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Grand Rounds-Resection of Pineal Region Tumors: Pearls and Pitfalls

Roberto Heros

March 17, 2014

Transcript

- Hello, ladies and gentlemen, and thank you for joining us for another installment of the Operative Grand Rounds. Today, our guest is Dr. Roberto Heros from University of Miami. Dr. Heros requires no introduction. He's an icon in neurosurgery. He has been an amazing mentor for many young neurosurgeons, and he's truly a master surgeon. I really appreciate his time today. He is planning to talk to us about resection of pineal region masses. Before we start, Dr. Heros, I really would like to take the opportunity and ask you to share your expertise with us and your opinion regarding what are the three important pearls and important features that would make a neurosurgeon a competent and powerful technical surgeon. Please go ahead.

- Tough question. But because you're talking about technical surgeon, you'd be surprised at my answer, but I think that number one, and number two are the most important, and that is, an excellent surgeon is one that has good results. And one that doesn't have bad luck in the operating room. And I tell you what I mean by bad luck. I mean, these things that happens to all of us, they happen to all of us and we say, "Oh, gee, I had bad luck, this happened in the operating room." And well, the less of those incidents of bad luck a surgeon has, the better surgeon he is in my opinion. And what that means is to to have had put together experience to avoid the situations in which bad things happen in the operating room. And I always remember my mentor, Dr. O'Gorman, he didn't have bad luck very often. His results were excellent and bad things didn't happen to him because he knew how to foresee and how to predict when bad things could happen in the operating room and when to call the precautions to avoid. Now, that'll maintain a times, a little bit more of a boring surgeon, because he took steps that many times were attempted to gloss over or not take, because when you're trying to prevent a complication that happens only very rarely. But I think that the more you strive towards preventing any adverse effect in the operating rooms, the better the patients do, and that makes you a better surgeon. And I think the third, so, no bad luck in the operating room, good results. And then I think it's important to remember your bad results and to learn from those so you don't repeat them. And even more important, to pay attention to the bad results of your colleagues and remember them, even if they don't, so that you don't then have to repeat with your patients those situations that lead to bad results.

- Thank you very much. I think those are so important. Having a good luck, really trying to avoid complications by thinking ahead of time and good preoperative planning and number three, learning from other people's mistakes. I think those are amazing three pearls that I personally try to remember every time. I've heard pineal region is a very favorite region for you to operate within. And we're really excited to have you talk to us about resection of pineal region masses and what it takes to stay out of trouble. So if I may please ask you to proceed, I appreciate your expertise.

