Investigational Stent Graft Shows Promise in EVAR for Infrarenal AAA
In patients with infrarenal abdominal aortic aneurysm (AAA), use of a new endovascular repair device is safe and effective with minimal adverse events through 1 year and no ruptures or AAA-related deaths. The results were presented June 7, 2014, at the Vascular Annual Meeting in Boston, MA.
|For the phase 2 investigational device exemption trial, researchers led by Christopher J. Kwolek, MD, of Massachusetts General Hospital (Boston, MA), enrolled 195 AAA patients with or without iliac artery aneurysms at 23 sites in the United States and Canada between June 2009 and May 2012. Patients were treated with the Anaconda One-Lok AAA stent graft system (Vascutek; Inchinnan, Scotland). Outcomes were compared with those of historical open surgical controls from the Society for Vascular Surgery registry.|
Technical success through the first 24 hours was 96.9%. The primary safety endpoint of freedom from major adverse events (all-cause mortality, MI, renal failure, respiratory failure, paralysis or paraplegia, cerebrovascular accident, and bowel ischemia) at 30 days was met in 95.9%. One nonaneurysm-related death, 5 MIs, and 2 cases of respiratory failure were reported.
There were no incidences of AAA rupture or AAA-related mortality over the study period. At 1 year, all-cause mortality occurred in 3.1% (6 patients) in addition to 7 MIs (3.6%), 2 cases of renal failure (1.0%), and 2 cases of respiratory failure (1.0%).
One-year primary efficacy was 93% with 96.4% of patients experiencing aneurysm sac shrinkage or stabilization. Limb occlusion occurred in 7 patients (3.6%).
Rates of type I and type II endoleaks requiring treatment were 2.6% and 3.6%, respectively. No type III endoleak occurred. Freedom from secondary interventions was 99.5% at 30 days and 95.1% at 1 year. The trial will follow patients to 5 years.
Useful Tool in the AAA Armamentarium
In a telephone interview with TCTMD, session moderator Benjamin W. Starnes, MD, of the University of Washington (Seattle, WA), said the unique features of the Anaconda system are that it has a low-profile, flexible, hydrophilic introducer sheath and is easily repositionable.
“If you deploy the graft and you’re not happy with it, you can completely collapse the device, reposition it, and deploy it again,” he said. The device also has potential for off-label modification to treat more complex anatomy since clinicians can unsheath it, modify it, and recollapse the device, he said, adding, “It’s uniquely suited for that purpose.”
Additionally, Dr. Starnes said the device has a magnetic wire attached to distal part of the contralateral limb to help facilitate gate cannulation, “making [EVAR] an easier and quicker procedure.” It also may simplify matters for clinicians who find gate cannulation to be a difficult step in endovascular aneurysm repair.
However, he observed, an issue of concern is a higher rate of type II endoleak on follow-up with this device compared with other types of endografts. “That’s something that is going to need to be sorted out,” he said.
Overall, the device appears to be another useful tool in the armamentarium of vascular interventionalists, Dr. Starnes concluded.
The Anaconda system received CE Mark approval in Europe in April 2005 and an expanded indication in April 2014 for the treatment of infrarenal AAAs in patients with proximal aortic neck angulation of no more than 90 degrees. It was voluntarily pulled from the market by the manufacturer late last year due to “a potential issue with the release wire in the delivery system,” which has since been resolved, according to the company website.
Kwolek CJ, Moore R. One-year results of the Terumo Anaconda One-Lok trial for endovascular aneurysm repair. Presented at: Vascular Annual Meeting; June 7, 2014; Boston, MA.
- Dr. Kwolek reports contracted research for Terumo, which owns Vascutek.
- Dr. Starnes reports consulting fees from Endologix and MAB.