Medtronic has announced the latest results from two clinical studies analysing the performance of the Endurant AAA stent graft system. The Endurant system has been used to treat more than 165,000 patients worldwide since it was initially introduced in Europe in 2008, which according to a company press release, is more than any other device of its kind, being selected for nearly one of every two endovascular procedures to repair abdominal aortic aneurysms around the world.
The latest results on the Endurant system’s mid-term performance come from a US investigational device exemption (IDE) study that led to the device’s approval by the US Food and Drug Administration in 2011 and an international study, called the ENGAGE registry, that was initiated after receipt of the CE mark in 2008.
The IDE study enrolled 150 patients at 26 centres with strict eligibility criteria compared to the international ENGAGE registry, which has enrolled more than 1,200 patients at 79 sites across six continents with very few exclusion criteria. As a result, the study has more complex baseline characteristics, including 17.8% whose AAA features placed them outside the device’s instructions for use.
Four-year follow-up for all 150 patients enrolled in the IDE study and for the first 500 patients enrolled in the international ENGAGE registry has now been completed. Three-year follow-up for all 1,263 patients in the ENGAGE registry has been completed. Outcomes for these three patient cohorts were presented in November at VIVA in Las Vegas and VEITHsymposium in New York:
- Four-year results for all 150 patients in the IDE study include a 99.2% rate of freedom from aneurysm-related mortality and a 90% rate of freedom from secondary intervention. In addition, 98% of the patients’ aneurysm sacs were stable or had decreased in diameter by more than 5mm at four years of follow-up. At four years, none of the patients had experienced a type I/III endoleak or a main body migration.
- Four-year results for the first 500 patients in the ENGAGE registry include a 98.4% rate of freedom from aneurysm-related mortality, and an 87.3% rate of freedom from secondary intervention.
- Three-year results for all 1,263 patients in the ENGAGE registry include a 98.5% rate of freedom from aneurysm-related mortality and an 89.5% rate of freedom from secondary intervention. In addition, 91% of the patients’ aneurysm sacs were stable or had decreased in diameter by more than 5mm at three years of follow-up. At three years, type I/III endoleaks had occurred in 1.5% of the patients; and main body migration in none.
“Aneurysm-related mortality, secondary interventions and changes in sac diameter are three critically important measures of stent graft performance,” says Edward Woo, director of the MedStar Regional Vascular Program, and chairman of vascular surgery and professor of surgery at Georgetown University in Washington, DC, USA. “Judging from the latest results from two high-quality studies, the impressive performance of the Endurant system has proven to be remarkably durable and consistent on these and other important measures across a wide range of patients and operators.”