So thanks for having me. So as Adam said, Dr. Nelson asked me to impersonate him here. And so just briefly, he trained me. And I come from a background which reflects our field, I guess, because initially I wanted to be a neurosurgeon. I was in training. At 37, I realized this is not going to happen for me. So I went back, quickly did a neurology residency, and then trained in neurointervention by a radiologist. And so just like our field that says, we don't know who is our son and who is not our son and who's an intruder, I'm kind of torn between the three fields. And I think all three have something to give and to contribute. And talks are always happening about, should we train fellows and stuff like that. And I'm of the opinion that, of course, we have to train fellows because you guys know what it is that you want to do with your lives. And our obligation is to help you achieve those goals, whatever way we can. And you'll sort out the market for yourselves, you're adults. Having said that, so let's talk about flow diversion. So I am a proctor and consultant with Covidian. And I have no experience other than pipeline. So forgive me if I'm only talking about pipeline or whatever I say only applies to pipeline because I don't know FRED or SILK. Essentially, a good rule of thumb with flow diversion is you have to expect the unexpected. Just like with glue and with onyx, you have something in mind as to what you think the end result should look like. And if you're honest, you have a 50-50 shot of getting there. So it's a little bit similar with the flow diversion in that the pipeline device is not an easy device to use. It has its quirks. It has its shortcomings. And there are things that are being done to fix those. And there are other technologies that are being worked out. Bottom line is we have to accept that that is the best that we have for now. And we have to pay attention to what the device is telling us as we're using it and try to recognize things that it's telling us early enough so that it doesn't paint us into a corner where it's difficult to get out of. And again, the great thing about being in New York City, working in one of the places I work in is a city hospital. You see unexpected things. So how do you define adequate flow diversions? What's the goal of the treatment of an aneurysm? Well, if you're a neurosurgeon and you clip an aneurysm, the goal of the treatment is to clip it completely and post-op have a picture where the aneurysm is no longer filling at all, but the parent vessel is filling completely. So the flow diver, whatever approach you have to aneurysms, that should be your goal. Of course, as we saw, these complex cases presented, that cannot be always achieved. And over time, with the balloon remodeling and the different iterations of stents, we're getting closer and closer to achieving that. But the point is that I think adequate flow diversion is defined by the outcome. If your outcome is you do a follow-up angiogram in six months, and the aneurysm is completely closed, and the vessel looks great, and you do a transaxial imaging, and the aneurysm has shrunk, gone away, or didn't change in size, and the patient is asymptomatic, then that was adequate flow diversion. Now, how do we approach flow diversion? It's a little bit, how should I say, some people say it's too aggressive. And I'm going to talk about it a little bit. We almost always use multiple overlapping devices. And that's not because I get paid by Covidien to proctor and say this, but because I remember the first day when Dr. Nelson showed me the first case that I had seen from one of his trips in Europe, that I was completely sold on the idea. And I think you have to have a kind of a, this is not exactly a science. You have to have a gestalt as to what you think constitutes enough flow diversion so that that aneurysm, based on the angiographic picture post-deployment, has no other way but to trombose and go away. In other words, similarly to clipping, you would never consider going into a clipping case saying, well, no matter what, I'm only using one clip in this case. Or going into the AVM, no matter what, I'm only using one vial of MBCA. I think that's a very short-sighted approach. There's no penalty for using whatever it is that you need to use. There's no penalty for coiling. If you think it's an aneurysm that is very large, especially if it's recently symptomatic, and you want to make sure that you shut it down as soon as possible, of course you can coil it. There's no penalty. Coiling versus multiple stents in those aneurysms. You don't need multiple stents. It depends on how, you know, if you have a giant, like the case that you sent the other week, 28-millimeter aneurysm, young woman, recently symptomatic. Obviously, you don't want to just flow revert, not to mention that you can't multi-cover the anterior coroidal in most cases, right? So you're kind of stuck with one or two devices. Now, so if you're stuck with one or two devices, one thing you don't want to do is lock yourself out of the aneurysm by putting insufficient amount of stents in a location where you know you can't come back later and put more because of the coroidal, right? So what you want to do is make sure you're one shot that you're taking counts. And so what you do is you decide up front, okay, I'm going to do, I'm going to put a micro catheter in there, put down one or two devices. If it really convincingly looks like it's super stagnant and I think it's going to be sufficient, you may pull out. You can decide that way. But I would say, you know, you just coil it down. Now, do you have to, how much you have to coil? That's another question. In that case, of course, you can coil a 28-millimeter giant to completion. I mean, ideally, you would put one stent and then completely coil it down and then