GAE Procedure Technique: Minimizing Side Effects & Complications

[Dr. Aaron Fritts]
Let's talk through how you do the day procedure. Are you doing femoral access? To start with the access, you're just standard, straightforward case. Then we'll talk a little bit about challenges after that.

[Dr. Osman Ahmed]
Yes, for sure. I think I'm lucky that, in our hospital, we actually opened up-- it's like an OBL. It's still in our hospital, but we call it the dialysis access center. We do procedures on a C-arm. I actually think this procedure is very well suited for outpatient work, if that makes sense. Meaning, these are patients who are essentially getting steroid injections.

I want to try to make this procedure, at least in my own practice, as close to that as possible. Meaning, I don't want them to think this is some big, huge procedure. Again, I think one of the ways to do that is I do that in our outpatient center. Those patients come in. Oftentimes I try to convince them to do it just with lidocaine only, and more and more patients are starting to trust me on that.

The way that we do this is they come in, I consent them, they come into the room, we prep the groin, but oftentimes if the patient's obese or has a hostile groin, I'll puncture the SFA. Where I puncture the SFA really is wherever I see it best, so I don't have to necessarily dig into the groin area, it can be proximal thigh. I access the SFA with a micropuncture set. I'd advance a wire down just to make sure that we are within the SFA and because it can be confusing, especially if you're sticking lower you may you may stick a small branch to the profender or something like that. Then I just place a 4 French Glide catheter over an Amplatz wire, so no sheath, nothing.

I really, again, in the spirit of trying to make this as low profile as possible, as outpatient-friendly as possible, I put just a 4 French catheter, do an angiogram, and then at that point it's off to the races. We're just going to go ahead and select whichever genicular artery that seems to be abnormal or seems to supply the region of the patient's pain as well. Again, as we talked about, if you do this enough, this actually gets quite easy over time. Just, the arteries have a relatively predictable origin, relatively predictable course, and once you do this enough, you can learn the shapes that you need to make for your microwire to select those arteries.

Once I select each vessel I do an angiogram, confirm that there's an inflammatory blush, and then we aim to reduce the blush. It's very important that we're not embolizing the actual parent genicular artery as the name seems to imply, which again goes back to why ortho, I think, initially balked at this procedure. The goal is actually not to embolize the genicular artery. The goal is to prune the neovascularity that grows in the setting of inflammation. What that really means is it's a very, very tiny amount of embolic.

I think when I first saw Okuno talk about this, he really stresses this and he continues to stress it. Once you start doing it, you understand why, because you have this-- We're trained to embolize. When you embolize, you take it to stasis and it requires a lot of embolic, usually. This is like the opposite of everything that we traditionally do, which is give a very tiny amount. You do an angiogram, you might still see a little blush and you're still tempted to give a little bit more, but as I've learned over time, really less is more and it's, again, you have to resist the urge to try to get this perfect pretty picture and trust that just a small amount of embolic will get the job done.

Once we've embolized all those arteries, we do a completion angiogram and then I just take the 4 French catheter out. I hold pressure where we punctured for about five to seven minutes, and then the patient goes to the recovery area. We watch them for usually about an hour and a half to two hours, and then they go home. If they were bilateral knee osteoarthritis, then I usually bring them back one to two weeks later. I just let them recover for a few days and we can talk about some of the post-procedure stuff. More often than not, they're in the hospital for only a few hours.

[Dr. Aaron Fritts]
Wow, that's amazing. It sounds like it's pretty streamlined.

[Dr. Osman Ahmed]
Yes. We, again, because a very brief practice is growing really fast, we typically try to do two or three procedures in a day, and I usually only-- I'm in that outpatient center only really in the morning, and I do clinic in the afternoon, so I usually can do those procedures. If we start on time at 8:00, usually by noon, we do two or three procedures, and I can go to clinic. I think we've gotten pretty efficient at it.

