Transcript

- Hello and welcome. During the AANS meeting in Miami in April of 2012, we presented a 3D session regarding operative nuances for management of complex cranial cases. Doctors Robert Spetzler, Gary Steinberg, William Couldwell, and Michael Lawton were involved with the presentation. This three hour presentation was subsequently recorded and you will be watching one of the three parts in the following movie. Thanks for joining us.

- Hello, ladies and gentlemen. Welcome, my name is Aaron Cohen from Goodman Campbell Brain and Spine in Indiana University Department of Neurosurgery. We have a great set of cases for you today thanks to our expert panel. I'm gonna go ahead introduce them right away led by Dr. Robert Spetzler, Dr. Gary Steinberg and Michael Lawton. Doctor William Couldwell is going to join us shortly. I would also like to thank the AANS staff for really allowing us to put such a heavily technologically loaded presentation together. There's been much work that has gone to make this possible and I would like to mention Keith Davenport from AVMG as well as Walker Kean and many others who have really relentlessly work on this, including from Zeiss and other folks from True Vision. Let's just go ahead and move forward with our presentation here. The format is rather unique. We're gonna go ahead and talk about vascular lesions to start with, followed by cranial nerve compression, followed by tumors and then some of the MVDs for cranial nerve compression syndromes. We really have tried to put in more of the everyday cases. In other words, nothing that necessarily is a giant aneurysm although some of our colleagues really wanted to include that and we have tried to show some of those as minimal as possible. The goal is to really give you guys some of the nuances in a general cranial practice. Not necessarily a course about who can clip the more larger aneurysm or necessarily do a more difficult bypass. Each round will be about five cases followed up like five minutes of questions. We really have tried to make this interactive. You can see a set of phone number, is actual phone number underneath that image there and you can go ahead and text your questions. Our great moderators here, I should specially thank Dr. Brian Lee from USC and John Edwards from our own program who are gonna receive some of those texts and filter it for me. I'm gonna subsequently receive it on my iPad and then we're gonna try to answer every question. This is about you guys trying to participate and therefore we'll do our best to make that possible. So after five cases, five minutes of questions then we'll move on to the next rounds. Please don't forget texting your question. Again, 317-855-8209. And for those folks that have joined us from internet, wherever they are right now, I know a number of them are from overseas. I think we have over 40 people right now joining us. They can use the chat function underneath the video windows and they will be also be provided with some attention in order to have their questions answered. Teaching has been a important part of my practice and I think this is what all this course is about. This is not a by showing off who does a more difficult case, it's about how we can all do better. These are the typical cases that we'll consider challenging. Not necessarily bypass or a giant aneurysm, but something that we could be running to every day. Let's go ahead and start our first video. That's a nice animation and really pinpoints the advantage of 3D using graphics. We're gonna get back to that using another video very shortly. I think 3D has a special place in education and I hope with the presentation today we'll all be able to achieve some of the goals of stressing the importance of 3D although it's a laborious task to present those in a projector format. My cases, as a moderator, will open up each rounds. At least the first and the third round and then we'll finish the presentation with more of my cases if we have time. P1 aneurysm on the contralateral side. This is a patient that I will review briefly, has a ruptured aneurysm, a right PCOM aneurysm that was coiled, but also has smaller aneurysm, a left PCOM and the right P1. And I wanna tell you that without fixed brain retractors we can do a lot. And protecting the brain, microsurgery is all about protecting the brain. And if you can do the surgery without a retractor, in this case it's probably the farthest path you will do in skull base. You've moved from the left side, to the right P1 aneurysm. And if we can do that with our retractors, there may be a place and maybe I can convince you guys as some of the experts today, I'm sure Dr. Spetzler will point that out as well. We're gonna talk about some giant aneurysm insular tumor, and we're gonna also talk about other cases that are exciting. So let's talk about the first case that I briefly talked to you about. A 52 year old female with a previously ruptured right PCOM and a smaller left PCOM and a right P1 aneurysm. Here you can see the aneurysm. It's not that large, obviously. Can we go ahead please to our point? Chris, would you lead us to the PowerPoint please? So this is the aneurysm that you can see here. It's not very large, it's on the right P1, relatively proximal, probably has some perforators incorporated, may not be evident on a cerebral angiogram. And this is the PCOM aneurysm on the left side. This patient has had a previous subarachnoid hemorrhage, therefore smaller aneurysm need to be treated. And we'll go ahead and show an animation again in 3D talking about the corridor and I think this is another way for future neurosurgical education. Just go ahead and run the first animation, please. As you can see, this is starting from the right going to left. I think I'm gonna show the opposite from left to right, but as you can see we're gonna do that. Get between the carotid artery and the optic nerve, and be able to sort of look across between the two and move to the other side. So let's see if we can do this without retractors and see if that would help in any way. Obviously I'm showing my couple of videos, but later the experts are gonna show better videos and really show me how it's done, the right way. Let's go ahead and go to the video of the surgery. We start with a 3D of positioning. This is a left side of frontotemporal craniotomy. As you can see, at standard the head of the patient is really turned very little. Dr. Spetzler Robert, do you have any thoughts here, please?

