Failure to rescue trends in elective abdominal aortic aneurysm repair between 1995 and 2011

Abstract

Objective: Factors affecting mortality after abdominal aortic aneurysm (AAA) repair have been extensively studied, but little is known about the effects of the shift to endovascular aneurysm repair (EVAR) vs open repair on failure to rescue (FTR). This study examines the impact of treatment modalities on FTR for elective AAA surgery during the years 1995 to 2011.

Methods: Data for 491,779 patients undergoing elective AAA surgery were collected from Medicare files. Patient demographics, comorbidities, hospital volume, and repair type were collected. Primary outcome was FTR: the percentage of deaths in patients who had a complication within 30 days of surgery. Data were analyzed by univariate and multivariate analysis.

Results: Patients undergoing AAA surgery have become progressively more complex, with 84.96%, 89.33%, 93.76%, and 95.72% presenting with one or more comorbidities in 1995, 2000, 2005, and 2011, respectively. Despite this, overall FTR after AAA surgery was stable from 1995 to 2000 (P = .38) and decreased from 2.68% to 1.58% between 2000 and 2011 (P < .001). In addition, FTR in EVAR decreased from 1.70% to 0.58% from 2000 to 2006 (P = .03) and then stabilized at 0.88% ± 0.9% after 2007 (P = .45). Unlike for EVAR, FTR for open repair remained stable at 3.06% ± 0.17% to 2.74% ± 0.16% from 1995 to 2000 (P = .38) but increased to 4.51% ± 0.21% in 2011 (P < .001). Mortality was highest after transfusion (20.86%), prolonged ventilation (17.37%), and respiratory complications (29.78%) for all AAA surgeries. Of note, high-volume hospitals had lower FTR rates than low-volume hospitals for both open (2.73% vs 5.66%; P < .001) and endovascular (0.7% vs 1.69%; P < .001) repair. Multivariate analysis showed that high annual volume hospital status (odds ratio, 0.6; confidence interval, 0.58-0.63) and endovascular repair (odds ratio, 0.3; confidence interval, 0.28-0.31) were associated with decreased FTR.

Conclusions: The success in AAA surgery of rescuing patients from 30-day mortality after a complication is associated with increased volume of EVAR. This increased success can also be attributed to the improved FTR outcomes and complication rates when surgeries are performed at high-volume hospital centers.