Predictive Factors of Aneurysm Sac Growth in Patients with a Type II Endoleak in the First Post-EVAR Control

Abstract

The objective of this study was to identify predictive factors associated with aneurysm sac growth over time in patients diagnosed with a type II endoleak (TII-EL) in the first postoperative control after endovascular aneurysm repair (EVAR). A retrospective analysis of all patients undergoing an elective EVAR procedure from January 2003 to December 2011 (9years) in a single center was performed. Patients with a TII-EL detected in the first post-EVAR imaging control and with over twelve months of follow-up were included. The primary end point was aneurysm sac growth > 5mm from the first month computed tomography angiography (CTA) to the last available CTA. Demographic variables, cardiovascular risk factors, comorbidities, aneurysm-related data, and procedural information were collected. Three-dimensional volume rendering with the Mimics ® software (Materialise NV, Leuven, Belgium) was used to measure the endoleak nidus. Descriptive, univariate, and multivariate analyses (Cox proportional hazards model) were performed. In this period, 220 EVAR procedures were performed. 63 TII-ELs (28.7%) were detected in the first CTA control (90.5% male, mean age: 75.7±8years). After a median follow-up of 54months (interquartile range [IQR], 56.5), aneurysm sac growth>5mm was detected in 19 patients (30.1%). Age (P=0.02) and dyslipidemia (P=0.03) were associated with sac growth>5mm, whereas the presence of chronic obstructive pulmonary disease (COPD) behaved as a protective factor (P=0.02). The craniocaudal length of the endoleak nidus (P<0.01) and the nidus volume (P<0.001) were the only aneurysm-related variables associated with sac growth. Age (HR: 14.1, 95% CI: 2.1-92.3, P=0.006) and the presence of COPD (HR: 9.6, 95% CI: 1.4-63.7, P=0.019) were the only independent predictors in the multivariate analysis. Reliable predictors of long-term aneurysmal sac growth are lacking, although some variables such as age or nidus volume appear to be associated. Strict surveillance remains mandatory.