Long-Term Outcomes of Abdominal Aortic Aneurysm in the Medicare Population

Abstract

Background: Randomized trials and observational studies have shown that perioperative morbidity and mortality are lower with endovascular repair of abdominal aortic aneurysm than with open repair, but the survival benefit is not sustained. In addition, concerns have been raised about the long-term risk of aneurysm rupture or the need for reintervention after endovascular repair.

Methods: We assessed perioperative and long-term survival, reinterventions, and complications after endovascular repair as compared with open repair of abdominal aortic aneurysm in propensity-score-matched cohorts of Medicare beneficiaries who underwent repair during the period from 2001 through 2008 and were followed through 2009.

Results: We identified 39,966 matched pairs of patients who had undergone either open repair or endovascular repair. The overall perioperative mortality was 1.6% with endovascular repair versus 5.2% with open repair (P<0.001). From 2001 through 2008, perioperative mortality decreased by 0.8 percentage points among patients who underwent endovascular repair (P=0.001) and by 0.6 percentage points among patients who underwent open repair (P=0.01). The rate of conversion from endovascular to open repair decreased from 2.2% in 2001 to 0.3% in 2008 (P<0.001). The rate of survival was significantly higher after endovascular repair than after open repair through the first 3 years of follow-up, after which time the rates of survival were similar. Through 8 years of follow-up, interventions related to the management of the aneurysm or its complications were more common after endovascular repair, whereas interventions for complications related to laparotomy were more common after open repair. Aneurysm rupture occurred in 5.4% of patients after endovascular repair versus 1.4% of patients after open repair through 8 years of follow-up (P<0.001). The rate of total reinterventions at 2 years after endovascular repair decreased over time (from 10.4% among patients who underwent procedures in 2001 to 9.1% among patients who underwent procedures in 2007).

Conclusions: Endovascular repair, as compared with open repair, of abdominal aortic aneurysm was associated with a substantial early survival advantage that gradually decreased over time. The rate of late rupture was significantly higher after endovascular repair than after open repair. The outcomes of endovascular repair have been improving over time. (Funded by the National Institutes of Health.).

Figure 1. Survival after Endovascular Repair or Open Repair of Abdominal Aortic Aneurysm

Shown are rates of survival among all patients who underwent endovascular repair or open repair of abdominal aortic aneurysms (Panel A) and among patients who underwent the procedure during the period from 2001 through 2004 and during the period from 2005 through 2008 (Panel B). I bars indicate 99% confidence intervals.

Figure 2. Freedom from Rupture, Aneurysm, or Reintervention for Complications Related to Laparotomy

Data are shown for all patients who underwent endovascular repair or open repair of abdominal aortic aneurysms (Panel A) and for patients who underwent the procedure during the period from 2001 through 2004 and during the period from 2005 through 2008 (Panel B). The inset in Panel B shows the same data on an enlarged y axis. I bars indicate 99% confidence intervals.