EVAS FORWARD IDE: Updated instructions for EVAR device confer improved outcomes

Patients with abdominal aortic aneurysms treated with a sealing system for endovascular aneurysm repair with updated instructions for use had improved outcomes, according to 2-year results presented at the Society for Vascular Surgery Vascular Annual Meeting.

“The overall 2-year results for [endovascular aneurysm sealing system] with Nellix are very encouraging,” Jeffrey P. Carpenter, MD, professor and chairman in the department of surgery at Cooper Medical School of Rowan University in Camden, New Jersey, said in a press release. “In particular, the refined [instructions for use appear] to offer excellent patient outcomes, and we look forward to validating these results in the upcoming prospective confirmatory study.”

One-year results of the sealing system (Nellix endovascular aneurysm sealing system, Endologix) were previously reported. At 1 year, patients in the pivotal trial had minimal AAAs (1.3%), major adverse events (6.7%), all endoleaks (3.1%) and no migration, with a 94% treatment success rate.

Jeffrey P. Carpenter

Imaging at 2 years showed device migration, leading to instructions for use revisions, according to an abstract.

In the EVAS FORWARD IDE trial, researchers assessed data from 333 patients with the application of updated instructions for use. Patients were from three separate groups: roll-in cohort (n = 29), pivotal cohort (n = 150) and continued access trial (n = 154).

At 2 years, most patients had freedom from type II endoleak (97%) and rupture (99%). Patients were also free from CV mortality (98.8%) and all-cause mortality (94%).

“Low all-cause mortality rates, including [CV] mortality could represent a major benefit for AAA patients and warrants further investigation,” Carpenter said in the presentation.

In root cause analysis, researchers analyzed data for the signal of sac enlargement and device migration. Results of the analysis were used to prepare refined indications for the device. The risks for type IA endoleak, migration and aneurysm enlargement were decreased by adjusting the parameters of patients eligible to receive the device, including aortic proximal neck diameter from 18 mm to 32 mm to 18 mm to 28 mm. Aortic neck diameter change (from ≤ 20% to ≤ 10%), distal seal zone (9 mm to 20 mm; ≥ 10 mm length) and the ratio of aortic aneurysm diameter to aortic blood lumen diameter (< 1.4 ratio) were also updated.

Once the instructions for use were updated, researchers compared patients whose device was implanted using the revised instructions vs. the original instructions. At 2 years, freedom from type IA endoleak was numerically higher in the revised-instructions group (99%) compared with the original-instructions group (96.6%). Compared with the original-instructions group, the revised-instructions group had greater freedom from migration (97.7% vs. 93.2%; P = .0125) and from sac growth (98.1% vs. 93.5%).

Patients in the revised-instructions group had a higher rate of freedom from the composite of migration, type IA endoleak or sac growth (95.9%) compared with the original-instructions group (85.1%; P = .0017), comparable to results seen in the EVAS FORWARD Global Registry.

“Using detailed imaging and statistical analysis, we have been able to understand risk factors for adverse events specific to [endovascular aneurysm sealing system] and define those patients best suited for Nellix,” Carpenter and colleagues wrote in the abstract. – by Darlene Dobkowski

Reference:

Carpenter JP, et al. Plenary Session 8: Late Breaking Clinical Trials. Presented at: Society for Vascular Surgery Vascular Annual Meeting; May 31-June 3, 2017; San Diego.

Disclosure: The study was sponsored by Endologix. Carpenter reports consulting for Endologix.