With Medtronic’s next-gen RDN devices and procedures advancing, Project Galileo is next

Medtronic Renal Denervation GM Jason Fontana offers an update on new Symplicity Spyral devices, procedures and a feature they’re investigating.

Medtronic’s renal denervation (RDN) business is in the early stages of a new project to add a key feature to its minimally invasive hypertension technology as it makes progress on a new catheter design and treats its first patients in a study of multi-organ denervation.

“We’re advancing our catheter and advancing our procedural approach at the same time,” Medtronic RDN GM Jason Fontana said in a Medical Design & Outsourcing interview.

Medtronic’s FDA-approved Symplicity Spyral RDN system delivers radiofrequency energy to a patient’s renal (kidney) arteries using a self-expanding nitinol catheter.

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Through what the team calls Project Pulsar, Medtronic has developed a next-generation catheter with a longer length for transradial wrist access instead of femoral access. Radial access is gaining traction for catheter procedures like percutaneous coronary interventions thanks to better outcomes than femoral access.

“We’re trying to head down the pathway of a wrist-based approach to doing renal denervation, because we know from the coronary perspective it’s safer with less adverse events for patients. They’re able to go home sooner. You don’t have that potential for femoral bruising or leg bruising,” Fontana said.

“Renal denervation is an incredibly safe procedure,” he later continued. “In all our clinical trials and clinical studies, there’s been very few adverse events. The general risks of the procedure, I would put into the same categories as any interventional procedure. The risks are more related to the procedure access than anything else. In an anything-that-could-happen world, the fear going into this was whether there would be any stenosis of the renal artery or impact to the renal artery. We’ve seen pristine safety from a restenosis perspective.”

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Feedback has been positive from physicians using the Symplicity Spyral catheter for RDN and in the multi-organ study, Fontana said. The catheter can expand enough to treat both the renal and hepatic arteries, so there won’t be significant changes to the therapeutic end of the catheter.

“The performance of the catheter has been really fantastic across the board: utilization, deliverability, it’s been great,” he said. “[At Medtronic, that’s] been something that we’ve been proud of forever with our stents, balloons and guides.”

Related: What Medtronic learned on its long road to RDN approval

Medtronic’s Project Gemini

Medtronic’s Spyral GEMINI pilot program (an abbreviation for Global pilot study of rEnal and hepatic coMbINed denervatIon) is comparing RDN against denervation of the arteries in both the kidneys and the liver.

“We’re trying to take more variability out of the conversation,” Fontana said. “There’s always variability with the patient, and we’re trying to get bigger drops in blood pressure and/or more response. Our approach to doing that is to lower the sympathetic nerve activity in the kidney, and then the next big area is the liver. … We did the preclinical work and we presented at ACC that [exactly] that happened: If you add hepatic to renal, you get bigger drops and tighter drops in norepinephrine, the signal from the kidney. We had all this preclinical work, we knew we could do it safely, we knew our algorithm was designed for the hepatic artery, and now we’ve had our first patients.”

“This is kind of a pilot design because it’s never been done before,” he continued. “It’s the first time we’re putting our catheter into the hepatic artery in a human. We have an off-med trial and we have an on-med trial, and we’re basically using the datasets we’ve created as our backdrop to compare this approach to.”

Medtronic has tweaked its RDN generator’s energy delivery algorithm for the multi-organ denervation procedure.

“What we’ve learned preclinically is that the common hepatic artery is made up a little bit differently than your renal artery for appropriate reasons — it’s a different organ,” Fontana said. “We adjusted the algorithm for the tissue we’re going to be delivering energy to in the liver. It’s a little bit thicker of a vessel wall, it’s got a little bit different adventitia.”

Medtronic is using two separate generators in the multi-organ study, but they’re working to offer both energy algorithms in a single generator, Fontana said.

The multi-organ approach offers a lesson for other device developers.

“At a macro level, if you’re an engineer, you tend to get focused on your one area,” Fontana said. “We were focused on the kidney and sympathetic activity in the kidney, and literally the liver has been staring at us the entire time. Every patient we’ve ever treated, it’s right there, and you realize there’s so much sympathetic activity in the liver that maybe we weren’t thinking about. Then you understand it, you learn more about it and realize you can take that opportunity. We learned there was sympathetic nerve activity there — it’s obviously there for a reason — and we’re able to take advantage of it. So if you’re an engineer, you may be focused on that one thing, but every once in a while, pull back a little bit and just see what you’re doing and where else it could be done or where else it could be applicable.”

Medtronic’s Project Galileo

As Medtronic moves forward on Project Pulsar and Project Gemini, there’s a new space-themed program in the works in Ireland. Project Galileo will try to find a signal of intraprocedural efficacy so the physician knows the job is done, Fontana said.

“That’s looking at changes in constriction of the vessels, both pre- and post-renal denervation,” he said. “… Think of it like mapping for atrial fibrillation. … With renal denervation, we treat and then we look to the blood pressure. If there was a way that we could do our treatment and then check and say, ‘OK, we got all the nerves, we’re done,’ that’s what we’re at the beginnings of right now with Galileo. … You’d want to use the same catheter, but use a different energy level and then measure an impact.”

While the Medtronic RDN team’s focus is on hypertension for now, there’s potential for multi-organ denervation to treat other conditions like diabetes.

Related: Medtronic execs say renal denervation for AFib could be on the horizon

“There’s some interesting cardiometabolic options that potentially down the road could be addressed,” Fontana said. “… We’re focused on making sure we can do a safe and effective procedure, and then the next steps will follow.”

We asked whether RDN can help Medtronic remain the world’s largest device company after separating from its diabetes business.

“Unfortunately, hypertension is a really big problem around the world,” he said. “… Our diabetes separation is about focus in both areas. We know diabetic patients need focus, and our team has done a great job there. The partnership with Abbott, everything we’re doing, that’s going to really drive focus there. And then on our side and on the Medtronic side, RDN, pulsed-field ablation, tricuspid, mitral, even in the cardiovascular space, there are these big areas of opportunity that now we can heavily focus on. And then if you think about Hugo and surgical and [neuromod], Medtronic’s been able to now really double down on some of these big areas. RDN for patients with hypertension has that opportunity to be one of these growth drivers going forward.”

Previously: RDN ‘could be the biggest thing we ever do,’ CEO Geoff Martha says