POEMA Clinical Study of Per Oral Endoscopic Myotomy (POEM) in Patients Suffering From Achalasia.

All patients will have routine pre-operative EGD, manometry, barium swallow, ph-metry. Equally all patients will undergo Eckardt's and grading systems of symptom severity before and after the intervention. The patients will have a gastro-graffin swallow in the first day after the surgery. Procedure: Under general anesthesia upper endoscopy is performed using a standard single channel gastroscope. Submucosal injection with 10 ml saline with 1% methylen blue at the level of the mid esophagus is initially performed. A small longitudinal submucosal incision is created using a standard needle knife. For a sufficient entry point as well as submucosal tunnel, a dilating balloon is inserted submucosally via the created incision similar to the technique used in standard endoscopic submucosal dissection. The balloon is slightly inflated to allow sufficient entrance of the endoscope. The gastroscope is advanced into the submucosal space and the tunnel is created via needle knife or blunt dissection as appropriate. The tunnel is created distally and is stopped several centimeters beyond the lower esophageal sphincter (LES), which can easily be identified. Using flexible scissors, a triangle tip- or respectively an isolated tip-knife the clearly visible circular muscles are divided starting 4 cm above the LES extending 2 cm beyond the previously identified esophageal border. The longitudinal and serosal layers are left intact. Finally the mucosal entry is closed with standard endoscopic clips. Patients will receive standard postoperative care for surgical myotomy, including long-term follow-up. If for any reason the endoscopic treatment is unable to be completed or infeasible, a standard laparoscopic treatment will be performed.