Theodore Schwartz

April 18, 2022

Transcript

- Colleagues and friends, thank you for joining us for another session of the Virtual Operating Room from the Neurosurgical Atlas. My name is Aaron Cohen-Gadol from our Atlas team. Tonight our guest is Dr. Ted Schwartz from Cornell Neurosurgery. Ted is truly an innovator, an internationally known innovator in skull base surgery as well as epilepsy surgery. His contributions in pushing the boundaries and refining the techniques of microsurgery across the skull base, specifically through the transnasal approach, is unparalleled. Today, however, he's going to talk to us about another topic which reflects his innovative spirit, and that's transorbital approaches to the tumor along the skull base. Importantly, he's going to have a course at Cornell on June 4th and 5th, I believe, Ted, where he will review this innovative technique at length. So I invite you to join the course if possible. He's going to talk to us at the end of the talk, his talk about that as well. Ted, you've been a dear friend. I've followed your career. You've been such a role model for so many of us. So tonight I'm really excited to learn from you specifically about this technique, and let's go ahead and just jump in, thank you.

- Aaron, thank you so much for having me. I'm excited to talk about this. You know, we both started out many years ago as epilepsy fellows with Dennis Spencer, so let's not forget about our epilepsy roots that took us to the skull base.

- Right.

- We can't overlook that.

- I agree with you, Ted, but you know, we both continued the epilepsy, at the same time, remained innovative, and I think in your case you took advantage of taking the endoscopic, endonasal surgery truly to a new level. So I'm really proud of what you have done and very much looking forward to learning from you, so let's go ahead.

- Well, you know, Aaron, what you've accomplished with this Atlas is really remarkable.

- Thank you.

- And it's an honor to be here, so thank you for having me.

- You're welcome.

