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Grand Rounds-Surgical Stratagies for Resection of Medial Sphenoid Wing Meningiomas

Johnny Delashaw

June 28, 2011


- Hello, ladies and gentlemen, thank you, again, for joining us for another session of the AANS Operative Grand Rounds, my name is Aaron Cohen. The following session will be a discussion regarding technical nuances for resection of medial sphenoid wing meningeomas. These are challenging tumors to deal with surgically. Dr. Johhnny Delashaw will be on our discussion. We're gonna show a numerous number of surgical videos and discuss some of the complications related to surgical management of these tumors. I hope you enjoy the session, thank you. Johhnny, thank you for joining us for another session of the AANS Operative Grands Rounds. This is a discussion for surgical management of medial sphenoid wing meningiomas. These are the disclosures and acknowledgements, none of which interferes with the presentation today. Since the time of the Cushing, meningiomas along this sphenoid wing have been categorized as the one that are inner, clinoidal, versus middle, versus outer, or pterional. And today's discussion will focus on those meningiomas that are along the medial one-third of the sphenoid wing and clinoidal region. Sphenoid wing meningioma comprise about 20% of all meningiomas, and therefore, they're an important group of meningiomas. And we're gonna pay special attention to them in terms of their resection. So let's talk about the basic principles, Johhnny, and before we start, can you tell us some pearls about these tumors, that you always have kept in mind throughout your experience at least over/along the years?

- Well, the medial sphenoid wing meningeoma typically presents, with a patient who complains of headaches, blurry vision, possibly double vision. And it's very common for them to present with a seizure, tend to cause a lot of temporal lobe edema, and they present with the seizure. So those are the common presentation as far as the symptoms of the meningioma.

- And apart from resections, are there any special pearls that you always remember when they tell you, "Well, we have a patient with a medial sphenoid meningioma?" In terms of technical nuances, what comes to your mind, the top three, would you say?

- Well, in order to remove the tumor, one has to be careful with the following structures, the optic nerve and the internal carotid artery, which are going to be a buddy of the tumor and could be even adherent to the tumor. So one needs to be careful in that location to be able to see those early on in the surgery. And the other is that usually these tumors are fed by several different vascular structures, the middle meningeal artery can participate in it, it may not have a high role in it, but it can participate in it, the orbital meningeal artery is involved, and if the tumor lays along the middle fossa floor, particularly right near the lateral wall of the cavernous sinus, the carotid arteries coming off the cavernous sinus can be involved. And those cannot be embolized whatsoever and one's gonna have to deal with that bleeding throughout the tumor, until you get the lateral-wall portion of the cavernous sinus removed from the tumor. So those three vascular structures, typically, are involved in a medial sphenoid wing meningioma.

- Thank you. And, again, the presentation is with no confusion-altered vision depending on the size of the tumor exophthalmos, and if, obviously, evaluation with neuro-ophthalmologist and potentially endocrinologist would be important. Let's run through some of additional details. Again, these are the tumors along the medial one-third of sphenoid wing. What is most critical that can attach to the optic nerve, carotid artery, perforators, lenticular striate perforators, P-COMM and when one thinks about these tumors, really, the first thing that at least comes to my mind is dangerous surgery, critical structures around, and, obviously, careful microsurgical techniques. They can reach a giant size, and they may involve the bone and cause hypersteatosis, and, occasionally, they can be atypical, the management of which can be challenging. The imaging modalities are usually three of them, CT to evaluate the bony invasion, and hyperostosis, if there is any evidence of erosion. Other pathologies may come to mind in terms of differential diagnosis. MRI: it is critical in an MRI to evaluate the location of the neurovascular structures, especially the carotid artery, the middle cerebral artery, the anterior cerebral artery, along the tumor, are they displaced? Are they stretched? Are they incased? And I really get a good idea as much as possible on the MRI and obviously extend up through involvement should be determined on the MRI. Angiography to determine blood supply, We don't regular do an angiogram on any of these tumors, however, my question for you is, do you regularly embolize these or just very selected cases, Johhnny?

- It's usually very selected cases, and the reason why is, is that the approach for these meningiomas, we tend to devascularize the tumor very early in the process of just removing the bone and coming along the base of the skull. That embolization techniques have not been that helpful.

- Okay, I believe that very well as well, and we use angiography and aneurysm is extremely rare in these cases, because I think that MRI and MRA is clearly a very valuable tool to define the relationship of neurovascular structures. Let's talk about nuance of technique for a resection of these challenging tumors. There are four Ds of meningioma resection that I always mentioned to our residents, and the first is dedress the tumor. For a medial sphenoid meningioma, I have generously used a lumbar drain, why? Because if there is edema there's mass effect. If you have a lumbar drain at the beginning of the procedure, Johhnny, it really decompresses the brain, you can open the dura without the brain coming at you, and more importantly you can devascularize the tumor with a very peaceful train of the brain pushing against you. You can actually lift up the tumor with the brain, initially, to devascularize, because the lumbar drain has created such a decompression for you. And I have never had a competition from putting a lumbar drain and opening the drain, especially, when I'm opening the dura, even for very large tumors. Do you agree with that or have you used a different method?

- I'm a big advocate of the lumbar drain. I use the lumbar drain frequently, I think if I feel the brain, it's gonna be under some tension. Having the lumbar draining will help with relaxation of the brain, and make the surgery easier at the very beginning. I do wanna say that if you over drain at the beginning of the surgery, it may be a little bit difficult to open up the Sylvian fissure. And then these medial sphenoid wing meningioma you frequently need to open up the Sylvian fissure to find the middle cerebral artery, again, dissecting a plane between the middle cerebral artery and the tumor, and continue the arachnoid plane dissection along the internal carotid and the posterior communicating artery. So you wanna be a little bit careful not to drain too much so you still have some CSF within the Sylvian fissure, but I'm a big advocate of lumbar drain, I totally agree with you.

- Thank you. And then devascularized the tumor either extradurally with removing the sphenoid wing and clinoid, or along the sphenoid dual attachments when you open the dura, that's the second D, the devascularize. The third D is debulk, and stay away from the medial structure, especially, in the case of medial sphenoid wing meningioma. And lastly is dissect. And it's important to stay along the anterior and superior edge of the pole of the tumor, and identified the optic nerve cartiod artery, middle cerebral artery, early on and protect them, rather than running to them within the tumor during the debulking procedure, and place them at harm's way. What are the considerations? So you said that arteriogram and embolization are necessary, do you do OZ, or this modified OZ that you have defined in terms of removing every one of these or only the big tumor, so, Johhnny?

