On June 22, 2018, FDA issued a release that permitted marketing of two different catheter-based devices that are designed to connect veins and arteries in patients with chronic kidney disease. One of these devices is called the Ellipsys Vascular Access System, and is a product from Avenu Medical. The other device is the everlinQ endoAVF System from TVA Medical. Now, we’re not here to do a side-by-side comparison of both devices. However, we do want to talk about this pretty innovative technology and discuss why it is uncommon for two devices to get de novo granting at the same time.
These minimally-invasive devices create a percutaneous arteriovenous (AV) fistula for hemodialysis access. "Huh?" Yeah, that's what we said too, until we read a little more about this procedure and device. Let's break it down a little, shall we?
The National Institutes of Health reports that more than 661,000 Americans have kidney failure, and two-thirds of that group of people are on hemodialysis. Hemodialysis is a kidney dialysis and blood-cleaning process, where blood is put through a filter outside of the body, cleaned, and then returned to the body. Dialysis is necessary and life-saving in many cases for patients with kidney diseases. Surgeons can create AV fistulas which allow blood to flow from the artery directly into the vein, increasing the blood pressure and amount of blood flow through the vein. This increased flow and pressure causes the veins (typically in the arm) to enlarge slightly. In turn, this enlargement provides the amount of blood flow necessary to ensure an adequate hemodialysis treatment. AV fistulas are the preferred vascular access for long-term dialysis because they last longer than any other dialysis access types, are less prone to infection and clotting, and can be relied upon for predictable performance. Unfortunately, AV fistulas can take several months to heal in order to become usable for hemodialysis. This process has been around for a while, and the procedure hasn’t changed in 50 years.
Both the Ellipsys Vascular Access System and the everlinQ endoAVF System takes a common surgical procedure and simplifies it, cutting actual procedure time down to 30 minutes or less, and requiring only the use of regional or local anesthetic. The Ellipsys Vascular Access System uses an intravascular approach and occurs in the upper forearm, where an outer access cannula, guidewire, and vessel capture construct all combine to create a connection between the vein and artery. A low-power thermal energy is then used to cut the walls of the vessels, and then fuse the tissue together, creating a cross-connection between the adjacent channels without leaving any kind of foreign material in the AV fistula. No stitches, no sutures, no implant.
For people interested in how this is done, here is the step-by-step procedure:
Ultrasound imaging is used to guide catheter to access perforating vein and puncture adjacent radial artery
Guidewire is placed into radial artery
Sheath is inserted over guidewire and into radial artery
Ellipsys catheter is inserted
Catheter is positioned to capture both artery and vein walls
Ellipsys catheter is activated
Catheter is extracted
AV Fistula created
While the Ellipsys device uses one catheter in the procedure, the everlinQ System uses two catheters. The two catheters are magnetic, and attract and lock together once they are aligned in the arm arteries (more specifically, the venous everlinQ catheter in the ulnar vein, and arterial everlinQ catheter in the ulnar artery). Once the everlinQ catheters are locked together, an electrode is deployed and radiofrequency energy is delivered to created channel between artery and vein.
For people interested in how this procedure is done using the everlinQ System, here is the step-by-step procedure:
Two thin flexible magnetic catheters are inserted into artery and vein in the arm through a small incision
Fistula is confirmed with arteriogram to show arterial blood is flowing to low pressure venous system, creating multiple options for cannulation
Venous catheter, which contains electrode, delivers a burst of RF energy to create connection between artery and vein. Catheters are removed
When placed in proximity, magnets in each catheter attract to each other, pulling vessels together. After confirming alignment, RF electrode is deployed
Both of these de novo-reviewed devices have undergone studies, and intense pre-clinical and clinical testing.If you geek-out on regulatory stuff like we do, you might have noticed that these two devices got de novo granting at the same time. In FDA’s guidance document De Novo Classification Process (Evaluation of Automatic Class III Designation), FDA states: “We do not anticipate that De Novo requests for the same device type will frequently be under review concurrently. However, in cases where a De Novo request is granted while another device of the same type is under review in a separate De Novo request, after the first De Novo request is granted, FDA intends to notify the submitter of the other De Novo request still under review that a predicate has been established and that the De Novo request still under review will be declined. The submitter of the declined De Novo request may leverage all information in the De Novo request by incorporating it by reference in a new submission but will still be required to demonstrate substantial equivalence in a subsequent 510(k), including conformity with the newly established special controls for the device type (if Class II).” So it looks like FDA did a solid for these companies and granted both de novos for this new product code (PQK) at the same time (June 22, 2018). Based on the de novo classification orders public on the FDA website, the Ellipsys Vascular Access System (DEN170004) and the everlinQ endoAVF System (DEN160006) were submitted at very different times. It’s nice to see that no one had to turn their de novo into a 510(k) after the other company got “first-to-market” advantage! This way, everyone wins, especially patients who want to get the best treatment possible when they talk to their doctors about this device!