- So why don't we start with the first slide. You know, I'm mostly known for the endonasal work that I've done, and I've started to do more and more work with the transorbital approach, and I really am excited about it, and it's something I wanna try to introduce to the world more so than it's already been introduced. You know, a lot of people do use this approach around the world but less often, I think, in the United States, and I think it's an approach that's not fully appreciated. And so I've learned to appreciate this approach more and more and introduced it into my practice, and that's what I wanna talk about. So I'm gonna start out with sort of how I got to the transorbital approach and the parallels with the endonasal approach, 'cause, you know, endonasally, I started out, I had never done a course, sorry, a case, endonasal course. I took my first course in Bologna in 2002 and learned how to do these approaches from these incredible Italian neurosurgeons. And then I teamed up with an ENT, and we did our first case in December of 2003, which is now about 18 years ago, and since then, we started this Institute of Minimally Invasive Skull Base and Pituitary Surgery at Cornell. It was myself and Dr. Vijay Anand. You saw a picture of Dr. Anand there, and I learned so much from him as an otolaryngologist who taught me a new way to get to the skull base, and there are parallels with the transorbital approach, and that's what I'm trying to get to. So in that limited period of time, we've done about 1,500 cases. About half are pituitary tumors, and the other half are anterior skull base pathologies of a variety that you see diagrammed here in this figure. And this just shows you, you know, what our operating room looks like, and the point is that we became very facile using an endoscope, operating with an endoscope, using those instruments working down narrow corridors, and it was that endonasal approach and learning how to do it and cognitively making that leap into a different type of approach to the skull base, different instruments, different visualization that helped me grasp the transorbital approach. Now, over time, we got better and better at doing the endonasal approach. The results got better over time, the results improved. We knew which cases to select, and that helped us. We figured out what we could do and what we couldn't do, and we also learned how to do the endonasal approaches through a graded experience, and that's what I wanna talk about with respect to the transorbital approach is sort of how do you start doing transorbital approaches? Where do you come from, and what are good early cases to do, and what are more complex cases? The other approach that I began to incorporate into my practice after the endonasal approach was the supraorbital eyebrow approach, which I began to use for all my olfactory groove meningiomas and other pathologies that I couldn't get endonasally 'cause they were too lateral. And that gave me familiarity working around the orbit and opening up the top of the orbit and removing the roof of the orbit and looking at the skull base through a different perspective and then also bringing the endoscope in through that narrow corridor and looking around to see things that you can't otherwise see with the microscope. So this is an example of what you can see with the microscope in blue outlined here, and the orange is what you can't see with the microscope, but those are the areas that you can see with the endoscope. So this is how I think about the skull base and divide it up in terms of approaches. The red shows you the view of the endonasal endoscopic approach, which is really the midline and ventral midline. There is some lateral exposure, but you know, the carotid really gets in your way, and the cavernous sinus gets in your way, and the optic nerve gets in your way. It's hard to see past those structures endonasally. And then the supraorbital approach, in my hands, takes me to the anterior fossa and all the way down to the cribriform plate if I use an endoscope. And in yellow on the right, what you'll see is the areas that I think are useful to get to with the transorbital approach, and those are areas that I don't feel I can comfortably get to using a minimally invasive endonasal approach or a supraorbital eyebrow approach. And that's why the transorbital approach is so useful because it now suddenly opens up a new area of the skull base, that being the sphenoid bone, lateral wall of the orbit, middle fossa, Meckel's cave, and lateral cavernous sinus, and that's what I'm gonna talk about here. So this is just a brief, quick overview. I'll show you some more details of the approach, but we make an incision in the eyelid, retract the orbit gently over, and then the bone you remove. And this is one of four transorbital approaches. There really are four. I'm only gonna talk about this superolateral approach, and if you read the work of Kris Moe and Doo-Sik Kong and some of the world experts in the transorbital approach who have much more experience than I do, there actually are four different approaches. But this is the one that I've used mostly as my sort of workhorse, the equivalent of the transsphenoidal endonasally. And if you drill out the bone in purple there, and I'll show you more details of this, between the supraorbital fissure and the infraorbital fissure, greater wing of the sphenoid, it then exposes the middle fossa dura, frontal fossa dura, lateral wall of cavernous sinus, and Meckel's cave. One structure that you have to learn to appreciate and visualize and then cut is the meningo-orbital band with this approach, and this is just a good picture of it that I encountered during one of my operations, and I'll show you some videos of that. But once you cut that meningo-orbital band, and we're familiar with cutting that through orbitozygomatics and pterionals and various approaches around the temporal lobe. But here you're seeing it from the front, and once you cut that it, allows you to dissect the middle fossa dura off the lateral cavernous sinus and Meckel's cave, and that really opens up the whole corridor. Can we show this video? This is a video I borrowed from Doo-Sik Kong, and he was an expert who really taught me about this approach and helped me visualize what you could see. And what you see here is when you remove that sphenoid bone and you move the temporal lobe laterally, you then see where Meckel's cave is, and you see where the cavernous sinus is, and you get a sense of what's the view you're gonna get when you come in through this approach. And that's really the view of the skull base lateral to the carotid and Meckel's cave and things that are difficult to do endonasally. Next slide, please. Here is a video that I have. This is actually Doo-Sik Kong doing this approach, and I learned so much from him and watching him do this cadaver dissection, I wanna give him all the credit. And just like I traveled to Italy to learn the endonasal approach, I traveled to South Korea to learn the transorbital approach from Doo-Sik. So here he is, he's gone and and dissected the periorbita off the lateral orbital rim. He's retracting the orbit medially, and you'll see the supraorbital fissure there, and he's gonna show you that. And then here's a example of the bone to be removed. You can see the supraorbital fissure above and the infraorbital fissure below. And here he is drilling off the bone to expose first on the right, let's see if I can telestrate this. This is the temporal fossa. So this is the temporalis muscle, and this is the middle fossa over here. So the bone of the sphenoid bone is being removed. This is the dura over the middle fossa, so the temporal lobe will be through there. And again, the temporalis muscle's over here. Here's the floor of the middle fossa, and he'll remove more of the bone. And then here he's dissecting the middle fossa dura off the lateral wall of the cavernous sinus to show you the view of Meckel's cave. This is the trigeminal nerve down here, and this is the lateral wall of the cavernous sinus with the third, fourth, and sixth cranial nerves. Next slide. So what I wanna talk about and answer are these questions that plagued me at the beginning when I