- Sure, well, in terms of pineal tumors, you have to begin at the beginning. And the beginning is what is a general categorization of tumors in the pineal region. And before I get into, I see that we have a slide in here that is actually a case presentation, but let me go forward to the classification of pineal tumors. I like to think of them in three categories and it's not just me, this is a way we think about pineal tumors, those tumors that are primarily of pineal cell origin. And of course, those are the pinocytomas, the pineoblastomas. The pinocytomas as you know, are relatively benign. They occur at a little older age than the pineblastomas. The pineblastomas is essentially, a primitive neuroectodermal tumor in the pineal region. And they occur in children and young adults, rarely in older people. And they're very malignant, very aggressive tumors, but fortunately, respond relatively well, better than other malignant tumors of the pineal region to radiation therapy and appropriate chemotherapy. And now, there is an intermediate grade that we also have to think about, and we've had some of those over the last two years, and that those are pineal tumors of intermediate or pineal cell tumors, if you will, of intermediate differentiation that falls somewhere in between pinocytoma and pineblastoma. And another more recent category that again, is considered as a primary pineal cell tumor origin is the papillary tumor of the pineal region. And they behave again, in intermediate fashion between the pinocytoma and the pineoblastoma. Then of course, there are the germ cell tumors. And the most common is the germinoma, its much more common in Japan, growing three times or maybe even five times more common than it is in this area in our country. And those tend to occur, of course, in young adults, more common in males and females. When they occurring in females, they're just as common in the suprasellar region as they are in the pineal region. And these are exquisitely sensitive to radiation therapy, to the point that it's probably not necessary to do a radical resection of a tumor or even a generous resection may not be indicated, because it responds so well to radiation. In this country, we generally end up, because they're not as common as in Japan, end up biopsying these tumors to find out what the cell of origin is of most of the tumors in the pineal region. But in Japan, there is a way of treating these tumors now that seems very reasonable. And its a trial of radiation therapy. And if after a short course of radiation, of relatively low dose radiation, the tumor shrinks significantly, then they proceed with radiation, assuming that the appropriation that the tumor is a germinoma. And if the tumor does not shrink after a short course of radiation, then the patient is explored assuming that the pathology is different. Then of course, they are the very malignant tumors of germ cell or the germ cell origin, and those are the embryonal carcinoma, the yolk sac tumor and the choriocarcinoma, and of course, there are very specific serum and CSF markers for these tumors that we all know about. I think we need to get into that. And then there are the teratomas and they can be relatively benign and they can be also very malignant, the teratomas' category. And then the third category of tumors is other tumors. And those depending on the age in older people, particularly women. Meningiomas of these area are relatively common that are pineal region masses. Also, of course, you could have exophytic tumors from the of the thalamus gliomas that can be relatively low grade, but can also be high grade. You can have the cyst and you can have a number of other rare tumors that occur on these area. So let me go to the next slide and see what... Okay, so approaches to the pineal region. And then I think we can show a short video. There are many approaches but basically nowadays, there are two preferred approaches to the pineal region. And one approach of course, is the supracerebellar infratentorial approach, it was developed in Europe many, many years ago before the microscope by Crouch, I'm sorry. And then was really modernized and made popular with now using a microscope by Ben Stein in New York who had a huge experience with this tumors and with these approaches, supracerebellar infratentorial approach. It is my favorite approach for most of these tumors, particularly, the tumors that extend below the splenium into the third ventricle, into the posterior aspect of the third ventricle. The alternative approach is of course, that the parieto-occipital, if you will, interhemispheric parieto-occipital approach, transtentorial cutting the tentorial parallel through the straight sinus. I don't have slides illustrating that approach. I use that approach when the tumor extends downwards in the cerebellomesencephalic fissure and it goes downwards in front of the cerebellum, rather than under the splenium to also, fourth ventricle. So, the difficulties with that approach, the transtentorial, that is interhemispheric transtentorial approach, which is the the anterior use on the lateral position with the ipsilateral side down so that the brain falls away. I use a spinal drainage for that approach and allow the brain to fall. So the ipsilateral side down. Interestingly, with that approach is not as easy as it seems in the anatomy books and so forth to see exactly where the straight sinuses, because the cutting of vectorial pressure but it should be close to the straight sinus and parallel to it. But it is sometimes not perfectly obvious. Where a straight sinus is because instead of being a right angle approach, of course, sometimes it just curves gently and is easy to get confused. And I think neuro-navigation is very appropriate to use, to make sure that constantly, you're identifying the straight sinus and not cutting into a straight sinus. That approach makes it a little difficult to look to the other side. So if the tumor is broad, of course, it's best to approach it on the side where most of the tumor is located, because it is difficult to see under the veins, under the vein of Galen to see to the other side. So by and large, I prefer to use the supracerebellar infratentorial approach. I like to do that personally, with the patient on the sitting position. The Concorde position is perfectly adequate for patients with a relatively long, thin neck. And that's why it was popularized in Japan, that happens to be the physiognomy of many of the Asian people. I think that with our peculiar physiognomy with thick necks and , thick necks here not like yours, yours would be very adequate for the Concorde position. But I find it more difficult to use. And I love the sitting position. I love to see that cerebellum fall down from the tentorium. The sitting position does have some inconveniences, but most of the inconveniences, if one takes the appropriate precaution are not for the patient, but for the surgeon. And that is said, it is an uncomfortable position with the arms hanging up for the surgeon. It's important to have your arms, particularly your elbows supported, appropriately supported for the sitting position. And one problem that we have had with the sitting position is the bulk of the body of the microscope with some