title: Impact of prior interventions on outcomes during per oral endoscopic myotomy.
abstract: Per oral endoscopic myotomy (POEM) is performed by accessing the submucosal space of the esophagus. This space may be impacted by prior interventions such as submucosal injections, dilations or previous myotomies. These interventions could make POEM more difficult and may deter surgeons during their initial experience. We sought to determine the impact of prior interventions on our early experience.
  
  
  
  Prospective, single-center study of consecutive patients undergoing POEM. Patients were grouped according to their anticipated complexity: Group A: no prior interventions (N = 19); Group B: prior interventions such as submucosal injections and/or dilations (N = 11) and  Group C: sigmoidal esophagus, prior esophageal surgery, balloon dilation >30 mm (N = 8). We compared operative times, inadvertent mucosotomy rates, complications and short-term outcomes between groups.
  
  
  
  A total of 38 patients underwent POEM for achalasia subtypes: I (N = 9), II (N = 19) and III (N = 7). Three had other dysmotility disorders. Patients between the groups were similar. Operative times were similar between Group A and Group B but significantly longer for Group C (133 vs. 132 vs. 210 min, p = 0.001). Mucosotomy rates were highest in Group A (6/19) with 1 each in Group B/C (p = 0.46). One patient in Group A required an esophageal stent. Eckardt scores improved in all groups (6-1; 8-2; 6-0.5, p = 0.73), and postoperative GERD-HRQL scores were similar. One patient underwent laparoscopic myotomy for persistent symptoms with no improvement, and one patient underwent esophagectomy for a sigmoid esophagus and persistent symptoms despite adequate myotomy.
  
  
  
  A prior intervention does not seem to impact short-term clinical outcomes with POEM. Patients who had submucosal injections or small caliber dilations are similar to patients with no prior inventions; however, patients with a sigmoid-shaped esophagus and/or a prior myotomy require nearly double the operative time. Endoscopists undertaking POEM should consider these during their learning curve.
authors.affiliation: Division of Thoracic Surgery, Swedish Cancer Institute and Medical Center, 1101 Madison Street Suite 900, Seattle, WA, 98104, USA. brian.louie@swedish.org.
authors.forename: Brian E
authors.initials: BE
authors.lastname: Louie
authors.affiliation: Division of Thoracic Surgery, Swedish Cancer Institute and Medical Center, 1101 Madison Street Suite 900, Seattle, WA, 98104, USA.
authors.forename: Andreas M
authors.initials: AM
authors.lastname: Schneider
authors.affiliation: Division of Gastroenterology, Swedish Cancer Institute and Medical Center, Seattle, WA, USA.
authors.forename: Drew B
authors.initials: DB
authors.lastname: Schembre
authors.affiliation: Division of Thoracic Surgery, Swedish Cancer Institute and Medical Center, 1101 Madison Street Suite 900, Seattle, WA, 98104, USA.
authors.forename: Ralph W
authors.initials: RW
authors.lastname: Aye
mesh_terms: D000328:Adult; D000368:Aged; D004931:Esophageal Achalasia / Q000601:surgery*; D000071041:Esophageal Mucosa / Q000000981:diagnostic imaging / Q000601:surgery*; D049630:Esophageal Sphincter, Lower / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D057605:Natural Orifice Endoscopic Surgery; D012086:Reoperation; D012189:Retrospective Studies; D016896:Treatment Outcome
keywords: Achalasia; Balloon dilation; Botulinum toxin; Myotomy; Outcomes; Per oral endoscopic myotomy (POEM)