A population-based study of post-endovascular aortic repair rupture during 15 years.

Objective: The devastating event of a ruptured abdominal aortic aneurysm (rAAA) in patients who have survived a previous AAA repair, either elective or urgent, is a feared and quite uncommon event. It has been suggested to partly explain the loss of the early survival benefit for endovascular aortic repair (EVAR) vs open surgical repair (OSR). The main objective of this study was to report the national incidence rate, risk factors and outcome of post-EVAR ruptures. Secondarily, the national incidence rate of ruptures after OSR (post-OSR ruptures) was investigated.

Methods: We conducted a nationwide, population-based, retrospective cohort study using the inpatient and outpatient entries for all patients >40 years of age, receiving their first (index) surgical procedure for AAA, from 2001 to 2015. Only patients surviving their index procedure were included. The primary outcome was rAAA, registered after discharge from the index procedure (EVAR or OSR), identified in the Swedish National Patient Registry and the Cause of Death Registry.

Results: In total, 14,859 patients survived their primary (index) AAA procedure. There were 6470 EVAR procedures, 5893 for intact AAA (iAAA) and 577 for rAAA. Of the 6470 EVAR patients, 86 cases of post-EVAR rupture were identified, corresponding with a cumulative incidence of 1.3% over a mean follow-up time of 3.9 years. The incidence rate was 3.4 (95% confidence interval [CI], 2.7-4.2)/1000 person-years. The independent risk factors identified for post-EVAR rupture were rAAA at index surgery HR 2.4 (95% CI, 1.4-4.1, p 0.002) and age (hazard ratio, 1.1; 95% CI, 1.0-1.1; P < .001). Freedom from post-EVAR rupture was 99%, 98%, and 96% at 3, 5, and 10 years, respectively. Total and postoperative mortality after post-EVAR rupture were 42% and 17% (30 days), 45% and 22% (90 days), and 53% and 33% (1 year). The incidence rate of post-OSR rupture was 0.9/1000 person-years (95% CI, 0.7-1.2).

Conclusions: Post-EVAR rupture is a rare complication that can occur at any time after the index EVAR procedure. This finding may have implications for the discussion of limited follow-up programs and for the choice of procedure in patients with an AAA with a long life expectancy. An rAAA as the indication for the index surgery and age were identified as risk factors for post-EVAR rupture. The mortality associated with post-EVAR rupture is high, but lower than that of primary rAAA. The much lower risk of post-OSR rupture was confirmed, but must not be neglected as a possible late complication.