[Dr. Aaron Fritts]
Are you the only one at University of Chicago doing them or are there multiple providers?

[Dr. Osman Ahmed]
Yes, I think because the way this started was only getting a few consults at a time, and I really wanted to make sure that I could do enough where I sort of felt comfortable. I'm getting close to the point where I think I'll hopefully have done enough where I can start bringing in some other members and the bandwidth. As the practice grows, I won't have the bandwidth to do all the procedures. For right now I'm the only person, but I would anticipate very shortly over the next six months or so I'm going to try to start bringing a few of my partners to help and especially as we grow and expand into other joints.

[Dr. Aaron Fritts]
Okay. Fantastic. The thing that everybody's always worried about is what kind of complications do we want to try and avoid here?

[Dr. Osman Ahmed]
Yes, definitely. I think because, again, this is where in the infancy of this procedure, it's really important that we focus on safety. I think as an academic, that's something we think about a lot. I would encourage people to think about safety, especially with a procedure that's new, that's not completely validated yet and where there's some skepticism outside of our field about. The way to, I think, ensure safety is to really be meticulous with your technique. Particularly, I think where docs will run into issues is with over embolization.

I think, again, really cautioning people to be using a very small amount of embolic. When I say small, we're talking 0.2 to 0.5 cc's. I, and I've seen some lectures from Okuno, for example, where he said, if you're using more than 3 cc's in a case, and he uses Imipenem which is a temporary agent, or at least primarily is Imipenem. If you're using more than 3 cc's in a case, you really need to stop and think what you're doing, meaning, making sure that you're not having some shunting or reflux or you're not seeing anything like that.

Even just a call to our own data, our study showed that, I think, if you used more than 2.5 or 2 cc's of embolic, the rate of skin discoloration and transient pain really increases a lot. If you're using more, it doesn't mean it's wrong, but it will potentially portend more complications. I think that's really the main thing.

Then the other thing I would say is really, as we'd sort of talked about earlier, really learn your anatomy, rely on your expertise as a interventional radiologist to know what the vessels are. There's a lot of overlapping vessels that essentially treat completely non-target areas. You can get fooled relatively easy, especially early on. If you have access to intra-procedural cross-sectional imaging, like cone beam CT or angio CT, I would encourage you to use that liberally until you get very comfortable with this procedure. I think those two things hopefully will keep you out of trouble.

[Dr. Aaron Fritts]
Yes. I was talking to a doc recently who's in the outpatient space who had a couple episodes of like skin changes around the knee and it freaked him out a little bit, got something back on the phone, figure out what to do. Any advice for that? Is that something to be expected on especially early days?

[Dr. Osman Ahmed]
Yes, definitely. I think that's another great point, is expectation management. I think just going back to the efficacy of the procedure, when I talk to patients, I tell them, look, this is not a cure. At least the literature doesn't suggest that this is a cure. We're going to improve your pain about 50%. At least that's the goal. We're going to achieve that in the majority of patients. Then when I talk to them about complications, I say, the side effects of this procedure are that invariably, there are tiny branches that go to the skin. Invariably, the majority of our patients will get some transient skin discoloration.

Now with microspheres, that's going to be much more common. Again, even if you use a small amount, everybody's going to get some, what looks like light bruising around their knee. If they know that, they don't freak out, you won't freak out. 99% of the time, almost probably actually 100% of the time, at least for me, fortunately, by one month it's all gone. As long as they know to expect that, I think that they're okay with that. This can obviously progress to ulceration, things like that. It is important that you follow those patients up and sort of make sure that that doesn't happen.

The other part of expectation or symptom management is you, more often than not, the first few days patients will get increased pain. I used to give everybody a steroid pack. I used to tell everybody give them narcotics or whatever. I think I've found that if you tell them you're going to get skin discoloration, you're going to get increased pain, it's going to last for a couple of days, they know that, they expect it. After that, they don't really need anything. I can actually just manage them with just even more conservatively. Don't even need to give them any additional pain medications outside of maybe like a Tylenol or something.

