title: Cumulative sum failure analysis for eight surgeons performing minimally invasive direct coronary artery bypass.
abstract: OBJECTIVE
  Analysis of average and individual surgical performance for minimally invasive direct coronary artery bypass was used to enhance quality control for that operation.
  
  
  METHODS
  A total of 1441 standard minimally invasive direct coronary artery bypass procedures performed from August 1996 to January 2006 were analyzed for mortality and 10 other major perioperative complications. Learning curves and assessment of perioperative outcome were calculated using descriptive statistics and cumulative sum observed minus expected failure analysis for 8 involved surgeons with a personal experience ranging from 27 to 443 procedures.
  
  
  RESULTS
  The incidence of in-hospital mortality was 0.9% and compared favorably with the predicted mortality calculated by the logistic EuroSCORE (3.6%, P < .01). Cumulative sum analysis revealed that 2 surgeons crossed the 95% reassurance boundary after 50 operations and that 2 surgeons crossed the 95% reassurance boundary after 100 operations. There were significant differences between surgeons with regard to the learning curves and perioperative complications (3.6%-29.6%, P < .01). Two surgeons crossed the 95% alarm-line indicating unacceptably high failure rates.
  
  
  CONCLUSIONS
  Minimally invasive direct coronary artery bypass has become a procedure with low mortality and low complication rates, but results are case-load and surgeon dependent. Cumulative sum analysis is a valuable method allowing for a breakdown of complication rates over time displaying individual surgeons' strengths.
authors.affiliation: Department of Cardiac Surgery, Heart Center Leipzig, Leipzig, Germany. dholzhey@web.de
authors.forename: David M
authors.initials: DM
authors.lastname: Holzhey
authors.forename: Stephan
authors.initials: S
authors.lastname: Jacobs
authors.forename: Thomas
authors.initials: T
authors.lastname: Walther
authors.forename: Michael
authors.initials: M
authors.lastname: Mochalski
authors.forename: Friedrich W
authors.initials: FW
authors.lastname: Mohr
authors.forename: Volkmar
authors.initials: V
authors.lastname: Falk
mesh_terms: D002983:Clinical Competence; D001026:Coronary Artery Bypass / Q000379:methods* / Q000401:mortality / Q000592:standards*; D006801:Humans; D019060:Minimally Invasive Surgical Procedures; D011183:Postoperative Complications / Q000453:epidemiology; D017211:Treatment Failure