Curriculum for training in peroral endoscopic myotomy (POEM) in Europe (Part I): European Society of Gastrointestinal Endoscopy (ESGE) Position Statement

Abbreviations

AE: adverse event

EMR: endoscopic mucosal resection

ESD: endoscopic submucosal dissection

ESGE: European Society of Gastrointestinal Endoscopy

GERD: gastroesophageal reflux disease

GRADE: Grading of Recommendations Assessment, Development and Evaluation

PICO: population/problem, intervention, comparison, outcome

POEM: peroral endoscopic myotomy

1 Introduction

Achalasia is an esophageal motility disorder, characterized by the failure of the lower esophageal sphincter to relax properly, associated with loss of peristalsis, leading to impaired transit of food from the esophagus into the stomach [1]. The incidence of achalasia is approximately 1.6 cases per 100 000 and it usually presents between the ages of 25 and 60, with men and women equally affected [2].

The treatment of achalasia is aimed at lowering the resting pressure of the lower esophageal sphincter [3]. Recent European guidelines suggest that peroral endoscopic myotomy (POEM) has comparable efficacy to graded pneumatic dilation and laparoscopic Heller’s myotomy, and treatment decisions in achalasia should be made based on patient-specific characteristics, patient preferences, possible adverse events (AEs), and a center’s expertise [4] [5].

Promoting quality in endoscopy is of great importance for the European Society of Gastrointestinal Endoscopy (ESGE) to ensure effective treatment and optimal patient outcomes. Achieving high quality endoscopic procedures requires a well-trained and competent endoscopist. Training programs should focus on both technical and cognitive skills, including an understanding of the indications, limitations, underlying pathophysiology, and alternatives, plus the recognition of AEs and their management. At present, there are no such standards for training in POEM in Europe. This curriculum sets out recommendations for an optimal training program in POEM that should produce an endoscopist competent in this procedure [6].

2 Methods

The development of the POEM curricula aligns with the current ESGE Publications Policy and the methodology of the ESGE curricula development for postgraduate training in advanced endoscopic procedures [6] [7]. A Position Statement format was considered appropriate given the educational significance of the topic and the limited expected body of evidence. This document focused on POEM training, irrespective of the specific esophageal motility disorder being addressed because the technical and theoretical principles involved are highly similar.

In May 2023, an email invitation to participate in the curricula was sent to all individual ESGE members. Applicants were required to submit a motivation letter and an updated curriculum vitae. The selection of participants was carried out by the project leaders and the chair of the Curricula Working Group based on applicants’ expertise in POEM, clinical and research background, experience in curricula development and educational activities, and diversity. The ESGE Executive Committee subsequently approved the final list of 23 panelists.

In June 2023, the project leaders (E.R.d.S. and D.T) proposed a preliminary list of questions and topics to all panelists, forming five taskforces (Appendix 1 s, see online-only Supplementary material). Questions were structured using a PICO (Population/Problem, Intervention, Comparison, Outcome) format. In cases where framing a PICO question was not feasible or appropriate, questions were addressed through expert-based reviews. A virtual online meeting was held on 3 July 2023, during which panelists provided feedback on the preliminary list of questions and the curricula's structure. A final list of questions was approved, leading to the following sections:

• pre-adoption

• training

• autonomous implementation and assessment of proficiency

• best practice technique – a "state-of-the-art" section was deemed suitable to facilitate the learning and implementation of the technique; this section is presented as a separate document (Part II).

To standardize the literature search and methodology, a structured template was developed. Taskforces conducted systematic literature searches in a minimum of two databases from inception to August 2023. Appendix 2 s details the PICO questions and search strategies used. Subsequently, taskforces evaluated the available literature (Table 1 s) using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system. The GRADE system was used to assess the quality of evidence by study outcome and overall certainty, as well as to grade the recommendations. The quality and risk of bias of individual studies were assessed using the ROB-2 scale for randomized controlled trials, the Newcastle–Ottawa Scale or Robins-I for observational studies, and the QUADAS-2 tool for diagnostic accuracy studies. In cases where evidence was lacking or insufficient to use GRADE, taskforces were requested to formulate Good Practice Statements to represent ESGEʼs position [8]. Where applicable, statements were updated from previous ESGE guidelines on endoscopic treatment for gastrointestinal motility disorders to address our PICO questions [5] [9].

Taskforces initially drafted a list of statements and the evidence-based text supporting the recommendations. These documents were shared with the entire group, and a second online meeting was convened. Taskforces were asked to consider all comments but not to modify statements during the meeting, to prevent the authority, personality, or reputation of some participants from interfering in the Delphi process. In February 2024, panelists voted on and provided feedback in a free-text box for each statement. Prior to voting, all members were instructed to consider the clinical benefits and harms for patients and healthcare systems, the costs, evidence quality, and the environmental impact of the statements.