- Yeah, the medial sphenoid wing meningioma, I'd like to use arteriogram but I have to emphasize that if the tumor has caused hyperostosis of the orbit, then I don't use the OZ craniotomy because I worried that as I take the bone off, that, as I try to crack the bone off, I may take part of the tumor with it. So I'd either use two-piece or maybe it's someone who's older, I wouldn't use a two-piece at all, I just do entirely normal. I'm gonna remove as much of the hyperostotic bone, anyway, because it's tumor, and I'll have a very good exposure without having to take the orbital rim. So I tailor the craniotomy to the problem. New hyperkeratosis, I would use a nosy craniotomy, loss of hyperkeratosis, I would do arteriorenal, see how it looks. If I still think I need to take the orbital rim, I'll take it, if I don't need it, I'll leave it intact.

- Thank you. And how aggressive are you around the proximal artery and the perforator, especially for giant tumors? We're gonna show a couple of videos of complications of MOD, which you will see. I should have been more conservative around the perforators. In young patients, the tumor is very adherent to the proximal carotid. Do you become aggressive or do you have it low threshold to read tumor along the artery?

- It's a judgment call here. Inside the dura, in the subarachnoids space, if it's the first operation, they typically have a very good arachnoid plane. And I try to be pretty aggressive with that if it's a first-time operation. If someone else has operated on the patient or it's a recurrence of mine, or they've been radiated, then the plane is not necessarily that terrific. And I'll be a little bit more conservative in that location. However, once you deal with the dural rim, with falciform ligament or the dura right along the paraclinoid# region, that tumor loses its subarachnoid plane. And if it's extending to that area and it's beginning to involve the carotid artery around the clinoid, the extradural, extra extracavernous carotid, or the carotid within the cavernous sinus. There isn't a good arachnoid plane. And I'm pretty conservative with that. I will remove the soft tumor, I will remove what's easy, but if you start to get very aggressive there, you can easily get into a carotid artery injury, a hole in the carotid, hole in the perforator going to the optic nerve, and cause a complication. So, again, it depends, one, is it the first time? If it's the first time and it's a young person, that's pretty aggressive, first time in an older person is a judgment call. If it's a redo, or it's been radiated, one needs to be a little more conservative, I think, because the tumor becomes very adherent to the vascular structures and anything the third cranial nerve.

- Thank you. And so how far do we chase the tumor in the optic canal? Obviously, if the tumor is going in there, you wanna open the canal. And do you use interoperative monitoring for extraocular movements muscles, or no, Johhnny?

- I don't typically do that, some people do. I don't think it's a problem to go ahead and do that. It hasn't seem to be that important to me. Maybe it would be, maybe it'd be a good thing. It seems like a lot of monitoring, I just haven't used it.

- Thank you. And for meningiomas that you leave a little bit of tumor in grade I, do you follow them every year or how often do you follow those tumors, Johhnny?

- Yeah, so I think it depends upon what the pathology is. If I get a pathology of grade I, then I will follow the tumor recurrence about once a year for a couple of years, then maybe do an MRI every two years and follow along for maybe 10 years. And then maybe I'll extend it out to three or four years and then 15 to 20 years it might give up. If it's a tumor that's more atypical, then I actually will consider radiating the residual tumor. But it becomes a little bit more atypical if they have a very high recurrence rate.

- Thank you. Let's jump into some of the additional details. And obviously one more important fact is to not chase the tumor into cavernous sinus#. And ultimately the most important factor is these are mostly benign tumors and quality of life comes first, and not to be aggressive around the cerebrovascular# structures, if they will adhere. Simpson Grade is very important. I think no matter how aggressive we are, these tumors are usually resecting the grade ii fashion, even if you'd really decline, there's always a little bit of bone dura that is infiltrated by the tumor over the cavernous sinus. And so I think caution should be exercised in terms of being too aggressive to injure any of the cerebral vascular structures. I left this image just to emphasize against the lumbar drain for this tumor, especial medium and large size. You wanna get into a brain that is relaxed, you wanna be able to do vascularize early. And to do that you may need to retract the tumor before debulking it, and therefore having the extra space is important. This is a regular incision we use and the head placement, turning the head around 30 degrees. I'm gonna briefly show a positioning video, as you can see here, of a patient in the pin, then incision, and where the pins are placed above the ear and superior temporal line and the other pin is indeed behind the ear and this really creates some extra space where the surgeon can work. It's a lateral to where the pin and the tumor is located. Let's go ahead and very quickly talk about some of the details. This is the operating room set up, placing the surgeon across the table, from the assistance in terms of handling the instruments. Again, the incision and the head placement, cutting the scalp, placing the borough hole for a regular drain pterional cardiomyotomy, where we have mostly tried to remove this tumors through a regular pterional craniotomy, unless there is a significant cranial extension where we have used orbithypomanic. We placed the initial bare hole just underneath the superior temporal line in order to be able to dissect the dura off very generously. Usually, if you put a bare hole here, or along the keyhole, the temporalis muscle fights against your number three penfield to dissect the dura away from the inner aspect of the skull bone. And as you can see, the dura is stripped away from this orbital roof and lateral spinal ring resection is completed and we are very generous with removing the orbital roof and creating a very flat trajectory in terms of reaching the pedicle, or the root of the tumor, and at the same time you can devascularize the tumor extradurally by quite coagulating the dura. Any thoughts there, Johhnny?

- Yes, the comment I would make is as you're drilling this bone away, it may be very basked or maybe a little high basked to very basked. And as I mentioned in another video, the diamond vidro can be your friend, it can make the drilling safer, but it also can heat up a little bit and help the coagulate those bone bleeders to allow you to see well, but also as you're doing it, you're really devascularizing the tumor. And it's gonna make the tumor dissection, once you open the dura, much easier.

