been defined based on high-resolution manometry findings in the esophageal body. Treatment of patients with achalasia has evolved in recent years with the introduction of peroral endoscopic myotomy. Other treatment options include botulinum toxin injection, pneumatic dilation, and Heller myotomy. This American Society for Gastrointestinal Endoscopy Standards of Practice Guideline provides evidence-based recommendations for the treatment of achalasia, based on an updated assessment of the individual and comparative effectiveness, adverse effects, and cost of the 4 aforementioned achalasia therapies.

Third Space Endoscopy: Lessons Learnt From a Decade of Submucosal Endoscopy

The field of third space endoscopy (TSE), also called submucosal endoscopy using a mucosal flap valve, allows secure access to the submucosal and deeper layers of the gastrointestinal tract without the risk of a full-thickness perforation. Since the first description of per-oral endoscopic myotomy (POEM) for the treatment of achalasia cardia 10 years ago, this field has expanded rapidly. Several new procedures, submucosal tunneling endoscopic resection, gastric-POEM, Zenker POEM, per-rectal endoscopic myotomy, diverticular POEM, and recanalization for complete esophageal obstruction (per-oral endoscopic tunneling for restoration of the esophagus), have been performed. All TSE procedures employ a similar technique-after a mucosal incision, a submucosal tunnel is created, a myotomy is performed, or a subepithelial tumor is resected distal to the site of mucosal incision, after which the mucosal incision is closed. Potential indications for TSE include resection of subepithelial tumors in the esophagus, gastroesophageal junction, or stomach; refractory gastroparesis; Zenker diverticulum; Hirschsprung disease or other forms of megacolon; and recanalization for complete esophageal obstruction. Data are currently available for POEM, submucosal tunneling endoscopic resection, and gastric-POEM, although mainly in the form of retrospective studies, and randomized trials and long-term follow-up data are limited. Submucosal endoscopy has an excellent safety profile with very few intraoperative adverse events, the majority being related to insufflation, although bleeding, perforation, and sepsis have been reported. TSE procedures require special training and have demonstrated a learning curve.

The Mexican consensus on non-cardiac chest pain

INTRODUCTION

Non-cardiac chest pain is defined as a clinical syndrome characterized by retrosternal pain similar to that of angina pectoris, but of non-cardiac origin and produced by esophageal, musculoskeletal, pulmonary, or psychiatric diseases.

AIM

To present a consensus review based on evidence regarding the definition, epidemiology, pathophysiology, and diagnosis of non-cardiac chest pain, as well as the therapeutic options for those patients.

METHODS

Three general coordinators carried out a literature review of all articles published in English and Spanish on the theme and formulated 38 initial statements, dividing them into 3 main categories: (i)definitions, epidemiology, and pathophysiology; (ii)diagnosis, and (iii)treatment. The statements underwent 3rounds of voting, utilizing the Delphi system. The final statements were those that reached >75% agreement, and they were rated utilizing the GRADE system.

RESULTS AND CONCLUSIONS

The final consensus included 29 statements. All patients presenting with chest pain should initially be evaluated by a cardiologist. The most common cause of non-cardiac chest pain is gastroesophageal reflux disease. If there are no alarm symptoms, the initial approach should be a therapeutic trial with a proton pump inhibitor for 2-4weeks. If dysphagia or alarm symptoms are present, endoscopy is recommended. High-resolution manometry is the best method for ruling out spastic motor disorders and achalasia and pH monitoring aids in demonstrating abnormal esophageal acid exposure. Treatment should be directed at the pathophysiologic mechanism. It can include proton pump inhibitors, neuromodulators and/or smooth muscle relaxants, psychologic intervention and/or cognitive therapy, and occasionally surgery or endoscopic therapy.

Comprehensive Evaluation of the Learning Curve for Peroral Endoscopic Myotomy

BACKGROUND & AIMS

Peroral endoscopic myotomy (POEM) is a minimally invasive endoscopic surgical procedure that is effective in treatment for spastic esophageal motility disorders. However, little is known about the learning curve for endoscopists. We aimed to evaluate the effects of various factors on the POEM learning curve.

METHODS

We performed a retrospective study of 1346 patients who underwent POEM for achalasia at Shanghai Zhongshan Hospital in China from August 2010 through July 2015. We used risk-adjusted cumulative sum and moving average methods to evaluate outcomes. The primary outcome was a composite of technical failure and adverse events. Secondary outcomes included procedure time and the composite outcome of technical failure, adverse events, and clinical failure of the first 192 cases performed by only the original, training surgeon.

RESULTS

The primary composite outcome occurred in 54 (4%) of the 1346 patients: 10 technical failures and 44 adverse events. This composite outcome was independently associated with the case number (P = .010), full-thickness myotomy (P = .002), and procedure time (P = .001). After we adjusted for these risk factors, cumulative sum analysis showed that the primary composite outcome decreased gradually after 100 cases. The procedure time was high during the first few cases and decreased after endoscopists performed 70 cases. The secondary composite outcome of technical failure, adverse events, and clinical failure for the 192 cases performed by only the original surgeon gradually decreased after 90-100 cases.

CONCLUSIONS

In a retrospective analysis of POEM procedures, we found that 100 cases were required to decrease the risk of technical failure, adverse events, and clinical failure (the learning curve). Seventy cases can be considered the threshold for decreasing procedure time.

Achalasia: current therapeutic options

Achalasia is a chronic incurable esophageal motility disorder characterized by impaired lower esophageal sphincter (LES) relaxation and loss of esophageal peristalsis. Although rare, it is currently the most common primary esophageal motility disorder, with an annual incidence of around 1.6 per 100,000 persons and prevalence of around 10.8/100,000 persons. Symptoms of achalasia include dysphagia to both solids and liquids, regurgitation, aspiration, chest pain and weight loss. As the underlying etiology of achalasia remains unclear, there is currently no curative treatment for achalasia. Management of achalasia mainly involves improving the esophageal outflow in order to provide symptomatic relief to patients. The most effective treatment options for achalasia include pneumatic dilation, Heller myotomy and peroral endoscopic myotomy (POEM), with the latter increasingly emerging as the treatment of choice for many patients. This review focusses on evidence for current and emerging treatment options for achalasia with a particular emphasis on POEM.