Thank you. Good afternoon. Welcome, everyone. It's my honor to welcome Dr. Groutenhuis from the Netherlands, who's going to be sharing a 25-year history of colloid cyst removal. Thank you. Mr. Chairman, dear colleagues, while this is the first of two lectures, Dr. Mathieson will follow this with a debate on the transcolosal. I have nothing to disclose on the conflict of interest in this lecture. I think that we all agree that surgical removal of a colloid cyst and not aspiration is the way to go. Nevertheless, there is a controversy about what is better, the micro-surgical removal or the endoscopic removal. And I repeat it, it's removal and not aspiration. There have been a number of studies, and unfortunately, because this is a rare disease, in the literatures, these are always small cohorts of patients. But this was a study using a national administrative claims data so they could collect more patients. And then you could see that if you compare these larger series, and of course they were all done by different surgeons, not always applying the same technique, that's the drawback of any kind of these meta-analyses, that 30-day post-operative complication rate was similar. There was somewhat more seizures in the micro-surgical group, and also the 30-day readmission rate was somewhat higher. But that is one of the cost things that you often now see in studies, that also the cost of micro-surgical procedures were higher than endoscopic procedures. Another study showed, and there is a big difference, that micro-surgery had a way higher gross removal of the colloid cyst. And if you see that there was only 58.2% of removal of a benign cystic lesion, that is of course a not proper technique used for this kind of disease. But then of course you will have a higher recurrence rate when you just leave half of the cyst in, and you will have a higher re-operation rate. So this study points to the fact that aspiration through an endoscope is not a proper technique for colloid cyst removal. Nevertheless, these are benign lesions. Mortality rate were similar, and overall morbidity rate was, they say, somewhat lower in the endoscopy group. This was more, well, still 10 years ago, but a single center cohort of the group from Spetzler, and they say that while the operating time and hospital stay was longer in the micro-surgical group, there was a higher rate of needing a VP shunt afterwards, and also higher infection rate. That was a little bit wondering for me. And also, well, there was of course a little bit more remnants again in the endoscopic group, although they attempt to remove it. But the outcome overall in this quite small group of patients were similar. So if I now look back to my own data, my first case that I did endoscopically was in July 1990, and to be honest, in the first years, we did the same, only aspirating the content and then trying to grasp a little bit of the cyst wall off, simply because we had a bronchoscope with a one millimeter forceps as the only instrument available. So that was of course not the proper technique. We realized it quite early on that we say, if we want to go on with endoscopic treatment of these cysts, and again, this is a lesion that is benign and we can cure those patients, then we should really change the technique. And since 1995, the only thing I promised my patient is that the cyst will be removed. I start with the endoscope. If it is necessary, I go on with the microscope. Well, we have developed a technique that it is possible, at least in the majority of cases, to really remove the tumor completely. The cyst is out. It is an arm block resection. It was not possible always, so we see that we had also five still piecemeal, which make it difficult. Then you can't really distinguish that cyst wall from the tela, and that makes it difficult. If you have nine little pieces and 10 little pieces and 11 little pieces, you never know if there still is a 12th piece left. And in two patients, it was clearly only subtotal, and also on the MRI scan, there was a visible remnant because sometimes we don't find the remnant that is there but is not visible on the MRI scan. So that whole group of 66 where we had the attempt of a total removal of the colloidal cyst, seven of those had previous surgeries, four had an attempt to endoscopic removal or aspiration, and three had micro-surgical removal previously. Of those, they all had a proven growth, and they had a recurrence. Some even had hydrocephalus, developed hydrocephalus again, and then we went in. And then the 59 cases with, let's say, primary cases that we did, the majority was larger than 15 millimeters and had hydrocephalus. So we hardly treat these two, three-millimeter cysts with no hydrocephalus and only headache. That is usually not an operative indication. 14 of them were acute cases. That means they had to be operated, well, within several hours after admission to the hospital. But you see there were also four cysts that were smaller and had no hydrocephalus. These were more recent cases. For the technique, I think what I saw in the patients that were admitted and had previous surgeries, they all had the burr hole at the same place as for an ETV, and that's just not the right angle. This will bring you to the anterior floor of the third ventricle, but that cyst is on the roof, more in the posterior part of the third ventricle. So you need to be more anteriorly and also somewhat more laterally. This will bring you in a much better angle to see also the attachment of the cyst. It is a single burr hole operation, indeed, so that's the way, that's an endoscopic procedure. We start by removing the choroid plexus. That is not the choroid plexus of the lateral ventricle. That's the choroid plexus that is pushed by the cyst wall from the tela towards the foramen. So that already points to the fact that this is the choroid plexus coming out of the third ventricle. You coagulate it, you cut it off, and then you can go to the attachment of the cyst wall. We always have somewhat more spilling, but in that whole cohort, only one case of chemical ventriculitis, because when you change instruments, there will be some