- [Robert] I haven't done a contralateral P1 aneurysm. I think the angle is probably fortuitous. Absolutely no reason not to do it.

- Okay, well then if you haven't done it, I should have never done it either.

- [Robert] I would agree with that.

- Thank you. So I'm starting already at a bad stage with a case that should never have been done this way anyways. Well, hopefully I can do better next time. So let's go ahead and place the clip. You can see I'm taking a lot of time. This is a longer clip because if you put the clip closer, you're gonna find yourself in a very small hole and injuring the cranial nerves and really taking your time and enjoying that moment of closing the clip. We do all that difficult surgery to get there so when you really wanna enjoy the moment of closing the clip you've gotta take your time. Just, this is a 3D fluorescence using fluorescein using Yellow 560 and you can see you see the images through the oculars. We're gonna see a better example of it momentarily, that how this works. Here again is the PCOM aneurysm was clipped, quite a few number of clips and here is the fluorescein in 3D. The dura does stain and the surgeon has to remember that. So fluorescein has some advantages. ICG remains a very important part of vascular neurosurgery because it's cleaner. But again, if you wanna see through your oculars, that has certain advantages. Again, there's no perfect technique. ICG, fluorescein, they both have-- Let's go to the next-- Stop the videos and look, let's go to the PowerPoint. There's no perfect technique. We're trying the fluorescein and hopefully we can see how are the advantages. I think people at Barrow have tried it before the Yellow 560 was possible.

- [Doctor] Aaron, I think probably why you're talking about first thing I think part of the problem is that it escapes the blood vessel. It's much easier, it's a smaller molecule and it's electrogenic. So that used to be tried in the very old days and it really was abandoned because of the electrogenic risks.

- I think that's a great point, two points. So it's epileptogenic and it can extravasate outside.

- [Doctor] And yet, it's being used in thousands and thousands of patients for other reasons. Why that would be for us be more of a problem, I'm not really sure.

- All right. Our experience has been that because of the Yellow 560 sensitivity, the dose is very small, it's almost 25 milligram which is much, much smaller than we used it before. And we think that the dose is safer and it has not had any epileptogenic activity, at least the small number of patients we have done. But I think that's a very important point that should be kept in mind. This is the postoperative angiographic. And clipping this aneurysm was not the goal, it's very easy when you get there. It's a matter of how far can you go with no fixed retractors which Dr. Spetzler I'm sure is gonna elaborate more. I'm gonna show one more case and get out of their ways. And this is a 42 year-old female with history of progressive pulsatile headache. And this is her arteriovenous malformation. A 42 year old woman, the risk of hemorrhage is significant, but as you see this is a pretty formidable AVM. And I'm not showing this again because how big of an AVM you can remove, it's because you look at this AVM and immediately, first of all, you see that it goes deep to the ventricle, which is not surprising. That's what these AVMs do, 'cause the form from the ventricle early on, but look at just exuberant white matter deep feeders, which are the most intimidating part of neurosurgery at least for me. Because the bipolar doesn't work in them, the clips may not work very well and you just find yourself in an impossible situation. You guys agree with me on that?

- [Doctor] Yes.

- [Man] Yeah.

- So looking at this AVM, many people say this is an inoperable AVM. This Spetzler-Martin grade is relatively high and I would say if I presented to my colleagues, a good number of you guys say this is inoperable. Is that agreeable, or Gary what are your thoughts?

- [Gary] Well, nothing's inoperable. It depends on what risks and consequences you wanna take. I think, Chris go back to the MRI for a second. So it's fairly frontal, I think that it's non-dominant. I don't think that I would shy away from treating it. How did the patient present?

- Pulsatile, just a headache. So essentially asymptomatic.

- [Gary] And how old?

- 42.

- [Gary] I think I'd watch the patient, but if I was gonna treat the patient, if they were more symptomatic, I think I would consider an embolization and either a microsurgery or radio surgery.

- It makes good sense. Robert, could you please advise?

- [Robert] Yeah, I think this is an eminently treatable one. One of the things I would have actually shown this morning in my comments that got subterfuge by Pittsburgh, I suspect. I'm kidding. It's the target that the portion of the AVM, with stereotactic radiosurgery, right on the MRI scan, when you looked at it, the periventricular one, which gets rid of the deep venous drainage. The other thing is the trick that Dr. Morgan from Australia has shown us is that when you have an AVM like this the reason really those steep vessels are so difficult is because you have surrounded the AVM and you've compromise the venous outflow. Even if you haven't taken any of the major veins, you've still compromised the venous outflow. So one of the tricks is to go right down to the ventricle on the pathway that is most opportune, get rid of the deep venous portion of the AVM first and then come on up.