The consensus on statements was determined through an anonymous and iterative Delphi process. All individuals who applied for the taskforce but were not selected for the core group were invited to vote and provide written comments. A maximum of three voting rounds was established to reach consensus. Statements were graded using a 5-point Likert scale (1, Strongly disagree; 2, Disagree; 3, Neither agree nor disagree; 4, Agree; 5, Strongly agree) via a web-based platform. Consensus was defined as ≥ 80 % agreement (the sum of Agree and Strongly agree) on each statement. Prior to the second voting round, statements were reviewed and revised based on suggestions. The second and third voting rounds occurred between March and September 2024 (Appendix 3 s). Subsequently, the project leaders prepared a preliminary manuscript, which was shared with all members for feedback. At this stage, no modifications were allowed in the content of statements that achieved consensus during the anonymous voting ([Table 1]).

Table 1 List of agreed statements.

Statement number	Statement
Pre-adoption
1	POEM trainees should acquire a comprehensive theoretical knowledge of achalasia and other esophageal motility disorders that encompasses pathophysiology, diagnostic tool proficiency, clinical outcome assessment, potential adverse events, and periprocedural management. Good practice statement
2	POEM trainees should attend conferences and courses related to POEM before starting POEM procedures. Good practice statement
3	POEM trainees should develop and integrate endoscopic nontechnical skills, including communication and teamwork, situational awareness, leadership, judgment, and decision-making. Good practice statement
4	POEM trainees should have completed general upper gastrointestinal endoscopy training and be proficient in management of endoscopic adverse events prior to initiating POEM training. Good practice statement
5	Experience in advanced endoscopic procedures (EMR and/or ESD) is encouraged as a beneficial prerequisite for POEM training. Good practice statement
Training
6	POEM trainees without previous experience in submucosal endoscopy may benefit from training on either simulation models for POEM or ESD to familiarize themselves with the complexity and the essential steps of submucosal endoscopy. Good practice statement
7	ESGE suggests that POEM trainees without ESD experience should perform an indicative minimum number of 20 cases on ex vivo or animal models before advancing to human POEM cases with an experienced trainer. The last five cases should be completed without perforating the gastric mucosa at the gastroesophageal junction and achieve complete mucosal closure. Good practice statement
8	ESGE recommends that the trainee should observe an indicative minimum number of 20 live cases at expert centers before starting to perform POEM in humans. Good practice statement
9	ESGE suggests that both stepwise progress and performing all POEM steps from the beginning are acceptable during the learning phase of the procedure. Good practice statement
10	ESGE recommends that the trainee should undertake an indicative minimum number of 10 cases under expert supervision for the initial human POEM procedures, ensuring that trainees can complete all POEM steps independently. Good practice statement
11	ESGE recommends avoiding complex POEM cases during the early training phase. Good practice statement
12	A POEM trainer should have expertise in managing adverse events of complex resection techniques such as bleeding and perforation. The trainer should have performed at least 100 unsupervised cases including difficult POEM cases (i. e. sigmoid esophagus, prior Heller’s myotomy). Good practice statement
13	A POEM training center should maintain a sufficient case load to initiate a training program. Additionally, the center should possess adequate infrastructure for diagnosing esophageal motility disorders and facilitating the endoscopic, radiological, and surgical management of adverse events associated with POEM. Good practice statement
14	A POEM training program should range between an indicative 6 and 18 months in a high- or medium-volume POEM Western endoscopy unit. Good practice statement
15	POEM trainees should actively participate in patient selection processes for POEM at multidisciplinary team meetings. Good practice statement
Autonomous implementation and assessment of proficiency
16	POEM competence should reflect the technical success rate, both the short- and long-term clinical success rates, and the rate of true adverse events
17	A minimum of 15 POEM procedures per endoscopist annually is advisable to maintain proficiency. Good practice statement
18	A minimum of 25 POEM procedures per center annually is advisable to maintain proficiency. Good practice statement
19	A POEM center should maintain a prospective registry of all procedures performed, including patient work-up and outcomes, procedural techniques, and adverse events. Good practice statement
20	The absolute number of procedures performed is not an accurate marker for competency in POEM. It should be combined with thresholds of procedural outcomes, including the technical and clinical success, and adverse event rates

EMR, endoscopic mucosal resection; ESD, endoscopic submucosal dissection; ESGE, European Society of Gastrointestinal Endoscopy; POEM, peroral endoscopic myotomy.

The peer review process for ESGE policy documents was followed. The ESGE board, the core members of the Curricula Working Group, and external experts reviewed the manuscript. The document was circulated to all national society members and individual ESGE members for feedback. The final ESGE curricula for POEM was approved by all authors and was submitted to the journal Endoscopy for publication.

