Intraventricular Tumor Resection

CHAPTER 1

My name is Marcus Czabanka. Hello. Today we're going to resect an intraventricular tumor - that's a 49-year-old patient. And you can here see the tumor in the T1 image over here in this area and in the T2 image over there, and you can see the lesion here entering the third ventricle and potentially compressing both foramina of Monro. The same thing you can see here in the corona reconstruction. This patient presented with persistent headaches, no focal neurologic deficit, and, because of this persisting pain, he finally received an MRI showing this intraventricular lesion. So our idea to remove the tumor is basically via an interhemispheric, transcallosal approach for this purpose. So, the first step obviously will be a craniotomy over the coronary suture to really enable an interhemispheric approach. The second step will be opening of the dura and then preparing the interhemispheric space. Third step then will be to really prepare both pericallosal arteries and to prepare the corpus callosum. Fourth step will be opening the corpus callosum and removing CSF and identifying the intraventricular tumor, and the fifth step obviously will be removal of the tumor. The first strategy for this step would be to really circumvent the tumor and to really identify any tumor supplying vascular structures and to really cut these structures, and after this, we'll try to remove the tumor en bloc, or we might have to remove the tumor in parts.

CHAPTER 2

Okay, the positioning of the patient is very simple. The head's positioned straight in the Mayfield clamp, and it's basically inclined as much as possible to actually allow the surgeon to operate towards the floor and not to operate towards the front. And it's a very small skin incision on the level of the coronary suture. The craniotomy will be divided into two parts. Two-thirds will be in front of the coronary suture, and one-third will be posterior to the coronary suture. That's our surgical approach for this one. So we start with a straight skin incision. So, we do intensive hemostasis straight from the– straight from the skin incision. Then we have the retractors. So, we need to create some more space, so–but all the things that we need to see we can already see, okay? So, here you have the sagittal suture. Here you have the coronary suture, so the craniotomy will be in this area over here. We're going to increase the skin incision a little. Okay, now it's–I think, it now it's very clear. Here you have the sutures. So, I'll use a pen now to show you where we're going to do the craniotomy, so that it's easier for you to understand– for you to see where we want to do our cuts. So, one burr hole will be here, and another one will be here, and then the craniotomy will be like this. Okay. Okay, now we mobilize the dura from the bone to get a good entry for the craniotome. Okay, come here to me. And then - and then we do the cuts. The cuts–we always cut away from the sinus so we have no risk, or we have a reduced risk of injuring the sinus. And in this case, we– we increase the craniotomy to the contralateral side. And then we lift the flap, and remove it from the dura. Okay, here you can see the sinus. We're going to do just superficial hemostasis. And some compression. So, the reason to go over the sinus is to be able to retract the dura a little bit more into the contralateral side, so that we have an easier access to the– to the interhemispheric structures. Okay, good– yeah, that's okay.

CHAPTER 3

So, we open the dura. For this purpose, we just put a stitch on it, and then we lift and incise it. You know? And that's it. Okay, once that's done - I just open the dura with the regular scissors. When we approach the sinus, we need to get as close to the sinus as possible without really opening it. That's why I do these small incisions, and I use the retractors to retract the dura further. Okay. There's too much epidural oozing. That's why I'm going to do– I'm going to use stitches to suture the dura to the bone. Okay, do a whole half. Okay, now we make it– now, we generate the access to the interhemispheric fissure. Okay, that's it. Okay, now we can start to prepare the interhemispheric fissure. So, I'm– I've prepared this, just in case. And now, we need to go down. And the first important structure will be the cingulate gyrus where we usually find many adhesions. We need to resolve these adhesions. Here, we're just about to start already. Okay, there we go. Okay. We do it also here on the posterior part, just to resolve the adhesions– arachnoid adhesions. Okay. And we go one step further.

CHAPTER 4

And here's what we already need to see. Do you see the corpus callosum? And here we have– see one of the anterior arteries? The other one should be on the other side. In this case, we decide to go in between them. For retraction purposes, I usually cover this with– with cotton. Okay, here's the anterior– artery– pericallosal artery. That's the right one. So, I just cover it for the manipulation. Okay, here we have the pointer. We are just above the entry to the lateral ventricle. Can you see it? So, in the depth– if we follow the navigation to the depth, we'll see the tumor. See? Now we've opened the ventricle. There's CSF running. Okay. Now we have the entry into the ventricle. So here we're on the contralateral side. We are approaching the contralateral foramen of Monro. Okay. So, it's mostly on this on this side, okay?