microscopes, for example, the Pentero microscope, the body is so wide that it's very difficult to reach because the focal lens of a microscope really starts at the lens and then it goes forward from that. So you have to add to that in the body of the microscope. There is a way, and unfortunately, I can't illustrate it here that you can reduce some of the bulk of the Pentero microscope. But now we use this lighter microscope that has a smaller narrower body, which I find it very useful, the latest generation, lighter microscopes for these procedures. Now, I can't emphasize enough how important it is to position these patients appropriately. And that it is the responsibility of the surgeon and not of the anesthesiologists. You can count in most institutions an anesthesiologists that knows how to do this perfectly well, when you are in the surgeon's lounge, it is a position that where the patient can have major problems related to the position itself on the sitting or position. We all know about the precautions against air embolism using a precordial Doppler. And I take personal responsibility of being there, making sure that the blood pressure is adequate, on the high side of normal for that patient. Making sure that before we start setting up the patient, the central venous pressure is adequate. And by adequate, I mean the central venous pressure of at least seven or eight and preferably, 10 or 12. So that I routinely tell the anesthesiologist to give the patients at least a couple of units of anbesol or some other colloid before we start sealing the patient up. And I don't start until the CDP is adequate. I think that that's important. I think it is very important to make sure that the anesthesiologists understand that the blood pressure has to be maintained during surgery. And the hypertension in this position is intolerable. And to make sure that they race the transducer that measures the anterior pressure to the level of the ear progressively as you're sitting up the patient gradually in stages. At the same time, they have to leave the transducer for the central venous pressure of the level of the heart, because that's where you'd really wanna measure the central venous pressure, at the level of the heart. So the central venous pressure transducer, they need two separate transducers; at the level of the heart, the anterior transducer and the level of the ear. I have to tell you that I also learned the very hard way, and I mean the very hard way. There is no hardest way. I had a patient that became an older patient. And I just tell you a story because if anybody hears this story and remembers they will not make the mistake that I made. This is a patient with cervical spondylosis. I didn't know the patient had cervical spondylosis, it became apparent afterwards, he was asymptomatic from cervical spondylosis. And the patient had had a hemagioblastoma of that brain stem that had been operated somewhere else. They took a biopsy in two hours to stop the bleeding, they didn't know its a hemagioblastoma. So I decided to operate on the patient. This is one of these typical hemagioblastoma in the medulla in the fourth ventricle as below in the medulla. And I decided to operate on the sitting position and did not use any monitoring for that surgery. I was used to doing pineal tumors before. Yeah, they're generally in young people who generally don't have much this kind of a problem. So I did not monitor that patient. And I tell you, to this day, I regret that time. Every time I have one of these cases, I think about that case, the patient during surgery, there was hypotension. And that was a mistake of mine. Because yes, we blame it on the anesthesiologist and in fact, there was a medical-legal issue with the patient that we were sued. And the suit was entirely against anesthesia because they could show on the medical record that the blood pressure had been low during surgery, excessively low. And they blamed the anesthesiologist. In reality, the fault was mine because we cannot count on the anesthesiologist to know how to do one of these patients if they do one a year. So, I didn't check constantly with anesthesiologists and instructed them about the blood pressure, I didn't monitor the patient. And that patient became quadriplegic from cervical spondylosis, hypertension, and an infarct on the cervical spinal cord. So I tell that story so that those of you who listened, remember, there's responsibilities to surgeons to keep the blood pressure adequate during surgery, at least normaL, transducer at the level of the ear, monitoring the patients with sensory and motor evoked potentials. And if I had done that, that patient today would not have been a quadriplegic probably from the flection of the neck, compounded by hypotension and not monitoring. So, we take responsibility for seeding these patients, and then I like to do, and I guess now we can play the video, you want to go on to the video at this stage. You can see that the decision is a long one because I'd like to expose. First of all, I like to have... You see that we have issue here in case we needed to close the dura at the end to achieve a watertight closure. So I go a little higher. And in this case, probably we went a little higher than we needed to. But it is important, I think, to have periosteum available for the closure if necessary. And then I like to expose on the midline, not only this suboccipital region, but a good portion of the occipital region, because I like to do a combined occipital, suboccipital flat in order to be able to elevate. And I think you can get at least a centimeter extra of space where you needed by being able to elevate the transfer sinuses and the torcular, as you open the dura to have that space, that precious space between the cerebellum falling down. And the sinus being lifted up. So, let me go on to the next. So this is the actual preview on that case. We use neuro-navigation to see the position of the sinus and mark the position of the sinus, sagittal sinus, and the transfer sinuses. And then I make burr holes. And let me just emphasize how I think it's safe to make these burr holes. Let me stop the video at that point. So I insist on making a burr hole before crossing each sinus, so that there'll be a burr hole just before crossing the sagittal sinus. And then there'll be another burr hole here, before crossing the transfer sinus. And then another burr hole here, before crossing again the transfer sinus going up. And then the direction of the cuts with the cranium tong, I insist with the residents that they separate the sinus, in this case, the transfer sinus and go from here to here and then to the next burr hole until they're sure that that transfer sinus in here is separated from the dural. Then cross with the cranium dome, go down and then come to another burr hole exactly before you cross upwards now to the transfer sinus. So that... A to come, I think it's ten years to come, without having a burr hole just before you cross the sinus. Now, you could do this in much more rapid fashion, again, not taking this precaution of separating the sinus almost on the direct patient before you cross it. You could just make a little hole and come along with the cranium tong and irrigate. And there are many ways to do these, but