started doing the transorbital approach. What are the good first cases to learn? When do we remove the lateral orbital rim? Should I place a lumbar drain? Is that important to get retraction of the middle fossa? If I get a big CSF leak, is that a problem? How do I close the dura? What are the indications? What are the limitations? So when I started doing this approach, this is what worried me, and so these are the questions I wanna address. I just wanna emphasize that I learned how to do this approach from other people, Iacopo Dallan, Paolo Castelnuovo, Doo-Sik Kong, Kris Moe. Those are really the people who taught me how to do this approach. So I recommend you read their papers, 'cause they've done many more of these cases than I have. This is a figure that was made by Alberto Di Somma, who's in Barcelona. We went to a, I taught a course there. They're also very experienced in this, and you should read some of their papers if you're interested. Just showing how there's different stages of these transorbital approaches and different places that you can get to to fix CSF leaks, sphenoorbital meningiomas, trigeminal schwannomas, things in the cavernous sinus, and then even get to the Sylvian fissure, medial temporal lobe. Some people have done epilepsy surgery through this approach. So the important thing is to start out with simple cases, which are these extradural cases, and then to move on to more and more complex cases. So this was the first case that we did. It was a perfect initial case to do, and what it is is an epidermoid of the lateral orbits. You can imagine if we come in through a lateral orbital approach, we're gonna fall into this small epidermoid that's just eroding this sphenoid bone and the lateral wall of the orbit. So let's show this video. So here we are drilling out the lateral wall of the orbit, the sphenoid bone. We've retracted the orbit already. You can see the retractor on the orbit, and we fall right into this epidermoid. We're using an endoscope, and the first thing was just to figure out kind of where to put the endoscope, which instruments to use. And we found that using most of the standard endonasal instruments were really the best for us. Here we are using an angled suction as well, removing that epidermoid, next slide. Here was the next case we did. This was a metastasis. It was really sitting right in the greater wing of the sphenoid lateral orbit. You can see this would be a great approach to do through a lateral orbital approach. I'll show you that video. Can we turn on this video, please? So we're retracting the orbit. I usually have an oculoplastic surgeon help me do the surgery. They do the approach, retract the orbit for me, and then here you see we fall right into this metastasis. We're gonna do a biopsy. And then in order to get the whole thing out, we'll drill out some more of that lateral orbital sphenoid bone. And again, this is an extradural case, very straightforward, simple, gets you comfortable with the anatomy. Here I'm seeing the middle fossa dura for the first time, getting comfortable seeing that, and we remove that metastasis completely, next slide. This was another, now this is the post-op scan just showing you that met has been completely removed. Here's another metastasis to the orbital apex. You can see this small little lesion here. This woman had lost almost all of her vision, was no light perception. Here you see it's a little bit deeper, right? We're going past the sphenoid bone to get this out. It's in the orbital apex, pushing on the optic nerve. And here's post-op. You can see we did a nice little lateral approach and took it out. And again, this is an extradural case. These patients can go home the next day. It's not a very complicated operation, and I learned a tremendous amount from the oculoplastic surgeons. We got a little more adventuresome. I wanna tell you about this case. This was a case I first saw in 2013. This is a woman who presented with diplopia and was found to have a dermoid in her cavernous sinus. So the first approach I did was to come through the endonasal approach because the tumor presented itself to the sphenoid sinus. So we went in and we drained the dermoid, and she did very, very well. Her diplopia resolved post-op. You can see we drained the dermoid. We couldn't take the whole capsule out 'cause it was stuck to the cranial nerves in the cavernous sinus. But about seven years later, her diplopia came back, and she presented with a recurrence of her dermoid. And now it really didn't present itself to the sphenoid sinus, so we needed another way to operate on it, so we chose this lateral. Let's see if I can get this telestration thing. Here we go. We came in this way through the lateral orbit, and you can see it's a straight shot right into the cavernous sinus. So let's show this video. So here's the incision we made. We're retracting the orbit. We are now drilling off the sphenoid bone. You can see there's this triangular wedge that exposes the middle fossa dura. We take our curette, expose the middle fossa dura, just take a standard Kerrison. It's all endoscope-assisted, work our way medially. We have some frontal dura exposed above, and we're gonna expose the bone, the meningo-orbital band. That's the meningo-orbital band. We're cutting it, cauterizing it, again, our standard endonasal instruments. And now we're retracting the middle fossa dura, the temporal lobe off the lateral wall of the cavernous sinus. There's a little more meningo-orbital band that we have to cut. And then it finally releases, and we work in that plane until we get to the lateral wall of the cavernous sinus, and there's our dermoid, which we open up. And again, our goal here was really just to drain this dermoid because the wall of it is stuck to all the cranial nerves we're trying to preserve. So we really didn't think we'd get the whole thing out. But we did our drainage. Again, we're still extradural, so there's no CSF leak, but I was a little worried. So I used a button closure here with an inlay-onlay of AlloMax, covered it with Tisseel, and then let the orbit fall against the closure, next slide. So there we are showing post-op. This is the amount of bone we removed through the transorbital approach in order to get that tumor, and you see we don't have to remove that much bone. It's just that bone between the supraorbital fissure and the inferior orbital fissure. And here's post-op with the drainage of the dermoid, and it's been two years now, and it hasn't recurred. So she's doing quite well. So I wanna talk a little bit about trigeminal schwannomas. As you know, trigeminal schwannomas can locate themselves either in Meckel's cave, they can be in the posterior fossa, or they can be peripheral, and the endonasal approach is great if they're in Meckel's cave or they're peripheral, but it's really not great if the tumor's in the posterior fossa. So it turns out the eyelid approach and the transorbital root is excellent if the tumor's in the ganglia with a posterior fossa component, and I'll show you how that looks. So this is a peripheral case that's mostly in Meckel's cave, and this is a case that we did endonasally, and you can see that the tumor presents itself completely in the sphenoid sinus. So this is the kind of case you could do endonasally, and you go in through the anterior door to Meckel's cave lateral to the ICA just below the cavernous sinus. And here's the post-op film for that. The first trigeminal schwannoma, or not the first, one of the, the second trigeminal schwannoma that I tried to do endonasally looked like this, and it did present itself to the sphenoid sinus, but you can see there's a posterior fossa component. And postoperatively, the problem was I was unable to get this little posterior fossa component out, and that's because, let me get my telestrator. When you're coming in endonasally, you're coming in this way, and this is the view you see kind of in this direction. It's very hard to then make a curve and get this way endonasally. So I think it's pretty easy to come into Meckel's cave, but it's hard to make that turn at the very end to get to the posterior fossa, at least in my hands. So you could do a subtemporal approach, but another great