CHAPTER 5

That's the tumor. So, I'm looking for the– for the boundaries over here. There's some bleeding. So, I try to first go around the tumor to see if maybe I– I can just cut blood supply and then resect the tumor. Yeah, so it's very hard– first of all, I see that I can get a very good plane towards the regular brain. So here, I have a good plane between the tumor and the regular brain. At the moment, still my strategy is the same. I try to go around the tumor to see if I can really dissect it from the regular brain without injuring too much physiological structures. What I think it is, I have no clue. To be honest. No clue. Maybe it's a– maybe it's a plexus tumor, but I don't see the plexus relationship at the moment. So, still difficulties to really say what it could be. The other problem that I currently have or– it's not a problem, but it's a surgical idea– I'm unsure of, for example– I'll tell you soon. See these are arteries. These, I don't want to– these I don't want to sacrifice or injure. See these small arteries down here? So, I have these little venous bleeding, but these arteries I'm sure I don't want to– I don't want to do any harm to them, because I might risk getting any form of ischemia. So that's very clear, so that's one of my anatomical landmarks where I say no. I'm not going to go further than this. I'm coagulating on the tumor because I know the tumor should not be– the tumor should not be my problem, right? If I coagulate on the tumor, I'm not going to see. Here, I have a good plane towards the brain again. You see regular brain underneath. So, the current question that I have is what I'm going to do with these big vessels over here. So I saved them so far. See right here? But, I still need to find out if they are just primarily for the tumor– then we have to resect them– or if these large vessels will have any effect on the brain. But, see, it becomes clear when you look here. If you have to– if you want to resect the tumor completely, you'll have to sacrifice them. So, I could coagulate them, and then I cut to have no hemorrhage. And then we continue resecting the tumor from the brain. Okay. So I have the front. Now, we have to change to the posterior part. I cover the foramen of Monro with a cottonoid, hoping that there will not be too much blood going to the– going to the remaining ventricles. Here, you see the– here you see the plexus– choroid plexus. Remnants of the thalamostriate vein. So it might very well be a plexus papilloma, for example. So, good border over here, see? Some little adhesions. We'll just remove them. So, I'll take the cottonoid to move it around the tumor. Ah, there we go. So here we need to go through the arachnoid. Okay. Perfect, regular brain. Vessels of the regular brain. Okay. Looks good. Okay, so I think we are almost set. See here– there's another one. Okay, so it's almost loose. I just need to make sure that I don't– I don't injure any vascular neuronal structures here on the posterior part where I don't have the complete... But here it looks good. Perfect.

CHAPTER 6

So now I have it loose, and I will try to remove it as it is. See the hole where I– the approach, the– the callosotomy is too small to resect it completely, so I just take it piece by piece. That's it. So we have removed the tumor now. We had to reduce it in size to remove it via the callosotomy because the approach is– again, the callosotomy is very small, so I can show you in a– in a smaller magnification. So that's the approach that we use to resect the tumor, so give me the tumor. That's just the part that we moved– that we removed after reducing it in size, so... Now I'm just going to check for tumor remnants and to check where the bleeding is coming from. Okay, so what did you can see very well now is– we look– now we look to the contralateral thalamus. Here we have the choroid plexus. Here we have the thalamostriate vein that we have somewhat distorted here. So if you go here, we have the– we have the left side foramen of Monro. There's a blood clot inside, so we need to get rid of this one. Okay, so that's the left side. I have to check what's going on back there. Let's do this one, over here. These are big veins. So now I'd like to see the important structures on the other side, on the– on the right side. For this purpose, I'm going to remove this. Okay that's the third ventricle down here. That's the right side foramen of Monro. Here you have the right side thalamostriate vein, so that's good. So we have that structure. Okay. Okay. Plexis– so I'm– this I'm just going to leave. This is plexus. This is also plexus. I think it was a plexus papilloma. I think that's it. We are all safe. So all the important structures are still present. So a lot of– a lot of hemostasis with water. Now we, in order to control a little oozing and bleeding, we just cover the tissue with this. See there's air coming out of the ventricles. See this? That's what's happens if you reposition the patient, put the head up, so that the air really gets out as much as possible– gets out of the ventricular system. Now I'm going to remove the cottonoids. I think now– now the hemostasis is okay.

CHAPTER 7

This is the contralateral pericallosa over here. The ipsilateral pericallosa– I think I've shown you before, which is right here up front. So, what we're going to do now is– we're going to close the callosotomy in order to hopefully reduce the incidence of a CSF fistula by using foam and glue. So I put it up here. Like this. So I seal it with fibrin glue. Okay. Now hemostasis of the superficial brain areas. But there's not much to do. So, now we going to start to close the dura. Okay, so we use these... how do you call it? That's what it's called. We use it to really seal the dura, if there's– if there's some small remnants where it remains open. So we put in the bone flap with foam sponge. So to just provide the second layer of potential dura, and to seal– to seal the defect on the dura. Nice. Okay. So we fill– we use the remaining bone to fill the gaps of the craniotomy.

CHAPTER 8

Okay, now we have finished the surgery. The surgery overall went quite well. The tumor was easy to prepare, and there was a clear-cut border between the tumor and the regular brain. In the beginning, I had some troubles really to make sure that I can ligate the rather big venous vascular structures that were overlying the tumor, but after some time, it became clear that these are really tumor-supplying vessels, so there was no problem for that. And I think after this, preparation of the tumor itself was quite straightforward without any real complications or problems. I think after surgery, I could really identify all important structures, which were the big thalamostriate vein on both sides and the foramina of Monro, which was compressed on the right side, but otherwise all the important vascular structures, also the pericallosal arteries, were patent and were unharmed, so there was no problem in this regard.