ABSTRACT
OBJECTIVE: The aim of the present study was to compare the long-term survival of patients with a stable aneurysm sac vs those with aneurysm sac regression after endovascular aneurysm repair (EVAR) and to identify the independent risk factors for aneurysm sac regression and mortality after EVAR. METHODS: We reviewed all the patients who had undergone EVAR from 2005 to 2018 with computed tomography angiography available at 1 year of follow-up. Aneurysm sac regression was defined as a diameter decrease of >10%. We used multivariable regression to identify the independent risk factors for sac regression. Kaplan-Meier analysis and Cox regression were performed to test the differences in 5-year mortality between a stable sac diameter and sac regression. RESULTS: The inclusion criteria were met by 325 patients, with 185 in the sac regression group and 140 in the stable sac group. Multivariable logistic regression analysis showed that treatment of a ruptured aneurysm was an independent risk factor for aneurysm sac regression (hazard ratio [HR], 0.26; 95% confidence interval [CI], 0.07-0.96). Age (HR, 1.05; 95% CI, 1.01-1.09), ischemic heart disease (HR, 1.94; 95% CI, 1.13-3.31), neck thrombus (HR, 2.72; 95% CI, 1.07-6.95), and a type II endoleak (HR, 19.21; 95% CI, 7.32-50.40) were independent risk factors for a stable aneurysm sac diameter. Multivariable Cox regression showed a significantly increased risk of mortality for patients with a stable aneurysm sac after EVAR (odds ratio, 2.25; 95% CI, 1.36-3.72). No significant differences were found in cause of death between the two groups. CONCLUSIONS: A stable aneurysm sac after EVAR was associated with increased mortality. Age, ischemic heart disease, neck thrombus, and a type II endoleak were independent risk factors for a stable aneurysm sac. However, a well-founded explanation for this finding is still lacking. Future research should focus on aggressive treatment of type II endoleaks and inflammatory processes as potential pathophysiologic mechanisms.
