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AAA stent graft system yields positive 5-year performance, durability
Final results of the Endurant Stent Graft System in the U.S. regulatory trial demonstrate positive late performance and durability at 5 years among patients with abdominal aortic aneurysm, according to data published in the Journal of Vascular Surgery.
The Endurant Stent Graft System (Medtronic) was approved by the FDA in December 2010. “The 1-year Endurant U.S. investigational device exemption pivotal trial results were very encouraging and concluded that the device was safe and effective. Since the publication of the Endurant 1-year data, a number of studies including a worldwide registry have confirmed its midterm durability and effectiveness even in challenging anatomies,” the researchers wrote. The current study presents the first report of long-term outcomes out to 5 years in the regulatory trial.
The prospective, multicenter regulatory trial was conducted at 26 sites in the United States and included 150 patients with abdominal aortic aneurysms (AAA) who were treated with a bifurcated graft (Endurant, Medtronic) between June 2008 and April 2009. Eligible participants had an AAA diameter greater than 5 cm (or 4-5 cm in diameter in cases where size increased more than 5 mm within the previous 6 months), neck length at least 10 mm and neck angulation 60° or less. All events were adjudicated by a clinical events committee, and imaging was reviewed by a core laboratory at 1, 6, 12, 24 and 60 months. The researchers compared outcomes with those of the Medtronic Talent eLPS study for regulatory reasons.
Clinical follow-up at 5 years was available on 94% of 101 eligible patients, and imaging follow-up was available on 87% of patients.
At 5 years, the rate of all-cause mortality was 17.7% and the rate of freedom from aneurysm-related mortality was 99.2%, according to Kaplan-Meier estimates. One aneurysm-related death occurred in a patient who declined treatment for a type I endoleak and died in year 4 from a ruptured AAA. No endograft migrations, fractures or open conversions were observed.
At 5 years, the study sites were able to evaluate for endoleaks in 83 of 101 (82%) patients. Seven of 83 patients (8.4%) had endoleaks at 5 years; six of these were type II endoleaks and one was of indeterminate origin.
In 53 patients (63.9%), the maximum AAA diameter was reduced by more than 5 mm at 5 years; this measure remained stable in 25 (30.1%) patients and increased more than 5 mm in 5 (6%) patients. AAA-related secondary interventions were needed for 15 patients (18 procedures; 11%). Twelve of these were needed for endoleak management, four for limb occlusions, one for stenosis and one for thromboembolism. At 5 years, the rate of secondary intervention was 11%, according to Kaplan-Meier estimates.
Five limb occlusions were reported, four of which occurred within the first 6 months. The rates of survival and reintervention in this study were superior to those of the Talent eLPS study, which followed similar inclusion and exclusion criteria (P < .133).
In two patients, more than one procedure was needed for new or recurring type II endoleaks related to aortic sac enlargement; all other procedures were deemed successful upon completion. An indirect association was seen between one adverse event and a secondary intervention.
stent graft system has proven to be a safe and effective device based on ... data and various midterm studies,” the researchers wrote. “The study results show a high freedom from reintervention, absence of late rupture, need for open conversion, stent fractures and device migration. The 5-year data continue to support device durability.” – by Jennifer Byrne
Disclosure: The U.S. regulatory trial was funded by Medtronic Endovascular. The researchers report no relevant financial disclosures.