- Thank you. And here is opening the dura. You can remove the clinoid extradurally. This is obviously a right side of the approach, here is extended removal more immediately. And it comes very tight here because the tumor is very much adherents to the dura, you can actually cut the dura and do a hybrid intradural versus extradural clinoid removal, while splitting the fissure. As you can see here, this is a left sided approach. In this case, the dura has been opened in a T fashion and the nerve is identified early on. Usually, there'll be a tumor here. And you can debulk the tumor as you're continuing your clinoidectomy medially. This is a left side of approach, the anterium of sylvian fissure id opened and the bridge remains coagulated. Critical is, again, the lumbar drain would make everything relax here, you can devascularize the tumor along the sphenoid wing and that would make your job a lot easier later. A CUSA may be used to remove the tumor, and then further debulking is done and attention is paid to a long, to anterior pole of the tumor. The tumor is then decompressed into itself and the middle cerebral arteries identified. Any comments along these steps, Johhnny, please?

- The comments you've made are terrific. You really wanna split the fissure wildly, find the vascular structures and protect them. I love this diagram right here with your bipolar debulking the tumor. There's a little artery right there along the edge, and that artery, it's so tempting just to coagulate that, but literally most of these arteries, you can actually have them develop a subarachnoids plane and be able to peal that off the tumor and preserve those little arteries. And you really don't know whether those are perforators coming off the M1, and so it's real important not coagulate those arteries unless it's going directly in the tumor and as a tumor vessel. So spend a little extra time on those arteries, they almost all peel off, and you can protect them with the patty and just to move around the tumor. So those would be my comment. The other comment is, as far as you're moving the anticlinoid, it's terrific, as you've come down there and remove the anticlinoid, you'll be devascularizing the tumor, but these very large tumors, it can be very hard to see the clinoid. The tumor is such a mass that you can't pull the tumor extragirly or integrilly to see the clinoid. So don't try to get carried away, devascularized as much of it as you can from that approach, from along the floor, then take the mass away, find the middle cerebral artery, find the internal carotid artery, and if you need to remove the clinoid you can remove it near the end.

- Thank you. And here actually this section is showing some of the MCA branches. And, Johhnny, please feel free to use your arrow through if you like to. The arteries are carefully elevated with a suction and the micro scissors is used# to sharply remove these branches. A curtilum may be placed on these MCA branches. And, again, the attention is directed toward the anterior part of the tumor, why? Because you see this sphenoid wing and you know if you follow the sphenoid wing immediately, you're gonna run into the optic nerve and carotid artery. And you wanna identify those early. So debulk the tumors, work along the superior and the anterior and inferior pole of the tumor to identify the neurovascular structures, and here you can see the carotid artery, the optic nerve that was displayed, open over the tumor, and, again, the anterior pole of the tumor is being mobilized more posteriorly, keeping all the erectile membranes intact, keeping the P-Comm and the perforators at A1 out of harm's way. Go ahead, Johhnny, please.

- So right here in this diagram, here is the middle cerebral artery and the internal carotid. And the P-Comm artery is right here. And when you begin to see the P-Comm artery, begin to think about where is the ocular motor nerve? The ocular motor nerve is gonna be right next to the P-Comm artery. And it's important to keep thinking about that as you get that plane of the medial sphenoid wing meningioma so you can get it away from the oculomotor nerve. And if you can keep an oracular plane on the oculomotor nerve, you're not going to get a third-nerve palsy post-operatively. If you can't, then you may have a mild third-nerve palsy, which should resolve. But I think when you see that internal coronary, find the posterior communicating artery, and begin concentrating on where is that third nerve? So you're protected and prevent a third-nerve injury from your tumor resection.

- Those are great nuances, thank you. And, again, the posterior pole is now mobilized, knowing where the important structures are. And here is what you very well mentioned, Johhnny. This is P-Comm antercoidal. And just as you see the P-Comm once you think about it. Go ahead, please.

- There's the third nerve right here, here's the P-Comm, third nerve, a nice diagram here, the anterior pole, you also wanna see that. And this diagram shows that if you keep that arachnoid plane in this location, you're not going to get a third-nerve injury and the patient's gonna wake up when completely attacked. If you have to manipulate the third nerve, it will come back. So it's not the end of the world, but they will probably have a mild third-nerve pause after surgery. Try to keep theoretically play to this location, and you won't have that post-operative deficit.

- Thank you. And here is an illustration, really, telling our viewers that if the tumor is engulfing the proximal carotid, the perforators, and really attached to the optic nerve, to leave some tumor behind. Here, you can see, Johhnny, we left this tumor as the final product of our resection because it was really engulfing the whole segment. If you become aggressive, some of these perforation may look okay but the patient will wake up with a basal ganglia infarct, with a devastating injury, with an anterior cordal injury. Do you agree with that?

- I absolutely agree with that. When you get down to the area where you're getting close to the dural ring, where the optic nerve is, there can be very tiny perforators also to find the optic nerve, but you need to be careful that you could also cause blindness. So you can remove this tumor if it's easy, but if it's not incredibly easy, it's okay to leave a little behind. The other thing I like to emphasize, I'm not, I think, an advocate in this area right here to use the bipolar, I typically, actually, just take the tumor out with a spatula and a sucker, and I tried to avoid using the bipolar as much as I can because if I might end up coagulating the tiny perforators, they'll result in a large deficit. So I typically do this a little bit without the bipolar using spactulars and suction, in hopes of reducing my perforator injury.

- Thank you. And as you can see in this illustration, the tumor over the optic nerve was removed, but, the rest of the tumor was left intact to protect those structures. Let's go ahead and go through our most important part of the presentation, which is our cases. And here's a 75-year-old male, with a progressive history of confusion and speech difficulty. And I think this is his MRI, showing the tumor along the middle to medial one-third portion of the sphenoid wing and a part of the clinoid, and this is again a coronal and sagittal image, defining what a middle to medial sphenoid wing meningioma would look like. What is critical for me is, looking at the MRI and defining this MCA, the carotid artery, and knowing what is the location of this tumor to these structures? I think that is the most critical thing for a resident or fellow to look for, approaching these fissures. What are the other factors you look for on an MRI, Johhny?