content going out. One trick that I use is I never empty the cyst completely. I want to have some content in it that I feel the cyst must have a mass to be dissected out of and luxated into the foramen of Monroe, and then finally you can go to the attachment. That is essential. Because at the end, you want to have a total removal, and if it is piecemeal, it's very hard to tell if that is a total removal. Only if you get the cyst out as, as we say, en bloc. This is an empty cyst, more or less empty cyst. If you hang it in the air, it still gets its round form again. In normal-sized ventricles, or if there is not a huge hydrocephalus, and somewhat more posterior-located or smaller foramen, we use the transcarodal approach. This is widening the carodal fissure that can also be done endoscopically. The beautiful thing is it brings you directly to the attachment of the cyst, and the cyst usually has divided the two cerebral, internal cerebral veins. And that is, that is, that makes it even easier. This is a technique that we use now sometimes also in the hydrocephalic cases, because it allows you much more easily to get to the attachment of the cyst wall. I can go through this quickly. Most of the time we have, if there is a symmetrical hydrocephalus, we will choose the right side, at least the non-dominant side. Sometimes it is clear that the cyst presents itself more into the left foramen of Monroe than you have to choose a left-sided approach. As I said, in the smaller cysts, when the foramen is not that big, we adapt a little bit more the transcarodal approach. And in those very small, they were all done with an endoscopic transcarodal approach. So we look now to these 59 arm block resections. And that is, of course, in also developing technique, there were no recurrence. But of course, still, the follow-up is less than 10 years. And we know this is a slowly, slowly growing lesion. So still we have to follow up that longer. The five piecemeal removal, where we were simply not sure if it was a total removal, one had indeed a recurrence within, after three years, we saw already a growing cyst that was removed again in a second surgery endoscopically. And that was now eight years and five months off. And it's still going well. The four others with piecemeal removal are followed with MRI scan. And that's one of the issues. If you move an arm block, you don't need to follow them up with MRI scans all the time. These others, they need MRI scans. So they have the longer follow-up. And these other four had no recurrence. And also the two subtotal removals. So with a clear remnant on the MRI scan, with a quite long follow-up, because this was also early experience from the 90s, it's still there and not growing. And also to the memory, from the elective cases, so the patients where we have time to test them properly, we had 31 cases who had a good neuropsychological testing. Interestingly enough, none of these patients, no, except one, one of these patients reported memory deficits. But if you test them, actually 17 of them had clearly nonverbal memory deficits. Four had verbal memory deficits, and that was quite severe. And three had really clearly both nonverbal and verbal memory deficits, but still not telling anything, any of these symptoms themselves. And seven of these patients, so only seven of the 31 we tested, had a complete normal testing. For us, that was a little bit surprise, because all of these 31, more or less, except one single patient, did not report memory deficits themselves. So you cannot easily say, well, they don't have that, until you test them. And interestingly enough, from those 17 with only nonverbal memory deficits, after surgery, four to six months is regularly the time that we wait and then test them again, 12 had now normal results, so they improved. Four had not fully normal results, but at least showed improvement, and one patient was worse. There was a patient that was operated first on the right side, an attempt elsewhere, but they didn't even see the cyst, tried to grasp something, but they couldn't. We went through the left side, and apparently, now we had a, on both sides, a fornicial damage. And that is, it was a permanent and rather severe, both nonverbal and verbal memory deficit. So there was one clearly worsening. The three patients with clear symptoms, with really verbal and nonverbal memory deficits, two remained unchanged, so kept those deficits, and one improved somewhat, but not fully. So they have not fully recovered. And all of the seven patients that had normal testing preoperatively had also normal testing postoperatively. So in conclusion, I can say that the endoscopic approach, if you use that, you should only do that if you are capable and at least know how to remove those cysts completely. Aspiration is not an acceptable technique. And if you use that proper endoscopic technique, then we have equal results in removal, like microsurgical techniques, but with less morbidity. So therefore, for me, the endoscopic way is indeed the way to go. Thank you very much. Thank you. Thank you, Dr. Grotnasch, for a spectacular talk. We're going to have the counterpoint in just a minute, but we do have a few questions for you. Dr. Al-Masry. Yes, please. It's very important. Thank you, Andrew, for a beautiful, thoughtful, experienced presentation of a very important subject for us. Dr. Gilad Najjar from Homs, Syria, came in and gave us a presentation where Professor Yazergeil and I were sitting and showed so beautifully, one case after another, how pulling out the whole cyst like you just saw it here, perfectly intact. It's needless to say, Yazergeil and I were very upset and angry that you can't do that. And our concern was two. One is just technical during the surgery, that you're really pulling that thing out. Of course not. That is ridiculous. In neurosurgery, the first rule, don't pull, because it might rupture one of the vessel or attach a choricle plexus or whatever. Then you will have bleeding, I can tell you. You will have bleeding, of course. And you got a hemorrhage that you cannot deal with. But say that you could technically overcome that question, what