approach is the transorbital approach. So the beauty of the transorbital approach is you're coming along the long axis of the tumor. The endonasal approach, as we showed coming in for medial collateral, doesn't get you to that posterior fossa component. The subtemporal approach is great for getting the tumor out. However, you do have to retract a lot of the temporal lobe. Whereas if you do the transorbital approach, the temporal lobe retraction is minimal, and the orbital retraction is minimal. So it gives you a straight-line approach down the long axis of the tumor. I learned this from Doo-Sik Kong, so I just wanna give him full credit. And this is a great example of pre and post-op of this kind of tumor that he showed me how to take out using the transorbital approach. Now, Aaron mentioned we're gonna have a course at Cornell June 3rd and 4th to teach this approach, and Doo-Sik is gonna fly in from South Korea to help as one of our instructors as well as a whole other group of international faculty who I'll introduce at the end of this talk. But I do wanna show you my experience. Now, one question is whether to remove the lateral orbital rim, and for some of these cases, we felt more comfortable doing that at the beginning because it gives you just a little bit of extra room, and then you can reattach it at the end. I don't think you have to remove the lateral orbital rim, it's not necessary, but when you're starting out, having a little extra room can be helpful to give you the confidence you need to do these approaches more comfortably. What about closure? How do you close these cases? Well, as I showed you, what we do is to do a button closure. So we just do an inlay-onlay of AlloMax with a suture in the middle. We don't harvest fascia lata. But the beauty of this approach is that unlike the endonasal approach where you're opening into an air-filled cavity, the eye will fall back and cover the opening that you make, and so the risk of CSF leak is extremely small. So the button closure I learned from the guys at Jefferson. This is their paper showing it above, Marc Rosen and Jim Evans. And it's this inlay-onlay concept with a suture in the middle where you put one half on the inside, one half on the outside, and I think it's great for the transorbital approach. And then we published a paper afterwards where we basically said you don't need fascia lata to close the skull base. You know, you can use AlloMax acellular dermal matrix so you don't have to make that incision in the thigh. What about lumbar drains? So there have been excellent, an excellent paper out of Pittsburgh. It was a randomized study showing that lumbar drains make a difference in high-flow leaks. We published a paper showing that lumbar drains make a difference in our obese patients with high BMIs. They definitely help prevent CSF leak. So lumbar drains do help prevent CSF leaks in high-risk cases, but it turns out you don't need to do, place a lumbar drain for a transorbital approach because the endonasal approach is very different because that air-filled cavity really doesn't give you any sort of packing, and it doesn't tamponade that space, whereas the orbit falls back and tamponades the space and reduces the risk of CSF leak. So this was the first trigeminal schwannoma that we did transorbitally, and you can see how it's a nice approach coming here. You just have to drill out this bone at the lateral orbit, retract a tiny bit of temporal lobe, and you're right in the tumor, and you can work your way down the long axis of the tumor and take the whole thing out. So let's go to the video tape. Can we show this video? So here we've taken off the lateral orbital rim. We have a little silicone sheet that retracts, that helps us retract the orbit over. There's the supraorbital fissure above. We're drilling out supraorbital fissures up here, drilling out the sphenoid bone, and we're gonna get to the middle fossa dura. Here's the meningo-orbital band, which we've cauterized and then we're gonna cut. We use the standard endonasal bipolar here. We're retracting the dura off lateral Meckel's cave. And then we get right into the tumor, and we take a biopsy, and then we start to debulk the tumor. So we have one person holding the endoscope, and then we have standard endonasal instruments, and we use a, so I guess it's a three-handed approach here. Here you see we're getting that last bit of tumor out of the posterior fossa, and you can see the CSF and the nerves in the posterior fossa. Here's the trigeminal nerve medially, totally exposed once the tumor is out. Here's our button closure with an inlay-onlay of AlloMax, and then we just close the lateral orbit rim with some miniplates, next slide. So post-op, you can see a gross total resection of the tumor, and you can see the pathway that we take and how little retraction there is of the temporal tip. This just shows you T2. You can see interestingly here, here's that little button closure that we did. And this shows you the bone that we removed, really very little bone of the lateral orbit. And here you can see the plating of the lateral orbital rim. So this was a bigger schwannoma. This was a woman who presented with a frozen globe. She had significant proptosis and this very large mass that was in her cavernous sinus in the back of her orbit. We weren't really sure which nerve this was coming off, but it seemed like a great transorbital approach. You could see there's a pretty large, extensive skull base tumor. Because it was so big, we removed the lateral orbital rim. We started out the case using the microscope and not the endoscope because it was such a huge tumor, we wanted to debulk it, and we thought we could do it faster with the microscope 'cause there wasn't much room in there. And then we brought the endoscope in at the end of the case, so we'll show you the value of that. So let's watch the video. So here's the view with the orbit retracted. Over here you can see we have a microscope. It's rectangular, but we do the same approach. Here we're removing that tumor in fast-forward. Now, we relax the orbit every 20 minutes. It's very important when you do this approach that you relax the orbit every 20 minutes and check the pupil, make sure you're not putting too much pressure on the orbit. Here we're removing the tumor, and then we go in deep into Meckel's cave with the endoscope so we can really see and look around. We have an angled, here we're using a straight suction, then we can go to the angled suction. This is just showing in fast-forward taking out all that tumor from deep within the cavernous sinus, cleaning it all out. And the endoscope obviously opens up, once you have the cavity, it gives you a great view around the corners that you really can't get with the microscope working through such a narrow corridor, next slide. So here's the post-op film showing you a near-gross total resection of the tumor. There was some tumor going into the sphenoid sinus that we didn't need to remove, honestly, in this woman. So she did extremely well, and again, these cases, these patients can go home in a day or two. I wanna talk a little bit about spheno-orbital meningiomas. These are tumors that also are in the lateral orbit. They invade the bone, they cause hyperostosis, they cause proptosis. And sometimes there's a large component in the middle fossa, but sometimes there's really not a large component in the middle fossa. So the first case we did was a case where it was really just hyperostosis of the sphenoid bone, no middle fossa tumor. And I think this is a great case to start out with spheno-orbital meningiomas 'cause your goal of surgery here is really just to drill down the greater wing of the sphenoid. It's exactly the bone that is easiest for us to drill transorbitally, and it makes a lot of sense to do the approach this way and not have to do a craniotomy and take down the temporalis muscle, cause a whole cosmetic problem. You're never gonna get 100% of this tumor out. It's invasive of the skull base. You just wanna get the majority of the sphenoid bone out and relax that orbit and get rid of the proptosis. So here's the view again, lateral orbit, hyperostotic sphenoid bone. I'll show you this first case. Can