- Yeah, that makes a great sense. I've never thought about it. So what you're saying is, you go around, maybe in a couple of spots, you'd go deep all the way to the ventricle, disconnect and then move on further.

- [Robert] Yeah. First go to the ventricle because it keeps everything else intact on your venous drainage, get rid of the deep-- Because once you're in the ventricle, getting rid of the deep portion is not a difficult job. And that gets rid of those incredibly tough and gorged vessels that we normally see when we've done everything else and just end up at the last tail.

- I wish I had to listen to that advice. Well, we'll get to the video in a second. Michael, please.

- [Michael] Just one additional comment about patient selection. This is, I would say Spetzler-Martin Grade III AVMs so it's really on the border between an operative and maybe a conservatively managed AVM. But if you look at the supplementary grading scale, which we think is useful, which assigns points for age, diffuseness and whether or not the patient has bled. In this supplementary scale, it's a five. So you've got a grade 5 supplementary AVM, you got a grade 3 AVM and it really helps you sort out that. On this borderline grade 3 AVM, adding the supplementary scale, it really tips you maybe in favor of managing this conservatively.

- Okay. Thank you. Those are great pieces of advice. And in this case, the patient was very adamant, very knowledgeable person, felt surgery is her only option. Some of the families had complications from radiation previously. So we went ahead and proceeded with surgery. On this one as you can see, it has a very large venule. Don't wanna take that early on. We all know that. I wish I had the idea of going to the ventricle earlier on and keeping all the major draining veins intact. And this is a 2D image, but it's HDI squeezed just because I really felt, we were recording this in 3D and unfortunately this case was so long, the video eventually went corrupt. So would you mind going to 2D, please? And I'll let you guys rest your eyes a little bit. So this is the positioning for the patient, very standard and large craniotomy. So I put the pin behind the ear just because increases the working distance. These are all obvious things, we all know very well to have a large craniotomy. I used fluorescein here, again, just because it defines the margins for me better. I don't use fluorescein on every patient, but you will see momentarily that it has an advantage of defining the brain, which is a normal brain and away from the AVM. As you can see the brain very beautifully picks up the fluorescein and clears it, but the part that is AVM, just because of the steal phenomenon or the sick brain is not gonna keep it. I also get an idea about the flow rate within the veins. As you can see this vein lifted up or picked up the dye later and it was slow. So obviously the emphasized vessels are clearly have to be protected first. So whatever you can do to protect them, open the arachnoid membranes, going around the AVM. Having a good setup bipolar is as critical and I personally found that you need four or five set of bipolars that would help you in different situation in different ways. I think the best one in terms of its ability to control bleeding is really what designed by Dr. Spetzler because it just has the right size, it doesn't stick and it just for the AVM, is a lifesaver. However, if you are doing the areas where it's not that critical and you can really zip through, you may use another bipolar, Isocool. By the way, I have no financial interest in any of these, that could let you move along a little bit faster. We like using this by bipolar more than any other one. Using permanent clips for deep white matter feeders is the only life server experience that I can advise. And I'm gonna go ahead and ask our panel, this is not very deep. It's sort of getting close. Gary, starting with you, what to do with these white matter feeders.

- [Gary] So, these are a real challenge. I switched to using the Isocool's 'cause I thought they were better and they are than other irrigating bipolars. Then I learned about the Sundt Micro AVM Clips. These are clips that Sundt designed, made by CODMAN and they're very small and I use the three, four or five clips and those can save hours of time from the deep feeders and are very, very nice for occluding them. And the bipolars that the Spetzler-Martin, that Robert helped design, I think are better than the Isocool's. I have no conflicts with any of these, but I like the Spetzler-Malis and I'll use those for the difficult AVMs. I don't use them for the straightforward ones 'cause they're expensive. But luckily Robert's making some money from it so I like to support him.

- [Robert] Not enough and you both will receive a check in the mail for that. But actually I designed them specifically for AVMs. And there is a trick that you can do to enhance any bipolar's function and that is to get an ice beaker of water and have the bipolar sitting in them. Because the heat sink is very important to determine whether you're gonna have stickiness or not. And so it's not unusual that in an AVM like this here, I would actually use two bipolars, one that's sitting inside the ice beaker and the other one that I'm using and exchanging them constantly so you have cold bipolars, which is really critical for that. The other point with bipolars is you don't wanna use fine, sharp bipolars. You wanna use broad ones because you've got very thin wall vessel. You wanna have enough protein on it so that when you apply the current, it can coalesce and shrink to close up the vessel.

- [Man] That's a critical point, which I learned early on. You want one millimeter, 0.75 to one millimeter tip in general. 0.5s are actually too small for most of the tough AVMs.

- Michael, any thoughts there?

- [Michael] Yeah, just a couple of strategic points. I think that these, as you've all alluded to are very difficult to control and sometimes what you'd like to do is to save those battles with the deep perforators for the very end of the resection so that everything else has been dissected. If there is aggressive bleeding at the base, you can easily visualize it and quickly remove the AVM. So I think when you encounter those--

- Pause the video, please.

