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

Background: 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).

Methods: A retrospective analysis of all patients undergoing an elective EVAR procedure from January 2003 to December 2011 (9 years) 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 > 5 mm 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.

Results: 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 ± 8 years). After a median follow-up of 54 months (interquartile range [IQR], 56.5), aneurysm sac growth > 5 mm was detected in 19 patients (30.1%). Age (P = 0.02) and dyslipidemia (P = 0.03) were associated with sac growth > 5 mm, 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.

Conclusions: 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.