the aneurysm is cured and you're done. But that may or may not be practical. The only part about that that I have trouble with is I still don't know how dangerous an aneurysm based on the inflow jet or how much stagnation because sometimes you see a lot of stagnation. That is a dangerous sign, too. So we used to talk about hyping until you saw cessation of the inflow jet. And I've kind of been burned and gone away from trying to read the danger of the situation based on the inflow jet in large symptomatic injuries. Right. That's certainly a very valid point. And, you know, anything, I mean, based on what you read and what you hear, I think there's kind of a, not a really written consensus, but kind of a consensus that if you have an aneurysm that is larger than 15 millimeters and it's intradural, especially if it's irregular and or recently symptomatic, you know, you may want to coil it because obviously you don't want to deal with a rupture in that situation. So we still look at the angiogram a lot and decide, you know, what we use. And the other thing is we spend a lot of time, maybe less so now, but historically, we spend a lot of time looking at the images and measuring and remeasuring and measuring in a reliable way because it does matter if that vessel is 3.5 or 3.8 millimeters. And this device has to be, you know, precisely placed and it has to be placed in a strategic way, especially if you have a longer segment that you have to bridge where the distal segment is significantly smaller diameter than the proximal segment. There's all kinds of issues that happen with that. What you should not treat. So it's easy to be kind of categorical about part of that and this is one of those cases. We've done, I think, a total of 10 of these and invariably, you know, the patient came up with some excuse to die within three months. And sometimes we try to say, well, it had nothing to do with what we did and our portion of what we did worked, but actually it doesn't work that way. So this is a lady from Wyoming who was until recently independent, but she kind of lost progressively her abilities to be that independent, can't horseback ride and take care of a branch. She developed headaches, gait difficulties. She had had several falls. Long and short of it is that she has this horrendous basilar aneurysm. So she went to Utah where, of course, she had hydrocephalus with this. She got shunted. She got somewhat better and then she was sent to us for treatment. And, you know, technically, you have a fantastic outcome. You know, you have a lot of flow diversion. You shut down the other vert and everything looks beautiful and she looks great, except, and this is the picture, and you're very proud of yourself and this is two or three days later showing progressive shutdown of the aneurysm. And then you're at the Cape of Good Hope and you're starting to look to the left. You have the Indian Ocean. To the right, you have the whatever other ocean there, Atlantic Ocean, and you're enjoying the vista. And then all of a sudden, you get a call from the ICU and lo and behold, this is what happens. So I could show you all of these cases, all of them. We may have one patient who's still alive, but it's just a disaster. So if you have a basilar aneurysm, in sum, if I can give you a piece of good advice, if you have a basilar trunk aneurysm that is in any way, shape, or form affiliated or associated with the icas or the superior cerebellar arteries, you have to stay away from it because there's no way that I know of, there's no way to treat it with low diversion. You can come up with the smartest plan, you're going to fail. And it has been shown by multiple people. We just have to wait until we have something better to offer. Yeah, I think it's important for people here to realize there's some things you can't fix. Right. Correct. I had an endowment recently, and it just went horrific. Yeah. It was a rusted aneurysm, and I tried to do what I could, but it just died. And yeah, I mean, and you can have a whole discussion about perhaps dying, going out fighting this disease if you're 75, and looking at it as, OK, I'm dying, but somebody is learning something from my experience. Or, as Nelson says, look at it as cancer. We are, at times, we are the oncologists. This is oncology. Do the oncologists not offer treatment to untreatable cancer? Yes, they do. So you could look at it in that way and say, look, all these patients are coming to me, they're in their 60s, 70s with horrendous disease, they're going to die from it. I might as well learn from it. And as long as we have a discussion with a patient, that's justifiable. But I don't want to go into that. I don't necessarily agree with that approach. And so what we've learned over time is, yes, you can do worse than the natural history of this disease. OK, so here's another case that I think should be done with flow diversion. This is a subarachnoid grade one. She was admitted. It's a youngish lady. Initial angiogram is up here. And it shows this segment is a little irregular of the subarachnoid carotid. But no aneurysms, nothing. We went through the whole angiogram. There's nothing, really. So a week later, she gets her surveillance NGO for vasospasm. And just to repeat, an NGO to see if we do find an aneurysm after all. And one of our juniors calls us saying, oh, OK, I'm ready to angioplasty. But I need some support. So we come over and we find this. Well, is this vasospasm? Definitely it is vasospasm. But how about this thing here? So the more you look at it, the more you realize this is a tiny little blister, dissecting blister aneurysm, with some reactive spasm just proximal to it. So if you angioplasty this, we all can imagine what would happen. So at this point, we backed out. And she was doing well. And we did a planned overnight loading with