Interventional neurologist Johanna T. Fifi, MD, reviews the use of embolization to cure arteriovenous malformations (AVMs) in the brain, a controversial topic in the field of neurointerventional surgery. Dr. Fifi presents various cases to support the approach and discusses how advances in techniques and technology, as well as novel scoring metrics, make embolization a viable option for curing AVMs.
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Introduction of current treatment options for AVMs History of embolization for cure of AVMs in the brain and recent supporting evidence Review of techniques and devices for curative embolization for AVMs Case examples Conclusions Mhm. Introduction side, give me just a minute, just a second, just activating the live stream. There we go next. We're gonna hear from Dr Fifi, there's somebody that everybody here knows very well but I think worth mentioning her pedigree just so you can see how much she's doing. Um She is associate professor of neurosurgery, neurology and radiology. She is associate director of the cerebrovascular Center. She has become co director of the pediatric super vascular disorders program. She's site director at Mount Sinai West for cerebrovascular services and co director of the fellowship. She got her medical degree from Bu did her residency in neurology at thomas jefferson And then accomplished multiple fellowships in vascular neurology and then three fellowships fellowships in their endovascular surgery. Including a pediatrics fellowship with Dr Berenstein and today we have the opportunity to hear about a very controversial topic that is becoming increasingly less controversial as new techniques and and new tools are developed. So dr V. V. Looking forward to hearing your presentation. Thank you chris for that invitation. I'm glad that there were no funny photos shown. Um Let me share my screen. Mhm. Is that that seems to be the that was good. It looks good. Um So yeah I'm gonna be talking about baby mm mobilization for cure as uh as we've heard this is a controversial topic and and chris uh dr Keller has contributed to the controversy by uh having a chapter in the humans neurosurgery about this topic. Um And uh some of the some of the slides there from that chapter as well. Um Me through here, yep. So these are my disclosures that are directly related to this. So multiple options exist for the treatment of brain a. VMS. We all know surgery, radiosurgery, embolization and of course uh embolism observation. Um embolization is traditionally has been used as a adjunct um to surgery. Um but it's it's more and more um I don't know if extremely prevalent but in in certain centers in certain parts of the world use it use more for the complete treatment of a VMS. It has of course become uh standard treatment for some of our other arteriovenous type of malformations such as durability officials um and vein of Galen malformations. Um The rates of procedural and peri procedural complications must be weighed against the natural history. So we often quote 2 to 3% annual risk of rupture for unruptured A BMS and then about 4.5% for ruptured A BMS. And importantly for ruptured a BMS. Most of that risk is in the first year, after a hemorrhage, 15.8% is commonly quoted risk after the first structure in the first year. Um And past studies looking at no treatment versus medical management such as Aruba have have produced a lot of controversy but new technology and techniques have been developed since these studies and at this point the type of intervention is tailored tailored to the specific a VM after discussion um by ideally by a multidisciplinary team such as what, how we do it at uh what we have at Sinai. Um So the history of embolization for cure has a is pretty long. This was a paper um published it uh by the group at N. Y. U. Which dr Bernstein was a part of in 1995. And um these were 14 deep central a. Bms of the thalamus and basal ganglia. So non operative and uh they saw a 15 complete percent complete obliteration by endovascular therapy alone. So fairly low. Um But this is a case example of the type of A B. M. That um even back then with the technology that was available was able to be cured. So um very compact notice um micro catheter in those days less trackable, but micro catheter placed in a deep feeder and then injection of glue leading to complete obliteration. Um a recent uh systematic review was published um looking at multiple articles uh talking about a VM embolization for cure. And they looked at in total of 598 Brain Navi ems treated with curative intent. And what they found was a 58.3% complete obliteration rate With a 13.6% procedural complication rate In a 24% clinical complication rate. Um what they did note was that more than there was a more than 90% complete obliteration rate and carefully selected patients. So um while overall the technique is not applicable to every a VM. These these two articles um Using liquid anabolic onyx um published uh this one in 2012 where they focused on small or medium sized superficial A. VMS. Um they're able to achieve a complete obliteration more than 90% of the time. So it really is a question of patient selection. Um And then in this article uh they you know this group in Chicago, they came up with a score um The arteriovenous malformation m broke your score A. V. Mes and uh with the idea that this would help choose patients for which intent to cure with with globalization would be um valid um and successful. So they looked at 39 patients retrospectively. It was validated on the same cohorts. So not ideal. But the score consists of the size of the A. V. M. Nine itis. You can see it divided into the traditional sizes here and then the number of particles um contributes to the score. Um The points are shown on the very right. Uh so and then the draining veins number of draining veins 123 giving