Some technical differences do exist between the POP and the POEM techniques. Unlike in POEM we prefer to keep a fairly short submucosal tunnel with the mucosal incision that is performed only about 2–3 cm proximal to the pylorus. Also the myotomy itself is fairly restricted to the pylorus and only extends proximally by about 1 cm. During the pyloromyotomy, no specific attempt is made to selectively divide only the circular muscular layer, and it is typically divided in a full thickness fashion down to the serosal layer. Special attention must be paid when performing the distal portion of the pyloromyotomy since the duodenal mucosa will drape over it in a perpendicular direction and could be easily perforated during this portion of the dissection. Finally, there is still some disagreement as to the optimal location to perform the myotomy. We prefer to perform the pyloromyotomy on the posterior aspect of the greater curvature, adjacent to the retroperitoneum, to benefit from the natural positioning of the endoscope. An argument however can be made to perform the myotomy along the anterior aspect so that the procedure can more easily be converted to a laparoscopic pyloroplasty in case of an endoscopic full thickness perforation.

The success of POEM expanded the indications and the acceptance of the endoscopic submucosal dissection techniques. This has an especially marked effect in the Western world where these techniques were much less well known and practiced as compared to Asia. The greatest testament to this may be the increasing reports in the Western world of gastroenterologists and surgeons performing advanced endoscopic techniques such as endoscopic tumor enucleation and endoscopic pyloromyotomy.

Further studies with larger number of patients are needed to determine long-term outcomes and indications of those endoscopic therapies. Endoscopic tumor enucleation particularly must be well studied to ensure that long-term oncologic results remain equivalent to laparoscopic or open resection. With time and operator experience, even more advanced techniques such as endoscopic full thickness resection (EFTR) will also gain popularity.

Significant challenges however remain with respect to adequate physician training to perform these advanced procedures. Only few centers have evaluated the learning curve for POEM. Kurian et al. reported that mastery of operative technique in POEM can be measured by the decrease in length of procedure and incidence of inadvertent mucosotomies. He found that 20 cases are needed to reach mastery [54]. Procedure time however can be quite variable between patients and can largely depend on prior esophageal interventions [55]. Patel et al. subsequently defined efficiency after 40 POEMs and mastery after 60 POEMs elevating the threshold established by Kurian and colleagues [56]. Obtaining this required level of experience can be quite challenging especially in the setting of such a rare disorder such as achalasia. Future research must therefore also focus on improvement in the training and simulation of these procedures. With time the available endoscopic surgical platforms will continue to improve and evolve making these techniques accessible to an ever increasing group of practitioners.