3 Pre-adoption

3.1 What is the theoretical knowledge needed before starting POEM training?

Some studies have emphasized the importance of cognitive skills (indication and diagnostic assessment) for the POEM procedure, but none have directly assessed the influence of theoretical knowledge or educational programs on POEM trainees or POEM outcomes [10] [11] [12] [13] [14] [15] [16] [17] [18]. To address this gap, ESGE has established and summarized good practice recommendations for the requisite theoretical knowledge prior to commencing POEM training. These recommendations fall into four categories: (i) clinical understanding and procedural context, (ii) diagnostic assessment, (iii) outcome assessment, and (iv) preprocedural and procedural requirements and settings ([Table 2]).

Table 2 Theoretical knowledge needed prior to commencing peroral endoscopic myotomy (POEM) procedures.

Area of knowledge	Requirement
Clinical understanding and procedural context
Pathophysiology of motility disorders	Understanding of the pathophysiology of esophageal motility disorders
	Knowledge of different types of achalasia
Indications and contraindications	Knowledge of the indications and contraindications for performing POEM in different motility disorders
	Knowledge of the indications and challenges of POEM in advanced (such as sigmoid achalasia) or pretreated motility disorders
	Ability to formulate an endoscopic plan for the POEM procedure based on prior surgical and/or endoscopic treatments
	Knowledge of potential adverse events during and after POEM procedure
Other treatment modalities	Knowledge of alternative treatment options
	Comparative understanding of POEM versus alternative treatment modalities
Diagnostic assessment
Pretherapeutic examinations	Competence in interpretation of HRM and TBE to identify types of motility disorders amenable for POEM
	Understanding of the role of EGD to rule out early squamous lesions and other causes of dysphagia
Adjunctive diagnostic tool	Familiarity with impedance planimetry (the endoluminal functional lumen imaging probe [EndoFLIP])
Post-POEM diagnostics	Knowledge of the incidence of GERD following POEM and the role of clinical reflux symptoms, EGD, and 24-hour pH impedance studies in its assessment and interpretation
Outcome assessment
Clinical outcome	Understanding of the expected clinical outcomes of POEM for different motility disorders
	Ability to assess clinical treatment outcomes using the Eckardt score and understand its limitations
Outcome assessment with different diagnostic modalities	Knowledge about the role of HRM and the esophagogram in the assessment of treatment outcomes
	Knowledge about EndoFLIP as a tool to assess treatment outcome after POEM in real time
Preprocedural and procedural requirements and settings
Prerequisites	Understanding of periprocedural antiplatelet and anticoagulation management
Anesthesia	Understanding of the requirement for general anesthesia during the POEM procedure
Equipment and settings	Understanding of the importance of using a distal attachment cap
	Understanding of the importance of using low-flow CO2
	Knowledge about the different types of endoscopic knives, coagulation graspers, electrosurgical generators, and appropriate electrosurgery settings for POEM
Procedure-related proficiency	Understanding of the principles of third-space endoscopy, including mediastinal, esophageal, and intratunnel anatomy
	Understanding of the prevention, management, and consequences of POEM-related adverse events
	Recognition of the anatomical landmarks to identify the anterior and posterior walls of the esophagus and landmarks at the gastroesophageal junction
	Identification of the orientation of mucosa and muscle layers in the submucosal tunnel

EGD, esophagogastroduodenoscopy; GERD, gastroesophageal reflux disease; HRM, high resolution manometry; TBE, timed barium esophagogram.

Prior to commencing POEM procedures, experts suggest that trainees participate in POEM-related congresses, attend didactic training courses, and engage in self-directed online learning. Trainees should grasp the pathophysiology of motility disorders, distinguish between various types of achalasia, and comprehend the indications and contraindications for performing POEM, as well as esophageal disorders that can mimic achalasia. They should also be aware of the indications and challenges associated with POEM in advanced cases (e. g. sigmoid achalasia) or previously treated motility disorders. Furthermore, they must possess knowledge of the potential AEs during and after the POEM procedure.

The ability to devise an endoscopic plan for POEM based on anticipated clinical outcomes, prior surgical and/or endoscopic treatments, and patient expectations is crucial [10] [14] [15] [16] [17] [18]. Trainees should also possess a comparative understanding of POEM versus alternative treatment modalities, such as pneumatic balloon dilation, botulinum toxin injection, and laparoscopic Heller’s myotomy.

Competence in the interpretation of high resolution manometry, radiological esophagograms, and esophagogastroduodenoscopy is essential. Trainees should also understand the principles of the endoluminal functional lumen imaging probe (EndoFLIP), although its clinical relevance remains unknown.

Trainees should be knowledgeable about the incidence of gastroesophageal reflux disease (GERD) following POEM and the significance of clinical reflux symptoms, endoscopy, and 24-hour pH/impedance studies for assessment and their interpretation. Understanding expected clinical outcomes for different motility disorders and the ability to assess these outcomes using the Eckardt score is imperative. Additionally, a comprehension of the relative role of high resolution manometry, EndoFLIP, and the esophagogram in evaluating treatment outcomes is necessary.