we show this video? So here we're drilling out the hyperostotic sphenoid bone, and it's a lot of drilling, but it's a beautiful approach because you're very quickly there. You're immediately staring exactly at the abnormal bone. You don't really need to take that much of the dura. Here's a small blood vessel that was supplying the temporal dura. I think that's it. So let's go to the post-op film. So this just shows you on the top pre-op. I'm gonna show you with the telestrator. Obviously this is the hyperostotic bone here, and this is post-op. You can see all that bone has been removed. And here we did not remove the lateral orbital rim. And you can see it's a beautiful, minimally invasive way to get all of that bone off. The same amount of bone that you would get off through a craniotomy we can get out through a little incision in the orbit and relieve the proptosis, and the eye falls back beautifully. This was another case that we did that was a bit more extensive. You can see there's an enormous amount of hyperostosis here, not just of the sphenoid bone but of the frontal bone. And here we had to get the anterior clinoid off as well. This shows you, I guess pre-op on the left, post-op on the right, the amount of bone we were able to remove. Let's see, I think I have a video. Yeah, this is just a paper by the Barcelona group, Alberto Di Somma, Joaquim Ensenat. I'm showing you that it's actually possible to remove the anterior clinoid through this approach. If you go a little, this is the normal wedge, but if you go just past the supraorbital fissure, you can see the anterior clinoid. Let me just get a telestrator. So the approach that I've shown you up till now was taking off this sphenoid bone here. But you can expose above the orbit up this way and remove the clinoid in blue. It's on the lateral side of the optic nerve. So you do have free access to the anterior clinoid. You can see it here in green is the anterior clinoid, whereas this is the sphenoid bone in blue. So let me show you how we did that. Can we play this video? So here's the approach, a lot of drilling, you know, which literally was like an hour or two of just drilling and drilling bone to get as much off as we possibly could to get all the way back to the middle fossa dura. Here we are flecking off that last bit of bone, and then we'll start drilling past the supraorbital fissure here. We're first we're gonna cut the meningo-orbital band. We had to do extensive drilling just to find the meningo-orbital band. But once we cut that, it allows us to retract again that middle fossa dura away out of the way, giving us a little more exposure of the frontal dura and the anterior clinoid. And the clinoid is just above where I'm cutting now, so we're gonna start drilling that. Now, what's interesting about this approach is that when you think about doing a clinoidectomy from the outside in, you really have to remove the entire clinoid in order to decompress the optic nerve. But when you're drilling a clinoidectomy from the inside out, you don't have to remove all the clinoid. You just have to remove the medial and inferior part of the clinoid, 'cause that's the part of the clinoid that's compressing the optic nerve. So you could really do sort of a hemi-interior inferior clinoidectomy in order to decompress and open up the optic canal. You don't have to do as extent of a clinoidectomy 'cause of the direction of the approach, next slide. So this shows you post-op. Let me get my telestrator working. I can't see the whole thing, but here, you can see the bone above. And then this is obviously on this side all the bone that we've removed in comparison. You can see how extensive that hyperostosis is above. So great approach for a case like this. And you don't really have to open up the dura at all. This is her eyelid showing you that approach and the cosmetic closure. What about intradural spheno-orbital meningiomas? Well, the one that we tackled was a small one. And again, you know we have, don't have as extensive experience as some other people who might tackle bigger cases, but we have done quite a few cases. This woman had a lot of edema in her temporal tip. She had this small spheno-orbital meningioma with a little bit of hyperostosis that you can see on the other side. So we thought this was a good case to do transorbitally. If there was a very large intradural component, I would consider doing a craniotomy, although it's you, you could do it transorbitally. It just depends how comfortable you are with that. Show this video. Here's a little more detail of the oculoplastic surgeons doing their approach, identifying the orbital rim, retracting on the periorbita. But then you get this same view down the lateral wall. We're drilling out the greater wing of the sphenoid. There's the supraorbital fissure above, drilling out the sphenoid bone. We'll get to the middle fossa dura. There's the anterior fossa above the meningo-orbital band. And then the middle fossa is below, and then here's the meningo-orbital band. We're actually using a standard bipolar here, cutting the meningo-orbital band. Now, the tumor is at the temporal tip. So we're gonna open up the dura of the temporal tip, and we'll come right down onto this tumor, which we will internally debulk, cauterize it away from the temporal tip. There was a large draining vein that we had to avoid and then get the tumor out as well as its dural attachment. Closure here, we did an inlay of Duraform, and then we'll do a button. There's the Duraform, and then we do a soft closure inlay-onlay of AlloMax. There's the inlay of the AlloMax, and then we have the onlay. There's again, we're finishing the inlay and then the onlay and then a little Tisseel, and then just let the orbit fall back and cover the defect, next slide. So postop, tumor's gone. We took as much, we could've taken more of the dura if we wanted to take more dural attachment. We took what we thought we had to do. And then all the hyperostosis is also gone, so essentially gross total resection, or you could say a Simpson Grade I. And this just shows you the T2, how, you know, you see there's really no brain retraction here. The edema's resolved. And you can see that little black piece of, here you see that little black piece of closure material that we used. This is three months post-op. This was another case that we did. This is a lateral cavernous sinus. Actually, I just spoke to McDermott. I asked him, like, "How do I classify this meningioma?" I wasn't sure, so he said it this is called a middle fossa lateral cavernous meningioma. That's what he called it. So it's partially a middle fossa meningioma, but it's also attached to the lateral cavernous sinus wall. But again, we thought this would be a great approach for the transorbital, come down the barrel of the tumor and really do very, very little retraction of the temporal lobe. Don't put the vein of Labbe at any risk on the dominant side. Can we show this video? Okay, here's the transorbital approach. We're used to it now. Here's the meningo-orbital band. We're gonna cauterize and cut it. You see the middle fossa dura below. We're gonna retract the dura off the lateral wall of the cavernous sinus. You'll see a little bit of the cavernous sinus nerves there. And then we're gonna open up the dura of the temporal tip, and we will soon get to the tumor. Here's the tumor. It was very firm and fibrous. We used a Cavitron to debulk it, 'cause it was so firm and fibrous. Here we're using the Cavitron. You see we're retracting literally just a, you know, maybe a centimeter of the temporal tip, that's it, coming right down into the middle of the tumor, and then dissecting it off the medial temporal lobe. This woman actually presented with seizures and a had very severe seizure disorder. And then here we are taking out that meningioma, and then get hemostasis, a little irrigation, some Floseal, some Surgicel to line the cavity. There's some Floseal and then an inlay of Duraform. And then you'll see we'll do our button closure with an inlay-onlay. Here we tried Duraguard just to mix it up a little bit, inlay-onlay of Duraguard. I think the AlloMax works a little better, personally, and then some Tisseel on top, and again, just