Hello, my name is Robert Rhee. I am the chief of vascular surgery at Maimonides Medical Centre in Brooklyn, New York.
Unmet Needs in the Treatment of Patients With AAAs
The unmet needs are primarily based on the sealing zone proximally. Originally, the stent grafts were developed for relatively straight and non-angulated necks. And in fact, most of these devices were designed to seal in a 50-millimeter seal zone. So, many of the patients that we've been treating up to now have been treated with devices that were really not intended for use in hostile necks, such as short necks and angulated necks. So the biggest unmet need is to have a device which is the precision and the deliverability of sealing in a zone that's less than optimal.
Excluder Conformable Stent Graft
The excluder conformable stent graft, which was the topic of my lecture, was developed in response to this unmet need. In fact, from the very beginning, it was engineered and tested to be used in hostile necks, namely highly angulated necks, up to 90 degrees of angulation, as well as a short neck, up to 10 millimetres of sealing zone. So the stent rows, as well as the structure of the proximal graft, was designed exactly to fit and function in this hostile neck situation. Of course, it will function in any neck but it was specifically engineered for this. The remainder of the device, including the iliac limbs, are essentially maintained from the previous version of the excluder or the C3 version. So this is actually the first true second generation or endovascular device.
I was the principal, and I continue to be the principal investigator for the USA trial. And the trial was divided into two arms, the short neck subset, as well as the high angle subset. The short neck subset composed of 80 patients, and that trial was completed at the end of 2020. And was submitted for FDA approval and was FDA approved in January of 2021. The trial results for this arm, which specifically looked at short neck aneurysms of up to 10 millimetres of sealing zone but less than 60 degree of angulation, looked outstanding. There was 100% technical success, 100% freedom from adverse events and zero mortality during the one-year follow-up period. And the publication is just being submitted for review.
The take-home message is that we are now able to treat much more variety of patients
because of the availability of this revolutionary new device. The fact that the device can be precisely deployed with angulation system to match the angles, as well as precisely create a seal zone, which utilises every millimetre of the proximal neck.
The next steps involve completing the remainder of the trial, which is the high angle trial. And the FDA has mandated 110 patients be enrolled in this trial. And we have only about 10 to 12 patients left. And after the completion, after one year of follow-up, we'll know whether this device will perform as advertised in the highly angulated neck situation. So, all of these patients in this high neck angle trial have aortic neck angles of 60 to 90 degrees. So, this will be the very first trial in the history of endovascular aortic aneurysm repair that this particular group of patients will be studied in depth and we plan to follow these patients for five years.
Next Steps in Improving Endovascular Treatment for Ruptured AAAs
Ruptured aneurysms should be treated as expeditiously as possible. So, using the conformable excluder, we are able to only stock about five sizes of the main bodies and it's a three-piece system, so we're able to treat ruptured aneurysm with an off-the-shelf device with maximal flexibility even with high-angle neck situations. So as the devices improve, I believe that the resources available to a physician to treat these ruptured aneurysms will be much improved as well, and will ultimately result in improved survival for ruptured aneurysms.