Transcript

- Welcome colleagues and friends. Thanks for joining us for our exciting virtual or webinar. This Monday evening, we have a very special guest, Dr. Robert Spetzler, from Barrow Neurological Institute, who requires no introduction. He is truly a pioneer in microneurosurgery. A great, amazing mentor for so many young neurosurgeons, who has pushed so many of us to be better. Dr. Spetzler, thank you for joining us.

- My pleasure.

- His lecture would be microsurgical management of deep-seated cavernous malformation. Something that he has truly pioneered and pushed the levels to completely a new platform. Before we start, Dr. Spetzler, and here your amazing lecture as always, this is something we always think about when we talk about microneurosurgery and that's what it takes to be excellent. We know you have described before that passion for technical excellence, that's such an important ingredient in becoming a great micro-neurosurgeon. Would you please tell us, in so many years of your incredible experience and legacy, besides that passion that we need, what else is important to really, truly become a great microneurosurgeon?

- Thank you, Aaron. First, it's a pleasure to transmit around the world, to all my colleagues from all the nations. And I do hope that this virus that is limiting our interchange so significantly pass this in their history relatively quickly. I think to be a, a microsurgeon of excellence really requires nothing more than what Aaron already mentioned, which is the passion, which is the underlying need from the inside to be really the best. But in today's world, the fact that we have so many courses where we can test ourselves, where we have such visual connections with videos and anatomical presentations that allow us to learn much easier, this is so much better than when I was a resident. And these courses with cadaveric dissection are just absolutely unique. However, to really be the best, the laboratory has to be available to use, so that you can practice your manual dexterity. It takes nothing more than a rat or a little bit of tubing just to learn and work through the microscope and the deep length to become the best you could be.

- Thank you very much. We'll discuss this further at the end of your lecture. So, let's go ahead and we're all excited to hear your thoughts about these challenging lesions.