let the orbit fall back on it. No lumbar drain, no CSF leak afterwards. Next case, next slide, excuse me. So here's the post-op scan, gross total resection of the tumor. So we've also written a couple papers on this approach showing that it's possible to get to the infratemporal fossa as well and the parapharyngeal space if you go more inferiorly, depending on what bone you drill out, This was a woman who had a recurrent GBM. This is, I think she was like eight or nine years out from her first surgery, and she needed a biopsy in the infratemporal fossa. So we did a transorbital biopsy just for staging so she could be treated. We've done an anatomic cadaver paper showing that you can use the transorbital approach to expose the Sylvian fissure. And in theory, you could clip an MCA aneurysm through this approach, although we have not. And vascular surgery is not my specialty, but this was more of a proof of concept. So here are the answers to the questions I posed. What are the good first cases to learn the approach? Well, metastases for us were great extradural cases to do. I showed you those, the sphenoid bone and the temporal tip in the orbital apex. Spheno-orbital meningiomas that are only hyperostosis with no intradural component, those are also extradural cases or excellent first cases to do. You get used to drilling out all the bone. When do you remove the lateral orbital rim? Well, for larger tumors, if you have to get a gross total resection, you need a more medial view, 'cause it gives you that lateral to medial view. Ultimately, I don't think you ever have to do it, but you can do it, and it may be something you wanna do in the beginning with the bigger cases to give you more comfort. Do you need to place a lumbar drain? Honestly, I don't think so. We had one case early on that had some swelling in the eyelid, and we weren't sure if it was CSF or not. So we thought it might be a pseudomeningocele, and we put in a lumbar drain, but I'm not sure it really was a pseudomeningocele. It might've just been orbital swelling. We closed the dura with a button, soft closure inlay-onlay AlloMax, more than enough. Other people use even less than that. And what are the indications and the limitations of the transorbital approach? Well, I would say only take on tumors where you think you can do a better job using a transorbital approach than you could do with another approach. If you don't think it's the best job for the patient, then you shouldn't be doing it, and as time goes on, that will include more and more cases the more facile you get at it. The cases take roughly four hours. They spend anywhere from two to three days in the hospital. The range is one to three, the average is about two days. If we looked at some ophthalmologic parameters, their proptosis got better by about three millimeters, and their visions remained unchanged. This is 'cause I collaborate with the oculoplastic surgeons. They do some more extensive examinations of the eye after surgery. Symptom improvement, 40% improvement in pain in the eye, vision better than 30%. There was some diplopia, and diplopia improved in 30% of our patients, excuse me. Cosmetically, they're, definitely don't look great in the first day, and that's really just about telling the patients to expect you're gonna have a black eye, but you can see about a month or two later, it starts to look completely normal. So there is one complication I wanna mention that we got. I'm not sure why we got it, but I felt obliged to mention it because obviously if it is something that could happen more frequently, we need to know about it. But we had a case of Terson syndrome, and I remember, you know, from studying aneurysms what Terson syndrome was, but it's basically blood in the vitreous body of the orbit. It was discovered and described, excuse me, in 1881 by a French ophthalmologist, and I learned about it associated with subarachnoid hemorrhages. You can get it from TBI, and it's thought to come from a sudden transient spike in intracerebral pressure that's transmitted along the optic nerve sheath, which gives a rupture of the retinal vessels, and then the treatment is a vitrectomy. So we did a patient who had 20/20 vision pre-op. Post-op day one, she had some blurry vision in the left eye, the eye where we did our surgery. She was discharged home, and surprisingly, for some reason her sister, instead of putting erythromycin on her eyelid incision, actually put Krazy Glue on it. So she came back for surgical debridement of that, and they realized that her vision was still blurry, and they did a fundoscopic exam and found that she had a multi-layered hemorrhage in her retina consistent with Terson syndrome. And she was then seen by the retinal surgeons. This just shows here her OCT showing this subretinal hemorrhage that tracks along under the inferior arcade, shows you a beautiful view of it. And at one month, they observed it. They thought it would go away, and it didn't really go away. So she had a vitrectomy and had it repaired. And you can see they were able to take out that small hemorrhage, and her vision got better, and it continues to improve after that. So that's just something to know about, that we did have this one case of Terson syndrome. I've never heard of it reported before, but obviously it's something we wanna make you aware of. So my new Vijay Anand is Kyle Godfrey. He's the oculoplastic surgeon that I do these cases with, and he's, you know, shown me things about the approach just like Vijay showed me things about the nasal approach that I wasn't comfortable doing on my own, and it was only because of that collaboration with oculoplastics that I felt comfortable taking on these new cases. And I do feel now that I can offer these transorbital approaches to my patients and get them a better outcome than I could through a standard craniotomy. So the conclusion here, transorbital approach is a versatile approach to the lateral cavernous sinus, Meckel's cave. You can even get back to part of the petrous apex and of course the lateral orbital wall and the sphenoid bone. The trajectory is often more favorable than a more traditional transcranial approach. The use of the endoscope and lateral orbital rim removal can be helpful in large or difficult cases. There's minimal brain retraction, if any orbital retraction. Also is well tolerated as long as you relax every 20 minutes the orbit, check the pupil, make sure it's still reacting, and then you go again for another 20 minutes. The key is to collaborate with oculoplastics. That makes me comfortable. I think Doo-Sik does this on his own in South Korea. I think he does the whole approach on his own, but I feel more comfortable doing it with an oculoplastic surgeon. It's fun to have a collaboration with another surgeon, so I really enjoy that. So I do wanna highlight that if you're interested in learning these approaches, we have a course on June 3rd and 4th. I'm directing it with Kris Moe, and we have a great international faculty, Paolo Castelnuovo's coming in from Italy as is Matteo de Notaris. From Barcelona, we have Alberto Di Somma and Joaquim Ensenat. Paul Gardner's coming up from Pittsburgh, 'cause he has a lot of experience with this approach. We have two visiting individuals from South Korea, Doo-Sik Kong and also Chang-Ki Hong, who's gonna talk about temporal lobe surgery that he's done extensively through this approach. People have done insular surgery through this approach. And then Darlene Lubbe from South Africa is coming, and she's taken out quite a few spheno-orbital meningiomas. So it's a remarkable course, I think. It's a two-day course. There's gonna be hands-on experience in the laboratory with cadavers, and then there's also a virtual option. If you wanna just watch virtually, you know, you can tune into the lectures, and then there'll be a pro section that you can watch and register for virtual attendance. So Aaron, thank you very much for hosting me. It's really been a pleasure. I don't know if you have had any experience yourself with the transorbital approach or thought about it. I'd love to hear what your thoughts are as an experienced skull base surgeon seeing these approaches. I'm sure you've read some of the papers.