[Dr. Aaron Fritts]
Got it. It reminds me of like early days Y90 where you put like the ice pack over their belly. You ever do that over the knee?

[Dr. Osman Ahmed]
Yes. Sorry. Yes, that's the other thing. You brought up a good point. Yes, we also put ice packs. Again, like you said, just like the Y90 correlate with the falciform. I don't know if that's actually doing anything. It might be just treating us, but it's such a low-risk thing to do that we still do it for all of our patients, can't hurt kind of thing.

[Dr. Aaron Fritts]
Right. Constricts the blood vessels at the surface. Maybe it minimizes skin changes.

[Dr. Osman Ahmed]
Correct, exactly.

[Dr. Aaron Fritts]
You just need to see, yes, if anybody does a study around that or something.

[Dr. Osman Ahmed]
I have a nice angio CT, actually, of a descending genicular where you can see vessels going to the joint. Then you see these tiny, little arteries that you couldn't see on the angio going to the skin, but then we have our ice pack right over it, right on the side of the target. Again, I don't know how much it's helping or doing anything.

[Dr. Aaron Fritts]
Oz, anything else like post-procedural or any tips or tricks as we-- We're going to go over these cases here in a couple of minutes, but anything else that's essential, I think, for people starting to do this?

[Dr. Osman Ahmed]
Yes, definitely. If I could make a small little plea or pitch, I think, again, this is an easy practice to build, because there's so many patients out there that need this type of therapy. I encourage people to try to do this academically, meaning really try to follow your patients, really try to record the data. We're working, I think, tirelessly to try to get registries open, try to get sham studies in the United States going. There's other giants in our field in America, like Sid Padia, who are also doing this. When those opportunities show up, we're hoping that people out there that are sort of capturing this data can hopefully join in, whether they're in academia or in the outpatient space or anywhere in between.

Then, I think, just as far as tips and tricks go, I would encourage people to-- now enough people are doing it, that you can get advice and recommendations from a multitude of people. Everybody that I talk to does it a little bit differently. One big difference, I think, is a lot of people do retrograde pedal approach. I think for the PAD experts out there, that's an easy transition to do that. Obviously, patients probably prefer that as well. For me, I've found that the anatomy is a little more difficult and a lot more complex to come that way. Again, I think I encourage people to talk to people to figure out what angles work best for them.

[Dr. Aaron Fritts]
Yes. I was going to ask you about that, if you were to consider that, the typical, peel access, of course, you're worried about like the outflow of the foot. If they don't have any peripheral disease, they got a healthy dorsalis pedis, it seems like a short way to get there, but yes, the angles are could be tricky.

[Dr. Osman Ahmed]
Yes. I've only done it once, and maybe that's why. When I did it, I found that the angles were more difficult. It's actually longer, believe it or not, than coming from the SFA. That was another thing. I found that my catheter is barely reached. Again, that's the beauty of IR. You talk to anybody who does like a perm cath. We all do it differently, but we all get it done. It's like, I always tell my fellows and trainees, again, as long as you do it and you do it right, and the patient has what they were supposed to get and you didn't take like six hours doing it, I'm happy.

[Dr. Aaron Fritts]
Thank you. Especially for a perm cath.

[Dr. Osman Ahmed]
Five hours, that's okay.

[Dr. Aaron Fritts]
Yes. Right. Right. You just posted a shoulder on Twitter, I think, the other day. Also very cool. It's just amazing what we're seeing.

[Dr. Osman Ahmed]
It's amazing. I tell people when we talk about this. I feel like the knee is Pandora's box. I'm very focused on the knee. It's a very prevalent disease, but also a lot of the data is there. I think if we work really hard as a specialty to try to validate this intervention, I think that then opens up the door for all these other therapies, like adhesive capsulitis, plantar fasciitis, all these, basically sports injuries, soft tissue injuries, all that sort of stuff.