- Thank you. So, my topic today is really the management of deep-seated cavernous malformations. And I wanna basically go through what we see here, the, what we know, the contraindications for surgery, which is just as important as the indications for surgery, some case presentations, summarize the safe entry zones, and make concluding remarks. Next. So, what we know is that there are cavernous malformations, which have veins going with them, and there are all these little branches, who I really think this is venous pathology. The prevalence, we know. The symptomatic bleed, we know. The re-hemorrhage rate has been published to be as high as 60%, that is if you've had one hemorrhage. The risk of having another hemorrhage can be as high as 60%. That was from a Japanese publication. I personally use, when I'm talking to a patient, I use 7%. It's a soft number as to what is my risk as a patient to have another hemorrhage if I've had one. Surgery for brainstem cavernous malformations is not benign, and there was a 36% temporary worsening and 11% permanent deficit. And all of this has been published and is easily accessible. Here's a classic example of a cavernous malformation and the large venous malformation that we see here, in association. And if you look at it surgically, you can see the vein coming in and you see the budding right here, for example, the budding of the large cavernous malformation. So there's no doubt in my mind that this is a venous pathology and it comes from a budding process of these abnormally large veins. It is also important to be very careful in assessing a success, for example, with radiotherapy, when you have a presentation like this. And then two years later, you see the cavernous malformation basically gone, but this was without any treatment. And the only thing that really has happened is for this large hematoma to have reabsorbed. It is very, very important to respect the floor of the fourth ventricle. When we see the floor of the fourth ventricle and the patient is asymptomatic or very minimally symptomatic, we are gonna have a very unhappy patient or family if we elect to have surgery. So, we should not have surgery, unless the indications are very clear. This is a study that we did prospectively over a two-year period of patients with brainstem cavernous malformation that were sent to us for surgery. It turned out that when we looked at them, we recommended conservative management in basically half of the patients. In other words, no surgery for half the patients that were sent to us for surgery, and recommended surgery for the other half. What are the indications for surgery? I think basically cavernous malformations that are accessible on the pial surface. Repeated hemorrhages that may have more than one hemorrhage. With each hemorrhage, the likelihood of another hemorrhage increases. A progressive neurological deficit, significant mass effect, and that you can get there safely. What is important is, I've said it a thousand times, but exposure is everything. If we can get there safely, then we can take care of the problem. The venous anomaly drains normal blood from the surrounding brain, so it needs to be preserved. Image guidance, SSEP's and MEP's, sharp dissection. I like EEG-burst suppression because it decreases blood volume and protects the brain in case of temporary ischemia. And then anatomy, anatomy, anatomy. And I personally like to avoid rigid retraction, wherever possible. Next. Light is incredibly important. And you could see in the middle of those videos, the fact when you have a little light on your bipolar, you get a beautiful picture. And so, because the angle of the light and the angle of your visual axis vary, depending on how long your focal length is. It varies between three to six degrees, and that's why you can have shadows. Next. In fact this, with my fellow, Leonardo Rangel-Castilla, we published this paper on just approaches to the thalamus and you can see how many different approaches we have depending on where we're going, six different approaches, just to emphasize the fact that it's the approach that is so critical. And here are the six approaches to the various components of the basal ganglia. We couldn't do any of the surgery without intraoperative image guidance and the excellence of our visual capabilities through the microscope. Here's an example of what we can do today. So, here's a small cavernous malformation. Deep posterior has bled several times. Here it is post-operatively. You see no brain retraction deficit. This is where it was. And you can set your robotic microscope to the entry point and the axis to your point of interest, and it automatically goes there. And then we can go right down and watch the little dot in the middle and follow it. So, this is an inner hemispheric approach. The head is horizontal. The, no rigid retraction, just gravity pulling down the hemisphere. And we go from ipsilateral to contralateral underneath the faults to get out this small cavernous malformation. And you can see how the light at suction is really quite helpful, made by catalysts at our request. And you can see the little hole in the faults and then just pulling it out. No retractors in place. Next. So, what do you do for this here? This is a young, beautiful medical student, and she's had a bad headache, and she has this cavernous malformation. Well, the first thing we have to consider really is, should we observe or should we offer surgery? If we offer surgery, what approach do we want? Do we wanna come in from the lamina terminalis approach or through the interhemispheric approach? And if we do the interhemispheric, what position? Straight up or lateral? I love horizontal, and that's what we're doing here. You can see her position on the table and you can adjust the operating room table, so it's completely horizontal. And then we just basically follow image guidance, right down into the ventricle, and take out the cavernous malformation. What is really important when we take out cavernous malformations is to spend significant amount of time at the end of the procedure, pulling out every little white speck, that could be some endothelial residual, which has the op of the potential of recurrence. And you can see here by looking lateral, we find some more cavernous malformation that might've been easily missed. And I think that is the best way to really reduce the risk of recurrent cavernous malformations. So, we just keep going. You could see the light at sucker providing illumination. And we just keep taking them out, tiny little specks. And then coagulating wherever we think there might be a source of little bleeding. And again, no retractor in place. And this young woman did remarkably well. Next. And you can see here, this is where the cavernous malformation was. Right here, just a little short straight incision. The bone always goes over the sinus, so that you could pull the sinus over just a tiny little bit for better exposure. So, what do you do with this here? Well, you have a cavernous malformation that's bled multiple times into the