- Yes, I have. You know, I've done a few of these, and my challenge with them has been that they're very select cases that are really applicable for this kind of surgery. As you, you know, you're a very busy tumor surgeon, and I think over 15, 20 years, you have had about 15, 20 cases, so.

- Well, I only started doing it about three years ago, right? So it's not over 20 year.

- Oh, I see.

- I haven't been doing this my whole career.

- Oh, I got you, so I misunderstood, I'm sorry. So the bottom line is that the select, the tumors that are applicable are very few, number one. Number two, a number of them are asymptomatic or are minimally symptomatic because these are relatively small tumors in such a location, and so one has to be really careful about what kind of, you know, if they're surgical or absolutely not, or you know, that's a relative indication question that's obviously beyond the scope of this discussion. So there's no question it's a nice approach. It's really very select cases and therefore has to be used as needed. And that's why I think although it's very effective in the select cases, its applicability is relatively limited. So that's really been my personal experience. The other issue that I have experienced is that it usually takes longer. I can do through a minimal pterional craniotomy, I can do it probably half of the time. That could be the fact that I've done much, you know, fewer than other people. But I think the time is important for me, not important to everyone, but if, you know, I can do it in an hour and a half, two hours through a minimal pterional versus, you know, three to four hours through a transorbital, I think that's something that one has to exercise judgment, so.

- You know, it's funny you mentioned time, because one of my favorite sayings to the residents when I'm teaching them about minimally invasive surgery, any minimally invasive approach, whether it's endonasal or supraorbital, I say, "These approaches are harder on the surgeon, and they're easier on the patients." So just because it takes longer doesn't mean it's an inferior approach, 'cause the goal is not the surgeon's convenience. The goal is the patient's outcome. So the real question that we have to ask ourselves is not can I do it faster a different way, but will the patient have a better outcome? Will the cosmetic outcome be better? Will the temporal lobe retraction be better? That's really the essential question. And the reason I'm excited about these approaches is that, at least in my hands, my patients, for the select, as you said, select cases, if you select the right cases, in my opinion, they do better with this approach than a transcranial approach. But as with the endonasal cases, we learned that just because you can do it that way doesn't mean you should do it that way and that sometimes cases that some people will say, "Try endonasally" really should be done with a craniotomy. And if you bite off more than you can chew and you don't select your cases right, you're gonna have bad outcomes.

- Right.

- So the indications for the transorbital are somewhat limited, but there are many approaches that we do transcranially where we only do it five or six times a year. How many pineal tumors do you take out every year? Just a couple, right?

- Very few, yeah.