Trainees should be proficient in obtaining detailed medical histories and understand periprocedural antithrombotic management. Familiarity with POEM equipment is crucial. Trainees should also be well versed in the electrosurgical generator settings used during the various POEM steps and understand the advantages and disadvantages of different types of endoscopic knives.

A solid understanding of third-space endoscopy principles, including mediastinal anatomy and recognition of anatomical landmarks, such as the anterior and posterior esophageal walls and gastroesophageal junction landmarks, is indispensable. Recognition of the spine, aortic arch, and left main bronchus is also advisable. Trainees should consistently recognize mucosa, muscle layer orientation, and spindle veins within the submucosal tunnel. Additionally, POEM trainees should promptly identify and understand the management of AEs.

3.2 What are the nontechnical skills needed for POEM training?

Technical and patient outcomes after any endoscopic procedure are affected by the endoscopic nontechnical skills (ENTS) of the performing team. ENTS involve all nontheoretical knowledge regarding good communication and the decision-making abilities of the endoscopist [19] [20] [21] [22] [23] [24] [25] [26] [27]. There are four recognized skills that should be assessed, and it has been suggested that each skill should be graded as either poor, marginal, acceptable, or good [28]. Performance measures for the team are also related to better outcomes, and quality principles as per the SACRED team-centered approach [29] are recommended. ESGE has adapted these methodological frameworks for POEM training ([Table 3]). As part of the nontechnical skills, the POEM practitioner should be able to discuss in detail the patient’s informed consent form, the advantages of the procedure related to other interventions, and possible AEs and morbidity associated with the technique and anesthesia [30] [31] [32].

Table 3 Endoscopic nontechnical skills for peroral endoscopic myotomy (POEM) training.

Element	Descriptor
a The endoscopic nontechnical skills (NETS) system.
Communication and teamwork
Exchanging information	Gives clear and timely information and instructions (including an appropriate informed consent)
	Seeks previous information to aid the procedure (e. g. clinical history, manometry/esophagogram/endoscopy report)
	Listens and responds to team input
	Confirms team preparation including equipment availability
Maintaining a shared understanding	Clarifies and confirms shared information with team (e. g. type of procedure, length of myotomy)
	Talks about the progress of the procedure, including difficulties and concerns
	Calmly indicates when a situation requires urgency
Maintaining a patient-centered approach	Greets patient and introduces self and team
	Regularly checks patient comfort
	Explains findings to patient and/or relatives clearly
Situation awareness
Preparation	Checks indications are appropriate, and the patient is fit for the procedure
	Checks if assistants are adequately trained
	Ensures equipment present and functioning correctly
	Optimizes environmental conditions before starting (e. g. equipment positioning)
	Does not perform any procedure beyond own level of skill (e. g. avoiding difficult POEM cases during the early training period)
Continuous assessment	Uses all available techniques to inform the decision-making process
	Monitors results from therapy (e. g. bleeding)
	Re-evaluates risk regularly depending on current status
Problem recognition	Identifies issues quickly and highlights them to the team
	Recognizes increased risk due to unexpected findings
Focus	Minimizes interruptions
	Stops distracting behavior by staff
	Keeps focus on the screen
Leadership
Supporting others	Maintains a relaxed atmosphere
	Gives praise for tasks done well
	Does not rush staff when not necessary
Maintaining standards	Follows unit procedures and protocols
	Ensures privacy and patient dignity
	Adequately documents procedure
Dealing with problems	Emphasizes urgency if needed and gives clear directions
	Delegates tasks to achieve goals
	Remains calm under pressure and assumes responsibility
Judgement and decision-making
Considering options	Generates options to resolve problems
	Seeks help or opinion of colleagues
Making decisions	Reaches and clearly communicates decisions and implements plan effectively
Reviewing the situation	Re-evaluates outcomes
	Ensures appropriate follow-up and checks for complications
	Makes changes based on reflection to improve practice
b The SACRED team-centered approach to advanced gastrointestinal endoscopy.
Principle	Descriptor
Selection	An MDT evaluates the case prior to the POEM procedure
Acceptance	Recognition of increased risk for AEs related to diagnostic procedures
Complications	Establishes pathways to deal with AEs and regular conferences to discuss cases with MDT
Reconnaissance	Establishes a communication system – verbal conscious competence may be relevant
Envelopment	The report should be available for the patient, along with instructions in case an AE occurs
Documentation	The outcome should be discussed with the MDT

AE, adverse event; MDT, multidisciplinary team.

