Higher preprocedural fibrinogen levels are associated with aneurysm sac regression after EVAR

Background: The aim of our study was to determine the diameter of the aneurysm sac 24 months after endovascular abdominal aortic aneurysm repair (EVAR); to identify factors associated with sac regression, and to determine the impact of sac regression on all-cause mortality during long-term follow-up. Patients and methods: We conducted a retrospective review of prospectively collected data from patients treated with EVAR between January, 2010 and July, 2016. Sac regression was defined as at least 5 mm decrease in aneurysm diameter in relation to the preprocedural diameter seen on computed tomography angiography. Sociodemographic information, comorbidities, treatment, laboratory parameters, selected anatomical and genetic factors were all analysed to determine their impact on sac regression. Results: During the study period, 124 patients with mean age of 71.2 ± 7.2 years met the inclusion criteria. Sac regression was found in 45.2% of patients. Higher preprocedural fibrinogen was found in patients with sac regression in comparison with patients with stable sac or sac expansion (3.84 g/l vs 3.47 g/l; p = 0.028). In multivariate analysis after adjustment for age, hypertension, sex, smoking, dyslipidaemia, volume and percentage of intraluminal thrombus higher fibrinogen was associated with an increased probability of sac regression (OR 2.47; 95% CI 1.29-4.72; p = 0.006). Persistent type II endoleak was associated with significantly lower probability of sac regression in univariate and multivariate analysis after adjustment for age, hypertension, sex, smoking and dyslipidaemia (OR 0.26; 95% CI 0.10-0.66; p = 0.004). Higher age was a significant predictor of sac regression in multivariate analysis after adjustment for hypertension, sex, smoking and dyslipidaemia (OR 1.07; 95% CI 1.02-1.14; p = 0.012). No difference was found between patient subgroups with and without sac regression in all-cause mortality during follow-up. Conclusions: Higher preprocedural fibrinogen, absence of persistent type II endoleak and higher age were predictive factors of aneurysm sac regression post-EVAR.