Mount Sinai increasingly is turning to embolization to help remove skull base tumors such as meningiomas more completely, selectively, and safely. Using a strategy devised by its biomedical incubator, Mount Sinai BioDesign , surgeons can now assess and quantify the extent of embolization through an analysis of an additional MRI sequence following embolization and preceding surgical resection.Joshua B. Bederson, MD , the Leonard I. Malis, MD / Corinne and Joseph Graber Professor of Neurosurgery, and Chair of Neurosurgery for the Mount Sinai Health System. “Not all skull base tumors are appropriate for embolization, and it does have a low level of risk,” says Dr. Bederson, “but for those challenging cases where large, highly vascular tumors are fed by dedicated arteries, the procedure can be particularly useful.”
Hello. My name is dr Joshua. Better person and I am professor and chair in the department of neurosurgery for the Mount Sinai health system. Today I want to discuss a case and a program we have two D vascular rise meningioma using preoperative embolization. In this technique catheters are introduced into the arterial supply of the tumor and those arteries are filled with anabolic materials such as glue, onyx particles and so on in an attempt to reduce the blood supply to the tumor which as you will see in this case can have major beneficial effects. These are my disclosures, none of which are relevant to the presentation today. In general resection of meningioma is safe but some tumors can be very firm. They can be adherent to the surrounding tissues and they can be very vascular in general. The softer a tumor and the less vascular it is the easier it is to remove the lower the risk with less vascular supply and software and this can sometimes be achieved by M belies ng or injecting the arterial supply of us. We've devised a strategy to assess the extent of embolization of these tumors. Through a sophisticated analysis of pre and post embolization M. R. I. Scans and we can then attempt to quantify and develop a paradigm to assess the efficacy of this evolving paradigm for treatment young man presenting with severe weakness of his right arm and leg due to a tumor that really arose from the midline fox. But as you can see with this left sided opening here it's covered by eloquent brain and this portion of the brain is his primary motor and sensory area, you can also see the superior sagittal sinus towards the right side and you see very important draining veins both in front of and behind the area of the tumor. That's gonna are gonna give us a small window uh that we can use to to operate. This is a preoperative M. R. I. Scan demonstrating this large parafoil seen tumor. This meningioma rises from the Fox itself and you can see the vascular supply originating from inside the Fox here, for example, and penetrating into the tumor. That was a coronal view. This is an axial view. This is a left sided tumor which is why he's got severe weakness on the right side. And you can see some of the vascular supply here coming from the Fox. We also see the central sulcus and pre central gyrus, demonstrating why he has weakness on the contra lateral side, The T. two Flair, which you see here demonstrates a Dema in the surrounding tissues as a result of the severe compression sagittal view which you see here shows the huge size of this tumor and the impact on the critical sensory motor fibers as they pass from the cortex. Uh and down as well as compression of the corpus callosum and the robust vascular supply shows a very different view. Very different appearance of the tumor, particularly in this area here where the most robust supply was before. You see all of this no longer takes up contrast and it's dark, demonstrating a beautiful D vascular ization from the civilization. Um If we look at the coronal view, we see that the inferior portion of the tumor still enhances here. You can see this down low but the majority of the tumor has been d vascular arised. This is a really beneficial um tumor embolization and it's particularly important in this patient because what you can see here is that there's eloquent meaning functional normal brain that completely covers the tumor. And so when we open up we are not going to be looking at the surface of the tumor. We're gonna be looking at the surface of the brain and this is functional brain. So we cannot go through this brain in order to reach the tumor. We have to develop a plane between the medial surface of this brain tissue here and the superior sagittal sinus. And try to find a space through which we can remove the tumor. That would be the challenge of this operation. Um A post embolization MRI scan. Um And so I'm gonna go through this video and show you how we first develop the space between these veins here. Over here. You see adhesions between the cortex and the dura in the form of arachnoid granule ations. Um And we'll slowly develop those here. We're using uh an inter operative recording electrode to map out the primary sensory motor cortex. Uh by putting suture in the dura and tying it. We can put gentle traction as you see here, pulling gently pulling the dura from lateral to medial and putting it on stretch. This allows us to develop this playing here which is very sticky. And we have to spare this critical underlying brain. But unless we can get between the dura and the cortex, we don't have access to the tumor. Unfortunately