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Use of endovascular aortic repair (EVAR) to treat ruptured abdominal aortic aneurysm (AAA) appears to improve perioperative and long-term mortality compared with open surgery, according to a study of Medicare patients published online December 16, 2013, ahead of print in the Journal of Vascular Surgery. The less invasive procedure also reduces several perioperative complications and shortens hospital stay.

Drawing on data from Medicare patients (age ≥ 67) with a ruptured AAA who underwent endovascular repair (n = 1,126) or open surgery (n = 9,872) between 2001 and 2008, investigators led by Bruce E. Landon, MD, MBA, MSc, of Harvard Medical School (Boston, MA), compared short- and long-term outcomes of 1,099 matched pairs. The only remaining differences after propensity scoring: EVAR patients were more likely to have cardiac arrhythmias (23.4% vs. 19.3%; P = 0.02) and peripheral vascular disease (16.3% vs. 13.1%; P = 0.04).

Rates of perioperative mortality and several procedural and postoperative complications were lower for EVAR than surgery. One exception was procedure-related hematoma, which favored the surgical arm (table 1).

Table 1. Perioperative Outcomes

In addition, among those who survived to discharge, EVAR patients had a shorter median hospital stay (7 days vs. 14 days; P < 0.001) and were more likely to be discharged home (62.8% vs. 40.7%; P < 0.001) than surgical patients.

EVAR was associated with a survival benefit that persisted for more than 4 years in all age groups (P < 0.001), although both endovascular and surgical reinterventions were more common after EVAR than after surgical repair at 12 and 36 months. In addition, EVAR resulted in fewer laparotomy-related complications over long-term follow-up (table 2).

Table 2. Outcomes at 36 Months

 
Over the study period, use of EVAR increased from 6% of repairs to 31%. During the same time, perioperative mortality decreased from 46% to 27% for EVAR and from 44.7% to 40% for open surgery, while 30-day mortality free from intervention held steady at approximately 80%. Overall, mortality for ruptured AAA declined from 55.8% to 50.9%.

The observational nature of the study raises the possibility that hemodynamically unstable patients preferentially received open repair, the authors acknowledge, although they point to several attempts to counteract any effect of unmeasured selection:

• Creation of matched cohorts using propensity score models
• Sensitivity analysis simultaneously modeling the selection effect and outcomes
• Examination of overall trends in rupture repair and mortality

According to Dr. Landon and colleagues, the current results contrast with those of 2 randomized, controlled trials showing no mortality benefit for EVAR compared with open repair. However, they add, these trials were small and had limited power to detect differences in mortality, much less in early and late complications. The trials also required preoperative imaging to assess eligibility for EVAR, thereby excluding patients too unstable to undergo a CT scan and limiting the generalizability of the results. “Large, more inclusive clinical trials are ongoing,” the investigators observe.

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