3.3 What are the technical skills required before starting POEM training?

POEM is a challenging advanced endoscopic procedure requiring extensive endoscopic expertise. Some authors and expert societies have addressed the need for prior adoption of specific technical skills, as well as experience in submucosal endoscopy [11] [13] [14] [18] [33] [34]. However, neither the definition nor the evaluation of these skills has been formalized, and the published assessment tools have focused on the actual training rather than previous endoscopic expertise [13] [35]. There is a lack of randomized evidence directly assessing technical skills requirements before entering dedicated POEM training and its impact on the POEM learning curve or treatment outcome. Therefore, we have produced good practice recommendations for mandatory and recommended endoscopic and nonendoscopic technical skills for future POEM trainees ([Table 4]).

Table 4 Technical skills required before peroral endoscopic myotomy (POEM) training.

	Skill
Endoscopic skills
Mandatory	Proficiency in general upper gastrointestinal endoscopy
	Endoscopic management of adverse events (bleeding)
	Maintaining stable scope position and manipulating the scope (precise targeting, tip control, torque)
	Competence in different methods of hemostasis (adrenalin injection, coagulation techniques with electrosurgical knife or with coagulation forceps, hemoclip placement, and use of endoscope/cap for tamponade)
	Practical use of different endoscopic accessories that are required during a POEM procedure (different endoscopic knives, electrocoagulation forceps, injection needle)
Recommended	Competence in colonoscopy
	Competence in snare polypectomy
	Competence in endoscopic resection techniques (EMR, ESD) in the upper and/or lower gastrointestinal tract
	Competence in mucosal closure and perforation management
	Experience with OTS clips and endoscopic suture devices
	Esophageal stenting
	Endoscopic balloon dilation (in achalasia)
Not required	ERCP and/or EUS
Other technical skills
Mandatory	Setting of the electrocautery unit
	Puncture of a capnoperitoneum
	Knowledge of other CO2-related complications (in cooperation with other medical specialists)
Recommended	Use of endoscopic tools from the nurse’s perspective including basic troubleshooting

EMR, endoscopic mucosal resection; ERCP, endoscopic retrograde cholangiopancreatography; ESD, endoscopic submucosal dissection; EUS, endoscopic ultrasound; OTS, over-the-scope.

POEM trainees should have completed structured general endoscopic training in upper gastrointestinal endoscopy and achieved competence in specific skills including maintaining a stable scope position and tip control, and endoscopic hemostasis (injection, coagulation techniques, clipping, defect closure). Trainees should be familiar with the practical use of all necessary endoscopic instruments (various endoscopic knives, distal attachment cap, hemostatic tools, clips), setting of the electrosurgical unit and insufflation pump, and basic troubleshooting of these devices. Competence in colonoscopy and polypectomy is beneficial, but not an absolute prerequisite. Competency in endoscopic retrograde cholangiopancreatography (ERCP) and endoscopic ultrasound (EUS) are not required.

Most of the studies on the POEM learning curve have involved endoscopists who have completed advanced fellowships, with a highly heterogeneous experience in submucosal endoscopy. Nevertheless, competence in endoscopic mucosal resection (EMR) and/or endoscopic submucosal dissection (ESD) could accelerate the learning curve for POEM, potentially increasing the safety and effectiveness of the procedure [36]. One retrospective study has assessed the influence of prior ESD experience in gaining proficiency in POEM, with endoscopists with greater experience in ESD acquiring proficiency in POEM faster, although there was no difference with regard to clinical outcomes or AEs [37].

It is required that trainees can recognize capnoperitoneum in a timely manner and adequately relieve it by puncture if needed. Although it should not be viewed as a requirement, it is advisable to be competent in alternative endoscopic treatment modalities for achalasia, such as botulinum toxin injections and pneumatic dilation.

4 Training

4.1 Steps to acquire competence

4.1.1 Is simulation and ex vivo/animal training recommended before starting POEM in humans?

Evidence-based curricula and standardized training protocols do not exist for POEM. For POEM trainees without previous experience in submucosal endoscopy, ESGE recommends a step-up approach with initial hands-on training on ex vivo models and/or POEM/ESD simulators, after which trainees can advance to in vivo animal models and, in a final step, clinical cases supervised by an experienced trainer.

Mechanical simulators and virtual reality computer simulators are available for various endoscopic procedures and are frequently used during early training for novice endoscopists. Simulation training provides a risk-free solution that introduces trainees to new procedures and enables them to learn specific skills at an individual pace; however, the tactile feedback and visual reality are inferior to training on animal models or clinical cases [38] [39] [40]. Most studies evaluating simulation training have primarily focused on novice learners, revealing some advantages in terms of performance and procedure time; however, there is no high quality evidence to demonstrate a definitive contribution to competency acquisition [38] [41]. Some studies have even shown that simulation training without expert feedback does not enhance trainee skills, so an experienced trainer is always needed [42]. A novel simulation-based training model called EndoGel (Sunarrow Co. Ltd., Tokyo, Japan) replicates the characteristics of the gastrointestinal tract, serving as a realistic and feasible model for training in mucosal marking, submucosal injection, and dissection [43]. With respect to POEM, there is a lack of evidence demonstrating that simulation training improves outcomes.