ventricle, you could go transcortical right frontal, you could go interhemispheric, transcallosal, ipsilateral, or you can go contralateral, interhemispheric, transcingulate through the cingulus like this here. And that's what we did. Again, the patient is horizontal. We're looking at the faults. And with image guidance, we're going to make an opening in the faults, cut it open. Then now, we're going through the cingulum, following our trajectory. I love these bipolars. I know they carry my name and they're made by Stryker, but nonstick bipolars make it so much safer. And there's that beautiful cavernous malformation. And then we just gently separate it. Bipolar all the little veins that are part of it like you see here. Those veins that are going into the cavernous malformation, obviously have to be sacrificed. And we just keep mobilizing. You could see the evidence of the previous hemorrhages, all the hemosiderin. And here it comes out. So, you see how it came down, right through here, through the cingulum, directly to the cavernous malformation. Next. So, we're gonna go through some case examples. So, we're gonna start off with the far lateral. This just a little cartoon showing the approach. I like a paramedian incision, so that the muscle bulk is not in our way as it is when you use a midline incision. Next. So, here's a classic cavernous malformation in the amygdala, sitting right here. This is a young woman from London. She was the editor of the London Times, the medical editor. And here we're cutting the dentate ligament. And then we see the cavernous malformation. We see the vein that was coming right here, but then we wanna get to that edge right there. And it really makes a very sharp dissection when, an easy to section, when the exposure is just right. You can see the 11th cranial nerve right here, we're working underneath it. And there it is out. Next. And this young woman wrote a book, it's available on Amazon UK, and it's very good because it reminds of what our patients go through. We see this day in, day in, and it's good to be reminded. Next, we're gonna do the suboccipital approach, telovelar. And this is obviously a standard exposure. Next. So, here we have a hemorrhage. You can see it right here off the line, recent hemorrhage. So, this is absolutely perfect for the telovelar approach. Anatomy, anatomy, anatomy. We wanna go out the foramen of Luschka, get to the middle cerebellar peduncle. So, here we are. The patient is prone. Little gel foam into the, into the fourth ventricle. Feed are up here. Head is down here. We're opening now the foramen of Luschka. And as we open the foramen of Luschka, there's PICA that's in our way, and you have the classic, you have the classic white floor of the foramen of Luschka. And then with image guidance, we make a hole in the middle cerebellar peduncle and get directly to the cavernous malformation. And then with tiny little pituitary-like instruments, we take out the cavernous malformation. And then don't forget to take the gel foam up. Next. So, retrosigmoid approach is a workhorse. I used to do a lot of petrosal approaches, but really don't do them anymore because you don't need them. So just with a patient, either in park bench or supine with the head turned. We just make a little opening, no retractors. Next. What's important here is that if you look at the blue lines, we are really coming right down the middle of the cavernous malformation. Very important not to get to where it gets closest to the surface, but you're going right down the middle, so that the corners of the cavernous malformation are equally distant from your exposure. Next. And so, you can see at the end, after we've taken it down, we have, we really have this knowledge that we're at the end of the cavernous malformation. And now the video. So, what we're doing is we're following our image guidance. Once we are in line with the trajectory you see down below, we make a little opening. This is really in the brainstem, right down the middle, and we get to the center of the cavernous malformation. And then we just continue to take it out, continue to take it out. But you notice that there are no retractors in place. And this is a very large one. They had to try to operate on this one through a subtemporal approach previously. And we just keep taking it out and keep taking it out, and then inspecting the bed. And then once we really have it all out, and we're sure that there's no more bleeding, this is a hemostatic agent, which I then wash out. Next. And you can see the line where we came in and the empty pocket. This one, I like to show because this is a cavernous malformation. And the only thing I really wanna show here is the opening of the petrosal fissure. By opening, you see the petrosal vein. And we just keep cutting the arachnoid. And then we're gonna open the petrosal fissure to allow us to get to the middle cerebellar peduncle here. Very, it is, it's just like opening the Sylvian fissure, except that the cerebellar hemispheres are much more fragile. But you can see how this just continues to give us more and more room. I like to keep the petrosal vein intact because it's a very good sign that you're not over retracting. Remember there are no retractors in place. And now, we're beginning to see the white of the deep structures, the middle cerebellar peduncle. And we wanna go right through it to get to this cavernous malformation. Now, we're way up, we're going right to the center. And then once, and the middle cerebellar peduncle, fortunately, is a very tolerant anatomical structure. It does not give us trouble by penetrating through it. And then now we see it. We see we're their at the cavernous malformation. And you can go to the next slide please, because that's really all I wanted to show. And now we're gonna do supracerebellar infratentorial. I love this approach because it is such a great way to get to deep structures of the brain along the entire tentorium. Next. So, here's a classic one. We can see the cavernous malformation, but notice, notice the line between the cerebellum and the hemisphere. It's a straight shot without having to go anywhere. Next. Now we see the sinus is just below us. The tentorium is right there, all the way down to the ambient cistern. No spinal drainage. The fourth cranial nerve. We get right to the cavernous malformation. No rigid retractor in place. And then removal of the cavernous malformation. All we're doing is what I call dynamic retraction, which is with the sucker and your instrument. Next. And you could see very nicely how we came in right into the cavernous malformation without doing any harm to any structure. This is a tough one. This is a young woman from Copenhagen, and she's been operated on before with the VP shunt. You can see that the cavernous malformation goes all the way up to the foramen of Monro. And so, we're going to, you could see the tentorium. We cut the tentorium because we'd have to go up. Cerebellum is above us. And we go right into the middle of the entry point. And then we take it out here. I was using a CO2 laser