- So T2-weighted image is really the image I like to use to find the vascular structures associated with the tumor. Here you are, this is a T2-weighted image, and you can see right here at the carotid bifurcation, the tumor comes up against it. You wanna be sure that the tumor is not surrounding the middle cerebral artery so that you know where that artery is. And early in the surgery, you wanna find this middle cerebral artery and protect it. Now this tumor is quite big and you know it's gonna involve a little bit of the internal chronic. It may be pushing into a chronic near you or maybe wrapped around it, and if you can find the vascular structure of middle cerebral early. As you did both the tumor, you can begin to go around the corner and then find the internal coronary and prevent an injury. So I always look to see if the tumor is wrapping around the middle cerebral artery or where it's extended so that I know what I'm gonna deal with early in the case, I split the Sylvian fissure early in the case, once I've got the door open, and find that so I can prevent brain injury. The other things you wanna look for is does it have cavernous sinus involvement? If it has cavernous sinus involvement, you need to counsel the patient about the fact that you may not get a complete removal, you may leave some tumor behind because quality of life is the most important. I will follow the tumor in the cavernous sinus. If it's soft, it's coming out easily, but if it's firm I typically leave that in the cavernous sinus and either follow it or radiate it, because I want my patients to leave the hospital with normal cranial nerves.

- Thank you. And here's the incision, the clamp placement. And let's jump into the surgical video and discuss those videos, I think those a very important. So here is that a patient's case, again, doing a left frontotemporal craniotomy, staying along the sphenoid wing and reflecting the dura, removing as much of the lateral sphenoid wing as possible. Go ahead, please Johhnny.

- Yes, so in this particular approach, again, it's the left side of the craniotomy, Dr. Cohen's done, a craniotomy, and he's now taking down the skull-based, right along the roof of the orbit. And by doing this, he's gonna improve it's visualization. But at the same time, as he takes this bone off, he's going to devascularize the tumor. This is gonna make the tumor surgery much easier. Coming down, he's coming down, he's gonna get the wing here, take as much of the wing off as possible. If he can get the coronary off through this approach, that's terrific, it's not totally essential, allows him to get completely around the middle part of the tumor, but it's not totally essential, but certainly removed as much of the base from the skull early on, leading the dural attack, it's just gonna make it that much easier when you open the dura.

- [Dr. Cohen] Thanks for Johhnny. And as you can see, again, removing as much of the bone early on, this was not a tumor affecting the clinoid, and the CT scan confirmed that finding. And here you can see the drill being used to remove the superior portion of the orbital roof and flattening really that's part of the bone as much as possible, filling those bumps that you see along the orbital roof, and making sure the inner portion of the skull is drilled away adequately, flat to the orbital roof. Go ahead please.

- [Dr. Johhnny] Yeah, what Dr. Cohen's doing here is, he's gonna get a nice, flat plane so that when he opens the dura, he's gonna run right into the tumor, right in the beginning of the case, and is gonna allow him to continue to de vascularize the tumor, and that's gonna be very important to increase this plane, 'cause once you de vascularized the tumor, the tumor tends to wanna fall away from the brain itself and makes the dissection easier. Here's drilling away more bone, I was going down towards the anterior clinoid is use a little bone wax to reduce bleeding. This is a great approach. You can also use, as I said earlier, a diamond vidro, the diamond vidro can help also remove the cyst.

- [Dr. Cohen] I have learned that the CSF rhinorrhea can be a big spoiler of a good surgery. And as you can see, laxing this area, maybe one more than once or twice, is very important and really removing as much of the bone here, Johhnny, as you clearly mentioned, is the key to get a low-enough trajectory and at the same time, both bipolar, this region of the dura under the retractor to get a very nice, de-avascularization early on. Obviously, if you have a lumbar drain, it really creates an additional relaxation where you can lift up the dural without necessarily placing the brain at risk.

- [Dr.Johhnny] So I think you're about ready to open the dura?

- [Dr. Cohen] Yes, I, you read my mind. I think we got enough bone removed and in a second, we're gonna open the dura. And we do take up the dural edges very regularly. Do you do that, or you are not a surgeon who believes in tagging up the dural edges?

- [Dr. Johhnny] Oh, I'm a big advocate of tagging up the dural edges. One is, it's gonna reduce the bleeding that goes into the cavity. The less bleeding you have, the more you can see. And then the dura edges here that you're seeing right here, as far as around the wing, it improves your visualization. Notice here, how Dr. Cohen has exposed the frontal temporal region, the tumor really is just right there. He's now developing a plane and splitting the Sylvian fissure# a little bit to get that plane. And as he devascularizing the tumor along the base of the skull, this tumor is going to fall away from the frontal and temporal lobe. He's, right now, revascularized the edges of the tumor developed a plane, and I think I got fortune to see this move forward, you'll see that he starts to debulk the tumor, to continually work along the base of the skull and devascularize it.

- [D. Cohen] These both loops are useful on very superficial parts of the tumor. Obviously, you don't wanna use it deep, where you can injure optic nerve or carotid artery, and they really do a good job in terms of making your debulking very efficient. And as the tumor is debulked, you just continue devascularization more medially, and try to focus on, now, the frontal portion of the tumor. Again, this is the frontal foster, this frontal lobe with the tractor, and trying to create a plane. This tumor did not have a clear plane along the arachnoid membranes, but again, the brain is being carefully dissected. Carotenoid maybe use to wipe the brain away from the tumor and keep the planes available and not missed. The tumors, part of them can be very fibers. As you can see, the other part of the same tumor can be very suckable with the bipolar and suction. And if you can remove as much of the tumor and debulk really aggressively without using your CUSA when you get more medial, it is much safer, as the CUSA usually has no mercy, right on the artery, even if you get close to it, it's vibrations can the wall of the artery. And unlike what surgeons believe CUSA does injure arteries very, very well, again, without any mercy. Wouldn't you agree on that, Johhnny?

- [Dr.Johhnny] I do, I think the Cavitron is a great instrument to debulk tumors, but when getting down to very fine structures, it can easily go up the Cavitron and result in a neurological deficit or vascular catastrophe. So again, I think it's important, when you get near the structures that you're trying to save, it's better to use scissors, bipolar and suction. There it is, he's getting ready, he's found the optic nerve here, as well as the arachnoid plane. He wants to be very careful not to injure into that area. And notice that he's still got a little bit of attachment there. And I think what he's gonna do here, is be absolutely sure where that optic nerve is, you see it right there. He's gonna be absolutely sure where the internal carotid is. And then he's gonna detach a majority of the tumor away from the sphenoid wing. And, that area is bipolar, once he does that, the plane between the brain and the tumor is going to dramatically change, and it's going to result in him having a much easier dissection. So again, I can't overemphasize how important it is to get the attachment early, but you have to see to get the attachment. So debulking the tumor's important to allow you to see and retract the tumor down to its detachment.