that particular way with just one little hole and depend on the footplate of the drill to separate the sinuses. I'll tell you another story I found. I've never done it like that, with one of my colleagues, I saw him do that and asked him, "Oh, my goodness, you train with me. "I never done it like that, "but this looks like an efficient way of doing this." And he said, "Oh yeah, it's very nice." So I did a fellowship elsewhere and I learned how to do that. And I said, "Oh, really? "Did you ever have a complication?" He said, "No, no." He said, "Well, yes, there was a patient that died "because the sagittal sinus was cut." But the patient died because the dressing didn't do it right. Well, of course, bad things happen always because you don't do it right. But I think that if you can minimize the possibility of not doing it right, you can avoid the potential catastrophe. That takes a little longer, but I like the idea of making a burr hole before you cross your sinus and separating carefully. So let's go on with the video and see what else can we learn here. the craniotomy, here's the transfer sinus. So we're gonna leave this in a minute. You can see the cut okay. And here is transfer sinus. This is probably a little higher in the occipital region than it needs to be, but you can see that now we're gonna be able to lift this dura. Two little holes made on the edge of the skull and give us this extra space in here. It is important that the craniotomy... I believe, that it is important that the craniotomy does not go all the way to the foramen magnum. And in fact, this craniotomy is a little too generous . You're unlikely to use less of a craniotomy here so that the cerebellum is supported by the bone so that it doesn't fall into your lap, so to speak. So then you have enough bone to support the cerebellum. And likewise, this dural opening is probably in this particular case, a little lower than it needs to be. It doesn't need to be quite down low. It could come just like that enough, so that you can look inside the dura into the cisterna magna. And with a lil' cerebrospinal fluid from the cisterna magna. But at the same time, not open the dura so low that the cerebellum is gonna fall away. But it is, I believe, important and essential to be able to have access on to the dura by looking down to the cisterna magna. So you can withdraw sufficient cerebrospinal fluid. Then at that point, the cerebellum will be relaxed and will be ready to fall down, but it won't fall down yet if you have some veins as we usually have some bridging veins bridging between the cerebellum and medulla. Now, I know that frequently one here is that no veins should be taken, all the veins are sacred. And you'll hear some of the master surgeons always making that point. Like, never take a vein. And I can tell you that I almost always, and not always, but almost always take routinely instant hole up the cerebellum against the tentorium and the bridging veins. Now, I've heard a couple of it, maybe more than two, three or four instances in which there has been a very large vein. And it's just a matter of judgment when there is a very large vein, you can then work to one side or the other, and it's a little more difficult because the cerebellum just doesn't fall as well. But I have had three or four cases where with impunity, and then that allows that view and that beautiful space over the cerebellum. Let's see if we can get moving with the video. And that's the position. There he's taking one of these bridging veins and cutting it. When taking those veins always insist in coagulating the vein and then cutting partially through the vein to see if it bleeds. And then coagulating a little more and then cutting it. And now I think we're getting to the incisura. And this point, its very important. Let me just stop the video to point out the anatomy a little bit in here. You have this tentorial lips in here. And then it's very common to have, particularly, with larger tumors and with some particular tumors, the arachnoid to be very dense, very opaque, and it's very difficult to see through the arachnoid. And frequently, in order to get the correct exposure, you have to cut the pre-center cerebellum, I call it the pre-center cerebellum vein, it's not the correct name, but that's what I call it, pre-center cerebellar vein. Now, let me just make a point that before cutting that vein, and the reason I make that point is because again, I remember one case where I actually made a hole on the vein of Galen, thinking that it was the superior precentral cerebral vein. Because this arachnoid here was so dense. So since then I take the precaution of just not assuming that you're looking at the precentral cerebellar vein, until I actually see the basal veins of Rosenthal coming into the vein of Galen. because it is very easy to be too high here. And to be looking at the vein of Galen, when you think is a precentral cerebral vein and to make a call on it. And in that particular case, unfortunately, it was a very small hole and with pressure and gel from surgery, so, the bleeding stopped from the vein of Galen. And fortunately, I realized what I was doing before I killed the patient. But I insist now, with particularly, the residents who are helping with the opening here, that they see clearly the basal vein of Rosenthals and their junction with the vein of Galen. And that then these precentrals are aware of being. I feel again, that almost always, if necessary can be taken, can be sacrificed without consequences. And usually, for most significant pineal tumors, it does really amplify the exposure. A big part of these operations in the pineal region tumor is to open wildly the arachnoid, which is easier said than done. But because again, there arachnoid is quite adherent, quite dense, quite opaque and-- But it is... It really relaxes the entire exposure and it really gives you access of the tumor. If you're careful to open their arachnoid along the veins, along the basal vein of Rosenthal on both sides. And again, I would say 90, 95% of the times, I do end up taking the precentral cerebellar vein, and that really then opens up exposure. So let me see if we did that in this. Yes, this is just the, again, opening the arachnoid around the precentral of cerebellar vein. Opening the arachnoid along the basal vein of Rosenthal on one side, and then in the other side. And you can see that, how that kind of opens, its amazing. This is just-- This vein in here is not... Obviously, that's a small vein, not a basal vein, which are higher here. We still haven't taken the precentral of cerebral vein, we're taking it, we're coagulating and then dividing it now. Again, open partially with a partial cut. And then when it's not bleeding, then you can pick it completely. And now you can see the tumor. This is a small pineal tumor in these case as I recall. And this is pineal cytoma on a young woman. And again, this is-- So now we're entering the capsule of the tumor per se. Again, the veins, the vein of Rosenthal here and here, the tumor here. Now we're taking a piece of the tumor for pathology, for a frozen section. And now we're dissecting around the tumor. Now we're opening on the other side of the tumor into the third ventricle. There's the third ventricle now.