to make these big nodule smaller, so that I could take them out. You can see how troublesome is, how big that is. And I couldn't get the scissors around it, so the laser was really quite useful here. And you just keep going and you keep going. Next. And here you can see the lesion all gone. And there she is. Since she did very well, then she went back to Copenhagen a week later. The orbitozygomatic approach is another workhorse that everybody's comfortable with. Whether you make a small opening or a bigger opening. It's really not the essential point. It is the direction to get where you wanna go. Next. So, here's a classic example of a very large cavernous malformation sitting right here. And what you wanna do is you wanna come in lateral, so that you're avoiding the motor fibers. So, this one here is a tough one. This is a patient that's had three hemorrhages. And you can see the cavernous malformation. It is just this little small through the peduncle. And so, the only way to really get there safely is to come this way. And that's obviously a contralateral approach for this cavernous malformation. So, here you see the internal carotid artery and the optic nerve, and it turned out that the best trajectory was between the carotid artery and the optic nerve. And then verifying that our image guidance was accurate by looking and focusing on the structures we could identify. Then within the interpeduncular space, we separate all these little vessels until we see the substance of the peduncle, and then make a small opening in the peduncle to the cavernous malformation. And fortunately, we're right on target. And just with little sharp instruments with teeth and these tiny pituitary like instruments, we were able to grab the cavernous malformation and take it out. And there it is. And then making sure it's dry. Next. So, now we're talking about transcallosal approach. I already showed you one case with the young medical student. And the supracerebellar approach along the whole fault, we have an approach to the deeper structures of the brain. Next. So, here we have a large cavernous malformation that you can see off to the side. And for this here, obviously, the approach is pretty straight forward. And so here, it's a pretty straightforward approach to get this cavernous malformation out. More difficult is this one. This is a young, relatively young man who has symptoms. And his cavernous malformation is really sitting just below the floor of the third ventricle, which you can see nicely there. So, here we have to go through the interhemispheric approach. Again, you notice the bone is across the midline, so we can pull the sinus over. Every millimeter of there makes a difference. And then again, opening the corpus callosum. We're looking at the foramen of Monro. And now, I'm gonna open into the third ventricle. I like to go lateral to the choroid plexus as opposed to medial, which is most textbooks recommend. And the reason for that is it puts one nice layer to the fornix and my instruments. Protecting the fornix I think is critical. We're now in the third ventricle. And again, I'm using the little laser, holding up the veins and separating the cavernous malformation from its attachment, right in the third ventricle, bipolaring, cutting. No retractor in place. And here it comes out. Next. And you can see the removal very nicely of the cavernous malformation. This one is a little more difficult. This is a young man from Israel, and he has this cavernous malformation, which is sitting really right in the posterior portion of the third ventricle as it enters the aqueduct. Here's another series of pictures you could see from the third ventricle sticking into the aqueduct. And again, you could see it very nicely here, posterior third ventricle into the aqueduct. We're gonna use the same approach as we did. Now, we're in the third ventricle, entering the aqueduct and then gently removing the cavernous malformation. The light of the sucker helps us a great deal on the steep exposure. Here I use rigid retraction to hold over the corpus callosum, so that it doesn't slide over into my view. I'm not saying you shouldn't use rigid retraction. It just shouldn't be an automatic move and only use it when you need it. And here it comes out. And then again, inspection until you're sure you've gotten every piece out that possibly can be. Next. And you can see very nicely the pre and then the post. The pre and the post. And then finally, the last case I wanna show you is just a giant cavernous malformation that's within the lateral sinus. This is a young boy whose family had, had owned hospitals, and they operated for 16 hours, had severe blood loss. What is important in this here is to recognize that a cavernous malformation within the vascular sinus is a totally different animal, even though histologically it's the same. They are very, very vascular and very positive. For example, if you do an angiogram. So, he was operated, then he was sent to the United States where he was operated, and they closed up because of blood loss. You could see the size of the cavernous malformation. So, Dr. Albuquerque found one little external vessel through which he was able to embolize and put in all this Onyx. And so, the first thing we did was we enlarged the craniotomy. Then I got control over the sinus, and separated the sinus from the cavernous malformation and cut the tentorium. And then it really became very easy. You can see the sparking from the Onyx as I just crudely remove the center of the lesion to get more working space, but very straightforward. Once we had separated the sinus approximately and distally, and allowed us to remove this lesion with relativities. Next. In here, you can see the post op. The large cavity filled with CSF and the smiling young man. And I was very disappointed that his Italian mother kissed him instead of me. Here, I had the ability to get a one-year follow-up. He was a great student and a great athlete. And you can see the reshifting of some of the structures. And then finding a nine-year follow-up where still he's an excellent student and soccer player. I think the safe entry zones are the big learning that we have received from all these cavernous malformation. There are so many places we can enter safely, as long as we know our anatomy and as long as we have learned from our experience. So, you notice that we don't go around where the seventh nerve and the sixth nerve nucleus is. Next. All these approaches we've summarized in these two Atlases that are readily available from Thieme. So, in conclusion, what I really wanted to emphasize is when to operate and when not to operate; surgical resection of symptomatic and accessible cavernous malformation is reasonable; anatomy, anatomy, approach anatomy; appropriate exposure allows your removal; but without image guidance, we couldn't do this; and I obviously liked to have minimal retraction, so that we don't have secondary injuries. Next. So, in conclusion, I wanna thank you for your attention, and I hope we can learn something from these fascinating lesions.

