Effect of gender on long-term survival after abdominal aortic aneurysm repair based on results from the Medicare national database

Abstract

Historically, women have higher procedurally related mortality rates than men for abdominal aortic aneurysm (AAA) repair. Although endovascular aneurysm repair (EVAR) has improved these rates for men and women, effects of gender on long-term survival with different types of AAA repair, such as EVAR vs open aneurysm repair (OAR), need further investigation. To address this issue, we analyzed survival in matched cohorts who received EVAR or OAR for both elective (eAAA) and ruptured AAA (rAAA). Using the Medicare Beneficiary Database (1995-2006), we compiled a cohort of patients who underwent OAR or EVAR for eAAA (n = 322,892) or rAAA (n = 48,865). Men and women were matched by propensity scores, accounting for baseline demographics, comorbid conditions, treating institution, and surgeon experience. Frailty models were used to compare long-term survival of the matched groups. Perioperative mortality for eAAAs was significantly lower among EVAR vs OAR recipients for both men (1.84% vs 4.80%) and women (3.19% vs 6.37%, P < .0001). One difference, however, was that the survival benefit of EVAR was sustained for the 6 years of follow-up in women but disappeared in 2 years in men. Similarly, the survival benefit of men vs women after elective EVAR disappeared after 1.5 to 2 years. For rAAAs, 30-day mortality was significantly lower for EVAR recipients compared with OAR recipients, for both men (33.43% vs 43.70% P < .0001) and women (41.01% vs 48.28%, P = .0201). Six-year survival was significantly higher for men who received EVAR vs those who received OAR (P = .001). However, the survival benefit for women who received EVAR compared with OAR disappeared in 6 months. Survival was also substantially higher for men than women after emergent EVAR (P = .0007). Gender disparity is evident from long-term outcomes after AAA repair. In the case for rAAA, where the long-term outcome for women was significantly worse than for men, the less invasive EVAR treatment did not appear to benefit women to the same extent that it did for men. Although the long-term outcome after open repair for elective AAA was also worse for women, EVAR benefit for women was sustained longer than for men. These associations require further study to isolate specific risk factors that would be potential targets for improving AAA management.