At this year’s VEITHsymposium (14–18 November, New York, USA), Alexander Yevzlin (Azura Surgery Center, Madison, USA) gave a presentation on the EndoForce endovascular anastomotic connector (Phraxis), a novel device that provides an endovascular method of attaching an arteriovenous graft (AVG) to a vein in the upper arm.
The first point that Yevzlin highlighted was that, since the introduction of the Kidney Disease Outcomes Quality Initiative (KDOQI) in 2019, “the new mantra”, as he put it, “is not fistula first, it’s the right patient, in the right access, at the right time, for the right reason.” This is due, he stated, to the fact that, whilst mature fistulas are better than grafts, “many [fistulas] don’t mature,” leading them to be abandoned and the patient requiring further intervention. This issue, coupled with the updated KDOQI, is why Yevzlin feels that “grafts are going to make a huge comeback in [the USA].” He continued by pointing out that the Centers for Medicare & Medicaid services (CMS) have “recently changed their rules [so that] grafts are no longer penalised in the Medicare rules.”
Despite this, there are some issues with grafts as well, Yevzlin adds. “We’ve heard a lot about the various different materials that are used to make AV [arteriovenous] grafts, but here’s the problem. No matter what material you’re using,” he averred, “you’re still taking the native vein out of its in situ position.” Yevzlin pointed out that no matter what material you use, you are still creating a sewn anastomosis, which is the site of 90% of AVG stenoses. The solution to this, then, would be the EndoForce endovascular anastomotic connector, according to Yevzlin.
“This EndoForce device is designed to minimise the cause of stenosis, which is neointimal hyperplasia, surgical trauma, and turbulent flow at the anastomosis,” Yevzlin began, to introduce the new device. Whilst showing an image of the device on the screen, he continued: “This is the device. It’s an endovascular anastomotic device [that is] transcatheter delivered, and it has some very interesting features that are unique from other previous devices that you may know.” These features are “anchoring barbs that make an endovascular anastomosis” and “two different varieties of nitinaol struts under its PTFE [polytetrafluoroethylene] covering.” The intravascular section of the device is “designed to be very flexible” and the other, intra-AVG section is designed to “create great radial force”. Yevzlin highlighted that this too is distinct from other stents, which he said are “designed just to create radial force.”
Another advantage of this device, Yevzlin explained as the presentation continued, is that the procedures are “very straightforward.” Playing an animation of the device delivery, he explained that the device is deployed through “an incision at the venous site,” and then is “manually inserted into the graft.” Finally, “one suture, just one, is put on the back of it through the graft and the connective wall.”
During his presentation, Yevzlin also expanded on some of the trials and evidence that have been gathered whilst developing and researching the EndoForce device. The main investigational device exemption (IDE) clinical trial, which was completed in 2022, was a multicentre, prospective study, made up of a single arm of 158 patients, with a six-month follow-up and a primary endpoint of six-month cumulative patency. Yevzlin explained that this primary endpoint was “92% [cumulative patency] for this device.” Continuing, he added that “the average [cumulative patency] for a suture anastomosis is 80%. So, what does that mean exactly? That means if you get 100 patients and you suture the anastomosis, 20 of them are going to have the graft be abandoned in six months, and if you use this endovascular anastomotic approach, only 8 of those 100 will be abandoned.”
Bringing his presentation to a close, Yevzlin concluded by outlining the additional data from the six-month follow-up. “There’s an estimated [intervention] rate of 1.22 per patient-year for the first six months; for the next six months it’s 1.32 per patient-year, and these intervention rates compare very favourably with the 1.58 interventions per patient-year found in a large study by our colleagues in 2016.”