- [Dr. Cohen] Thank you, Johhnny, and as you very well mentioned, you do want us debulk just enough to mobilize the tumor, to go around anterior pole, identify optic nerve and carotid artery, and then come back and remove the additional attachments, knowing well where the important artery and nerve is. If you go all the way along this sphenoid wing, without knowing where the artery and nerve are, you can easily coagulate the nerve and injure the artery. So leave some tumor medially until you go around the anterior pole, identified the several vascular structures, and here is the temporal part of the tumor being delivered. And that when you devascularized, this whole tumor almost rolls to out. Obviously you wanna be careful around if there is an attachment on the MCA, here there was none. And you can see the tumor just delivering itself so well, and really makes the job of the surgery very efficient and effortless, almost. Go ahead, please.

- [Dr.Johhnny] Yeah, so again, you can see, by debulking the the tumor, Dr. Cohen said, surgery has become a lot easier. Sometimes it gets so easy, you really do need to make sure that nothing's attached to it. It's very easy to just try to remove the whole tumor in one piece. I can do that, it's fun, but you wanna make sure it's free of any important vascular structure. So if any doubt at all, still debulk it in large pieces, and be sure you're seeing all the vital structures so that you don't have an injury at the very last minute. It's so tempting to take out a big tumor in one peace, but that's not important, what's important is to get the tumor out and now the patient be neurologically intact.

- [Dr. Cohen] Thank you. And here is the last piece of the tumor being shredded off the dura and the dura is going to be a very well coagulated and if necessary, and the patient is beyond, a piece of dura in this region will be excised. Again, showing that optic nerve, keeping their arachnoid membranes intact and keeping all those neurovascular structures within their arachnoid membranes. Let's go ahead to our second case, Johhnny. I think this is a post-operative MRI, from our first case, showing adequate resection. 82-year-old female with a one-year history of progressive memory difficulty and speech dysfunction. And you can see this is a very medially-located meningeoma, almost along the medial sphenoid wing, and possibly arachnoidal, causing a lot of edema. And again, looking at where the vascular structure is important, and here's a surgical view. And let's go ahead and review the surgical video for this lady. This is our second surgical video for the meningeoma series. And here is again, a left frontotempora craniotomy and the tumor is being debulked early on, the CT scan did not show any evidence of hypostasis. And the tumor again, being devascularized early on, and then even without much retraction, if you debulk well, you can have the tumor falling into itself. Go ahead and tell us about your thoughts, Johhnny, please.

- [Dr. Johhnny] So in this particular case, this is somebody who is a little bit older, it's probably gonna have a little bit bigger cisterns, it's gonna make that inspection a little bit easier. And then it had a dura tail, and had a little bit more, I think, extension into the middle foster floor. That all is very easy to remove. You can go right along the lateral wall, the cavernous sinus, and devascularize it. And there really aren't any serious structures in that location. So that's easy so you can take off real early to begin your plane along the floor, but as you go up again, more towards the sphenoid wing in to the anterior coronoid, you wanna be real careful about those structures and be sure that you don't injure the optic nerve or the internal carotid artery. And an 81-year-old lady with this tumor, it's not critical that you get every last bit of tumor out. It's very critical that you leave all the structures that are important there, intact and functioning.

- [Dr. Cohen] Thank you, and as you can see here, working on the temporal side of the tumor, superiorly, we identify the carotid artery through the arachnoid membranes, early on. And here you can see some proferators. And it's hard to know what's going on. And that's what I wanted to emphasize with this video, is don't take them, unless you follow them. And you see if you follow this one, you see the ends on the tumor capsule and doesn't go anywhere. And you definitely wanna make sure which ones are you coagulating? Is it an emphasize vessel or is the vessel that really is important? And here is the anterior edge of the tumor, the optic nerve, the carotid artery after they have been carefully identified. And this is the attachment of the tumor, keeping the arachnoid membranes intact is very important. Here as a carotid artery, and I think showing the edge of the third nerve would be evident, keeping the section cavity dry, obviously, is very helpful. Don't suck aggressively on the arachnoid membranes. And here is the edge of the third nerve and the carotid artery optic nerve. And again, treading the dura and further by polarization of the dural edges to get the Simpson Grade resection. And here A1 carotid artery, again, the edge of the third nerve. Would you have done this case any differently, Johhnny?

- [Dr. Johhnny] I think it looks terrific. I might've started, maybe, along the middle parts of floor first, just because it's very easy to do, and there's no structures there, but ultimately the principles are the same. You wanna find the vascular structures in the optic nerve, and start that arachnoid plane there and avoid a cranial nerve injury and avoid a vascular injury.

- [Dr. Cohen] Thank you. Let's go ahead to our next case here. And let's first look at... That's a post-op MRI. As you can see, you can easily get these tumors with a good, clean resection, as long as you do the curating. This is a younger woman, 45-year-old female, with a right-sided visual dysfunction. And obviously, if you have a medial sphenoid wing meningeoma that means usually is very medial. And is a right-sided, you can see the full void of the 81 potentially more medially. And again, the MCA is wrapped posteriorly along the tumor. It's a smaller tumor, probably has invaded the optic canal. And let's go ahead and review the surgical video for this lady. This is a left frontotemporal craniotomy and the Sylvian fissure is being dissecting open, early on, as suggested by you, Johhnny, and following those MCA branches to identify them early on, we use a bistoury knife. I think everybody has their own technique in terms of opening the fissure, but, officially, usually, this knife works very well. Do you use the knife or how do you open the fissure in this situation, Johhnny?

- [Dr. Johhnny] I like that knife a lot, I use that very frequently. Sometimes I just use an 11 blade. The important thing is, is once you open up the along the Sylvian fissure is you dive straight down and find the arteries, not the bank, find the arteries. And once you find the arteries, you can just follow the fissure down and split open very easily. And if it is split open, you're gonna run into the tumor, which you show here. Remember you try to keep most of the Sylvian vein along the temporal region. They tend to drain into parietal sinus. And so you wanna keep the anterior veins really on the temporal lobe as you can, and come down and then you'll find the tumor. And as you see here, you're dissecting out those important branches, the middle cerebral artery along the tumor, so as to avoid injury.

- [Dr. Cohen] Yeah, and the sharp dissection is the key here, as you can see. Try to keep the field very dry. This tumor was, again, devascularized early on, and that really helps in terms of keeping the field dry. This is the end-tip pole of the tumor, and you can see the olfactory nerve anteriorly, Johhnny. And the poles were not as clear more internally, and we tried to dissect it off of the frontal lobe. Obviously we're coagulating, right now, the capsule of the tumor.