aspirin and Plavix and then put a pipeline. In fact, we had to do two devices. But that had nothing to do with our plan. It just had to do with not having the available. And that's another thing. You have to have the appropriate size devices. Because if you don't have them, you can get burned in many different ways. And unfortunately, speaking of pipeline all the time, there's a limitation as to how many the reps can bring you. And so you get burned if you don't have a big selection of sizes that you can choose from. And that's what happened here. We had to put a second one. Because the one that we had was too long. It came down to the proximal distal cavernous segment where it was undersized. So now we had to put a second one that was also oversized. Bottom line is she did well. And we have done maybe six or seven of these over the past five years. And knock on wood, so far, all of them have done great. And this is one case where even in the posterior circulation, I have done one. And even there, so I don't think posterior circulation, even though, of course, it's not FDA approved, the posterior circulation is not an absolute contraindication here. You can use it. But you have to be judicious. And you have to understand what you're using for, and why, and how. So here's a very difficult aneurysm. She was sent to us from Atlanta, from Emory, five years ago. She was recently symptomatic in her late 50s. Lovely woman, recent headaches. Initially was managed with some pain medications. Bottom line is that she was found to have this aneurysm. And as it turns out, the aneurysm incorporates the choroidal artery, which comes off its dome, which I was told many years ago by several people that that can never happen. Well, I can tell you that it can happen. And so this is the end result of immediate post-procedure. So you can see, this is what we consider flow diversion. So you don't put one device and then get out of the procedure and say, OK, well, in six months, if it's not completely closed, then we'll come back, because I don't think that should be the goal. I think the goal should be give it your best shot, because we're talking about somebody's life. And so the question is, are we too aggressive? I would say we are very conservative. In this case, being aggressive, in my interpretation, is being conservative. Conservative meaning, I don't want to do four procedures on this person. I want to do one procedure, and I want that to take care of the whole problem. And if you look at this picture, this I took from somebody's case that was shown me. This patient came for a Gamma Knife treatment at NYU, sent from another institution with the label of, oh, this is a super complex dural fistula, very, very complex fistula, all over the place, everywhere. And they did all this, and it was occluded several times. But another fistula just came up again, and we need gamma knife. So when you go back, there's 10 disks associated with the case. When you go back to the first angiogram, it's a single hole, the simplest run of the mill, single hole transfer sigmoid dural fistula that you can just coil down the sinus, be done, walk away, and it will never come back. However, Onyx was new at that time. And the operator, even I remember showing it in a, he showed it in a EMBO club meeting. Look how cool it is. The Onyx goes here and there, and you can see all the branches, and it's just mesmerizing. And well, the only place the Onyx didn't go, and it's nothing against Onyx. You have to know what you're doing, understand the anatomy and the pathophysiology, have a plan, and execute it, just like in surgery. The only place the glue didn't go is the fistula and the vein. It can never be occluded, so I don't want to belabor it. I think this is too aggressive. I think taking the sinus, even though it sounds like a very aggressive move, that's a conservative move. So this is the choroidal aneurysm outcome. Perfect. This is a year later. The choroidal, interestingly, is reconstituted from medial lenticular striates from the ACA. And you know, I don't know. Anyways, she's fine, never had any problem. And this was the aneurysm, and now it's gone. I'm sorry, it's a little dark, especially dark in this light. But the mass is gone. And I always like to do, after the follow-up angiogram, I just stick them in the CAT scan and get a transaxial imaging showing that the mass is going away. Because you hear about these cases, oh, I did this aneurysm, and it was great, angiographically occluded, but it kept growing. Well, I'll show you a case about that as well. But that's our hypothesis as to why it's happening. There's such a thing as adequate flow diversion and inadequate flow diversion. I'm not saying we know the answer at NYU better than anybody else what the right amount of flow diversion is for an individual aneurysm. But I think you need to think about that and discover it for yourself where you feel comfortable with this technology. And again, another case, large symptomatic cavernous. Here it is on AMR. Crazy aggressive with, I think, four devices, crazy aggressive treatment, or three devices. And here, the aneurysm is gone at one year and five years. It stays gone. Here's another case, the same thing. I don't want to belabor the point. So let's talk a little bit about technique. So fundamentally, I'm sure most of you, if not all, have been involved in pipeline cases. Essentially, it's a quirky device. And the good news is this part, the distal capture coil is going away. They're coming out with a new thing called pipeline flex. And it's going to be better in that sense. There's going to be other issues related to that. But everybody will have to figure that out. We don't know enough about it yet. But the bottom line is that there's this capture coil under which the distal part of the device is tucked like