- I see that you are not using fixed retractors.

- No, no, I don't think it's necessary in the great majority of the cases. I think you've talked about it, but I think its from you that I learned that sometimes putting a stitch deep to the transfer sinus and the torcular, helps lift even more of that tentorium to the point that you don't have to use it retracted, because I think it just gets... This takes a few millimeters to put that retractor, so. And we're gradually removing the tumor. Okay, I think that's after the tumor removal. Anyhow, we can stop this. I don't think there's anything else. The closure is pretty standard. If the dura doesn't come together nicely, we use a graft. So again, this illustrates more of the same. This is a different way to do it. And by putting up a hole, this is in a cadaver, that works best in a cadaver, to put the hole right over the sinus. Its pretty safe to do it on it on a cadaver. But I think the way we do it, it's just a little safer. And again, to have these data for exposure.

- I really liked the discussion. I really liked the fact that you focus on avoiding complications, Dr. Heros. And your huge experience, for sure, is a great learning for all of us and for generations to come. So if you don't mind, I'm going to show you some slides. And I want you to just give me your opinion, how to stay out of the trouble, which is obviously, safety is number one when it comes for patient care. So this is an 18 year old young girl who presented and came to me after a severe headache. And the neurologist did an MRI. And as you can see here, they found this hemorrhagic lesion in the pineal region area. And here you can see the blood on T1 without contrast. And we thought a diagnosis and potential resection of this mass is indicated at her age. Because it just didn't look like a benign lesion. Positioning the patients, I completely agree with you in terms of safety factor as you mentioned. It could have not been put more eloquently on what it means to put patients in a sitting position and having the center line avoiding too much flexion if it's possible. And so I'm not gonna obviously review any of those factors. Staying in the middle arachnoid lane, preventing the muscles, I think may control postoperative pain. I do put the burr hole sort of along the inferior edge of the sinus. So you can see the sinus comes all the way to here. So the burr hole is half above the sinus half below, that would tell me exactly where the sinus is. And then obviously, the last cut is over the sinus. This would let us know how we can dissect the sinus away from the inner surface of the skull bone. And then we go to the first cut here and we use a B1 without the foot plates to go over the sinus. In other words, we never cross the sinus with the foot plates. I think your technique is safer. I think my technique is sort of... Maybe it's not as... It's sort of not as conservative, but maybe again, in some hands would say, "You know what? We like to have the burr holes on both sides". And I highly recommend that for complete safety. If you have any feeling the sinus is adherent, you should not use this technique necessarily. But if the sinus, especially in younger individuals and the dural sinus wall is not adherent to the inner skull bone, you can put two burr holes, you can dissect away and just use the B1 without a footplate. Do not use the footplate to cross the sinuses. Even one small adherence that injures the sinus in sitting position or not a sitting position can be fatal. And just as you very well mentioned, I think the next slide illustrates the fact that the bony removal is done. And we just make sure the tentorium cerebella that obviously has on dural sinus, is coagulated and cut. So here is the video of this technique. As you can see, what we really like to do if possible is try to put stitches underneath the tentorium. In this case, the stitches were placed just along the posterior edge of the tentorium to lift up the sinus a little bit and make the tentorium a little bit horizontal. And that few extra millimeters may help to extend the operative corridor through the supracerebellar infratentorial route. May ask you to comment here, please?

