title: The light at the end of the tunnel: a single-operator learning curve analysis for per oral endoscopic myotomy.
abstract: BACKGROUND
  Per oral endoscopic myotomy (POEM) represents a natural orifice transluminal endoscopic surgery approach to Heller myotomy. Our center was the first to offer POEM outside of Japan, allowing us to accumulate what is likely the highest single-operator POEM volume in the United States.
  
  
  OBJECTIVE
  To define the POEM learning curve of a gastroenterologist by using a larger data set and more detailed statistical analysis than used in 2 other reports of POEM performed by surgeons.
  
  
  METHODS
  Prospective cohort study.
  
  
  METHODS
  Tertiary-care academic medical center.
  
  
  METHODS
  We analyzed the first 93 consecutive POEMs on patients with achalasia aged >18 years without contraindications to POEM performed by a single operator from October 2009 to November 2013.
  
  
  METHODS
  (1) Efficiency estimation via cumulative sum (CUSUM) analysis, (2) mastery estimation via penalized basis-spline regression and CUSUM analysis, (3) correlation of operator experience with clinical outcomes (Eckardt score improvement, lower esophageal sphincter pressure reduction) and technical errors (accidental mucosotomy rate), and (4) unadjusted and adjusted regression analysis to assess how patient characteristics affected procedure time by using a generalized linear model.
  
  
  METHODS
  Clinical outcomes, procedure time, technical errors.
  
  
  RESULTS
  Efficiency was attained after 40 POEMs and mastery after 60 POEMs. When we used the adjusted regression analysis, only case number (operator experience) significantly affected procedure time (P < .0001). Improvements in clinical outcomes were excellent but not significantly affected by operator experience, as was the case with accidental mucosotomies. Procedure time was not significantly affected by age, sex, achalasia stage, baseline lower esophageal sphincter pressure, baseline Eckardt score, prior treatment of achalasia, prior botulinum toxin injection, incidence of accidental mucosotomies, length of myotomy, or type of knife used (all P > .05).
  
  
  CONCLUSIONS
  Our analysis may underestimate the number of POEMs required to achieve mastery for operators with limited or no endoscopic submucosal dissection experience.
  
  
  CONCLUSIONS
  These results offer thresholds for efficiency and mastery of a single gastroenterologist operator that may guide the efforts of novice POEM operators.
authors.affiliation: Department of Internal Medicine, Winthrop University Hospital, Mineola, New York, USA.
authors.forename: Kumkum Sarkar
authors.initials: KS
authors.lastname: Patel
authors.affiliation: Department of Biostatistics, Winthrop University Hospital, Mineola, New York, USA.
authors.forename: Rose
authors.initials: R
authors.lastname: Calixte
authors.affiliation: Division of Gastroenterology, Winthrop University Hospital, Mineola, New York, USA.
authors.forename: Rani J
authors.initials: RJ
authors.lastname: Modayil
authors.affiliation: Division of Gastroenterology, Winthrop University Hospital, Mineola, New York, USA.
authors.forename: David
authors.initials: D
authors.lastname: Friedel
authors.affiliation: Division of Surgery, Winthrop University Hospital, Mineola, New York, USA.
authors.forename: Collin E
authors.initials: CE
authors.lastname: Brathwaite
authors.affiliation: Division of Gastroenterology, Winthrop University Hospital, Mineola, New York, USA.
authors.forename: Stavros N
authors.initials: SN
authors.lastname: Stavropoulos
mesh_terms: D000328:Adult; D000368:Aged; D004931:Esophageal Achalasia / Q000601:surgery*; D049630:Esophageal Sphincter, Lower / Q000601:surgery*; D004945:Esophagoscopy; D005260:Female; D006801:Humans; D059032:Learning Curve; D008297:Male; D008875:Middle Aged; D057605:Natural Orifice Endoscopic Surgery / Q000592:standards*; D011446:Prospective Studies; D055815:Young Adult