this. And it's kind of a corkscrew thing. So you can unwind it and let the device deploy open. Unfortunately, the opening may or may not happen spontaneously. And my or our observation is that the more tortuous the anatomy and the larger the device, the more difficult it is to pop the device off distally from under the capture coil. Now, as you're pushing the device out, a good rule of thumb is to center the microcatheter in the center of the vessel and have this wine glass appearance. We push the wire most of the time. And I'll show you a case. Push the wire, and it will deliver the microcatheter backward. And you need to see that this wine glass appearance, like the curtain, is falling down like this. It keeps the same appearance. If you have this appearance, that means you're pushing too hard. You have too much load on the microcatheter and pushing the wire. And you're ready to intersuscept the device. If you have this look, this means that you don't have enough forward tension. You can see the microcatheter is not loaded. And it's taking the shortest possible route. And so the same amount of push on the wire will translate into more backward movement of the microcatheter, resulting in stretching of the device. Because the device, think about it as a spring. It's a spring that is put inside the small lumen microcatheter. And it's stretched out to 2, 2 and 1 half times its intended length. So in order to deploy it in a stable fashion, you have to push it out primarily so that you can't, how should I say, you release the spring and release the energy in the spring in the process of deployment, rather than deploying it like this, stretched, and be surprised two weeks later that you have a migration. This is not migration. If you put a spring stretched out like this, I guarantee it's going to jump forward. It's going to want to take its intended length. And it will, over time, just do that. So as I said, it's a difficult device to use. And I'm going to show you a couple of cases. This is a very difficult case, a giant symptomatic aneurysm with terrible trigeminal neuralgia. She's been on morphine and unit for a couple of years. And she continues to have pain on a daily basis. She has had an ACOM clip in the past. And so this is the pre. Let's see how the movies are going to play. This is what it looks like on live subtraction run before. So it's already stagnant on its own. It looks like maybe you already have a pipeline in there or some other flow diverter, but you don't. Now, of course, she has a tonsillar loop here on the carotid artery. So as I mentioned earlier, this is very, very important to have a strategy of the approach. Many times, you can get away with just, let's say, a six French envoy and a microcatheter and just deploy the devices like that. This is not one of those situations where you want to risk it, because you exert a lot of effort in getting where you need to get just to find out that you can deploy the device. You have to pull everything out or exchange and upsize everything. That's not the best strategy. So here, in this case, I think we went with a seven French shuttle. But these days, we would go with a six French Neuromax, for example. And then we put an avian or whatever you want, but an intermediate catheter. Up as high as you can, and then you can start attacking the aneurysm. Now, crossing this is not that easy. Of course, this is just an example of you have to meticulously take measurements. And if you see these individual measurements, we have a Siemens system. The measurements are very different from the 3D and from the 2D. And so I find that the more you measure, the more confused you get. So you have to decide on your particular system which number you believe. And in traveling around, I have observed that Philips is better about you can more reliably measure on a 3D. In Siemens, it's less predictable. So what we usually do is we do, before being ready to deploy the devices, we have an angiographic run where you have the guide catheter in the picture. Let's say it's a five-inch Navian. You know that the outside diameter of the distal marker is 1.68. Then you come sit down at the control panel, and you measure on the unsubtracted, measure how much that catheter measures. If it measures 1.7 or something like that, you know you can trust the measurements that you take on the other things. You can calibrate also, whatever you want. But I think, at least when you begin independently doing this, my recommendation would be to spend a lot of time. Don't try to save time by just looking at a CTA from before and decide on the CTA, because that's the most exact way of looking at it. It's not. Just based on the CTA source images that I'm going to use this in this device. That's not going to work. Anyway, so crossing this aneurysm is not exactly an easy task. And this is where having a person like Dr. Nelson around all the time comes handy, because he can do these things with impunity. I would not recommend it on a routine basis, but this is one of the techniques that you can do, the loop-to-loop thing, and then just engage. Then you bring your microcatheter just into this inflow area. Then you take this wire back, take a softer wire, gain distal access. Once you gain distal access, then you can start thinking about reducing that loop, that extra loop that you have in there. And the way to do that, essentially what you do is we have the wire here. Let me stop this. How are you doing on time? How many minutes I have? You're getting towards the end of your time. OK, good. I'll go through this case, and that's going to be it. I think it should be sufficient. So essentially, reduce the loop and establish yourself so that the catheter is now going through like this, as opposed to like this. And then you start deploying your devices. As I said, you