- [Dr. Johhnny] So ultimately, this is a smaller tumor than the other that Dr. Cohen has showed, but this is a tumor that's very important because it's really invading right along the optic canal# and it's causing her to have a visual disturbance. So when you take this tumor out, you know it's gonna be more adherent to the optic nerve, and it's likely to surround the optic nerve. And so in this particular case, what I would do, is spend a lot of time finding that other nerve, I would drill out the optic canal, so as to have a good idea where it is. And again, I probably, near the end of the surgery, would open up the falciform ligament, that's the thick dural membrane around the optic nerve, open it up to give the operator more decompression, and stick a blunt nerve hook underneath the optic nerve and see if I can remove additional tumor. Now, remember if the tumor extends up into the optic canal itself, it's very important to decompress the optic nerve, but if you get too aggressive in trying to remove the tumor in that location, you can easily devascularize the nerve and result in increased visual disturbance and maybe blindness. So one needs to be a little careful in that location, I don't like the bipolar right around the optic nerve, I like to do a little bit more blunt dissection, cause I'm afraid that I might bipolar a small perforator that's important to the optic nerve function.

- [Dr. Cohen] Thank you. I use this #angled dissector, as you can see here. This is, again, along the anterior pole of the tumor, Johhnny, trying to find the optic nerve. I think we see a structure right here, that I'm suspecting is important. Obviously there is an arachnoid membrane arachnoid thing that we tried to preserve at all times. And I think, as you can see, the tumor is being mobilized posteriorly, carefully coagulating the capsule# in order to keep that capsule tight. So your dissector can use it as a handle and move the tumor posteriorly. Again, it's critical here, not to get too close to the optic nerve and stay on the capsule. And here you can see again, the arachnoid membrane along the medial structures, and this is here, the optic nerve right there and here trying to use a fine dissector. My suction is located, I think, just on the optic nerve right now. And as you can see, looking through the membranes to see if there is any residual tumor left. And again, using fine micro scissors to further debulk the tumor more posteriorly. And here is, again, more superiorly finding the carotid artery.

- [Dr.Johhnny] Reginal coronary right here.

- [Dr. Cohen] Right, and that's key to keep that mid tumor dissection... I tried to create almost routes, or what's called cleft, along the carotid artery, and divided two into two pieces, one anterior to the carotid artery, one posterior, and then peel the tumor off proximately to distally, to protect the optic nerve. And here you can see the optic nerve right there, Johhnny. Again, this is a right frontotemporal craniotomy, and the tumor is being delivered from its attachment. Again, carotid artery, optic nerve, and this is more posteriorly, the additional piece of the tumor that was attached to the medial coronoid. Go ahead please.

- [Dr. Johhnny] Yeah, so here this portion here, one needs to be really careful to identify the carotid artery, you remember, it's just lateral to that, and be cognizant of where the posterior communicating artery is. And if it's up to it, you might be right near the third nerve. So you wanna be very careful in that location. It's very tempting, just to pull that last bit of tumor out, but be sure that you preserve the third nerve, which is over here in this location. Now, it looks like, to me, that you're exposing it there and trying to determine whether you need to do an optic nerve decompression.

- [Dr. Cohen] Right, and as you can see, I put that blunt hook in there, and there was no tumor, and there was plenty of space. So in that location, we did not do further because there was plenty of space in the optic-

- [Dr. Johhnny] If you found tumor in this location, what you'd like to do, is take a diamond vidro and drill this bone away and open up the parts that form ligament and try to tease a little tumor out, but don't get wild here because you couldn't vascularize the optic nerve. I think taking the bone off and opening up the for a ligament, will improve vision and keep vision at a reasonable acuity for quite some time. And so it's very important to decompress the optic nerve if you find tumor in that location.

- [Dr. Cohen] Thank you, I think that's very important. Let's go to our next case, which is our fourth case here, of another meningeoma case. And before we show the video, I'm gonna go ahead and talk about the case itself. This is the post-operative image from that case, again, showing adequate resection. The patient very well would improve vision. 65-year-old female, with a two-year history of progressive confusion and right-sided visual loss. And this tumor was much larger than the other ones, very medially located, and really was quite a challenge. You can see the arteries are posteriorly on somewhat engulfed by the tumor. And that's where I got into trouble. I don't wanna get your opinion during the surgical video. So keep that in mind, what we see in terms of avascular relationships. And here is, again, right frontotemporal craniotomy. The fissure is being opened, Johhnny, and we're gonna try to devascularize the tumor early on. And here's the tumor being very fibrous, attached to the sphenoid wing. Any thoughts on this case, Johhnny?

- [Dr. Johhnny] The approach you're taking looks very reasonable at this point in time, come down and again, devascularized the tumor along the floor of the base of the score.

- [Dr. Cohen] This is a tumor you recommend on the dezygomatic craniotomy, wouldn't you?

- [Dr. Johhnny] Yes, I would, because it's pointing up a lot and I want to be able to see up with risk reduction, and brain retraction, I think, it's also quite medial, so you know it's not gonna involve the orbital rim and I would use an OZ craniotomy, just to help my exposure.

- [Dr. Cohen] Okay, well, I would drilled the bone a lot, but I think OZ would have been a good idea. You can see how fibrous these tumor is, Johhnny, in terms of tumor removal. And it got more posteriorly, you can see some of that MCA branches, here you can see one of them, and this is again, temporal lobe tumor under the dissector, dissecting the tumor off and hoping we can get it good plane between the MCA branches and the artery. And here he is again, trying to be as careful as possible. And then you'll see, in a second, we started getting bleeding. What would you recommend in this case? You don't see very well, there is bleeding, the artery is very attached.

- [Dr. Johhnny] Yeah, at this point in time, for me, I would stop in that location, go on to some other location and begin debulking the tumor, and potentially come back, maybe if I devascularized the tumor a little bit more, I will have a better plane. If not, I would try to find the tumor around that artery and leave a bit of tumor on the artery and come back one last time and look at it. But I really don't want to cause a vascular injury. So if I have to leave a few bits of tumor behind, I will, rather than causing the vascular injury, because it makes the case a lot more difficult, once you have a lot of profound bleeding.