this draining vein in front and the draining vein behind also have to be carefully spared. So through careful sharp dissection we can, over a period of several minutes we can gently develop this plane and eventually find our way into the inter hemispheric fisher. And so as that plane gets developed we can hear you see gently retracting the brain. And we're getting right onto the top of the tumor here. That different. This is the tumor right there. That's the top of a very large tumor. M. R. I. Scan is really quite a large tumor. So we're really literally just seeing the tip of the iceberg. Um But our our goal here will be to retract that brain and get into the top of the tumor. And here you see a retractor with a cot annoyed protecting the brain. You see that we've spared this critical draining vein over here and this is our access, this is our entire access to the tumor right now. Unless we can slightly increase it. And this demonstrates how you can cut the very fine arachnoid along these veins, sparing the veins and providing that extra couple of millimeters. That will be so important as we continue this tumor resection, increasing the magnification. We can then start to develop a plane between the tumor and the brain and here this I'm using the scissors to cut into the tumor. And this demonstrates beautifully how the preoperative embolization has converted a living vascular tumor into something that is soft and suckle. This is necrotic dead tumor material that I'm able to use a sucker to remove and that would just not be possible unless the embolization had been done frequently. These tumors have large veins over the top of them and as we begin to develop the attachments, we see those veins and and here you can see beautifully the gray and I'll freeze the video here for a second. This gray is the onyx embolization that has been injected into the fox on the midline, supplying the arterial flow into the tumor and by closing off all these small arteries, we've killed a big portion of the tumor. This allows me to cut through them as you can see using a scissors here cutting through these vascular branches that have already been included. Makes us a far safer and easier operation so now over a period of several hours um the tumor can be entered and gutted. And again, you see the soft suck herbal necrotic nature. This is not a regular meningioma but this is a meningioma that has been successfully immobilized, successfully immobilized. Um And really can't emphasize enough how different this is from the normal experience in an a nimble ized tumor, how much safer it is to remove such a large tumor in such an eloquent area of this young man's brain ahead to a later phase of the operation. We've continued to de bulk and remove the tumor. And as we get to the very bottom there is some there is a component of the tumor that has not been immobilized. And so you see a little more bleeding from around the edges. But we're getting deeper and deeper all the way towards the end because we have a very narrow point of access. I spent a lot of time shifting the head to change the angle. And what we just did here was tilt the patient to allow me to look behind the tumor. You see a cottonwood along the eloquent brain and peeling that soft the vascular rised tumor from lateral to medial and from posterior to anterior advancing a cottonwood along the brain to protect that brain and slowly delivering the remaining tumor into the very narrow field. So we've now come around almost the entire tumor. Um We've gone from the side to the back to the medial side. And now we're coming across the front of it and we'll go back and forth. Now we're gonna we've we've delivered the tumor interior early. We should be able to remove the remaining tumor and there you go. That was the last portion of the tumor. And the remainder of this operation will be just to finish homeostasis, inspect the cavity. Make sure we've gotten every last bit of tumor, remove the cotton Lloyd's reinspect and uh confirm homeostasis. And in the end we have a very clean surface. So here we're finishing up with homeostasis. And as the last continent voids are removed, we see that the eloquent brain, the primary sensory and motor cortex are intact. The very fine draining veins that are both in front of and behind the tumor are intact. We've used we've removed the entire tumor through this very small interval uh between the important portions of the brain and the superior sagittal sinus. And I think that this is really only possible so safely because of the effect of globalization and the reduction in tumor vascular charity. This young man did extremely well and noticed an improvement in motor function immediately after surgery. If we then go to a postoperative M. R. I. Scan, this is the same corona view. We can see a nice resection with no evidence of residual tumor and we see that the brain that was covering this has now expanded um had been so so compressed. We can also see this the resection on the sagittal view and you may recall how large that tumor was now is completely gone. And this brain that had been compressed has now begun to re expand back into its normal space. And that partially explains why he improved clinically after the surgery. So I hope that I have been able to demonstrate the concept of extensive preoperative embolization to reduce the vascular supply of a tumor and make a safe surgery even safer for our patients.
