Genicular Artery Embolization (GAE) for Knee Osteoarthritis: Filling Gaps in the Treatment Algorithm

[Dr. Aaron Fritts]
We touched on a little bit last time with Mark Little about what the ideal patient looks like for this, because like you said, sometimes it's even just younger patients who have really bad OA. You don't want to put an implant in them because they're going to have to have a repeat implant at some point. Orthopedics are really happy about this procedure, it sounds like. For the uninitiated, will you just tell us about the knee OA disease process, like you were saying, the incidence and prevalence, and how these patients are typically presenting in your practice?

[Dr. Osman Ahmed]
Yes, for sure. When we talk about knee OA, it's a highly prevalent disease. About 15 million patients in the US alone suffer from it. Huge public health problem. It's the number one cause of chronic disability, physical activity limitation in patients. The way that I think about it also is that it's the number one thing that a "healthy" person experiences, I think, as they grow older. I think because of that, there's a lot of other negative diseases that are tied to it. Specifically, there's an increased incidence of coronary disease linked to knee OA, and there's also an increased incidence of depression, suicidal ideation, mental health consequences, essentially.

Again, I think this is all related to the fact that you basically were otherwise a healthy person and now have this disease that prevents you from doing all the things that you used to do. Because it's such a major, major highly prevalent disease, I think there's a large population of patients that really would stand to benefit from improved therapies, because the primary way that knee OA is dealt with is with medical management. Medical management includes physical therapy, NSAIDs, whether it's oral or intraarticular, as well as intraarticular gel injections, corticoids, hyaluronic acid. Then you have a ton of other therapies that are out there that really actually aren't that well established in guidelines or accepted.

Again, I think for the patient who has knee OA that is suffering, they're willing to try anything. That includes a ton of other stuff like acupuncture, like PRP injections, things like that. When those things don't work or fail, then you have to start thinking about knee replacement. Again, if you're going from getting like a knee injection to a complete arthroplasty, that's a big jump, and that can be very scary. My mom had a knee replacement, so I saw upfront exactly what that means in terms of the recovery, the pain, all that sort of stuff. It's a great procedure, but there's a lot that's to it.

[Dr. Aaron Fritts]
Yes. My in-laws both have gone through it and it is no joke. You're right. The recovery is not-- they actually recovered faster from spinal surgery, from fusion surgery than they did from their knee. Just you forget how much you rely on that knee joint for just mobility, right? How it can be very painful. Just to back up a little bit about how these patients are coming to your practice, are you seeing them in clinic? Is ortho sending them over? Tell us about how you're building this GAE practice.

[Dr. Osman Ahmed]
Yes, definitely. I think as I mentioned earlier, I started a long time ago, I think probably relatively early adoption phase. When I first learned about it and was very interested by it, the first people I went to was orthopedics. They, I think rightfully so, looked at this and they said, we don't really buy this. You're going to mess up our arthroplasties. You might cause ischemia to the joint. They weren't really terribly excited. That obviously put up a little bit of a roadblock when I first wanted to get this practice going.

Then I turned towards other specialties that manage OA, because that's another interesting thing about knee OA, is there's not just one specialty that gatekeeps this disease. There's actually, because of how prevalent it is, there's many providers out there that are taking care of these patients just because there's so many. I had a very close relationship with my pain management colleagues, primarily because I was doing a lot of oncology work with them in terms of MSK oncology.

Just in our natural conversations, GAE came up as a alternative therapy for OA and they were performing nerve ablations and they really felt like that procedure didn't work well for their patient population. When I told them about GAE, they got really excited. We set up a study. We got an IDE from the government. We started performing it on some patients. Again, the results spoke for themselves and the practice naturally grew just from that.

By the time we finished that study, the university had advertised that study. I was getting a ton of self-referrals. I was getting every day maybe a couple of patients emailing me interested in the study. By then, I started offering it as standard of care. By then, now that I had my own patient base, I found that orthopedics was a little bit more willing because I had some data. I showed to them that I was doing this in the right way in terms of doing this academically. One person specifically within the orthopedic department who's a KMNR doctor, who's their non-orthopedic orthopedic person, was the person I really specifically collaborated with and he's now my primary referrer. I have also spoken with Rheumatology, I did Grand Rounds. I think, again, what's really rewarding about this procedure is now my referrals come from multiple specialties. Orthopedics, rheumatology, pain management, self-referrals, and also some family medicine. Even just in the community, just people are googling and other docs are seeing that I do this and reaching out. It's great because I don't have just one sort of source that I have to rely on kind of thing.

[Dr. Aaron Fritts]
For docs who want to add this to their practice and they're talking to potential referrers like ortho or non-ortho docs that treat OA, even primary care docs, are there any pivotal studies that you can direct the audience to to just say-- A lot of times they want to hear about the data. They want to know, okay, how do you know this works? Maybe they're not aware. Is there anything that you use as evidence, either part of the discussion or you send it to them later?

[Dr. Osman Ahmed]
Yes, definitely. I think the data is very important. Again, just thinking about this academically, just pain in general is a hard topic or subject to show beneficial data, if that makes sense. There's obviously a lot of studies led by some of the prior guests that you've had on this, including Mark Little and Jafar, who are trying to help push this field forward with the critical studies that they're doing. When I talk to a new doc or a referring doc, I tell them a couple of things. One, I tell them, believe it or not, this procedure has been around for a long time. It actually was first described by Okuno 10 years ago, 2014 I believe. This is not some wild new concept. It's been done overseas for a while now.

Then when I start talking about studies, I obviously refer to some of his data because, again, he has some of the largest experience. He has MRI correlative data that shows reduction in synovitis. We have some imaging correlates or some imaging biomarkers to show that what we're doing actually reduces the synovitis, shows that on MRI. Then I point to some of those pivotal studies related to some of the guests like we've just talked about, like Mark's GENESIS 1 study, which again recently just published the final cohort with two-year data, which is obviously really, really impressive stuff.

Aside from that, the other data that we like to point out is that the data that exists is not just from one country. I like to point out that we have global data from multiple countries, including the US, Australia, Korea, Japan, England, Netherlands, and all those studies from all the different countries show very similar results in terms of the improvement. It's been validated in that sense as well. There's still ways to go with the data specifically, but I think the existing data is pretty compelling to give a lot of these patients at least a shot to sort of say, hey, you don't have many other options, the data on this is encouraging, it's something that's worth doing.

[Dr. Aaron Fritts]
Yes, exactly. Fantastic. The GENESIS one that you said is probably a great place to start, right, since it just came out? It's the most sort of most recent data out there. How did you learn how to do this procedure?

[Dr. Osman Ahmed]
In short, I taught myself, but I didn't do it, I didn't just jump into it, if that makes sense. I did do a ton of reading. I looked at, obviously, Okuno's. I think Sunny Bagla was one of the early adopters in America, and I remember watching some of his lectures. I think I had actually also had emailed him, he sent me a PowerPoint, it was great in terms of helping me just understand the procedural basics.

I do remember the first case that I did, thinking, okay, I've memorized everything, I know everything, but you do that first angiogram, and it's like, it just hits you. You're like, whoa, there's a lot of little arteries here. Now having done a bunch, it gets really easy really fast. Again, I think that's just a testament to being radiologists, obviously, and that's in our wheelhouse in terms of recognizing anatomy and variants and things like that. I wouldn't say it was trial and error, but definitely, it took a few procedures to get comfortable. The first few procedures, I would say, were a few hours long, but then, now we're doing them routinely in 30 or 40 minutes.