- [Dr. Cohen] I agree, and that's exactly what we did, Johhnny, thank you. We redirected our approach anteriorly, As you can see, this is the funnel foster, this was the area where we're getting to the bleeding posteriorly. This is the optic nerve, opening up the falciform ligament,# as you very well mentioned to release the optic nerve. And again, put the probe after opening the falciform ligament to make sure the optic nerve is released. And we left this small show of the tumor more posteriorly. And as you can see in the post-operative video, there is a shell of tumor over the MCA. And I intentionally included this case to really emphasize the fact that if you feel it's attached, you get a little bit of bleeding, stop, redirect your attention elsewhere, leave a little bit of tumor behind, and that patient did fine. This is another case of a young woman with the left sided visual dysfunction, Johhnny. And as you can see this as a tumor, maybe a little bit more attached to the medial vascular structures, rather high, you can see one of the MCA branches transversing through the tumor, and a challenging tumor all in all. Again, you can see some of the MCA branches around the superior pole of the tumor. This is the carotid artery more out of harm's way. This is a case, I think, it would be very useful, and that's what we did, because the tumor has a very high extension. The CT scan doesn't really show a very serious, bony implant from the tumor, or hyperostosis. And here is the MRA showing how the vasculature are displaced and draped over the tumor. This is a nice case, I think this is our fifth case, if you don't mind, that I'm gonna show, in terms of the surgical applications and how we can take it out. Do you have any thoughts about this case, Johhnny, while I get the video up?

- [Dr. Johhnny] Well, as you see the, from the MRI, there was quite a bit of narrowing there. So it's very likely that the M2 branches are gonna be wrapped around the tumor. So the goal here should be, after you've done your OZ and devascularized as much of the bone and dura as possible, what you wanna do is you want to find that middle cerebral artery and dissect those artery those branches away from the tumor, so you don't get into them. So I wouldn't be thinking middle cerebral artery very early on in my tumor, I can go ahead and to debulk it as you're showing here, but as soon as I can, I wanna find out where those branches are and try to develop a plane between the branches and the tumor to prevent a vascular injury.

- [Dr. Cohen] That is very well said, Johhnny. As you can see, this is my dissection early on, after debulking, seeing all the MCA branches, draped, and so engulfed almost by the tumor. So your point is very well taken. Again, you can see the M2 branches are draped and somewhat engulfed by the tumor. Do you have any special magic you do here, in terms of dissecting these tumors from the vessels?

- [Dr. Johhnny] I typically use a microburn head and I use the spread, and then I use sharp dissection, as soon as I can see the vessels, and cut any attachments near the vessels, and then I put a patty there to protect it. Once I know where those branches are, I'm pretty aggressive with the Cavitron to debulk the tumor as much as possible. Away from those vessels, I debulk the tumor because it's gonna allow me to manipulate the tumor even more, to continue to follow those branches down to the M1 and down to the meticulous strides and the internal carotid artery#. And this is such a big tumor, if the tumor itself is gonna be part of your problem in seeing, you wanna get out as much of as you can, but you've gotta know where everything is. You have to know where the important structures are, so your Cavitron doesn't get into it.

- [Dr. Cohen] I agree. And, again, here is dividing the tumor anterior section, trying to have in the middle, all of the visualization trying to have, in the middle, all of the visualization you can over the carotid and the MCAs. As you can see, MCA joining the chronoid, a piece of patty was left over them, using cadotroins adotroins there. so if you are using Cavitron, you're out of harm's way. Here is an attachment to the tumor. It's unclear again, what this is, is this an MCA branches, is this something else? And in this situation, you really wanna roll the tumor round, make sure there's nothing coming out of it. In other words, this is just not an emphasized vessel. And if that's the case, that attachment can be a sacrifice. Any other thoughts here, Johhnny, nuance of technique to remove this tumor?

- [Dr. Johhnny] I think that's the great thing, once you find the branch, that's the middle and you know where the direction of that is going towards internal carotid, splitting the tumor into two components, one that's dealing with the vascular structures and the optic nerve, and the other, that's really not dealing with anything but it's attachment to the middle part floor and to the sphenoid wing, is a great way to do that. Then you can take out the easy part, separately, from the more difficult part and it'll improve your visual of the arteries.

- [Dr. Cohen] Yeah, I think that, that works well. And here is really, after that portion has been removed. These are the MCA branches draped over the tumor that are intact, again, skeletonized. One has to be very careful in this situation not to be too aggressive with the tumor removal. And again, the arachnoid membranes more immediately have been left intact at the tip of it suction. And here is the attachment of the tumor. And in this situation, part of the tumor was invading the cavernous sinus#. Here is me trying to show the optic nerve, and then carotid artery. These attachments were very well curated away. This tumor between the optic nerve and carotid artery was just delivered as you can see, trying to make sure you can remove as much as possible in this very young patient, and again, all the cerebral vascular structures are intact. This region is very well curated away, this is the medial part of the cavernous sinus dura. And the rest of section has to be carefully thought about. Let's go ahead and talk about... This is a postoperative image, again, showing a good resection. Let's talk about postoperative complications. And this is our last video showing the complications, This is a first complication case of a very giant one This is a first complication case of a very giant one a woman with confusion. As you can see, the vessel's going right around in the middle of the tumor. And this is a case where I thought I can do a good job by removing a little more tumor. And although I handled the vessels, okay, you can see an aggressive resection. I think it was too aggressive, because you can see an infarct on the ADC map into the cordal artery distribution. She woke up with weakness on her left side. Unfortunately, her leg never recovered enough for her to be able to return to work. And again, this is a case where you have to remember aggressive resection of these giant tumors that are very adherent, has to be cautiously avoided. This is another case that I'm gonna show the video. Again, a giant, left medial sphenoid wing meningeoma not much bone involvement. As you can see, the vessels are draped over. And here's the surgical video of this complication. Again, this is a very tough tumor to take out because of how large it is. And I would like to know your opinion in that regard. Extradurally, we're removing the clinoid. This is the temporal dura, frontal dura, this is the clinoid. And again, the optic nerve would be viewed in a second. Go ahead and use your arrow if you can, Johhnny, please. And here is the optic nerve, the right where I'm removing the bone over it with a curate.

- [Dr. Johhnny] And so you bend out the bone and now you're carefully removing it. There's a bone here, right around the optic nerve, you decompressed it?

- [Dr. Cohen] Yes.

