title: The association between a surgeon's learning curve with endovascular aortic aneurysm repair and previous institutional experience.
abstract: The purpose of the present study was to determine whether an institution's prior endovascular experience influenced the learning curve of subsequent surgeons. A prospective analysis of the initial 70 endovascular abdominal aortic aneurysm repair (EVAR) cases attempted by an individual surgeon was performed with the primary outcome variable being achievement and 30-day maintenance of initial clinical success. Along with standard statistical analyses, the cumulative sum failure method (CUSUM) was used to analyze the learning curve, with a predetermined acceptable failure rate of 10%. Seventy elective EVAR cases were performed by this surgeon during a 4-year period (2000-2004) (mean age, 73.7 -/+ 5.4 years; mean aneurysm diameter 63.3 -/+ 7.2 mm). Initial clinical success was achieved in 68 of 70 cases (97%), which differed significantly with that of our initial surgeon (88.5%, P = .01). Causes of failure in the present series included 1 early mortality (1.4%) and 1 case of conversion to open repair with no instances of type I endoleak or endograft limb thrombosis. Both surgeons' cases were plotted sequentially with CUSUM curves revealing a significantly shorter learning curve for the second surgeon. Optimal results were achieved following 10 to 20 EVAR cases, as opposed to 60 cases in the initial series. Such an analysis confirms that as an institution's experience with EVAR increases, an individual surgeon's learning curve shortens considerably.
authors.affiliation: Division of Vascular Surgery, London Health Sciences Centre & The University of Western Ontario, 800 Commissioners Road E., E2-119, London, ON, Canada. Tom.Forbes@lhsc.on.ca
authors.forename: Thomas L
authors.initials: TL
authors.lastname: Forbes
authors.forename: Guy
authors.initials: G
authors.lastname: DeRose
authors.forename: D Kirk
authors.initials: DK
authors.lastname: Lawlor
authors.forename: Kenneth A
authors.initials: KA
authors.lastname: Harris
mesh_terms: D000046:Academic Medical Centers / Q000706:statistics & numerical data*; D000368:Aged; D017544:Aortic Aneurysm, Abdominal / Q000473:pathology / Q000601:surgery*; D019917:Blood Vessel Prosthesis Implantation / Q000193:education / Q000706:statistics & numerical data*; D002983:Clinical Competence; D015331:Cohort Studies; D004503:Education, Medical, Graduate; D017558:Elective Surgical Procedures / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D008297:Male; D009864:Ontario / Q000453:epidemiology; D011183:Postoperative Complications / Q000453:epidemiology / Q000209:etiology; D011446:Prospective Studies; D011474:Prosthesis Design; D012042:Registries; D012086:Reoperation / Q000706:statistics & numerical data; D013997:Time Factors; D016896:Treatment Outcome