Although prospective comparative studies are lacking, evidence suggests that preclinical training using ex vivo and live animal models can prepare trainees to perform POEM safely and effectively in human cases [39]. Ex vivo models are a cost-effective alternative to simulators and offer superior haptic and visual realism for advanced endoscopic procedures [40] [44]. Animal models provide the highest degree of realism and can simulate conditions such as intraprocedural bleeding, perforation, and pneumoperitoneum/pneumomediastinum; however, the associated costs and ethical concerns around animal research limit their utility in training [39] [45] [46]. Published studies provide little information on the number of animal procedures required for preclinical training, which varies widely (five to 12) and may also depend on prior endoscopy experience [47] [48] [49] [50] [51]. Studies on the learning curve in ex vivo or animal models have shown that approximately 26 POEM cases are needed before mastery is achieved in terms of AEs and speed [52]. Given the potential for serious AEs and the availability of alternative training options, initiating POEM training in humans is strongly discouraged. In expert centers with close supervision, initial training experience in humans may be considered for endoscopists with sufficient ESD experience; however, clinical evidence supporting this strategy is lacking.

In summary, the existing evidence supports the use of preclinical models and underscores the importance of specialized training programs, aligning with the recommendation for a step-up training approach within the POEM curriculum [53] [54] [55] [56] [57].

4.1.2 Is the observation of live cases at expert centers recommended before starting POEM in humans?

The available evidence suggests that observing cases before engaging in POEM procedures is crucial in acquiring proficiency. Although none of the studies directly compared the outcomes of those who observed cases with those who did not, a unanimous consensus exists among all the studies regarding the significance of this observational phase. The studies, which are all observational [13] [33] [34] [37] [49] [58] [59] [60] [61] [62] [63] [64], uniformly stress the importance of observing expert practitioners performing POEM to gain insights into the procedural workflow and grasp the technique's subtleties.

The number of cases recommended for observation varied, with some studies indicating the observation of as few as two cases [61], while others suggested up to 22 cases as an adequate learning experience [49]. Furthermore, these studies evaluated endoscopists actively engaged in endoscopy training programs. The results consistently revealed high rates of clinical success and a low incidence of AEs, underscoring the safety and efficacy of the procedure when performed by adequately trained individuals.

4.1.3 Is stepwise POEM training recommended?

Stepwise POEM learning entails training in the procedure in a step-by-step manner, repeating each procedure step as many times as necessary to achieve competence, before performing a complete POEM procedure. A suggested order is proposed for the completion of each stage, determined by the difficulty level of each step rather than the sequence of procedures performed. It is suggested that the first step should be learning dissection/tunneling, followed by learning myotomy, and finally learning to create a submucosal tunnel orifice [13] [64] [65]. Training in mucosal closure and the management of perforation, including stent placement, are key parts of POEM training. Once proficient in each stage, the trainee would be ready to commence training in the next step.

No studies have directly compared different POEM training methodologies, complete procedure versus stepwise training. Both methods are cited as a safe and suitable approach for learning [13] [64] [65].

4.1.4 Is expert supervision needed during the first POEM cases?

Several observational studies [33] [34] [37] [49] [60] have reported on the role of experienced endoscopists' supervision during the initial stages of performing the POEM technique. All identified studies advocate for the importance of supervision during the early stages of POEM, emphasizing its potential benefits [33] [34] [37] [49] [60]. It is worth noting that none of these studies directly compared the outcomes of supervised versus unsupervised procedures; however, it is common sense to be supervised during training in a new invasive procedure. Likewise, there is a lack of comparative analysis regarding the optimal number of procedures that should be conducted under supervision, and the recommendations provided in these articles vary considerably in this regard. The cutoff of 10 cases was agreed upon as reasonable by this expert panel.

4.1.5 Should complex POEM cases be avoided during the early training phase?

For the POEM training program in Japan, the initial 2 months of training are dedicated to laying a solid foundation [66]. During this period, trainees focus on studying the anatomical features of the disease and assisting experts in performing the procedure. In the subsequent months, trainees gradually transition to performing POEM on uncomplicated cases. As they develop the necessary skills, they progress to handling more complex cases, such as sigmoid-type achalasia, prior Heller’s myotomy, elderly patients with co-morbidities, type III achalasia, and those with distal esophageal spasm or hypercontractile esophagus.

Regarding the selection of cases during the training curve, only Zein et al. found no statistically significant association between procedural time and pre-POEM patient factors (age and baseline Eckardt score) [61]; however, other studies reported that case selection was crucial in influencing endoscopic operative time and AEs, notably increasing the risk of mucosal perforation during the procedure [60] [63]. In this regard, defining a case as complex is essential, and there are some tools that can be used for case selection. Complex achalasia patients are usually defined as those with multiple prior treatments, prior myotomy, achalasia type III, and sigmoid-type achalasia [67]. Other models have found age, disease duration, antithrombotic use, severe esophageal dilatation, mucosal edema, submucosal fibrosis, and tunnel length to be predictors of difficult POEM [68] [69].