- But you need to know how to do the approach when those pineals come around. And so I feel the same way about the transorbital approach. It's approach that we should know how to do. It's not gonna be your main approach for everything you do, but when the right tumor comes around, in my hands at least, is the right approach to do for certain cases.

- Absolutely, which brings up the most important point is that as a skull base surgeon, you have to be really equipped with every skull base approach. You're not an endonasal skull base surgeon. You're a skull base surgeon that can do endonasal, transorbital, transpetrosal, you know, supracerebellar, a whole 360. This idea of us as surgeons believing, "Okay, I'm an endonasal skull base surgeon," it's extremely unfortunate because what it does it that it pigeonholes you into doing tumors endonasally when they're a better fit for other approaches because there is that subconscious bias that we all have. No matter how much we think that the, you know, the patient's interest is the only interest, subconsciously, because we do it that way, we feel like that's the best way to do it. So if you're a very skilled skull base surgeon, you have to be able to do endonasal, transorbital, supraorbital, you know, transpetrosal and really have that complete comprehensive approach to the skull base, that's just so critical. And therefore transorbital is one of them, and one cannot oversee that significance, don't you agree?

- Yeah, absolutely, I do agree. The other comment you made was about sort of indications for surgery, and obviously if the patient doesn't need surgery, they don't need surgery, and then they shouldn't be getting a transorbital approach if they don't need surgery. The tumors that we have taken out that were small were patients that had a lot of edema in their brain from a small tumor. We didn't wanna make it worse with radiosurgery, or they had proptosis that was getting worse from a spheno-orbital meningioma, something like that, double vision from a small dermoid tumor, what have you, whatever the issues were. Certainly if they're asymptomatic, we don't do anything. We may follow it, but if it's growing and it's gonna cause symptoms and it needs to come out and the approach is it's suitable for the transorbital approach, it's been very helpful for me to gain a facility with that approach and be able to offer it to my patients. 'Cause the truth is, when a patient is told, you know, "Well, you know, we can either do this and take down your temporalis muscle and go around your temporal lobe and do that, or I can make a little incision in your eyelid and you'll go home in a day," it doesn't take a lot of convincing for them to decide what they wanna do, assuming that the outcome is the same, the ultimate outcome, that you're not compromising what you can do. Just like with the endonasals, we're not compromising what we can accomplish by doing a craniopharyngioma or a planum or tuberculum meningioma, as long as they're well selected, endonasally. Otherwise, you should be doing a craniotomy. And as I tell most people, 2/3 of my cases are craniotomies. Only 1/3 are endonasal. The majority are craniotomies.

- Right, right, I agree with you on it completely. And I said that in general, not specifically for your cases about indications, that in general you wanna be able to do these cases when they're symptomatic, which I think in all your cases you eloquently mentioned they have been or they have shown evidence of growth, therefore intervention was warranted. So all of that is extremely well taken. At the end of the day, I believe innovation in skull base surgery they have been demonstrated, it's truly what keeps us going, what keeps us excited, what keeps us really on the edge of being sort of the passion for excellence in innovation. And these are critical, these are critical aspects of neurosurgery. You don't wanna be static. I always say, "The moment you feel like you know everything and there's no space for innovation, that's time for you to retire" because that's really when you have lost that excitement, enthusiasm for neurosurgery.

- Yeah, look, think of there were a lot of people in 2005 who thought, "Endonasal surgery, too many CSF leaks, it's crazy. Who are these nuts who are doing endonasal surgery?" And now as we've shown, it's, you know, it's the right thing to do for all those cases. A lot of people thought Tesla was gonna be a bad stock. "Don't buy Tesla. Who's gonna charge their cars? It's crazy," but you know, it worked, it's innovation. I think the transorbital is the same way. I mean, you can be skeptical about it, but I think eventually it's gonna be an approach that we're all gonna do for certain select tumors, in the right hands, for people who are skull base experts who wanna spend the time to learn how to do it and wanna treat those cases where it should be applied.

- I agree, you know, I think the passion you have shown in innovation, your persistence, Ted, and demonstrating, you know, that we wanna compete with ourselves, we wanna demonstrate that every day we're gonna do something better and better. In other words, if we're doing something well, we're gonna do it even better the next time. And that sense of sort of what we call passion for excellence that I have, you know, emphasized so many times, such an important component of a neurosurgeon. And for you to be able to be as good as an athlete, to compete essentially with yourself and get better every day, I think that's the kind of passion that really I've admired you. And I think it's such a great example of a neurosurgeon who always wants to do better and better, and that always leads to better outcomes, in my opinion, for the patient. So with that, I wanna really thank you. Again, June 3rd and 4th, I mistakenly said 4th and 5th, in New York, Cornell University. It will be, you have amazing group of expertise coming in from out of country. I think this is a great opportunity to see how their people do it. The technique you are using through transorbital are applicable to other, you know, parts of skull base such as endonasal, potentially endoscopic, supracerebellar. So all of those are sort of makes us better, not just necessarily transorbital. So again, thank you, Ted, for being a dear friend, a great colleague, an immense writer and author and publisher, which I have followed you, all your publications very religiously.

- Aaron, thanks for having me. I'm a big fan of the Neurosurgical Atlas, and I really appreciate having this forum to present some of my thoughts no matter how crazy they might seem.

- Not at all, it was a pleasure. I learned a lot. Thank you again, Ted.

- Thank you, Aaron. Take care, good night.

- Good night.

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