can get in trouble in many different ways. And so let me just show you a couple of things that can and will happen to you during this, if you use pipeline. So one of the frequent things that happen is, and I don't want to talk about torsion and kink, because it's just going to take too much time. But look at this. So you have your distal wire here, the capture coil here. The stent is starting here, and it ends somewhere down here. We're pushing. We're all loaded. We're pushing the device, and it's starting to cigar, but it's not popping out. What is the point where you want to start torquing? You can torque only a certain amount of time. So the bottom line is that sometimes it just doesn't come off. When it comes off here, you have to anticipate, as it opens up, you'll see in a second, watch the distal end of the stent. As it opens, of course, it's going to jump back to somewhere here, because all this is stretched. Even though you're pushing, it's still stretched. So as it pops off, if it does, OK, anyways, it pops off ultimately, and you'll see that it jumped back. Now what happens if you can't pop it off? I'll show you in the end, in a minute. Then you continue the deployment. In a corner, you start seeing this kind of a picture. You have to be careful and be able to differentiate, is it just being collapsed because it's being pushed into a corner with a lot of force, or is it being, you know, torsion is developing? Essentially, as long as you see two somewhat parallel lines in one projection that stay parallel and never cross each other, it's not a torsion, obviously. But sometimes it's difficult to tell. Here, what you do is you just judiciously, you have to carefully balance between the pushing and the unsheathing forces so that you need to paint it into this corner, but not too much force so that it gets into a torsion or into a susception. So let's go to the, sometimes this happens. You're putting down a third device here, and you'll see that it is fully opened here. It popped off, but it's constrained because it's in this corner. It's constrained by the struts of the previous device. So what you do is you deploy this thing, and then as you cross back with a microcatheter, then you move it back and forth with a microcatheter and the wire inside, pop it open somewhat more, and then go on with your case. In the end, we like to do this most of the time, not always, but most of the time, what we call the wire post-processing. That is because you want to make sure when you're done with the case, you want to make sure that you're, since it's very difficult to see the individual struts of this device, you want to make sure you have a continuous good lumen without stuff, you know, pooching in in the middle. And also you want to make sure that it's opposed to the vessel wall, and you also want to make sure your construct is solid enough, because if you break it apart by, you know, minimal manipulation, you might as well find it out now and fix it rather than have the patient come back with a broken construct. And this is how we do that. And I'm going to be done in about a minute and a half. So you form a J, usually we use the transcend wire, and the reason I'm pointing it out is the synchro doesn't do this for some reason. It's very difficult to make it loop, at least for me. And then we go back and forth through the entire construct. I don't know if this movie is playing, but you get the idea. It's not playing. Yes, it is playing. And just to make sure that we're completely open everywhere. And finally, I'm going to show you this. So what happens, and that is a fear of people that I see when I proctor is, oh my God, it doesn't pop off distally, what do I do? Nine out of 10 cases, you can go through the deployment with the device not popping off, then come back with a microcatheter and just pop it off with a microcatheter from inside. Can you get in trouble with that? Yes, you can. So the one thing is this device is not resheathable, but it's retrievable until 90% of it is out. You can just pull this distal capture coil back into it, cork it and pull out. Now, obviously you can't pull it back if it's not popped off. So then you may end up, if you can't pop it off, you may have to quickly go through the other groin, gain access, get a balloon in here and try to pry it open with a balloon. You can get, it can get very complicated, but most of the time it can be handled. So I think my time is up. I just want to point out that there's a beauty in what you do. And I think it doesn't matter what it is that you do. If you're a doctor or whatever you are, you have to be able to be proud. Look at what you did and say, wow, that's beautiful. I really like it. There's an aesthetic component to what you do. And I think it's worth time, worth the time to do your things meticulously and get beautiful pictures in there. You see the devices are all nicely aligned. They're all open to the vessel. They're all, you know, it's a very solid construct. It looks great. There's no way there's going to be an endoleak. It's not going to fall apart. The aneurysm is not coming back. And I think it's very important to have, you know, just consistently have the time and the drive to look at the end result. And it's difficult to sit down in the end and tell the fellows, don't pull out yet. Let's look at the things. Look at all the things. Is there something going on in the brain? You may have missed the tiny little nick in one of the arteries that you did during the exchange. And there's a Sylvian hematoma that's brewing very slowly over time. So you have to look at everything. And you have to be, you know, I'm not going to go through this. That's all the time I think I have. Thank you.

flow diversion

pipeline device

aneurysms

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successful outcomes