title: Trends of Heller myotomy hospitalizations for achalasia in the United States, 1993-2005: effect of surgery volume on perioperative outcomes.
abstract: OBJECTIVE
  Achalasia is a rare chronic disorder of esophageal motor function. Single-center reports suggest that there has been greater use of laparoscopic Heller myotomy for achalasia in the United States since its introduction in 1992. We aimed to study the trends of Heller myotomy and the relationship between surgery volume and perioperative outcomes.
  
  
  METHODS
  The Healthcare Cost and Utilization Project Nationwide Inpatient Sample (NIS) is a 20% stratified sample of all hospitalizations in the United States. It was used to study the macro-trends of Heller myotomy hospitalizations during 1993-2005. We also used the NIS 2003-2005 micro-data to study the perioperative outcomes of Heller myotomy hospitalizations, using other achalasia and laparoscopic cholecystectomy hospitalizations as control groups. The generalized linear model with repeated observations from the same unit was used to adjust for multiple hospitalizations from the same hospital.
  
  
  RESULTS
  The national estimate of Heller myotomy hospitalizations increased from 728 to 2,255 during 1993-2005, while its mean length of stay decreased from 9.9 to 4.3 days. Of the 1,117 Heller myotomy hospitalizations in the NIS 2003-2005, 10 (0.9%) had the diagnosis of esophageal perforation at discharge. Length of stay was negatively correlated with a hospital's number of Heller myotomy per year (correlation coefficient -0.171, P < 0.001). In multivariate log-linear regressions with a control group, a hospital's number of Heller myotomy per year was negatively associated with length of stay (coefficient -0.215 to -0.119, both P < 0.001) and total charges (coefficient -0.252 to -0.073, both P < 0.10). These findings were robust in alternative statistical models, specifications, and subgroup analyses.
  
  
  CONCLUSIONS
  On a national level, the introduction of laparoscopic Heller myotomy for achalasia was associated with greater use of surgery and shorter length of stay. A larger volume of Heller myotomy in a hospital was associated with better perioperative outcomes in terms of shorter length of stay and lower total charges.
authors.affiliation: Department of Medicine, Temple University School of Medicine, Philadelphia, Pennsylvania 19140, USA.
authors.forename: Y Richard
authors.initials: YR
authors.lastname: Wang
authors.forename: Daniel T
authors.initials: DT
authors.lastname: Dempsey
authors.forename: Frank K
authors.initials: FK
authors.lastname: Friedenberg
authors.forename: Joel E
authors.initials: JE
authors.lastname: Richter
mesh_terms: D004931:Esophageal Achalasia / Q000601:surgery*; D004947:Esophagus / Q000601:surgery*; D005260:Female; D006760:Hospitalization / Q000639:trends*; D006801:Humans; D015994:Incidence; D007431:Intraoperative Complications / Q000453:epidemiology; D010535:Laparoscopy / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D016896:Treatment Outcome; D014481:United States