A Narrative Review of update in per oral endoscopic myotomy (POEM) and endoscopic esophageal surgery.

The field of endoscopic esophageal surgery is based on the concept of natural orifice transluminal endoscopic surgery (NOTES). Submucosal space surgery or third space surgery with the use of flexible endoscopy allows for decreased morbidity and hospital length of stay with equivalent outcomes for patients. In the case of achalasia, per oral endoscopic myotomy (POEM) allows for management of refractory cases in setting of previous Heller Myotomy or in patients whom laparoscopic or thoracoscopic surgery is contraindicated. Lastly, POEM more directly divides circular muscular layer of esophagus without destroying surrounding structures that exist to prevent reflux. The innovations in endoscopic surgery began in the animal lab with experiments in the porcine model to develop a way to access the peritoneal cavity through an entry point in the gastric mucosa. Over the last 10 years, the biggest treatment innovations in endoscopy have focused on management of achalasia with the use of POEM. POEM became possible as technology was developed that revolutionized the use of flexible technology and the methods of mucosal closure. In addition to benign esophageal disease, endoscopic methods improved in management of esophageal malignancy with endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD). The innovations of endoscopic surgery have been developed through the utilization of the submucosal space as a method to ensure adequate closure of the mucosal entry point into the peritoneal cavity. The goal of this review paper is to explore POEM and other techniques in endoscopic esophageal surgery for the management of esophageal diverticulum, submucosal tumors, gastroparesis, and gastrointestinal esophageal reflux disease.