the lowest and more than six giving the highest score. And then also including vascular eloquence um as part of the score. So and using the score um applied to those patients they could they showed that um with the lowest score um a vi mes of three. Um They're able to achieve complete obliteration 100% of the time. And then this falls Um as the score goes to 45 and then um very low um once the score is greater than five. Um and then the you know the opposite kind of for the complications um complete cure with no complications in the sky. AVMs. With a score of three and then low percentage of care with high complication rate of 30%. Uh With score greater than five. So this seems to be a useful tool to try to choose patients in which we should be using this technique. Um I'm gonna go on to show some of the the techniques of that have been developed and are still under development for curative embolization for for a VM. Um So the standard technique for a VM embolization has been trans arterial uh symbolic injection. And you can do this using a micro catheter. And then more recently with the development of dual lumen balloons. Um This is more easily achieved. Um There's a technique that's uh sort of a very advanced transfer material technique called multi plug flow control. Um And that this picture is kind of showing it here where you place multiple catheters all at once into the arterial feeders and do simultaneous symbolic injections. Um And I'll show their paper um in a couple of slides and then the trans venus techniques. So this is going back into the vein uh And then trying to retrograde lee um retrograde lee penetrate into the night as that's uh um Another technique that I will show in a case example of, and then um what's recently been published is something called a pressure cooker. Which is basically a way to to force the symbolic aging backwards. So before I show those techniques, I'm just going to talk briefly about the devices because that's really um been a a big advance advancement and really allowed um allowed us to to really uh use these techniques. Um The technology that that's advanced that's coming out um every year is you know, for stroke. It's it's been very, I'm good and it's transformed the field and probably will do the same for a VMS. So the detachable tipped catheter was something that came out um uh several years ago now but has been very helpful. Um and then the dual lumen balloon catheter has been very useful And of course symbolic agents have advanced and continued to advance um as uh as as time goes on in the United States, we really only have two on the market right now, but there's multiple agents that are used around the world. Um This was a slide from another conference but the, the Apollo um onyx delivery micro catheter was developed to be detachable so you can see what it looks like on the table. Um but what you, what you see here in the detail is that it's a single woman and hold micro catheter. So it's the onyx comes out here. And then this, the very tip of it is held by friction onto the body of it. Um That detachable tip varies in length. Um We have 1.5 or three centimeters attachable tips In the United States in Europe. They actually have a six cm on the market. Um But basically once you inject the m bolic material and uh and sometimes and if you leave the catheter there long enough the tip of the catheter will become essentially glued into the, glued into the uh cast right here. And so the the once it is glued in um is sometimes you can trap the micro catheters. So with this kind of detachable tip, you you simply pull back and once it reaches passes the force necessary necessary to hold it here, it will detach and you can remove the entire thing. Um So this comes, this stays in the patient and this part of it will will come out. Um So that that allows you to do more prolonged injections with the anabolic agent. The dual lumen balloon catheter has also been a big advance. uh this is a illustration of the newest one Um that actually we started using um I believe last year. So it's really only been on the market for a short period of time. The distal tip. The the reason why this took a long time to make is that the distal tip is 1.6 French. So very very small. And despite having a balloon on it, it's very navigable. Uh so you can advance this into vessels and I'll show some examples uh inflate the balloon and therefore allow all of the symbolic agent to go forward into um the knights of the A. V. M. Without coming back and causing reflux. Um this this balloon in the mini balloon that we have is nine in length and it's about two in diameter. And then anabolic agents we have, like I mentioned NBC A which is uh acrylic. It's like similar to Krazy glue. Um We have onyx which is a co polymer of ethylene and vinyl alcohol. Um It's in a it's a in a solvent and it problem arises it when you inject it into the body. Um This agent called fill, which we're currently using here at Sinai in a trial is essentially the same agent, but it's uh slightly in a different solution. Um and then there's others that are are also in trials in the US and not yet FDA proof but used in other countries. I'm not going to go into too much detail. Um This was the first report that showed of onyx embolization via a dual lumen balloon catheter. Um and that we did this in a in a mandibular a Vm. So uh not not in the brain but um close and you can see here um extensive a Vm in the mandible um a balloon in the uh balloon catheter in the in the artery here with the balloon inflated. And then um with the balloon inflated the ability to penetrate deeply and um into the vein of the A. V. M. Um and fill in the venus pouches and the bone. Um So the that is one technique that is still currently in use. And with the new mini catheters, I think that it's going to be be a significant advancement in our ability