Long-term Clinical Outcomes and Predictors of Type-III Endoleak in a Large Cohort of Patients Treated With Anatomically Fixed Stent Grafts Over 20 Years

Objective: To assess the incidence, outcomes, and predictors of type III endoleaks (TIIIELs) in patients treated with different generations of Endologix unibody devices for abdominal aortic aneurysm (AAA). Methods: Patients treated with unibody endografts between 1999 and 2020 in a single unit were prospectively enrolled, retrospectively analyzed, and stratified according to device generation. The primary outcome was the incidence of TIIIEL in patients treated with unibody devices. Secondary outcomes included: (1) TIIIEL incidence among the different device generations; (2) comparison of type IIIa (TIIIaELs) and type IIIb endoleaks (TIIIbELs) incidence, treatment, and complications; (3) risk factor analysis for TIIIEL; (4) overall survival and survival free from TIIIEL. Results: A total of 872 patients who underwent endovascular aortic repair (EVAR) were analyzed. The cumulative incidence of TIIIEL was 4.8% (42/872). The incidence among different generations was 2.4% (10/414), 21.7% (15/69), and 4.6% (16/341), and 2.1% (1/48) for Powerlink, AFXs, AFXd, and AFX2. Freedom from TIIIEL by device generation was significantly lower in the AFXs group (p<0.001). Type III endoleaks was higher in urgent EVAR (p=0.011), large AAA (p<0.001), angulated and calcified necks (p=0.002), and when more than one modular component or non-proprietary extension was used (p<0.001). AFXs was found as independent risk factor for TIIIEL (hazard ratio [HR]=3.1, p=0.003), while the use of a single component decreased the risk (HR=0.3, p=0.005). Finally, every 10-mm increase in AAA diameter resulted in a 2-fold increase in TIIIEL risk (HR=2.0, p<0.001). Conclusion: The first generation of AFX endograft was associated with an increase in TIIIEL risk by 3.1 times, claiming a strict and careful follow-up in patients implanted with this device. Clinical Impact: The old-generation of unibody endograft AFXs was associated with an increase in TIIIEL risk by 3.1 times. Angulated and calcified neck, large aneurysms and the use of nonproprietary graft extension were found as independent risk factors for TIIIEL. Patients implanted with these devices and with these anatomical features should be intensively monitored during follow-up.