Thank you. Well thank you very much it’s a pleasure to be here with the Canon family. We feel we are part of a family, maybe distant cousins sort of because we are in academics, but I can tell you I put this slide up. On average somewhere between 75 to 100 times a year, with a different title of course, but you can see up there is the Canon Stroke and Vascular Research Center, which we are very proud of in Buffalo where we have really been partnership with our friends and colleagues from Canon for a long period of time and what I am able to show you today is some of the work that we have been able to perform on a clinically approved new detector system for x-ray systems for neuro intervention.
So a little sort of introduction. I am a neurosurgeon. I do both open surgery for vascular diseases, brain aneurysms, arteriovenous malformations, as well as interventional therapy for these same diseases, whether with coiling and other endovascular techniques and so for the longest period of time till about the early 70’s aneurysms and AVM’s were not treated. The reason for that was this was how neurosurgery was performed. It was performed with loops with a headlight. This is not me as you can hopefully tell, but this was with poor magnification, two to three times whatever was the natural sort of visualization with the eye and with some external light that was of varying quality and this was the way treatment for aneurysms and AVM’s was considered and so when it was considered using these tools with the same hands it was better to let the patient survive with bedrest. That was the treatment and then microsurgery came about in the late 60’s to early 70’s and that allowed you visualization of aneurysm, such as these four examples on the screen under 20-25 fold magnification. So the surgeons were able to actually see what they were doing and therefore preserve critical functions and preserve critical structures. When you think about what we do on the endovascular realm, the interventional realm, I think our problem is that we continue to currently have challenges using traditional detectors. The devices that we are using, most blood vessels in the brain are under 3 millimeters in size. The largest ones are about 3 millimeters and so when you are trying to manipulate devices 150 centimeters away from where your hands are around a varied, complex anatomy with tortuosity, critical structures, fragility, it’s really hard to see through that skull and visualize everything you need to see. So maybe we thought that we could have higher resolution imaging, which would be one of the things that really, we partnered with Canon very early on over a 10 15 period, years period of time and finally we got a commercial system which really does solve this problem to a large extent. So this allows for better precision during treatment.
So the next detector that I want to talk to you about is this high def detector. It’s gone through a lot of different names, high def is pretty cool a name. It could be better, but it could be worse. I think the advantages that we have the flat panel detector system, which has become ubiquitous and it does have the low dose frequency. So let me tell you those loops that I just made fun of I start every cranial case with those loops because I don’t need to see micro resolution when I am opening the skull or opening the skin. I really just need that when I go into the brain. The same way when you are starting an endovascular procedure, you are doing the femoral, you are going up the aorta, you are trying to select off the arch, you don’t need high definition. So the ability to go seamlessly from a flat panel to a high def detector really has a lot of value and then the zooms that occur from the standard flat panel to high def are also seamless. You can just switch through with the touch of a button and easily go back and forth and there’s no time lost when we are doing this. So here’s an example. This is part of the work that was being done when we got the system prior to its approval in the lab and you can see it’s a phantom skull. This is not one of my patients, with all these different contraptions, the same person with malposition stent. This is just a phantom and you can see multiple devices, which are positioned in there. On the left side of the screen visualize using flat panel detector. On the right side of the screen visualize using the high def detector. You can see how much better resolution you have of looking at these devices.
