To what extent has endovascular aneurysm repair influenced abdominal aortic aneurysm management in the state of Illinois? 
This study was performed using population-based data to determine the changing trends in the techniques for abdominal aortic aneurysm (AAA) repair in the state of Illinois during the past 9 years and to examine the extent to which endovascular aneurysm repair (EVAR) has influenced overall AAA management.  All records of patients who underwent AAA repair (1995 to 2003 inclusive) were retrieved from the Illinois Hospital Association COMPdata database.  The outcome as determined by in-hospital mortality was analyzed according to intervention type (open vs EVAR) and indication (elective repair vs ruptured AAA).  Data were stratified by age, gender, and hospital type (university vs community setting) and then analyzed using both univariate (chi 2 , t tests) and multivariate (stepwise logistic regression) techniques.  Between 1995 and 2003, 14,517 patients underwent AAA repair (85% for elective and 15% for ruptured AAA).  The average age was 71.4 +/- 7.9 years, and 76% were men.  For elective cases, open repair was performed in 86% and EVAR in 14%; and for ruptured cases, open repair in 97% and EVAR in 3%.  Elective EVAR was associated with lower in-hospital mortality compared with open repair regardless of age.  No differences were observed with age after either type of repair for a ruptured aneurysm.  Men had a lower in-hospital mortality compared with women for open repair of both elective and ruptured aneurysms.  For EVAR, the mortality of an elective repair was lower in men, but there was no difference after a ruptured AAA.  In men, the difference in mortality between elective open repair and EVAR was significant; the type of institution did not influence outcome.  Patients >80 years of age had a higher mortality after open repair for both elective and ruptured AAA and after EVAR of a ruptured AAA.  The average length of stay was 9.9 days for open elective repair, 13.1 days after open repair of a ruptured AAA, and 3.6 days for EVAR.  The independent predictors of higher in-hospital mortality were female gender, age >80 years, diagnosis (ruptured vs open), and procedure (open vs EVAR).  The year of the procedure and type of hospital (university vs community) were not predictive of outcome.  EVAR has had a significant impact on AAA management in Illinois over a relatively short time period.  In this population-based review, EVAR was associated with a significantly decreased in-hospital mortality and length of stay.  Octogenarians had higher mortality after both types of repair, with the exception of elective EVAR.