- No, no, I think that that's a beautiful exposure. And I think that technique that you have described of putting the stitch deep to the transfer sinus, does add a couple of millimeters as they're very useful in this area. In general, that just like in my case where the dural opening was too low, I avoid coming this far down on the dural opening, again, for fear that the cerebellum is going to fall too much. So I preferred a dural opening that holds the cerebellum, that is not as deep as this. This obviously exposes this, its there in , which is very nice. But, even if you don't open the dura this much, just by looking inside, you can get fluid from the cisterna magna, then you have the dura provide some support for the cerebellum.

- I completely agree. The dura, the bony exposure is excessive here. I think all you need is really up to this level. And that's all you need. So, in this situation, I think the craniotomy could have been much smaller and still get us where we need to be. So I think that its okay. Releasing these adhesions are important to be able to look over the cerebellum, over colon. You discussed how to be careful along the thick arachnoid membranes here and coagulating the precentral cerebellar vein, and really opening very gently with arachnoid dissection, using a sharp dissection. If you just continue dissection here, you're gonna end up on the vein of Galen and . So you have to always remember to change the angle of the microscope down. If you just continue off-- Thank you. If you continue here, as you can see momentarily, I'll just start a resecting tumor. This is really where vein of Galen is. So if you just continue up there and feel like, "Oh, the tumor is gonna be where I'm gonna look." You're gonna be exactly in the wrong place and you're gonna cause some damage. You have to reposition your microscope field of vision. Would you like to comment here, please?

- Yes, no, that's absolutely right. Generally the first view you get is too high. You're looking straight at the vein of Galen and you have to kind of gradually start looking down. I do it usually with... Rather than repositioning myself, I'd reposition the patient a little bit by giving the patient a little more trendelenburg position. And that allows you to have exactly more downwards view towards the... Because the tendency is to be too high. And that's a very important point. And then you can injure the vein of Galen and you can injure the internal cerebral veins and you can miss the tumor and be looking over the tumor and opening the arachnoid in the wrong place, just above where you have to be. So I think that it's very important to change an angle location.

- Right. And the change of angle is very steep. And I really like what you said just a moment ago, you said you're gonna look lost and look for the tumor and you say there is no tumor. That's absolutely right. It happened to me early on in my career. I just followed the and went up, and I couldn't find the tumor. Well, I was absolutely way too high. So, this is critical to look at. Here, is we changed the angle and you can see the tumor right there. And we went ahead and remove this pilocytic astrocytoma. And I think the details of the resection of the tumor were very well illustrated in your video. And we don't have to necessarily go through further details. You can see the tectum here, the superior tectum. You can see obviously, the resection cavity. And this is the blind view of the surgeon. Right here in front of the colon, We end up missing that tumor that is more posterior and inferior. And here's the opening to the third ventricle. So when you remove the tumor, always look just behind the lip of the colon and make sure you haven't left any tumor that you missed, in my opinion. What are the other blind spots, Dr. Heros, that you would say people fall into traps in terms of missing the tumor?

- Well, no, I think we discussed those. The point I was gonna make that I forgot to make in my video is that frequently, and we keep talking about resecting the tumor and resecting the tumor. But frequently, some of this tumors cannot be resected completely. And then your goal, in addition to always safe maximal resection is to open into the third ventricle to relieve the hydrocephalus. And I have for years used, frankly, I don't know how many times it is functional and how many times it's not, but if I cannot do a complete tumor removal, at least, I make an effort to open into the third ventricle. And then frequently in those cases in which I have not removed the tumor completely and don't have a beautiful view of the third ventricle, I have left a tube. And what I use for that is we have a particular kind of ventricolostomy that is a little bit bigger than the usual ventricolostomy that we use in trauma patients, it's a little thicker. I don't have a name for it. We call it the trauma ventriculostomy, which is about twice the size of a normal ventriculostomy. And then I lift it into the third ventricle and pass it over to cerebellum and insert it in the cisterna magna. Now, I've called that total some chant. And one of the residents pointed out that I was wrong about that, but that's not what total some did show, what total some described. When he described what's an occipital burr hole, and then putting it to, into the lateral ventricle and then bringing it to a cisterna magna. So this is not properly a total some chant but I have been calling it that for years. So, whether it works or not, the problem with those is that you don't have a way of knowing whether it's... If a patient doesn't need a chant then you don't know if it is because you opened up the pathways and we do that with the aqueduct, or because of drain issue too, because it's all internal, you have no way of checking. But I think it doesn't hurt. I did have one tube that migrated. So I tried to secure it, it migrated upwards interestingly, over the cerebellum and it went completely into the third ventricle. And so I tend to anchor it somewhere, so that it stays down in the cisterna magnus. Whether it helps or not, I don't know, but it's just helping and an extra precaution to take, to try to avoid having to have a chant or a third .