So there’s the same skull. Now there’s a 3-D model printed inside the skull. So what you see there is a guide catheter in that carotid artery and then you see a carotid artery with some branches and then you see an aneurysm with some contrast sitting in there and what you might not recognize is that there’s an actual stent across that aneurysm neck. Now that’s 12 inch, now if you start going down the flat panel detector, a 10 inch gives you a little bit of magnification and you start seeing I think there is a stent there and then you got to an 8 inch screen and you say well there’s definitely a stent there and six inch, yeah I see it. It’s there. Okay this is the end of what flat panel detector would show you. This is what high def goes to. Starts off at 3 inch and you actually start seeing the structure of the device. Now what about the structure of the device, everything we use in the brain is symmetric. Meaning here’s the same device at 2.3 and here’s the device at 1.5 inch. This is the resolution at which I like to deploy this device now because there is no question in my mind what this device is doing. There is no question in my mind it is open or it’s not open or it’s torqued or it’s not torqued or it’s compressed or it’s elongated. All those things that the device does, which were impossible to see with conventional flat panel detectors become overly abundant here. The second thing is all neuro devices are symmetric. I said that a few seconds ago. What I mean by that is when you look at this device you can turn it around any which way and it looks the same. It looks the same, why? Because we have no ability to visualize an asymmetric device because we have had no ability to have a high def system for neuro devices before. Now that we have a system that allows us to visualize devices as well as high def, I bet you over the next 5 to 10 years we will start getting asymmetric devices because, guess what? The disease is asymmetric. There is a single aneurysm on one side of the blood vessel. Why do I need to treat the blood vessel for 4 centimeters on all sides, when the disease is just on one side over maybe a centimeter? So I think that is a big revolution that this technology is going to unleash just like the operative microscope did in the 70’s and 80’s.
So I will share some cases with you. This is a 31-year-old who had prior family history of a reruptured aneurysm, came in with new onset headache and we wanted to treat her with this device called flow diverter_________. There you can see the device as its’ pictured in this schematic. So this is an 8 inch flat panel detector. These are some standard runs and what you can appreciate and I don’t have a pointer here, is that there is an outpouching in the back wall of the carotid that I will show you in just a second when we go into high def. Also appreciate the branches, including the smallest branches that you see off this injection, which are called the perforators, which supply the base of the brain. Now we will start going into high def and this is now not a digital zoom, but an optical true magnification of image with equal resolution and so the small branches that were barely noticed now look like massive trunks and you can actually start appreciating this outpouching on the lateral. The right window where the aneurysm is and let’s see when we start deploying the device you can actually start seeing, you can see incredible detail of the device including the tiny 1/8000th of an inch diameter wire which is in the center of the device. You can see how the device is getting compressed, how it’s elongating, how it, how much zone you have left in terms of before you run out of the device and what it exactly does when you are recapturing it. So it allows for a faster deployment. You don’t need to take single flouro shots 20 times during a single deployment because you are going to actually see what you are doing as you do it.
Here’s the same procedure done under flouro and what I want you to show is the wall apposition between the device and the blood vessel, which is normally impossible to see. So normally with a flat panel detector what I need to do is after I am done with the procedure, I have to do a cone beam CT, which we call low contrast imaging or LCI to be able to visualize vessel wall apposition. I don’t do that when I am using the high def system because I can clearly see where I am apposed and where I am not. Here’s the final case after it’s done. Again, it’s very hard to even see the device with standard flat panel detector.
Here’s another young person who has multiple intercranial aneurysms and the plan here is to deploy this. Now this is an awake patient. The patient will be moving. Again, you can see flat panel detector. You can see multiple outpouchings from this woman’s blood vessels. She clearly has very fragile blood vessels and so here we are going to deploy and the patients coughs in between the procedure. Even with patient movement, even with a patient who is coughing, the resolution of the imaging is so good that there’s no question in my mind how the device is getting deployed. As you can see, we are recreating this very long architecture and you can see the kind of anatomy. Now you see my catheter is going back and forth. These are reflecting the movements that I am making with my hand to allow the device to push forward and backwards to get to, to get it to open up. Usually I could make those motions expecting that they might be something like that going on. Now I can actually see it and I think that’s quite remarkable when it comes to extra systems and there’s a device deployed and I am making sure what is open and again it really allows for optimal visualization. There again you can see how well I can see the vessel wall apposition and going back to our system with the regular flat panel detector I think you can overall see the brain but it doesn’t really give you the kind of detail to even be able to appreciate the devices.
