ENGAGE Registry Subset Analysis for Challenging AAA: An Interview With Hence Verhagen, MD

The Endurant AAA Stent Graft System received FDA approval in December 2010. At the Charing Cross International Symposium in 2012, Medtronic presented 2-year results of its US investigational device exemption (IDE) study of the Endurant AAA Stent Graft System, which demonstrated strong clinical performance in long-term follow-up for the graft system. Of 150 AAA patients at 26 US medical centers, 97.6% of the aneurysm sacs that were treated with the Endurant AAA Stent Graft decreased or remained stable in size at 2 years post procedure, with only 0.8% type I endoleaks and no type III endoleaks. 

In November 2012, at VEITH symposium, results were presented that showed continued success with the stent graft through the US IDE study as well as the ENGAGE registry. The international ENGAGE registry has enrolled 1,263 patients to date at more than 80 sites across six continents since the Endurant system received the CE (Conformité Européenne) mark in June 2008. Two-year results on 500 patients from the international ENGAGE registry showed that more than 98% (490 patients) were free from aneurysm-related mortality through 2 years of post-procedure follow-up. The type I and type III endoleak rate was low (1.1%) for this real-world patient population, with more than half (56%) of the aneurysm diameters among these 500 patients showing a reduction in size of 5 mm or more.

At the 2013 Charing Cross symposium, additional results from a study of a subset of the ENGAGE registry were presented. Vascular Disease Management interviewed the presenter of the data, Hence Verhagen, MD, chief of vascular surgery at the Erasmus Medical Center in Rotterdam, the Netherlands. 

Q:  Please describe the Endurant AAA Stent Graft System and its application.

A: The Endurant AAA Stent Graft system is designed to treat abdominal aortic aneurysms through endovascular aortic repair (EVAR). The stent graft system creates a new path for blood flow in the patient’s aorta, reducing pressure on the aneurysm and the risk of rupture. The device is designed to conform to a broad range of aortic anatomies, enabling physicians to offer EVAR to a wider population of patients, including those with challenging aneurysm characteristics.

Q: Please describe the subset of patients from the ENGAGE registry who were studied for these additional results: How many patients were studied, and what were the distinguishing characteristics of their disease or treatment?

A: Overall, the ENGAGE registry has enrolled 1,263 patients to date. This analysis was undertaken in order to assess what impact neck length has on clinical outcomes. The patients were divided into three subsets: 123 patients with neck lengths of 10 mm to 15 mm, 226 patients with neck lengths of 15 mm to 20 mm, and 873 patients with neck lengths greater than 20 mm. 

For the purpose of this study, “short’”neck lengths were classified as 10 mm to 15 mm and “standard” were defined as greater than 15 mm. Historically, shorter neck lengths have been associated with limited eligibility for EVAR and greater risk of adverse events.   

Q: What were the findings from this subset? 

A: The 2-year results showed no statistically significant differences between the “short” and “standard” neck length segments across major clinical endpoints, including type I endoleak, migration, rupture, conversion to surgery, or the need for secondary procedures. These impressive results showcase Endurant’s benefit when treating not only the most straightforward cases but also the most complex cases.

Q: Were there any surprising results or limitations found? 

A: Given that patients with shorter neck lengths were previously associated with worse EVAR outcomes, this positive 2-year data was definitely enlightening to both myself and my fellow investigators. 

Q: What challenges could these results help vascular specialists overcome? 

The results provide vascular specialists with confidence that Endurant is a viable and durable treatment option when they encounter AAA patients with shorter neck lengths. This subset analysis is an important first step in critically assessing the role of EVAR in more complex patient populations. 

Q: What, in your opinion, could the results mean for the future use of this device and other similar devices?

A: Medtronic has undertaken a significant effort to establish relevant clinical evidence on the performance of their graft so that physicians and patients can make their decision based on solid evidence. Perhaps most importantly, the results of the entire ENGAGE registry, and in particular this subset analysis, will open up EVAR to patients who were previously considered ineligible for EVAR. 

It’s important the vascular community is aware and takes note of the clinical implications of new EVAR research, especially as it is related to the role of EVAR in complex patients in order to continue improving patient outcomes and delivering the best patient care possible. 

Hence Verhagen, MD,  is chief of the division of vascular surgery at Erasmus Medical Center in Rotterdam, the Netherlands. Dr. Verahgen reports consultancy to Medtronic and W.L. Gore.