Considering these findings, it becomes evident that careful patient case selection is paramount during the initial stages of POEM training. This approach ensures trainees develop their POEM skills safely and progressively as they navigate the learning curve.

4.2 Requisites for training modules, trainers, and training centers

4.2.1 What are the requirements for a POEM trainer?

Our search did not find studies directly evaluating the skills and case load required to serve as a POEM trainer, mentor, or proctor. Previously, the case load defining an expert, mentor, or trainer has ranged from 50 to 300 cases [37] [59]. All studies mentioned that trainers were experienced in ESD and the management of AEs. The cutoff of 100 cases was agreed upon as reasonable by the expert panel.

4.2.2 What are the requirements for a POEM training center?

No studies have been published evaluating the necessary infrastructure, standards, and case load for POEM training. In addition, there are no accreditation procedures specifically for POEM training centers. Most studies reporting on training or on the establishment of a POEM service relate to large tertiary care centers with experience in interventional endoscopy and ESD, and access to emergency thoracic and abdominal surgery, interventional radiology, and an intensive care unit. In Japan, the Ministry of Health, Labor, and Welfare requires the following institutional criteria to perform POEM [70]:

1. designation as a specialized institution of gastroenterology, gastroenterological surgery, and anesthesiology

2. more than 10 cases of POEM to have been treated

3. at least one full-time doctor with over 5 years of clinical experience in gastroenterological surgery or gastroenterology and more than 20 cases of esophageal ESD; the surgeon should have treated over 15 cases of POEM as the primary surgeon or as an assistant

4. more than three full-time doctors, including at least one gastroenterological surgeon, on the POEM clinical team

5. a full-time designated specialist anesthesiologist

6. capability for urgent surgery.

4.2.3 How long should a POEM training program take?

A POEM training program encompasses observing real cases, attending courses about POEM, theoretical self-learning, practicing on ex vivo or animal models, and performing procedures on human patients under supervision [11] [13] [18] [33] [34] [36] [37] [49] [50] [52] [58] [59] [60] [61] [62] [63] [70] [71] [72]. Considering that several of these activities may or may not overlap, and that learning is conditioned by previous experience in therapeutic endoscopy and ESD [37], learning curves can be highly variable. Accordingly, a minimum training duration of 6 months is advised in high-volume Western endoscopy units, which typically handle 60–100 POEM cases annually. In contrast, for units with lower case volumes, an extended training period ranging from 1 to 1.5 years is recommended. Additionally, this timeframe may vary depending on whether the trainee is involved in a dedicated POEM program, if the program is combined with other ESD or third-space endoscopy techniques, or if the trainee intermittently attends the expert center.

4.2.4 Should POEM trainees be involved in the selection of patients for POEM?

A formalized multidisciplinary team (MDT) approach is recommended in advanced endoscopy [29]. The selection of patients for POEM is a complex procedure that involves an understanding of the various types of achalasia and their treatment options, while at the same time taking patient factors into account. At best, an MDT comprising an interventional endoscopist, a surgeon, a radiologist, and a (neuro-)gastroenterologist should be involved in the discussion of cases. Involving trainees within an MDT has the potential to improve their understanding of achalasia and POEM. POEM trainees will profit from the discussions around the process of case selection and gain deeper insights into the indications and contraindications for POEM.

4.2.5 What are the minimum requirements for a POEM endoscopy report?

A summary with the key elements that should be included in a POEM endoscopy report is provided in [Table 5].

Table 5 ESGE’s recommended peroral endoscopic myotomy (POEM) report template.

	Items to be included
Basic information
Basic data	Patient identification, operators (including trainees)
Indication	Type of achalasia, hypercontractile disorder, etc.
Procedure time	Start of procedure till closure of mucosotomy
Medication	General anesthesia, intraprocedural antibiotics, others
Equipment	Endoscope, accessories, electrosurgical unit, and settings
Esophageal preparation	Describe presence of food remnants/time required for cleaning the esophagus
Anatomical landmarks
Lower esophageal sphincter	Description of endoscopic appearance, location relative to the incisors
Esophageal anatomy	Description of appearance of the esophagus, tortuosity, sigmoid-type, straight lumen, spastic segments
Other landmarks	Visualization of the spine, aortic arch, left main bronchus
POEM steps
Submucosal injection and mucosotomy	Type of submucosal solution
	Mucosotomy length and distance from the incisors
Tunnel length and intratunnel anatomical landmarks	## to ## cm from incisors
	Visualization of spindle veins, oblique muscle, and penetrating vessels
Esophageal myotomy length	## to ## cm from incisors
Gastric myotomy length	## cm
Type of myotomy	Selective vs. full-thickness myotomy
Location of myotomy	Anterior, posterior, greater curvature
Intraprocedural assessment of the LES	EndoFLIP, double-scope method, other
Mucosal closure	Number and type of clips, additional closure methods
Factors pertaining to difficulty	Fibrosis, orientation, distensibility of the tunnel, tortuosity, esophageal spasms, etc.
Adverse events
Adverse events	Type, severity, and management of adverse events (bleeding, CO2-related adverse events, mucosal perforation, etc.) specified
Summary and follow-up recommendations
Summary	Diagnosis and summary of the procedure
Recommendations	Short term: post-procedural pharmacotherapy and diet plan
	Mid-term: clinical, endoscopic, and manometric follow-up

