title: Per-Oral Endoscopic Myotomy: A Series of 500 Patients.
abstract: BACKGROUND
  After the first case of per-oral endoscopic myotomy (POEM) at our institution in 2008, the procedure was quickly accepted as an alternative to surgical myotomy and is now established as an excellent treatment option for achalasia. This study aimed to examine the safety and outcomes of POEM at our institution.
  
  
  METHODS
  Per-oral endoscopic myotomy was performed on 500 consecutive achalasia patients at our institution between September 2008 and November 2013. A review of prospectively collected data was conducted, including procedure time, myotomy location and length, adverse events, and patient data with short- (2 months) and long-term (1 and 3 years) follow-up.
  
  
  RESULTS
  Per-oral endoscopic myotomy was successfully completed in all patients, with adverse events observed in 3.2%. Two months post-POEM, significant reductions in symptom scores (Eckardt score 6.0 ± 3.0 vs 1.0 ± 2.0, p < 0.0001) and lower esophageal sphincter (LES) pressures (25.4 ± 17.1 vs 13.4 ± 5.9 mmHg, p < 0.0001) were achieved, and this persisted at 3 years post-POEM. Gastroesophageal reflux was seen in 16.8% of patients at 2 months and 21.3% at 3-year follow-up.
  
  
  CONCLUSIONS
  Per-oral endoscopic myotomy was successfully completed in all cases, even when extended indications (extremes of age, previous interventions, or sigmoid esophagus) were used. Adverse events were rare (3.2%), and there were no mortalities. Significant improvements in Eckardt scores and LES pressures were seen at 2 months, 1 year, and 3 years post-POEM. Based on our large series, POEM is a safe and effective treatment for achalasia; there are relatively few contraindications, and the procedure may be used as either first- or second-line therapy.
authors.affiliation: Digestive Disease Center, Showa University, Northern Yokohama Hospital, Yokohama, Japan. Electronic address: haruinoue@yahoo.co.jp.
authors.forename: Haruhiro
authors.initials: H
authors.lastname: Inoue
authors.affiliation: Digestive Disease Center, Showa University, Northern Yokohama Hospital, Yokohama, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Sato
authors.affiliation: Digestive Disease Center, Showa University, Northern Yokohama Hospital, Yokohama, Japan.
authors.forename: Haruo
authors.initials: H
authors.lastname: Ikeda
authors.affiliation: Digestive Disease Center, Showa University, Northern Yokohama Hospital, Yokohama, Japan.
authors.forename: Manabu
authors.initials: M
authors.lastname: Onimaru
authors.affiliation: Digestive Disease Center, Showa University, Northern Yokohama Hospital, Yokohama, Japan.
authors.forename: Chiaki
authors.initials: C
authors.lastname: Sato
authors.affiliation: Digestive Disease Center, Showa University, Northern Yokohama Hospital, Yokohama, Japan.
authors.forename: Hitomi
authors.initials: H
authors.lastname: Minami
authors.affiliation: Division of Medicine, Graduate School Department of Interdisciplinary Research, University of Yamanashi, Yamanashi, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yokomichi
authors.affiliation: Kobayashi Internal Medicine Clinic, Kobe, Japan.
authors.forename: Yasutoshi
authors.initials: Y
authors.lastname: Kobayashi
authors.affiliation: Digestive Disease Center, Showa University, Koto Toyosu Hospital, Tokyo, Japan.
authors.forename: Kevin L
authors.initials: KL
authors.lastname: Grimes
authors.affiliation: Digestive Disease Center, Showa University, Northern Yokohama Hospital, Yokohama, Japan.
authors.forename: Shin-ei
authors.initials: SE
authors.lastname: Kudo
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D004931:Esophageal Achalasia / Q000601:surgery*; D049630:Esophageal Sphincter, Lower / Q000601:surgery*; D004945:Esophagoscopy / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications; D016896:Treatment Outcome; D055815:Young Adult