- [Michael] You can pause and work around to other areas before really tapping this at the end.

- It's gonna be hard with our live-streaming to go back. I wanted to show an important step here, but unfortunately-- So we did the first step of this operation and we were able to go around the AVM very well, but the brain started swelling and so at that point, we decided to do a second stage. I think it is foolish if the brain is swollen, you're doing a large AVM and become a maniac and try to remove all the AVM no matter how the brain is acting. The brain will dictate what you're doing. You don't dictate to the brain what the brain should do. So if the brain is swollen, you have a large AVM, you will close, you will come back. And that's what we did. If you look at the angiogram that we just briefly presented, you see that AVM is much better defined. It doesn't all that diffuse, but still it has the deep feeders. Let's go ahead to the second stage. And this is the second stage of the-- we remove a lot of the clips that we initially placed because obviously all of those are gonna thrombose and we thought we really went around them. This didn't seem to be a large vein and I didn't think so either, but as you will see, as we went deeper and deeper in this AVM, this brain become just more and more intolerant of a surgical manipulation. As you can see, you try to put a clip and then coagulate them, use the irrigation as very eloquently mentioned by Dr. Spetzler and others and then we cut across it and see how it helps you or how the vessels act. It's sort of a learning and a familiarity and getting to know the other side of the fence of how these things act. As you can see, the brain starts having these ooze, you don't know what's coming from, but the brain is just getting swollen. You can see things are moving at the edge of my craniotomy. A lot of clips. You can see the depth is less. I'm irrigating with thrombin, which I thought was maybe saving me at some point. But again, things are just popping on their own. I'm trying to put clips on, I put a clip and other place things go off and start bleeding. Well sort of that's the most difficult situation. So what's the right thing to do? Make this a third stage or what's the right answer?

- [Doctor] So I think all super vascular surgeons who deal with AVMs have encountered this. When I get to a point where the brain is bleeding from areas that didn't bleed before when everything was under control, you have basically two choices. One is to stop. If you can get the bleeding under control and stage it and pack it and keep the pressure down. And these are the patients you probably wanna keep the pressure 55 to 65 postoperatively, I mean arterial pressure. The other is actually to go ahead and bite the bullet and take the rest of the AVM out and you'll get bleeding and you may have to have an , but once you get the entire AVM out, you'll find things will come down and that's what I'll often do, but I've staged the cases as you did.

- Thank you, before we go to the other experts, here as you can see, I sort of tried to tap it off, put an EVD, remove the AVM. When we were trying to put the bone flap back, this patient blood pressure jumped to 150, the bone flap went through the roof. We had tremendous bleeding. Hold off on that video, please. And eventually got hemostasis. This was a very, very torturous operation. Some of the ones that I never forget, but as I say, sometimes it's better to be lucky than anything else. And the patient did very well despite having a facial weakness that is very noticeable here and has continued to improve. One thing I wanna mention, as you can see on the angiogram, when the angiogram, when intraoperative angiogram showed that the entire AVM was removed, we saw another AVM on the frontal, and that's not unusual, unfortunately, that when you remove an AVMs, some other shunting appears that was never apparent on the preoperative angiogram. So with a very diffused large AVMs an intraoperative angiogram after resection is your best friend. With that in mind, I would like to ask Dr. Spetzler who's truly a master surgeon to come here and show some of his great three magical videos. Thank you, Robert.

- Thank you, Aaron. Please go right ahead and start so we can move right along. Yeah. Thanks. I'd like to particularly acknowledge Dr. Ahmed, Rodney Samuelson, Mark Garret, Giac Consiglieri and Guido Hattendorf for helping me with these. These are some of the fellows and chief residents. And I wanna just go through cases that are relatively well edited. You see here that little PICA aneurysm with an acute bleed. Oh, there we go. Okay. And as you can see this being where it's located, we wanna do a paramedian posterior fossa incision. The reason for the paramedian instead of midline is that it doesn't mean you have to retract the muscle. This is a far lateral approach, just drilling off the condyle, the medial third of the condyle, which gets you then beautiful exposure of PICA. Here you see some of the blood that's being removed from the hemorrhage. And here you see the lower cranial nerves. You see these beautiful bipolars. And as we removed the clot, we get better and better visualization and here's actually the little culprit. There was a discussion about the size of aneurysms that bleed in the Brad study, which included every subarachnoid hemorrhage that came in. The mean size of the ruptured aneurysm was six millimeters. So it's not a lot that large aneurysms are the only ones that bleed. It's just that there are so many small aneurysms that the vast majority of subarachnoid hemorrhages really represent the culprit, the main culprit of subarachnoid . Here you can see on the ICG the thrombus within the aneurysm, the loop of PICA that you wanna preserve through that branch of PICA. And so you really wanna preserve this flow through here and that's what we're doing here. You can see very nicely how the flow is maintained. The aneurysm is obliterated. So clearly, if there are any questions that come up, don't hesitate, don't be shy. Yeah. Yeah. For somebody that told us not to show extreme cases, you really started off well. And then for a 3D session, you showed us a half an hour of 2D. Just kidding, Aaron.