- Thank you very much. So, Dr. Heros, we talked about the midline approach for pineal region tumors. That was what I did for the first three years of my career, but I completely abandoned the midline suboccipital supracerebellar approach or any other approach to the pineal region. And I have been using the paramedium supracerebellar approach. In other words, I always come from the left, no matter how large the lesion in the pineal area is. And I would like to share with you my experience in about 20 cases of large, more than three centimeter pineal region tumors. And I would like to see what your feelings are. The reason I came up with the idea is that we have been doing bifrontal craniotomies for giant olfactory groove meningiomas. And I started using the pterional craniotomy and it worked beautifully. I never violated the frontal sinus, I never took part of the superior sagittal sinus, I never retracted on two hemispheres of the brain. I just went unilateral. And the reason I come onto that side in the suboccipital supracerebral wrapped with midline lesions of pineal area, is because the left side has less chance of having dominant lengths. We're gonna talk about why it's good to come from unilaterally left side. Number one, I hardly ever take veins along the midline. And most of the veins along the supracerebral space are focused in the midline. So if you can avoid the midline you avoid the veins. Number two, is I never exposed it to . And I only place one transfer site at risk, the non-dominant transfer sites. So if you don't mind, I would like to share this video and then get your opinion, about if you are a... If you buy into it or you say, "You know what?, I don't think it makes a big difference for me." And I respect that either way. So this patient is 36 year old has this pineal blastoma. It's a very large tumor. And anybody would say, "Well, such a large tumor, it would be difficult to do through any unilateral approach." Why do I like the unilateral approach in this case? Because as you can see, the tumor comes really low to the superior cerebellar vila. And when you come over the cerebellum, it is really a lot of retraction you have to do to resect this part. But if you come to laterally through the wing of the cerebellum, the cerebellum is the architects that closed the tentorium, the surface of tentorium. When you come lateral, you're gonna be able to have a more inferior trajectory over the cerebellum. So in these tumors, actually, you require less retraction over the cerebellum. As you can see in this patient position, and we use a linear incision, Stealth for the transfers in sigma and sinus. We extended above that a little bit. And just to harvest, just like you say, pre-cranial or place a burr hole for stereotactic placement of the catheter into the ventricle, in this case, the patient did have hydrocephalus. And you can see, I stay completely away from the midline, equal space between the mastoid groove to the incision versus incision to the midline. Would you like to comment so far, on this technique, please?

- No, no. I think that this is a very adequate technique. To be honest, I have not used it for pineal tumors, but I have used this paramedian approach for things such as cavernomas of a mesencephalon and cavernomas in that area. As I recall, I have not used it for pineal tumors. So I'm very interested in seeing your video. And obviously, this is a beautiful way of thinking, that because the cerebellum slopes downwards and you actually can have that inferior view much better than if you come over the midline, over the bumps in the midline. And having done it for large pineal tumors like you have, so I'm looking forward to your vi--

