Per-oral endoscopic myotomy (POEM) is an incisionless procedure used to treat esophageal achalasia, performed by GI endoscopist without cutting any surface of the human body. The main constituent of the procedure is the myotomy part, through which the endoscopist cuts the muscle fibers in the submucosa. Since this procedure is completely new to the area of treatment of achalasia, it is unknown whether a posterior or an anterior myotomy is better in relieving the symptoms. Thenceforth, this study aims at randomizing patients with achalasia presenting for POEM to getting either the posterior or the anterior myotomy. Patients will be followed up for symptoms and complications; data will be extracted and the appropriate analysis will be employed to determine if there is any difference of outcome between the two techniques of myotomy.

Peroral Endoscopic Myotomy (POEM) is an effective, minimally-invasive treatment for achalasia that has been adopted over the past few years. As more programs attempt to adopt the novel technique, there is an increased need for trials to help guide the growth of the procedure. Review of the current literature reveals that most endoscopists prefer an anterior approach, with an incision in the anterior/ anterolateral wall of the esophagus. This approach has been used with tremendous success in decreasing the symptoms of dysphagia and lowering esophageal sphincter (LES) pressure since the first description of the procedure in humans in 2010. However, it can be technically challenging in patients with anterior scarring from prior surgery or radiation, in whom a posterior approach has typically been used. Alternatively, the posterior approach, with incision in the posterolateral wall of the esophagus, has been adopted with great success by several endoscopists as the primary approach to myotomy. Reports involving the posterior approach have also shown significant symptom relief as defined by symptoms score (Eckardt score) < 3, decreased LES pressure, and low complication rates.

However, despite high rates of technical and clinical success, the posterior approach has not been as widely adopted as the anterior approach. Without comparison of the two approaches in terms of efficacy and safety, the optimal technique to myotomy for POEM is yet to be defined. The investigators main hypothesis is that the posterior myotomy is as efficacious as the anterior myotomy in terms of improvement of achalasia symptoms as indicated by reduction in the Eckardt score and LES pressure. Adaptation of both techniques may increase options in approach for routine POEM and increase the number of patients that are able to undergo the procedure, thereby promoting its applicability.

Inclusion Criteria for Participants

• Adult patient age greater than 18 years old
• Confirmed diagnosis of achalasia via high resolution esophageal manometry (HREM)

Exclusion Criteria

• Previous surgery of the esophagus or stomach
• Active severe esophagitis
• Large lower esophageal diverticula
• Large > 3cm hiatal hernia
• Sigmoid esophagus
• Known gastroesophageal malignancy
• Inability to tolerate sedated upper endoscopy due to cardiopulmonary instability, severe pulmonary disease or other contraindication to endoscopy
• Cirrhosis with portal hypertension, varices, and/or ascites
• Pregnant or breastfeeding women (all women of child-bearing age will undergo urine pregnancy testing)
• Acute gastrointestinal bleeding
• Uncorrectable coagulopathy defined by INR > 1.5 or platelet < 50