Endologix's Nellix EVAS Device Studied for Treatment of Aortoiliac Aneurysms With Preservation of Hypogastric Artery Flow

November 10, 2016—In the Journal of Vascular Surgery, Dainis K. Krievins, MD, et al published findings from a study that sought to to determine the long-term effectiveness of endovascular aneurysm sealing (EVAS) using the Nellix endograft (Endologix, Inc.) in the treatment of complex aortoiliac aneurysms with preservation of hypogastric artery flow (2016;64:1262–1269).

The investigators reviewed all patients with abdominal aortic aneurysms (AAAs) and common iliac aneurysms (CIAs) enrolled and treated in prospective studies of EVAS at two centers from 2008 to 2014. Patients with ≥ 1 year of CT follow-up underwent quantitative morphometric assessment by two independent vascular radiologists blinded to clinical outcome results. Hypogastric patency and CIA diameter changes over time were assessed and compared in three treatment groups: totally excluded CIA, partially excluded CIA, and untreated CIA.

Of 125 patients who underwent EVAS, 68 patients (mean age, 75 ± 8 years; 79% men) had both AAA (mean diameter, 55.8 ± 2.0 mm) and CIA (median diameter, 23.4 mm; interquartile range, 21.3–27.0 mm), and 33 patients had bilateral CIAs. Treatment of 101 CIAs included complete CIA exclusion in 40 (39.6%), partial CIA exclusion in 33 (32.7%), and no CIA treatment in 28 (27.7%), with successful AAA exclusion in all patients.

The investigators reported that internal iliac flow was preserved in all 122 hypogastric arteries that were patent before treatment (14 hypogastric arteries were occluded at baseline). 

During 5-year follow-up (median follow-up, 24.7 months; range, 11.5–61.7 months), internal iliac flow was maintained in 98% of at-risk hypogastric arteries. Three patients required secondary treatment with hypogastric occlusion and graft extension to the external iliac, with no other aneurysm-related clinical events.

Totally excluded iliac aneurysms did not change in diameter over time (P = .85), whereas untreated CIAs enlarged at a rate of 0.16 mm/year (95% confidence interval, 0.09–0.23; P < .0001). Partially excluded CIAs enlarged at a higher rate of 0.59 mm/year (95% confidence interval, 0.47–0.71; P < .0001). Enlargement ≥ 3 mm occurred only in partially treated CIAs larger than 3 cm.

The investigators found that EVAS was effective in treating aortoiliac aneurysms with preservation of internal iliac patency in most cases. Complete CIA exclusion prevented aneurysm enlargement over time, whereas partial exclusion did not prevent continued CIA enlargement, particularly in larger aneurysms.