- Thank you, sir. So we go ahead and position the patient. As you can see here in a lateral position, we use lumbar drain. Obviously, if we're gonna do the ventriculostomy, we don't use the lumbar drain. And here's the exposure. And I would like to, again, emphasize, this is the transfer sinus on the left, sigmoid sinus is right here, midline is over here. And we put two stitches on the tentorium. Again, this is the sinus, not over the edge of the dura, but over the tentorium. To lift the whole tentorium and sinus up. I know this patient was very young and a very tight cerebellum. And you still see, we can go there without any retraction. And please remember the tentorium is essentially horizontal. And that really helps. So you can see, right now you see the whole length of the tentorium without any retraction. We use our arachnoidal dissection to be able to see where we need to go. This is again, another one of those tentorial stitches, just to lift up the whole tentorium as you can see here. We use very thin carotenoids to avoid any sort of the thickness preventing our view. This is the fourth nerve exit zone and you can see the superior cerebellar artery. We hope this is the dorsolateral mesencephalon and we really go lateral. And here is really, very midline, coming over the other side and this is the tumor. The left side of the tumor, we go ahead and coagulate the capsule and debark. And as you can see here, this is very standard. This tumor was very fibrous, nothing would come into this suction. And that's why I'm using this case to show you that in very difficult tumors that are giant, this will work just fine. So we go ahead and again, here it is, and another point that I want to emphasize here is look, I came from the left side on the midline without much retraction on the cerebellum. I bet your criticism would be, "Well, you've come from the left, you may not have a good view of the right extension of the tumor, way to the back side." I'm right at the midline and I'm crossing actual midline and I'm looking at the tumor capsule on the contralateral side without any difficulty because you're coming cross court. It's the same principle as pituitary surgery. If you wanna look far to the left, come from the right nostril. And that's why we use the cross-court principle. So here is the contralateral extent of the tumor, this is the tectum on the other side, this is the arachnoid over the posterior lateral mesencephalon on the right. Again, we're working on the left side. I'm just demonstrating that we don't need that fixed retractor because I'm on the lower slope of the cerebellum. We'll go ahead and use the CUSA because the suction did not work at this tumor at all. This is the left side of the tumor, this is how adherent it was to the tectum. And here we had to violate the PR to remove some of this tumor. You may argue that I was too aggressive and I respect that, but this was a young patient. Here is a tumor, all the while I'm working on the left side until the third ventricle is exposed, that you can see here, the bilateral walls of the ventricle. And here again, de-bulking the superior pole of the tumor. But this tumor was glued to everything, it was a pineal blastoma. So we had to lead a small portion of the tumor onto the Galen and basal veins of Rosenthal. And you'll see them all internally. But there's plenty of space to work on a giant tumor without necessarily using fixed retractors. Here is the vein of Rosenthal. You can see how adherent it is to this tumor. I first tried to dissect it, I was unsuccessful. So I used sharp dissection and could mobilize some of it, but as you can see here, Galen is in the confluence of sinuses and extremely adherent. This is where aggressive dissection has to stop and you have to leave a small piece of the tumor over the vein. And here is sort of trying to do my best and see if I can dissect it off using sharp dissection, I couldn't. And again, further dissection of vein of Galen along the superior pole of the tumor. Obviously, this is the vein of Galen. You can see using number six on the sector, to see if the tumor can be dissected off. But as we got closer to the vein, we saw that it turns out more adherent. This is again, the right extension of the tumor adherent to some of the veins. And we're preserving every vein in this area, because these are too medial too anterior and you're done with cephalic veins, they have to be carefully preserved. The tumor again, is very adherent to the tectum. We are violating part of the tectum here. We know that the patient most likely is gonna have temporary post-operative Parinaud syndrome, that she did, but it was purely temporary and it resolved within two weeks. Here is again, their posterior aspect of the third ventricle. I work on very high magnification because I think it helps me to see around the tumor and preserve the structures carefully. And here's ultimately, removing the tumor adhering to the inferior aspect of the tectum. Going back to the posterior wall of the ventricle, you can see it's very adherent here. This is the so called the tumor. The piece of tumor adherent to the veins is being shrunken with the CUSA or the ultrasonic aspirator and coagulation. And you see a very generous way into the ventricle. This is the final view through the ventricle. This is again, that last view. Over the slope of the cerebellum, you can see how the tentorium has been tacked up. The ventriculostomy had to be used. And essentially, and here goes, total resection was completed in this case. And the patient did well besides temporary Parinaud syndrome. Any other thoughts regarding this approach? Would you advise it? Or what are your reservations?

- No, I think that's beautiful, I'm impressed. I think that that's a very, very nice way and I probably we'll try it the next time. I liked also the fact that you can do it on the lateral position and avoid the issues related to the sitting position, which are looking over common by being very careful, but it does take time. And it does put particularly older patients at at some risk. Particularly, if they have a tally up problems and so forth, Fortunately, as you know, of course, the pineal tumors are generally tumors of younger people. But, this is a beautiful approach, avoids the sitting position and it showed us how you get a beautiful view, not only of ipsilateral side of the tumor, but also of the contralateral side. I think it's beautiful.

- Dr. Heros, I wanted to thank you again for your time today. I also want to personally, sincerely thank you for what you have done for neurosurgery. I think many young neurosurgeons including myself, look up to you. And again, I look forward to working with you hopefully, in the future on one of these webinars.

- Thank you so much, Aaron, a pleasure. And thank you for the compliments, thank you.

Comments:

Aaron Cohen-Gadol

Dear Maximiliano: I sincerely appreciate your words of encouragement and support. Best wishes, ACG

Apr 9, 2018 09:46 AM

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