POEM is a mature procedure endorsed by societal guidelines as a first line therapy for achalasia and spastic esophageal disorders. Nonetheless, several questions remain, including expanding indications for POEM, periprocedural evaluation and management, and the optimal POEM technique to enhance clinical success while mitigating risk for reflux.

There is uncertainty regarding several technical aspects of the POEM myotomy; though aggregating evidence supports the use of real-time impedance planimetry to guide the myotomy. While post-POEM reflux remains a concerning long term sequela, there is an increasing focus on the potential role of endoscopic anti-reflux interventions. Lastly, with the widespread adoption of POEM, we continue to witness ongoing efforts to standardize post-procedural care and training in this procedure. POEM is no longer a novel but rather established procedure. Yet, this technique has continued to evolve, with the aim of optimizing treatment success while reducing adverse events and risk for post-procedural reflux.

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.

Peroral endoscopic myotomy (POEM), which has been used to treat achalasia and other esophageal motility disorders for the past 10 years, has proven to be secure and efficient. Every year, more and more essays on this subject are published. We sought to investigate the global scientific outputs and hotspots of POEM produced by various nations, organizations, and authors. From 2010 to October 2022, there were 875 papers on POEM that were found in the Web of Science Core database. The bibliometric visualization analyses of nations/regions, institutions, authors, journals, references, and keywords were conducted by CiteSpace V.5.8.R3. Eight hundred seventy-five publications were included in this analysis. With 68 publications, Inoue H had the highest output. While Showa University in Japan was the most productive institution, the United States was the most productive nation. Among the journals, Surgical Endoscopy published the highest number of articles, followed by Gastrointestinal Endoscopy and Endoscopy. The top 10 keywords that appeared most frequently were achalasia, peroral endoscopic myotomy, POEM, myotomy, esophageal achalasia, dysphagia, heller myotomy, endoscopy, gastroparesis and peroral endoscopic myotomy. Seven frontiers, including meta-analysis, high-resolution esophageal manometry, geriatric patient, third space endoscopy, adverse event, endoscopic submucosal dissection, and gastric peroral endoscopic myotomy, had an impact on future research on POEM. The previous 10 years have seen a considerable rise in POEM research, and this trend will continue. The most recent research frontiers, which require more attention, are meta-analysis, high-resolution esophageal manometry, geriatric patient, third space endoscopy, adverse event, and gastric peroral endoscopic myotomy.

Per-oral endoscopic myotomy (POEM) is a rapidly emerging minimally invasive procedure for management of achalasia. Same-day discharge after POEM is safe and feasible; however, some patients may need hospitalization. We aimed to identify characteristics and outcomes for achalasia patients requiring hospitalizations after POEM in the United States (US).

The US National Inpatient Sample was utilized to identify all adult achalasia patients who were admitted after POEM from 2016 to 2019. Hospitalization characteristics and clinical outcomes were highlighted.

From 2016 to 2019, we found that 1,885 achalasia patients were admitted after POEM. There was an increase in the total number of hospitalizations after POEM from 380 in 2016 to 490 in 2019. The mean age increased from 54.2 years in 2016 to 59.3 years in 2019. Most POEM-related hospitalizations were for the 65 - 79 age group (31.8%), females (50.4%), and Whites (68.4%). A majority (56.2%) of the study population had a Charlson Comorbidity Index of 0. The Northeast hospital region had the highest number of POEM-related hospitalizations. Most of these patients (88.3%) were eventually discharged home. There was no inpatient mortality. The mean length of stay decreased from 4 days in 2016 to 3.2 days in 2019, while the mean total healthcare charge increased from $52,057 in 2016 to $65,109 in 2019. Esophageal perforation was the most common complication seen in 1.3% of patients.

The number of achalasia patients needing hospitalization after POEM increased. There was no inpatient mortality conferring an excellent safety profile of this procedure.

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.

Submucosal endoscopy or third-space endoscopy utilizes the potential space between the mucosal and muscularis layers of the gastrointestinal tract to execute therapeutic interventions for various diseases. Over the last decade, endoscopic access to the submucosal space has revolutionized the field of therapeutic endoscopy. Submucosal endoscopy was originally used to perform endoscopic myotomy in patients with achalasia cardia, and its use has grown exponentially since. Currently, submucosal endoscopy is widely used to resect subepithelial tumors and to manage refractory gastroparesis and Zenker's diverticulum. While the utility of submucosal endoscopy has stood the test of time in esophageal motility disorders and subepithelial tumors, its durability remains to be established in conditions such as Zenker's diverticulum and refractory gastroparesis. Other emerging indications for submucosal endoscopy include esophageal epiphrenic diverticulum, Hirschsprung's disease, and esophageal strictures not amenable to conventional endoscopic treatment. The potential of submucosal endoscopy to provide easy and safe access to the mediastinum and peritoneal spaces may open doors to novel indications and rejuvenate the interest of endoscopists in natural orifice transluminal endoscopic surgery in the future. This review focuses on the current spectrum, recent updates, and future direction of submucosal endoscopy in the gastrointestinal tract.