- [Dr. Johhnny] , and a diamond bit drill, which is very appropriate for decompression of the optic nerve. It's very important that the drill does not eat up too much to cause vascular or optic nerve injury.

- [Dr. Johhnny] And here's you can see optic nerve, Johhnny, this is a frontal dura. So we really did an aggressive, extra-dural bone removal, and coagulated the dura extradurally. Here is the retractors were removed and we got into dural nerve superior pole of the tumor, frontal lobe, temporal lobe. And you can see early on, we identified some of the MCA branches that's after the tumor was devascularized. This is the anterior pole on the tumor. Again, frontal lobe, funnel fossa, anterior pole of the tumor, retracting some of the tumor posteriorly. And in this case, these branches were very enclosed in the tumor. This is more of a zoom-out view, showing the retraction on the frontotempora lobes in this large tumor, the fissure was open as much as necessary. This is again, most likely a one optic nerve. Early on, we identified those structures. And when I got into trouble here is, I think, as we direct their attention more superiorly along with the MCA branches, again, this is leaving the arachnoid intact This is the carotid artery. You can see how thin it had become as it's going to skull base. And I thought by staying away from it, coagulating the dura, not heating up the carotid, I could get a good resection. You can see the two M2 branches in this case. This is the #bifurcation right there, M2, M2 and carotid artery. Would you have been so aggressive in this situation, Johhnny?

- [Dr. Johhnny] You know, it's a judgment call, these vessels could be quite adherent, they look very small. It's a real judgment call, you have to decide if you've got a good plane or not. If you're not, just leave a portion behind and call it a day, or leave a portion behind and come back and look at it at the end of the operation. It's very hard to know what I would have done, it just depends on how difficult it is. I think if there's any questions, just leave a portion of tumor right on the artery and come at the end, when you can see a little bit better and have a better idea of how to manipulate things.

- [Dr. Cohen] Right, in this situation we lift the carotid after doing an hour of microdissection. Here's the posterior part of the tumor where additional tumor was removed. And again, the capsule was coagulated, in a very fibrous tumor, despite our aggressive bone removal. Again, coming back, this is the carotid artery, the proximal part going into the skull base, would try to stay away, but as you can see, the left carotid and MCA is very much scrutinized in this situation. We thought, well, she's relatively young, maybe we can get away with it. And here is trying to dissect the tumor as carefully as possible. Do you think this is a reasonable plane or this looks to you like a plane that, pretty much, we should have given up early on?

- [Dr. Johhnny] Well, it's hard to give up early on, but it looks like you're gonna probably have to leave some tumor behind.

- [Dr. Cohen] Yeah, and that's exactly what happened, Johhnny. You can see this is the carotid artery, this is the MCA branches and the tumor, again, being dissected off here, but I think one mistake here is that there could be branches, or in other words, perforators like anti colloidal attached here. So when you're removing some tumor along the skull base, here you can see the carotid artery is so narrow, a piece of the tumor was ultimately left in. As you can see, we've left some tumor, we removed slightly more of this piece, the optic nerve here was ultimately decompressed.

- [Dr. Johhnny] Yeah, when you get into a situation where you're not getting a very good plane on the vessels, at that point in time, it's probably best to just leave some tumor there. And particularly when you're dealing with the interior core 'cause it can be such a devastating deficit.

- [Dr. Cohen] I know.

- [Dr. Johhnny] And just to leave some tumor there and to follow it along, rather than trying to resect it.

- [Dr. Cohen] This is the optic nerve, Johhnny. I used the small incurator to deliver tumor within the optic canal. These tiny are so nice for removing tumor within the optic canal. So even though I was not able to remove all the tumor along the carotid artery, proximately, you definitely wanna make sure that optic canal is very carefully decompressed. And eventually we opened up the falciform ligament and here's the final product, that piece of tumor was left in. These are some of the perforators going along the capsule of the tumor, and we left some tumor here, we protected the perforators and probably is a good idea, just to call it a day. And as you can see here, the perforators, again, are coming to the capsule, at the end of... Again, I'm trying to show more of the tumor being delivered between the carotid artery and the optic nerve, just in that cleft. These are really, I think, some of the most challenging skull-based tumors, just because they have the tendency to move around the corridor so much. The a post-operative MRI, as you will see in a second, showed a reasonable tumor resection, Johhnny. This is, again, extend of our bone removal along the clainoid, she didn't have a edema before surgery, as you can see in the temporal lobe. Unfortunately, she suffered from this capsular infarct. And as you can see the dark areas in the ADC map. And she definitely had some speech difficulties immediately after surgery, has recovered, definitely has not returned to normal preoperative status. And again, that points out the important principle of leaving the properties along, don't be aggressive. And I'm just gonna take a quick minute and review some of the pearls and pitfalls, if you would like to add something, please stop me. And again, don't be aggressive with resection of giants tumors engulfing carotid artery, especially its proximal segment, managing articular tension the lumbar drain seizure prophylaxis. What's your role? If they don't have a seizure, before surgery, do you just continue anti-convulsants for a week after surgery and weaned them off, or do you do a different plan?

- [Dr. Johhnny] I'm sorry, what was the question?

- [Dr. Cohen] If they don't have a seizure before surgery, how long have you continued your seizure prophylaxis post-operatively?

- [Dr. Johhnny] I'm not very aggressive with seizure medication. If they don't have a seizure, I may not even put them on seizure medication.

- [Dr. Cohen] Okay, and obviously don't tackle initially doing your interdural part of the procedure, don't go too far medial to injure the carotid artery or optic nerve, along the clinoid process, and mobilized anterior and superior poles of the tumor before getting deeper. And most importantly, keep the arachnoid membranes intact. The first time is the best time for pure meningeal surgery, so be aggressive, but not too aggressive along the perforators. And identify the path of each vessel before sacrificing it, watch for the perforators, or the P-Comm, as the quality of life comes first. And don't chase the tumor in to the cavernous sinus. Ultrasonic aspirator can be an enemy of perforators and the carotid artery, or neurovascular structures. And there's always a rare chance of postoperative vasospasm in these surgeries, where the vessels could be slightly manipulated and therefore an index of suspicion should be always kept in mind. Johhnny, I would like to thank you very much for your expert opinion to make this presentation useful.

- [Dr. Johhnny] Thank you Dr. Cohen, those are terrific videos and great surgical expertise, and I appreciate being involved, and I look forward to working with you again.

- [Dr. Cohen] Thank you, Johhnny.

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