- [Aaron] No problem. We can take it.

- Okay. So here, this is gonna be a approach for bilateral aneurysms. Here's one side and you saw the one on the other side and going down, we've published, we've talked about dynamic retraction instead of rigid retraction. And the residents don't even set up the retractor system anymore, which I don't know that that's really good. Here's the hemorrhage of the ophthalmic artery aneurysm into the optic nerve. You can see it going all the way through. There's clearly a aneurysm on the contralateral side. So we're gonna go over to the other side and take care of that first since we don't want the clip for the ipsilateral ruptured aneurysm to be in our way. What is unique about this one here? Here's you have the ipsilateral optic, the contralateral optic nerve. Very unusual for us to be clipping in the ophthalmic artery aneurysm over the top of the optic nerve rather than underneath. Most of the time, this is the space where you're clipping contralateral, optic ophthalmic artery aneurysms. Here it was over. And here, now we're going to the culprit, the cause of the problem in the first place. Opening the aneurysm, because we wanna decompress the optic nerve and that red stuff has blood. Readjusting, the clip, cause they're obviously enough atherosclerosis and part of the neck so that you still have bleeding through it. So we're gonna add a second clip to make sure that it's closed off properly and has decompressed, here's the postop. And you can see the two clips.

- [Man] Are you using CTA for your postop.

- Yes. Yeah, yeah. We really don't use angiography either pre-op or post-op except for special circumstances or when we're considering endovascular treatment. Here's an SCA aneurysm, very broad based. Our endovascular team turned it over to direct clipping. And I really think most of the SCA aneurysm should be clipped because it's an area without perforators. It is a high risk of losing the SCA when you treat it endovascularly, especially if a stem is required. So here opening the Sylvian fissure, typical opening down deep carotid artery, optic nerve and as we open the arachnoid plane so we get more and more room and you can see that really you've got a beautiful visualization without having to place a rigid retractor. It's a large PCOM, which is gonna take us right to the P1 and the superior cerebellar artery. As we open deeper, one of the tricks really to open this space is to follow the anterior carotid artery. By following the anterior carotid artery, you just widely open that fissure, which gives you more room where you're truly interested. So here is the aneurysm. This is basilar artery up here. That's SCA on this side. PCA is above the aneurysm. We clean it off some more. And so here we have the aneurysm itself.. There you see P1. Tight space because it's a such a large PCOM. So here you see the neck of the aneurysm, a long, long neck, basilar artery superior cerebellar artery, posterior cerebral artery, over here, that's the base of the aneurysm. But with this exposure, it is a relatively straightforward to apply a clip which has to go across the neck. There really are no perforators on the other side. Nevertheless, you have to be very, very careful that the clip doesn't go on too far so that you catch something underneath. So here are the clip is going on superior cerebellar artery, basilar artery, P1. And when it gets dark like that, obviously we are obstructing part of the light pathway which is one of the reasons why I like lighted instruments when we were working in really deep holes. And here you can see that both SCA and PCA are a nicely open. Inspecting to make sure that the areas in the brainstem that the clip hasn't caught any of it. And here's the post op. You can see the aneurysm nicely obliterated. That's definitely not my case. It's got way too much blood. Gary?

- [Gary] That was a ruptured aneurysm, actually, unlike the unruptured that you treat.

- Dr. Spetzler, thank you so much for those great points. There was a question from the audience that asked when you made a comment about deep venous drainage. Robert, if you take the deep venous drainage, do you think you will hamper any of the venous drainage potentially that could make the AVM more aggressive? Because it's venous drainage.

- [Robert] Yeah, no, I don't think so because you have both arterial supply and venous drainage down deep. If you only had deep venous drainage, it would never be a problem, because all you need is one small arterial vessel to still engorge an AVM.

