Name:
10.3171/2024.10.FOCVID24107
Description:
10.3171/2024.10.FOCVID24107
Thumbnail URL:
https://cadmoremediastorage.blob.core.windows.net/af840945-4e92-41e6-a4cf-7923bae69f73/videoscrubberimages/Scrubber_367.jpg
Duration:
T00H10M57S
Embed URL:
https://stream.cadmore.media/player/af840945-4e92-41e6-a4cf-7923bae69f73
Content URL:
https://cadmoreoriginalmedia.blob.core.windows.net/af840945-4e92-41e6-a4cf-7923bae69f73/7. 24-107.mp4?sv=2019-02-02&sr=c&sig=i5IEYmwMls03M9Bv0kae4ihbHV9pEPtrLrrPKkAWYiU%3D&st=2025-08-06T10%3A48%3A49Z&se=2025-08-06T12%3A53%3A49Z&sp=r
Upload Date:
2024-11-21T00:00:00.0000000
Transcript:
Language: EN.
Segment:0 .
[MUSIC PLAYING]
SPEAKER: Brain mapping during resection of high-grade brain arteriovenous malformation surgery. This is a large AVM in the left cerebral cortex, which has deep venous drainage and is fed by the ACA/PCA territory. The eloquence is what mapping is really used for here. The corticospinal tracts are just anterolateral in yellow. And the visual fibers are posterior. The AVM comes into the sensory cortex proper and gets very close to the posterior thalamus.
SPEAKER: We will use mapping for these eloquent areas. The approach is a semisitting supine biparietal craniotomy to get the ACA/PCA territory arteries first, without embolization, and then intraoperative angiograms as necessary. Here, the neurophysiologist adding the motor and sensory leads into the scalp, and then posteriorly, the visual evoked leads.
SPEAKER: She's now putting visual evoked glasses on the patient's eyes and securing it with tape. The bicoronal incision is opened, and we have access to the skull with burr holes placed to make two separate craniotomies, one on the right and then dissect the sagittal sinus from the one on the left, which is safest. The convexity dura are brought together in the midline and sutured in order to avoid any more bleeding.
SPEAKER: We begin, placing the lead on the left motor cortex and checking that we're on motor. And you can see the video evoked potential grid on the occipital lobe. We're going in the deep interhemispheric fissure to find the ACA target with the Brainlab overlay in the microscope. This is facilitated. We find the ACA.
SPEAKER: We place a temporary clip on that. And now, I'm opening the falx to get from the right to the left. This facilitates the medial exposure of the AVM where the PCA artery is going to be found against the vein of Galen. Navigation, again, giving confidence to the dissection. Clip is placed on the PCA. And we go to the anterior aspect of the AVM against the splenium now to begin dissection towards the lateral ventricle, with the goal being to get the posterior lateral choroidal, closing as much of the inflow as possible for this large AVM before a real resection occurs.
SPEAKER: Now, on the margin of the AVM nidus, the bipolar and suction are utilized down the margin. Here, we use the stimulator to assure ourselves of where motor is on the medial aspect before making any cuts into the cortex to go along the superior lateral aspect of the AVM. We find sensory and go just behind that, making a cortisectomy along posterior cingulate.
SPEAKER: The navigation aids in the trajectory of this dissection, as I want to stay right on the nidus in order to get down to the ventricle in an efficient manner. Any of the loops of the AVM should be brought back into the nidus. Because this is a rather diffuse AVM, it does pose a challenge as to where the border is.
SPEAKER: But we continue dissecting, progressing in the white matter. The dissection is really just the bipolar suction, bipolar suction. And here, we see the lateral ventricle. This is a 0.5 millimeter bipolar. And the goal being to find that posterior lateral choroidal artery.
SPEAKER: This is the big draining vein in the ventricle itself. And here, we get around it and we start to see the artery coming in the posterior lateral choroidal. It's coagulated. And a clip is placed on it both to mark it and to reassure ourselves that it is not going to bleed.
SPEAKER: Then it is cut. This has decreased the total blood flow to this AVM. Here, the picture-in-picture confirms our position. The next step is to go anterolateral where the corticospinal tracts as well as the thalamus could be found. We're using the subcortical mapping.
SPEAKER: And at that, my neurophysiologist tells me I'm now 1 centimeter away from the leg and arm. And this picture demonstrates, as does the navigation. Then I turn my attention, posteriorly, to the remainder of the dissection. Now, what was challenging here was that the AVM did come out in piecemeal fashion, certainly not something we want to do routinely.
SPEAKER: But the blood supply had been cut, and it was diffuse. And that was how it came out here. The main draining vein in the ventricle is cut. Now, this dissection certainly took a long time. But for the purposes of this video illustrating the brain mapping, much of that has been left out. We remain in the ventricle.
SPEAKER: And pieces of the nidus come out posteriorly. Now, the interior margin was difficult. Therefore, at this point, I elected to stop and get an angiogram. You can see either side of the falx. The motor strip is removed. We do a soft closure and do an angiogram. And there is a small residual early vein.
SPEAKER: And we come back on a second day, coming slightly more anterior along the corpus callosum, cross-clamping the artery more proximally. Now, we're going to be even closer to corticospinal so the suction stimulator is very, very helpful. Subcortical mapping showed that we got very close to leg at 3 milliamps, which translates to 3 millimeters, giving the surgeon confidence.
SPEAKER: I try to stay right on the nidus, out of the corticospinal tracts, with small movements guided by both the resection of what I see under the microscope, as well as the feedback of the subcortical mapping. And that's a constant communication between the surgeon and the neurophysiologist. The goal in my mind is to stay right on the AVM. And that means to follow those nidal vessels, both medially and laterally.
SPEAKER: We focus both on the lateral aspect and now, the medial aspect in the ventricle. And it's important not to go across the ventricle because the posterior thalamus is just adjacent to that tissue there. And you can see there was that nidus that was demonstrated in the angio.
SPEAKER: That's an en passant artery, and it is left intact. ICG demonstrates better flow, less early venous drainage. And I do another angiogram but continue to find early vein, a different one than the last angiogram. So we continue our resection, very focused along the superior posterior margin of the dissection, the cingulate gyrus. This point, we can be a little more aggressive about the distance from the nidus as we are past motor adjacent to sensory.
SPEAKER: And the ventricle is, again, exposed and EVD catheter is placed. And the remainder of the AVM is then taken out. And we prepare for a final angiogram, where there was no early venous drainage. At this point, we do our final closure where the dura is brought back together in the midline.
SPEAKER: Craniotomy is put back, a JP drain, and then really good galeal stitches to hold this bicoronal together. Postoperative, she had a cranioplasty and a VP shunt for hydrocephalus and, at two-year follow-up, has a modified Rankin score of 1 for numbness and a small superior quadrant field cut. But overall, returned to her life and is doing very well.
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