Here’s, I think this might be another, this is a ruptured aneurysm case. So this patient presents with a subarachnoid hemorrhage and we see this large aneurysm which is there and this is being treated in a delayed fashion because she came to us after some period of time. Again, flat panel detector shows you that large globular aneurysm. You can see at the base of the carotid artery and now we are deploying a stent, which is of a different kind. This is the Elvis Blue stent and you will see how well you see those individual tines as this device comes out. You can see those helical structures which show you the device is opening up. Now they can be seen under flat panel detector as well, but the ability to really finely control the deployment of the device and to have the assurity that it is opening up the way you think it should really is unparalleled and I wanted to show you something that will happen during the course of this case. As the device is getting deployed it has elongated around this last turn and there you can see the edges of the stent are much more open distally than proximally. So when we go forward and we start deploying coils inside you will see the stent’s opened up a little bit better and now the coils are being placed inside the aneurysm and there you can see the coils kind of trying to escape. So we are going to try to adjust this and here you see the coils are being adjusted and as we do that the stent is gradually moving up and is really getting pushed back into much better place. Now these things would happen and after the case we would say oh my god I think the stent moved, but in this case because we can visualize the devices so much better it really helps us quite a bit and this is sort of the final result where you can see the final position of the stent struts is right where we would have wanted it at the angle, with the aneurysm well treated and when you compare that without flat panel detector you can see the value being able to see versus just imagine.
I think imagination is a great thing, except for when you are getting operated on. So 75-year-old comes in, last case, a subarachnoid hemorrhage and I just want to show you a different kind of technology from an endovascular standpoint. There is a ruptured aneurysm that’s the PCOM. You can see that piece of aneurysm which it jutting out with a little excrescence at its end, which marks where it’s ruptured. So what we are trying to do is really visualize exactly where the neck is and you can see the kind of detail with high def that’s just impossible to see with flat panel detector and here under roadmapping we are using a balloon to place across the neck of the aneurysm and then we are going to put some coils in and there you can see the coils are being positioned and when the coils, coiling is done you will see something that will happen that will cause us to change our strategy where we have deflated the balloon and that coil loop has herniated out. So we are positioning a stent right in the of the procedure and there’s calcium in the wall of the artery that I could not visualize under standard fluro and that’s why I am not nervous about the tines being less open proximally because I can see the artery is actually narrowed because of concentric calcium in this person, which is so much easier to visualize. You can actually visualize that very well by yourself under just naked flouro there and this is sort of the final result. You can again see when we do the angiogram you can see the stent is perfectly open that’s just how wide the vessel is, which you would be not able to see or do under flat panel detector and again there is the final result under flat panel detector.
So the big question that will come up which is intuitive is, well if you got better resolution you are probably using a higher dose and you are probably exposing these patients to greater amount of energy to derive these images. I mean that is sort of the standard way of thinking about this. The fact of the matter is there is another thing that has been incorporated by Canon, which is the dose tracking system, which is another one of the Buffalo contributions, which we are very proud of, which looked at actual dose contributions. So what you need to keep in mind is when you measure dose you are actually measuring the dose to the, for the whole case to the skin and so what happens with these high def system is that you are collimating much more aggressively than you normally do with flat panel detector. So overall the total amount of dose imparted to the patient actually declines because one you are collimating much more effectively. Second the duration of the procedure is smaller and so when you combine that we looked at our own cases, these are interventional all neuro related procedures that you can see that when you look at more than 2 Gy or more than 3 Gy under standard neuro interventional procedures we are at about 39% versus 18% for more than 3 Gy and compare that to our procedures with the high def system in place is a massive reduction in the total proportion of patients which acquire excessive dose.
So in closing I think high def, the way I think about it as a neurosurgeon is that it’s a microscope for angiography. I think that truly is the value, I am able to see so much better what I need to do and I think our field is going to evolve to catch up with this discovery of yours. I think it’s very fine tuned, it’s seamless. The workflow is very fluid. So it does not require some new machine coming on. The first system we had in Buffalo we had to bring in an extra detector in front of the old one and that was never going to fly and Canon taught us that’s not the way to do things. They built the one that we actually really do like and I think there is no dose penalty and the visualization is truly unsurpassed.
Thank you very much.