- I think the point that Robert makes is a good one. On difficult AVMs, I will often try to go deep. Also that's when I'm fresh and start with some of the deep portion. If there's too much bleeding at that time, then I'll pack it and circumferentially go around and leave it for the end. Can you go to my first slide? This is, how do you even go backwards? It's not going backwards. There we go. Okay. So thanks for the opportunity to talk. And I wanted to acknowledge, and my other fellow Ramon actually helps select the cases because I wanted their opinion of what they thought would be useful for someone starting out or someone who doesn't do just cases. And I have no disclosures except for these grants from NIH, NINDS and CIRM. So the first case I wanted to show you, I'm gonna show you a couple of basilar artery aneurysm cases. Not 'cause you see lots of these, but because you don't see lots of these and I don't see lots of these anymore. It's much less frequent that we operate on basilar artery aneurysm. But I think it's important to know the anatomy and how to do these from different approaches when you do encounter them. So this was a 70 year old female. Normally we would coil or treat endovascularly in good grade, put an EVD in after she deteriorated or she came back to normal neurologic status. You can see it's an anteriorly pointing aneurysm. They didn't think it was amenable to endovascular treatment 'cause of the wide base incorporating the P1s. And so we took her to surgery and I'm gonna show you first a right pterional approach that's at Trans-sylvian. I spent a year with Charlie Drake and so I first started doing all my basilar aneurysm subtemporal like he did, but I find that this is actually easier on the brain. There's less retraction. And I still do use retractors for most of the time. And I think there's a lower incidence of third nerve palsy. So I prefer this if you can do it through a trans-sylvian approach. Can you go to the video? So I'm gonna show you, this is a right sided approach, and here's the carotid and I'm drilling the posterior cranial. Third nerve is over here. So wide space between the carotid and the third nerve. Here's the optic nerve. This was a ruptured aneurysm, obviously. So this is an important maneuver to master. That's a two millimeter diamond drill and often it's a little bloody, but this will gain your exposure to the basilar trunk so that you have proximal control buzzing the dura back. And I agree, opening the Sylvian fissure widely proximately and following the anterior choroidal. Now I'm using a one millimeter Kerrison Punch. I like this instrument for posterior cranial removal and anterior cranial removal at certain times. There's the basilar trunk, the upper basilar trunk, clearing some of the subarachnoid hemorrhage away. Here's the superior cerebellar artery on the right. Here's the superior cerebellar in the left. You wanna start exposure lower here at the superior cerebellar is when you have a ruptured basilar tip aneurysm. So you carefully take the clot out. Now, taking advantage of the opticocarotid triangle here and visualizing the opposite P1. It's easier to see both P1s through a trans-sylvian approach than through a subtemporal. So I haven't even looked at the dome of the aneurysm that ruptured. Getting ready to clip a temporary clip, often you can't get a clip between the superior cerebellar arteries and the P1s. Here I was able to clip just below the P1s bilaterally. That's a CODMAN clip, which makes a long temporary clip which is useful for these deep situations. And then now we can start working on the neck of the aneurysm. So removing more clot. Ipsilateral P1 is a perforator coming off there and here's the contralateral P1. And now we're dissecting the neck of the aneurysm. Again, there's some perforator coming up the proximal P1 on the other side. And now getting ready to put the permanent clip on. And remember, the first clipping is not necessarily gonna be your final clipping, but you feel more secure once you've got a clip across the most of the neck of the aneurysm. Now you'll see I'm taking some time adjusting it to make sure I've got the entire neck clip and there's a little bleeding from the aneurysm. And so just gradually advance the clip. I tell the residents, don't panic if they're doing this and it starts bleeding, don't start firing clips in. Suction usually easily controls it. Now for the perforators, they're not as well seen from this approach as from the subtemporal, but you can usually gain adequate visualization. I spend a lot of time after the aneurysms clip to make sure there are no perforators incorporated. And then finally take the temporary clip off. So we gained just enough room with the drilling of the posterior clinoid, to be able to get the temporary clip on. And then finally, there's the basilar apex now, there's a contralateral P1, and this is a small Doppler that's useful in confirming symptom 'cause it ruptured when we were clipping it. Okay, stop. Go back. And I should say the 3D is a great teaching tool and people have embraced it in our OR. We usually have five to eight people, including residents, fellows, visiting neurosurgeons and all the staff were wearing the glasses. It gives a great perspective. So they very much enjoy and take advantage of it. So can I have the slides again? I'll show you the second case. Got it. And that just shows you the postoperative view. I did give her a third nerve palsy which recovered after four weeks. So this is the second case. This is a young man. Is 52 young? 