A cumulative analysis of an individual surgeon's early experience with elective open abdominal aortic aneurysm repair

Abstract

Background: Several studies have reviewed the role of hospital and surgeon case volumes in determining early mortality after elective open abdominal aortic aneurysm (AAA) repair. Few, however, have analyzed this relationship at the individual surgeon level. The purpose of this study was to display the usefulness of a unique statistical tool as a form of an ongoing practice audit.

Methods: All patients who underwent an elective open AAA repair by an individual surgeon at a university-affiliated medical center over a 5-year period were analyzed. The cumulative sum failure method was used to analyze the results over time. Failure was defined as the presence of early mortality, myocardial infarction, or a complication resulting in another surgical procedure or prolonged hospitalization. A target failure rate of 10% was chosen, and 80% alert and 95% alarm boundary lines were established.

Results: One hundred thirty-eight patients underwent elective AAA repair by this surgeon over a 5-year period (1998-2003). There were 5 early mortalities (3.6%), 15 myocardial infarctions (10.9%), and 3 major morbidities (2.2%). These results were plotted on a cumulative sum curve as an example of an ongoing practice audit.

Conclusions: The cumulative sum failure method provides a tool whereby a surgeon can prospectively audit his practice and recognize trends in performance before their recognition by standard statistical tools.