EndoFLIP, endoluminal functional lumen imaging probe; LES, lower esophageal sphincter.

5 Autonomous implementation and assessment of proficiency

5.1 What is the definition of POEM competence? What volume of POEM procedures is recommended to maintain proficiency?

There are no data assessing how to define competence in performing POEM, and no performance measures or quality indicators have been defined thus far. Likewise, there are no data about the number of procedures needed to maintain proficiency.

A prospective registry that includes all procedures performed is an essential component for all POEM training centers to assess proficiency and outcomes. This registry serves several critical purposes.

• Quality control and improvement Training centers must monitor the quality of the procedures performed. This enables them to identify trends, both positive and negative, and implement changes to improve outcomes.

• Research, training, and education For trainees, having access to a comprehensive registry of procedures is a valuable tool. It allows them to learn from past cases, understand the variety of scenarios that can occur, and appreciate the nuances of different approaches.

• Accountability and transparency Keeping a record of all procedures ensures accountability. It shows that the training center is committed to maintaining high standards and is transparent about its practices.

5.2 Is the number of POEM cases an adequate marker of POEM competence?

Studies evaluating the learning curve to establish proficiency in POEM suggest that 7–70 cases are needed to master the technique [34] [36] [37] [50] [60] [62] [63] [66] [71]; however, these studies exhibit several limitations. Firstly, they are all retrospective and conducted at single centers. Moreover, they encompass heterogeneous patient populations and procedures of different complexity. Predominantly, these studies focus on the learning curve of experienced endoscopists, which may not be representative of all POEM trainees. A significant concern is their reliance on procedural time, either total or per cm of myotomy, as a surrogate marker of competence. This approach is problematic because controlled studies have not demonstrated a correlation between procedural time and the clinical success or safety of POEM. Lastly, the consideration of AEs as a metric for assessing competence is often overlooked, which could lead to an incomplete evaluation of an endoscopist's proficiency.

Therefore, ESGE does not favor using a threshold number of procedures performed to define an endoscopist as being competent in POEM, advocating instead for a comprehensive assessment of skills, knowledge, and outcomes. A formal assessment tool to assess technical proficiency is provided in the POEM Curriculum Part II (Best Practice Technique).

6 Conclusions

This ESGE Position Statement was crafted by an international working group with diverse POEM-related expertise from Europe, Brazil, and the USA, including specialists in neurogastroenterology, educational methods, POEM techniques, and medical and educational research. Notably, the consensus-based statements, derived using the Delphi method, are mainly grounded in expert opinion rather than evidence-based data and are designed to guide best training practices without carrying legal weight.

The document offers current insights that are crucial for creating a structured POEM curriculum aimed at fostering expertise and competence in a standardized step-by-step approach ([Fig. 1]). It outlines theoretical and technical prerequisites for POEM trainees and trainers, and underscores the importance of ongoing proficiency evaluation. We propose a set of indicators that require validation in prospective studies. This groundwork paves the way for future creation of an evidence-based educational framework [73]. Part II of the curriculum delivers a comprehensive technical guide, providing trainees with a detailed description of best practice techniques for performing POEM procedures.

Fig. 1 Illustration of a standardized step-by-step approach to learning in peroral endoscopic myotomy (POEM).
EMR, endoscopic mucosal resection; ESD, endoscopic submucosal dissection; GI, gastrointestinal; HRM, high resolution manometry; PPAT, Precision POEM Assessment Tool; TBE, timed barium esophagogram.

Disclaimer

ESGE Position Statements represent a consensus of best practice based on the available evidence at the time of preparation. This is NOT a guideline but a proposal for training in POEM. The statements may not apply in all situations and should be interpreted in the light of specific clinical situations and resource availability. Further studies may be needed to clarify aspects of these statements, and revision may be necessary as new data appear. Clinical considerations may justify a course of action at variance with these recommendations. This ESGE Position Statement is intended to be an educational device to provide information that may assist gastrointestinal endoscopists in providing care to patients. The recommendations made are not rules and should not be construed as establishing a legal standard of care or as encouraging, advocating, requiring, or discouraging any particular treatment. The legal disclaimer for ESGE guidelines applies to the present position statement [74].

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