52's, I think it's young. Polycystic kidney disease, headaches and he's got a one centimeter aneurysm, again, not optimal for endovascular treatment. And it's a multi-lobed with a lobe projecting posteriorly, as well as anteriorly and superiorly and the P1s are incorporated. And so this I did a sub temporarily. Turn on the video, please? I just advance? Got it. Great. So here, now this is the right temporal lobe so we are using retractors here. I don't know if you can do this approach without using retractors. Lots of CSF aspiration, I'm opening membrane of liliequist. Here's the tentorium. And you see one of the nice things is you do have a much wider room for manipulating instruments with a subtemporal approach than the pterional. But I think it's tougher on the brain. Here's the third nerve and you can either put a stitch in the tentorium or you can cut it posterior to the entry of the fourth nerve. That's what I did here. And the fourth nerve comes in right here. You'll see it. It looks like it's fused to the third nerve. So cutting the tentorium is always tedious. It's bloody and you can get into venous lakes, but it increases your exposure exponentially for a posterior fossa case like this. Here's the fourth nerve now. So taking it back almost to the petrous ridge and now we can see here is the basilar artery. The posterior clinoid is not in the way. So this aneurysm was low below the clinoid, quite considerably below and for that, I think this gives a much better exposure or you can combine a trans-sylvian with a subtemporal and I've done that in the past. So here's the basilar trunk. Now there's the anterior lobe of the aneurysm, which is easily accessible. The posterior inferior projecting lobe is more treacherous because the perforators come off the back and it's easier in my hands anyway, to see the perforator is sometimes coming from this approach. So here's the posterior projection of the aneurysm with perforators around it, actually on both sides there were perforators. Often with the subtemporal approach and here you see I'm extending the opening of the tentorium to get a little more view. Often with this kind of approach to a basilar apex aneurysm, you will need to use a fenestrated clip to encircle the P1 on the ipsilateral side or the third nerve. Here the bleeding is controlled with Gelfoam, Floseal, Surgicel and you just have to be patient. Raise the head of the bed if there's too much venous bleeding. Now again, that CODMAN long temporary clip is being put on just below the superior cerebellar arteries, which were small in this case. Now we're dissecting out the posterior lobe of the aneurysm and there's a perforator. The P1 comes up this way. And so in this case, I didn't need to use a fenestrated clip, but I clip in front and in back of the P1 for the two separate lobes. This is now the posterior lobe, which I wanted to do first 'cause I find that more difficult. And again, take plenty of time to place the-- And no matter how you expose these basilar aneurysms, it's always a small space that you're working in. And now here's the anterior lobe, which is easier, anterior superior projecting lobe and that's more straightforward. And I'm clipping that with a second I'm using Sugita clips here. You wanna use a clip that's longer than you actually need because it's so deep. So typically I will use a 15 millimeter long clip, or even an 18, even if it's an aneurysm that's a centimeter because you have to have access to the spring mechanism so you can load it and get it on and off, and then take off the temporary clip. And usually the temporary clipping periods are not very long. And then just as important part of the case it's confirming flow in both P1s, as well as the Basilar with the microvascular Doppler. Okay. You can stop that. And he did very well. When I was clipping the posterior lobe, there was a perforator coming out of the contralateral P1 and I debated whether to encroach on that. You can't encroach on perforators, but I deliberately left some and we did an intraoperative angiogram and you can see there's a little residual and you can see it here in the post-op. And I don't know what the natural history of that is, but we're following it. He's a year and a half out, it hasn't changed. Do you want me to keep going?

