The implantable Endurant Endograft stent system (Medtronic) used in the minimally invasive treatment of abdominal aortic aneurysms (AAA) delivered strong results through one year of patient follow-up in the U.S. pivotal study, according to data at the 37th annual symposium of the Vascular and Endovascular Issues, Techniques, Horizons (VEITHsymposium) in New York City.
“We’ve been searching for improved iterations of the current endografts for 15 years, and every new generation improves on the older generation, and we believe the Endurant improves on the profile and accuracy of deployment,” Michel S. Makaroun, MD, professor and chief of vascular surgery at the University of Pittsburgh School of Medicine, told Cardiovascular Business News.
Approved by the FDA under an investigational device exemption, the single-arm, prospective study included 150 patients at 26 U.S. medical centers.
“In this study, the procedure was performed by a variety of practitioners, including vascular surgeons and other specialists, and performed at small community hospitals as well as large academic medical centers,” said Makaroun.
The study included those patients with AAAs of at least 5 cm, neck length of at least 10 mm, neck angulation of at least 60 degrees and iliac fixation length with more than 15 mm. The safety endpoint was the major adverse event at 30 days, and the effectiveness endpoint was a composite of technical and clinical success of AAA therapy at one year.
The deployment was successful in 99.3 percent of the procedures. One AAA ruptured during the procedure (still completed successfully), and one patient required a blood transfusion. The mean duration of the procedure was 101.5 minutes and the mean hospital stay was 2.1 days.
In the study, the Endurant system was associated with no post-operative aneurysm ruptures or aneurysm-related mortalities at one year, and there were no mortalities from any cause at 30 days.
The major adverse event was 4 percent, which Makaroun described as “extremely low.” Specifically, 0.7 percent of patients experienced an MI, 0.7 percent experienced renal failure, 1.3 percent experienced respiratory failure and 0.7 percent experienced stroke. Also, two patients had limb occlusions on day one and day 20.
While there were six deaths during the first year, none were AAA-related. In general, Makaroun defines the one-year outcomes as “really good.” Also, there were no type I or type III endoleaks out to one year.
“Based on these data, the Endurant stent graft appears to be safe and effective in the short term,” said Makaroun.
The researchers concluded that the results up to one year with the Endurant Endograft are “quite encouraging. The Endurant Endograft appears to be a safe and effective new device for the management of AAA.”
Makaroun also pointed out that the results from the Endurant U.S. Regulatory Study are similar to the interim analysis findings of the ENGAGE global prospective registry of post-market use of Endurant Endograft for the treatment of AAA. That post-market registry enrolled 1,200 patients at 80 sites globally, where the stent system is currently approved, through five years of follow-up.
Based on the interim analysis, ENGAGE has enrolled 839 patients, with 88.2 percent with AAA size of greater than 50 mm and a proximal neck length of 27.8 mm. As of Oct. 5, the deployment success was 99.6 percent, implant duration was 90 minutes and the average length of stay was five days.
“The data from ENGAGE are also very good with less than 1 percent mortality and approximately 4 percent major adverse event rate,” Makaroun said. “Because it’s a registry, it is not as easy to collect specific patient characteristics, especially compared with the U.S. regulatory trial, but the ENGAGE results are more representative of how the device performs in real-life clinical practice.”
While he noted that he couldn’t be certain of a date of the FDA’s decision, Makaroun speculated that the FDA could move to make its decision by the first quarter of 2011.