Thirty-Day Data Published for Pivotal Trial of Endologix's Nellix EVAS System

January 5, 2016—In the Journal of Vascular Surgery (JVS), Jeffrey P. Carpenter, MD, et al published the 30-day results of the United States pivotal trial for the Nellix endovascular aneurysm sealing EVAS) system (Endologix, Inc.), which is a novel approach to endovascular repair of abdominal aortic aneurysms (AAAs) whereby a biocompatible polymer is employed to exclude and seal the AAA sac (2016;63:23–31).

The investigators concluded that in selected patients, perioperative outcomes with the Nellix EVAS system are encouraging, with very low 30-day morbidity and mortality rates and high procedural success. The primary safety endpoint has been achieved, and longer-term follow-up is in progress.

The company-sponsored EVAS FORWARD-IDE investigational device exemption (IDE) clinical investigation trial is designed to evaluate the safety and effectiveness of the Nellix EVAS system for the endovascular repair of infrarenal AAAs. In June, these 30-day data were presented by Dr. Carpenter at the Society for Vascular Surgery 2015 annual meeting in Chicago, Illinois. Dr. Carpenter, who serves the EVAS FORWARD-IDE clinical study’s National Principal Investigator, is Professor and Chairman of Surgery at Cooper Medical School and Chief of Surgery at Cooper Health System in Camden, New Jersey.

As summarized in JVS, the trial enrolled consecutive, eligible, consenting patients at 29 sites in the United States and Europe. Inclusion criteria required an asymptomatic infrarenal AAA, with an aortic neck length ≥ 10 mm and angle to the sac of ≤ 60º, aortic neck diameter of 18 to 32 mm, aneurysm blood lumen diameter ≤ 6 cm, common iliac artery lumen diameter of 9 to 35 mm, access artery diameter ≥ 6 mm, and serum creatinine level ≤ 2 mg/dL. 

Follow-up at 30 days included clinical assessment and computed tomography angiography evaluation of endoleaks and device integrity as assessed by a core laboratory. The trial’s primary safety endpoint is the incidence of independently adjudicated 30-day major adverse events (MAEs), with success defined as superiority with reference to the Society for Vascular Surgery open repair control group (56%).

Between January and November 2014, 150 trial patients who had a mean AAA diameter of 5.8 cm were enrolled and treated with the Nellix system with 100% procedural success. One early death (0.7%) occurred secondary to multisystem organ failure. All 149 surviving patients completed 30-day follow-up. There were no aneurysm ruptures, conversions, limb thromboses, stent fractures, or stent kinking. Five early MAEs occurred in four patients (2.7%) and included one death, one bowel ischemia, two renal failures, and one respiratory failure. One (0.7%) secondary intervention to treat inadvertent coverage of a renal artery was performed. The core laboratory identified nine (6%) endoleaks (one type I, eight type II) on 30-day computed tomography angiography. Freedom from MAE was 97.3% (95% confidence interval, 93.3%–99%), reported the investigators in JVS.