to secure a VMS with this technique. Um And then this technique uh without the balloon catheter. Um You know the the this group in Turkey has been doing curative a VM. And realizations for quite some time. And they published um a report looking at 350 patients and basically similar numbers to before showing 51% complete obliteration, one mortality uh And then on delayed follow up angiograms of the patients that had been completely obliterated. Two out of the of 100 and 78 had some small Um recruitment so they thought they were cured. Um but they had small residual or or recruitment on the on the delayed angiograms. It was a small number um less than 1% or about 1%. Um And that group when they moved on to using like I said this multi plug flow control technique. And I just wanted to show um it in bigger detail. It's it's it is a very complicated technique. So this is uh and A. VM. Here uh that they use this with its being on this picture. You see the A. V. M. Has feeders from multiple middle cerebral artery branches. And then over here poster cerebral artery branches. This picture shows I believe that they use you know I can't remember but it looks like at least four micro catheters going into the multiple feeders. And then the reason why you're you're doing that is that um in this kind of of A B. M. If you start injecting into the night as um you may go through the nineties and then end up into normal um normal uh proximal branches. So in having micro catheters in each of the feeders you don't go through the nineties and back into another uh feeder and into normal branches. So uh you have injections of of the m bolic material in this case onyx occurring from multiple branches simultaneously or in turn but um going you know from one to the other until you make sure that the entire night this is completely filled. And this is uh this is the case that they reported. Um We have not used really this technique here and then the trans venous techniques um You know there's been this is kind of the um I guess recent kind of advancement that's becoming more and more um popular as a way to completely cure an A. B. M. There's still there's still and there is controversy. And um and the rates of complications are were significantly higher in the beginning now coming down. But at any rate um the in the reports in the literature uh this group actually uh did a review of the articles that had been published up to that period of time um which was about three years ago. And so um the first report of this technique was actually quite a while ago in 1999. But not much was this was using coils which we don't really do anything more to completely obliterate trans venous lee. Um This is because as you might imagine you you should try to um actually get uh uh the night is closed and it's very difficult to do that with with coils. Um And then the technique advanced using Onix and then uh squid. So these are liquid and bollocks like I was describing. And then recently the technique is has evolved in to really involve um combination of quills, onyx um and different catheters. Uh so in this review there it was small number 68 Patients but 63 out of 68 had complete obliteration and about 4.3% complication rate. Um And to speak a little bit more about the techniques. So this group developed um something called a pressure cooker technique for brain a VMS in that is basically um where you uh you you go trans venus li uh into the vein of an A. V. M. So that the catheter is the two catheters are in this vein here and then you create a plug um using coils and sometimes using glue uh to prevent um as you inject the symbolic material to prevent it from coming back at you because of course the flow of the A. V. M. Is backwards along the catheter. Um So you coil off the vein first which um is obviously a when you're operating or at any other time, you would not want to coil off the vein of an A. B. M. First. So you when you do this technique you're doing it with the absolute um need to cure the A. V. M. Um after you do that. And so uh you you close off the vein. This prevents the symbolic material from coming back at you and then you inject the symbolic material, retrograde lee through the night. This until you fill the entire night as without getting into normal brain tissue. Um Mhm. They recently published there There um results using this over a period of I think the last seven years or so. Um and so they published 51 patients um most were Spetzler Martin 3-5. Um they were deep seated 60% of the time. 33% had prior trans arterial treatment um which is sometimes necessary necessary to do this technique. and uh but 96% went on with With the one session um to be completely cured. The one trans venous session to be completely cured. There's a 6% rate of intracranial hemorrhage no deaths and one permanent significant morbidity. So it's a promising technique I think the importance and and um the risk of using this technique is that uh you have to basically um basically completely get rid of the nitrous. Uh So it's a very technically challenging um kind of procedure to do. But you have to once you start this you have to completely get rid of the notice um in that treatment. Um So I think I'm going to show some case examples just because it's these are kind of abstract concepts without looking at a couple of cases. Um uh And uh I don't know if anyone has any questions right now. I should just go show the cases and we can do the questions at the end. I think going forward with the cases You know and just give you a sense of time about 10 minutes including questions. Okay I'll try to show quick cases. So yeah this is a patient 56 year old man who presented with unruptured A. B. M. He Had it discovered because of increased my migraines after COVID. So this was actually discovered in 2020. This is uh the angiogram showing it's a a frontal medial