title: Effect of peroral endoscopic myotomy in achalasia patients with failure of prior pneumatic dilation: a prospective case-control study.
abstract: OBJECTIVE
  To investigate the effectiveness of peroral endoscopic myotomy (POEM) surgery in achalasia patients with failure of prior pneumatic dilation (PD).
  
  
  METHODS
  Twenty-one patients with a history of failed PD were prospectively recruited as the case group, and 30 patients with no history of prior treatment for achalasia were included as the control group. Outcome of POEM procedures was evaluated through esophageal manometry, timed barium esophagogram and short form 36 (SF-36) questionnaires, which were performed before surgery, at 5 days after surgery and at the last follow-up, respectively. Relief of patients' symptoms was considered as the primary outcome. Secondary outcomes included lower esophageal sphincter pressure, esophageal emptying, quality of life of the patient, and procedure-related complications.
  
  
  RESULTS
  The two groups were matched in terms of age, gender, body mass index, and results of preoperative examinations. For patients with failed PD, it was observed that Eckardt score, lower esophageal sphincter pressure, and height of the barium column were significantly decreased after POEM surgery. Besides, the mean physical component summary and mental component summary of patients at the final follow were significantly higher than those before surgery. Complications that occurred during the surgery included three cases of subcutaneous emphysema (14.3%) and one case of pneumothorax (4.8%). Patients with failed PD were found to have the significantly longer operation time than the control group. There was no significant difference between the two groups in terms of surgical outcome at the final follow-up.
  
  
  CONCLUSIONS
  POEM is a promising therapeutic modality for achalasia patients who have failed to respond to PD therapy. Previous dilation procedures might have no obvious influence on the efficacy of POEM surgery.
authors.affiliation: Department of Gastroenterology, Nanjing Drum Tower Hospital, Nanjing, China.
authors.forename: Tingsheng
authors.initials: T
authors.lastname: Ling
authors.forename: Huimin
authors.initials: H
authors.lastname: Guo
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Zou
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D004106:Dilatation / Q000379:methods; D004931:Esophageal Achalasia / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D049630:Esophageal Sphincter, Lower / Q000503:physiopathology / Q000601:surgery*; D004945:Esophagoscopy / Q000379:methods*; D004947:Esophagus; D005260:Female; D006801:Humans; D008297:Male; D008365:Manometry; D008875:Middle Aged; D011446:Prospective Studies; D017211:Treatment Failure; D016896:Treatment Outcome
keywords: achalasia; effectiveness; peroral endoscopic myotomy; pneumatic dilation