- Thank you so much. Incredible lecture, as always, illuminating. Really amazing wealth of knowledge and huge legacy. Absolutely huge legacy. Very few people can claim such a legacy you have had. Before we close up today, I wanted to ask you, what are the pitfalls that you have seen young neurosurgeons who are passionate about neurosurgery run into? We have, not very often are fortunate. Not very often fortunately have seen very technically good surgeons get into practice after residency, and they run into trouble from different perspectives trying to be too bold, too confident, not understanding the limits of surgery or at the same time, not having the right temperament and collegial personality. As we know, technical aspect of neurosurgery is only part of the business. There's a lot more into neurosurgery to become an innovator, a leader, and truly a surgeon that you have become. So, if you could tell me what are the pitfalls that you would like to alarm or warn young neurosurgeons to watch out for, I appreciate it.

- Thanks, Aaron. I think you answered every one of the critical points. I think when you're young and you're going out into practice, the hardest thing to do is really to recognize that you're nowhere near the end of your journey, but you're really at the beginning of your journey. And there are number of things that are very important. Just don't take on the big case that start offer. Take on what you are comfortable with, where your results are gonna speak for themselves and where your referral base recognizes your skill. As you stimulate good results, you then can venture into more and more difficult cases. The golden rule applies. When you see a patient in front of you and their family, make sure that what you are recommending to them is exactly the same thing you would recommend for your loved ones and for yourself. Keeping that in the back of your mind will always get have you give the right recommendation.

- I truly appreciate all your thoughts. It's been truly an illuminating lecture. I already answered some of the questions. Doing the hiccup, we had, we had consistently over 270 people staying for the whole lecture, which is incredible. Everybody is really typing in, you know, capital letters, "Amazing presentation, Professor Spetzler. Congratulations. God bless you and your mind and hands and teamwork." Everybody is truly thankful to you for what you have done for neurosurgery. There's absolutely no question about that. So, with that in mind, I wanna again, thank you so much for being with us this evening, and I hope that we can have you again with us, knowing that there's so many fans of yours on this platform to see you again. Thank you so much.

- Thank you, Aaron. It was a pleasure. And I wanna send my greetings to all my friends around the world.

- Thank you. This is officially the closure. We love to have you again. I know you have a lot of canned lectures that are all spectacular. We're not gonna bother you too soon, but just keep us in mind. We love to have more people have the right platform to see the amazing videos you have, because I think zoom or some of the other platforms don't do the justice.

- This is, this is really despite the hiccup, and I'm used to hiccups, this is by far the best platform. Really remarkable quality.

- We really appreciate it. You have a great evening. Thank you.

- Thank you.

- Thank you. Bye.

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