our concern was in the big cyst, in the big cyst, that you are stretching the fornix as it comes out. And the result is what you showed us, is those people have a significant number of them, even if they improve after 10 months or they did not improve, they have memory problems. And that is a- No, that was preoperatively. It was preoperatively. The 31 was preoperatively already memory deficits. Actually they improve after the surgery. So they don't have a few months of deficits and then improve. But from the 17 you tested- Preoperatively. Who were preoperatively okay. How many of them postoperatively did have a memory deficit being a transient or permanent? One. One of them. The 17, 31 patients were tested preoperatively because if somebody comes in comatose or acutely you don't simply have time to do proper testing. Because they go to a neuropsychologist and that's, they had a whole battery of testing. So 31 were tested pre-op and for us amazingly, 17 already had memory deficits that they didn't report themselves. They said, I'm fine. I have some headache and I have, well, and sometimes morning vomiting and the symptoms of hydrocephalus. But they did not report the memory deficits that we found in the testing. So that was more or less the surprising fact. That we often hear that many of these patients don't have memory deficits. In our cohort that was not true. If you don't test them, you will not find that. And of course this was quite a battery to find also subtle deficits. But it was clear. And interestingly enough, the 17 with hydrocephalus and memory deficits, 16, no, 12 improved completely. Four at least improved somewhat but had still some deficits remaining as they had preoperatively. And one was indeed worse. One got a permanent severe memory deficit due to the surgery. You are not concerned in large cysts when you pull it out from the foramen. That is really stretching the foramen. No, because I don't pull it out of the foramen. And that is because of the constraint of time. If I would show you the video, it would have been the 15 minutes of my talk, what we do, you empty the cysts somewhat and then you have to luxate the cysts slowly. The core plexus is removed which allows you from that angle to go to the attachment. You coagulate that, you take a scissor, coagulate, scissor, coagulate, scissor until the cyst comes out and is free. And then of course it is taken out completely together with the endoscope because it never gets through the working channel of course. And what's the difference in doing it with the endoscope versus doing it with the microscope? There is no known, in most of the cases you do bimanual dissection, you have a second working channel that you can grasp the cyst and then cut it off. So of course if you just go in with the grasping forceps and pull the cyst out, that is not an acceptable technique for me. I'm sure you get bleeding from that. Because you need to free the cyst from its attachment. That's the essence of colloid cyst removal. And that is on the top of the tela between both internal cerebral veins. If you just pull that, that would be very strange to do so. So this is first dissecting the cyst off and therefore we don't stretch that foramen. You empty the cyst partly. In the beginning I did the mistake fully and then you have a floppy membrane. That makes it much more difficult to dissect it off. You need some substance and then you can stretch it and then cut the attachment. That is so important in this technique. Now Dr. Methenius is here and he looked exactly in that issue and they have a little different finding. There's another question in the back. We're going to keep moving. But yes. So just a quick follow-up. Yes. Of course. Of course. Well he's going to come in. Thank you very much for your present. Oh, I'm sorry. Another person. Okay, sorry. Hi there. So Dr. Grotenhaus, Tom Beaumont from Wash U. So real nice study and we've been studying these things intensively for quite a while and have our series coming in a follow-up to our 2016 paper with the colloid cyst risk score. Our data mirror yours exactly. I think our surgical technique is perhaps a bit different. But what I wanted to say is over the last decade, 50 patients where we've now converted completely to endoscopy from open cranial approaches. The operative time has decreased. There's absolutely no need for observation in the neuro ICU. There's no need for a prophylactic placement, even clamped of an EVD. We've had no major intraoperative complications. Right now we're a center who does a lot of neuro endoscopy and I think that's one other point I want to make here at the end. But also we've had, you know, our mean hospital stay decreased by 50%. And one thing that's very important in all healthcare systems, but particularly in the climate in America today is the cost of the procedure for us, excuse me, has decreased by threefold. And then if you look at the patients who had complications in the open cranial operations, you know, it's a significant cost savings. So from a health economic standpoint, it makes sense too. The patients like it better and every one of the endoscopic patients have been discharged home regardless of their age. So I think that in a big series, both yours, both and ours, and I think as these data mount, you know, it's going to become clear, at least to me, that endoscopy is the way to go. And the last point I would make in that, in skilled hands. So that I think a lot of the early data show very clearly that there were problems with residual cysts and there were problems with memory deficits, but that was because basically the procedure was in its infancy. But if you actually do it well and carefully and can handle large cysts, use the nicomyriad if you have to, et cetera, et cetera, that's a whole other issue. You can do this very safely. Yeah, no, fully agree. That's the point. Yeah. Yeah. Thank you. There was another question over there? Or shall we just wait with the questions after Dr. Matjeson's talk? Sure, okay. Yes, we can. I would suggest that.

Dr. Groutenhuis

controversy

micro-surgical removal

endoscopic removal

colloid cysts

studies