frontal A. Bm. With one really one ah real cedar. And then this is the navigation of a scepter. So the balloon catheter coming up into that major feeder to the A. V. M. Um And here the injection right before that navigation from a little bit more approximately showing uh the feeder then itis. And then um you know in any avm embolization you wanna know exactly where the vein begins and where it's going. So this is after um the the initial embolization the balloon is inflated. The onyx went forward. It went through the night. It's and it has filled the vein. So uh once you're feeling the vein you had like I said you have to go for complete cure. Um importantly it's just uh showing this as a teaching point there's some nitrous left. So you checked during the procedure. Is there are you done? Is there still notice if you see something that looks like night is you should keep going because that could bleed once you're if you were to leave this there. Um So in injecting more of the um onyx through the through the balloon catheter, onyx is traveling through the night it's and then eventually filled in that section. Uh And so once you see that you can do your angiogram and if you don't see anything that looks like nice anymore you're done. So this this patient had um uh complete obliteration of that A. VM. He actually recently had his uh one year follow up and it's it looks great. Um and then another example this is a 31 year old man who presented with hemorrhage. He did have a session of trans arterial embolization for an acceptable A. VM. And then he he returned for trans venus. Um So this is a left vertebral artery injection. Left uh pc a feeder to the occipital A. VM. Here you see it's a very compact notice. One draining vein. Um So the ambo school care scare score would be low. Um And that is uh there was glue already in one of the feeders. This is the remaining feeder. Um This is again navigation of a catheter balloon catheter up into the feeder. Um And uh you can see from the selective injection compact notice straight into the vein. Um This was one of our first trans venous um avian brain a VM cases. So we did a a french guiding catheter in the superior sagittal sinus um The detachable tipped catheter um into the deep into the draining vein. And then another catheter um ready to put coils if necessary. Um And then here's trans arterial onyx injection. And there was still some nitrous filling to towards the vein. It's a little hard to see here but this was thought to be some night is here. So then injected onyx retrograde lee through the trans venous catheter. And that's you can see it filling in and then finally it filled downward and into the night. This um and then that's the final cast. And that's the uh angiogram after. And he also had. This was a few years ago. He also had follow up angiograms that showed um uh permanent or long lasting obliteration. Um And quickly this is 22 month old we recently treated. So this is the last stage treatment after trans arterial sessions for vein of Galen Malformation. Um And this is the initial uh angiogram showing the vein of Galen malformation After five trans arterial sessions at 22 months. This is the glue that's there from the trans material sessions and this case may be a little bit complicated but we can maybe show it in in detail um at another time since we're running short. But after multiple sessions of trans virtually you see how the vein has become very small. Um So we can basically shrink with trans arterial sessions. This sort of vein into this sort of vein and then this sort of vein becomes amenable for a trans venous uh last session to cure the A. P. M. Um and here is our eight French catheter being navigated up and this time placing it into the fall scene sinus which drains vein of Galen malformation. And uh after that is placed um having a micro catheter in one of the feeders, looking at the residual and the and the venus catheter here in this technique um pressure cooker. We place a detachable tipped catheter that you're going to inject onyx in first. Or actually this is uh mm hmm. Um Yeah you can place it first or second but the second Catherine you places one that you're gonna put coils with. And so there's two catheters through there. Um This is a coil mass being formed. This is acting as a backstop for any liquid anabolic that your again you're going to try to inject retrograde lee. That's the coil mass. And then looking now from an ap projection. That's the coils that have been placed. The coiling catheter is gone. And uh you have um onyx being injected to fill in that coil mass and create the backstop. And once that backstop has been created, what you can what you then see is as you continue to inject onyx you then see retrograde traveling of the symbolic materials through the night. This um and then uh towards the in this case it was going towards the micro catheter that was in the arterial side. Um at the end this is the onyx cast. And uh and you can see that the A. V. M. Is obliterated. This was a procedure we did a couple of months ago. Um and the patient will come back so I'm gonna stop there in the interest of time. Those were kind of quick. Um So um you know techniques have advanced and we have this new score that will help us uh choose patients. I think it's not just the score but expert consensus by multiple by multiple. Multidisciplinary culinary team is very important. And and this knowledge and ability to do this is rapidly advancing. Yes. I don't think that it's it's fantastic work. I don't think there's time to do justice for questions. So, Um it needs to be discussed, but I don't think there's time at 9:00. Maybe we can come back to this issue and you can do recap or something. Sure. Yeah, we can do some of the cases in detail. That would be great. Thank you very much. Thank you. Yeah. Thank you, Joanna. Okay, we'll stop here.