EVAS I Study CP-0008 Rev. 02
Research type
Research Study
Full title
Prospective, Multicenter, Single Arm Safety and Effectiveness Study of Endovascular Abdominal Aortic Aneurysm Repair using the Nellix® System
IRAS ID
108841
Contact name
Paul Hayes
Contact email
Clinicaltrials.gov Identifier
Research summary
Summary of Research
Aortic aneurysm management has changed dramatically since the introduction of a minimally invasive treatment has become available, endovascular aneurysm repair (EVAR). Short term mortality after traditional open repair is around 5-6% but this has been reduced to 1-2% with EVAR. Recovery times and complication rates are likewise reduced.
However, the long term durability of EVAR over a 5 year follow up period does not match that of conventional open repair. The design of current endovascular stents allows some blood to flow around in the aneurysm sac despite the introduction of the stent, all be it at a reduced pressure that decreases aneurysm rupture risk. This continued blood flow around the stent and in the aneurysm, can lead to changes in the stability of the stent with subsequent failure of the stent to keep the pressure low in the aneurysm sac. This is called an endoleak and places the aneurysm at a risk of rupture comparable to that present before the stent was introduced.
The Nellix System is a new type of treatment that may overcome some of the limitations of the current technology. This system uses two stents to maintain blood flow to the lower half of the body whilst excluding the aneurysm sac with blood compatible bags that are filled with polymer during the procedure. This complete seal of the whole aortic sac will prevent blood flow into the aneurysm. This should provide the benefits of a minimally invasive treatment, along with much improved long term durability.
This trial aims to study the safety of the initial device implantation, as well as providing long term, 5-year, follow up data.Summary of Results
This prospective, multicentre study enrolled 333 participants at 29 sites. The 1-year data indicated no issues with device integrity. The 2-year follow-up data showed a higher than anticipated rates of device migration, Type Ia endoleak and aneurysm enlargement which led to the study enrolment being put on hold with 333 subjects. Further analyses demonstrated that these higher rates of migration and aneurysm enlargement were associated with challenging anatomy. The Instructions for use (IFUs) were subsequently revised to exclude patients with such anatomies. Based on the new IFUs the study patients were split into an On- and Off-label groups. 77 of the 333 patients were On-label. The data from the 5-year FUP for On-label patients show a 96.8% freedom of significant migration compared with 62.8% in the Off-label group. Similarly, Freedom from Aneurysm enlargement was observed in 79.4% and 60.3% on the On- and off-label groups respectively. These results demonstrate that Nellix is safe and effective, with an acceptable risk/benefit profile, when used in accordance with the currently approved IFU.REC name
East of England - Cambridge Central Research Ethics Committee
REC reference
13/EE/0080
Date of REC Opinion
17 Dec 2013
REC opinion
Further Information Favourable Opinion