- [Aaron] Yeah, I'm gonna just ask, please do bring your questions to the text message you see there. That other question's for Dr. Spetzler do you have any evidence Robert, that lack of retractors makes your patients do better based on your opinion?

- [Robert] That's something that's basically impossible to determine, but I think if you use common sense, if you think of back a few decades ago where we saw all the retractor injuries that we saw on MRI scan, we just don't see them. Anterior communicating artery aneurysms, we never take a gyrus rectus. It makes a very big difference. It's just one of those evolutionary steps and I don't know how you would test to see--

- I never take a gyrus rectus with retractors.

- [Robert] Well, yes, you do. But from the ischemia, from the retractors--

- I see what you're saying.

- [Aaron] Well, let's run through quickly on that and see

- Okay, so this next case I'm gonna show you is a bypass. We do a lot of bypasses. I've done almost 1,000 just for moyamoya disease. We do about 100 a year for moyamoya 'cause of our referral base. And I think it's a very, very important tool to have in your armamentarium because you never know when you may need to provide extra blood flow. And it's a simple operation. It's not a high risk kind of procedure to do or to master. So this is a patient who is 17 with moyamoya. She's had right hemisphere TIAs and a minor stroke. You can see the watershed ischemia, she's got bilateral moyamoya and she has some left arm weakness. And here's her right carotid injection. You could see the moyamoya vessels, very poor filling. And here I actually used the parietal branch although I usually use whatever branch is larger, the frontal or the parietal. The parietal is a little easier. So I'm gonna show you and I wanted to make one point, which is I worked with designing a special clip. This is the smallest Sugita temporary clip and I found it was a little too big and I wanted something smaller so we designed an Aesculap clip, a Yasargil clip that is smaller and profile in two planes, you can see, and it's much gentler. And we also designed a special ruler since we're using measurements of the STA and the MCA in sub-millimeters. This is a millimeter, sub-millimeter measurements to correlate with our flows and predict outcomes. So go to the video if you would. We're on the right side. And the color is a little off on this. Let's see. Go back. Start the video again if you would, from the beginning. No, next video. Okay, let's see. That's not quite the view. There's the STA, isolating it and measuring then size. This is a little bright and we should have adjusted the color. You have to do that with the True Vision at the time you're recording. Opening the arachnoid and here the artery can go into spasm. You can see a little spasm and when you're measuring the artery size don't go to another vessel when you think the artery is too small 'cause it's in spasm, put some papaverine on and it'll dilate up. Choose a vessel that's perpendicular to you so there's no real back wall and try to find a spot. This is an M4 branch coming out of the fissure. Find a spot that is free of a perforator or tiny arteries coming off it if you can. Putting papaverine around. Here's the STA we harvested with a generous couple of soft tissue to protect it and provide additional vascularization and then just isolate the end, temporary clipping the STA proximately. Coagulating the stump after cutting it, flushing it with heparin saline, and then fish mouthing the end where it's been uncovered. There's the flow. We actually send the piece of STA for analysis, we're doing immunocytochemistry and protein and RNA analysis. Now taking off the rest of the soft tissue so you've got a clean artery, that's fish mouth. This is the donor. And then here are the clips being put on. And this is a segment about seven or eight millimeters in length. It's just under a centimeter. Then I like to cut an elliptical portion of the superior wall and we actually are analyzing this using some special array tomography microscopic techniques and the found abnormalities in the M4. That's indigo carmine dye and the vessel is so thin sometimes that it's nice to be able to stain it when it's still translucent. Always put the toe ending first, so that you can adjust the heel end if you need to. You can extend it or extend the arteriotomy. I use 10-0 sutures, I use interrupted sutures. It's nice 'cause the residents and the fellows can sew. Typical occlusion time now is about 15 to 22 minutes using interrupted. And we have not seen problems with intraoperative ischemia. Here's the heel end. That's Mike Lawton's needle holder that I pinched from his set. I like this, it's got very fine tips. So you owe me a check also Mike. And here we're putting it into the other side of the arteriotomy. And you have to be very gentle with the vessels. When you're pulling the needle through, pull in the curvature of the needle. I actually put four ties in, you probably only need three. And then very careful not to catch the back wall, I still occasionally catch the back wall on the very, very thin arteries. And then you can pick up the suture with your forceps and then stabilize the anastomosis. Tie both vessels with your forceps, your other forceps as you're pulling it through so it doesn't tear. And usually you need the two end stitches and two to three other sutures. It's not even that many sutures. Now you flip it over you see the advantage of not having a vessel parallel to you but rather perpendicular. You don't really have a back wall. Here I put the stitch into the recipient first and then into the donor. You just wanna catch the edge of the donor STA. And the residents chose a case here to show you a little problem at the end. They didn't pick the perfect case where there's no blood around. And I think that it's good 'cause it shows you, now we're gonna occlude and you're gonna see some bleeding. This is a high visibility background I put under it. I don't use a suction in place all the time. So here you see a little bleeding and it's coming right out of that one spot. It's often hard to tell where it's going to leak, where it's gonna leak from as you're putting your sutures in. And here you don't need to re-occlude. What I'm using is the suction, five Brackmann Suction in my left hand as counter traction and then just pull the needle through and then tie it. And here's where someone can sometimes help if there's a little blood in the way, the resident or the fellow. And this amount of blood, that seals thanks to platelets, even on aspirin. All the patients are on aspirin by the way, when they're operated. They're not on Plavix though. And then I use this flow meter to get that designed with Transonics to measure quantitative and directional flows so we're using that to predict who has various outcomes.

- Thank you. Thanks so much. I have a couple of questions here we'd like to talk about from our audience. One of them is, what is cerebral protection we are using for temporary clipping and why not to do an EDAS plus or minus burr hole? So the second question, Gary, if you could be so kind you come and answer that.

- [Gary] Yeah, so the first question, for temporary occlusion and this is a little bit of voodoo, 'cause it's never been prospectively proven that these measures work, but we used to use thiopental for burst-suppression. Now we use propofol 'cause you can't get thiopental. And probably more importantly, I use hypothermia, mild brain hypothermia, reducing the brain temperature from 37 to 33. And we found it is so protective in the laboratory even though it hasn't been proven for focal ischemia in humans it has been proven and is a standard now for stroke, secondary to cardiac arrest from V-fib and for neonatal hypoxic ischemic injury. It is the standard of care to use hypothermia. So we drop the brain temperature to 33. We use burst-suppression and we use electrophysiological monitoring. Your second question was?

- The second question was, the use of cerebral protection during temporary clipping?

- [Gary] No, that was your first question.

- I'm sorry, use of EDAS plus or minus burr holes.

- [Gary] Oh, okay. So EDAS plus burr holes in general works in kids. I don't think it works as well in adults. I'm a believer in the direct bypass, plus you're getting an indirect. When you do a direct bypass, we harvest enough of the artery with soft tissue STA, you're laying it on the surface so you get a terrific indirect graft as well. But if you do angiograms afterwards and we've compared them, I still think the direct graft is better and it gives you immediate increase in blood flow. So some of the patients we have are having ongoing ischemic episodes, and an EDAS or burr holes would not have any effect for usually weeks to months. But I think in kids who aren't that symptom, you don't need immediate blood flow. It works, it doesn't always work, we have 16 patients, 12 of whom were children that I had to redo because of a failed EDAS.

- [Aaron] Thank you. Dr, Speltzer? Thank you.

- [Doctor] One comment about cerebral protection during temporal clipping that I might add is that probably the most important thing is surgeon speed, how quickly we do what we need to do to finalize that dissection and put that clip on is I think critical. And as soon as that clip is on and you don't need that flow arrest, you should take the clip off.

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