[MUSIC PLAYING]
TIM OLSEN: Hi. My name is Tim Olsen. I'm a vitreoretinal surgeon at the Mayo Clinic in Rochester. And today we have a challenging case. This is a young person, a 24-year-old, who's been diagnosed with a large choroidal melanoma. Our goals for today are to demarcate this tumor. We use ceramic fiducial marker to demarcate the tumor on the external wall of the eye.
We also want to biopsy the tumor to see what the pathology is and what the genetic risk factors are. So we'll do an external transscleral biopsy.
The muscle you see here is the lateral rectus muscle of the left eye. And the tumor is located-- there's a mound in the center.
The area with the sentinel vessel right here is the area where the tumor is involved. So at first we'll just transilluminate and see how much we need to open. So what we're doing is just an incisional opening of the conjunctiva for 360 degrees, opening [INAUDIBLE] capsule around each of the four rectus muscles, so that we can get a vital suture around the rectus muscles. I'm going to come in perpendicular with the [INAUDIBLE] and bring it up anteriorly, get it with the heel of the hook. So we've got the lateral rectus and the inferior rectus secured.
This dark shadow is the edge of the tumor. So we're just going to draw a line around that with a marking pen.
OK. So we have the lower border of the tumor marked at this point. And we're going to find the upper border. So what we'll do is we'll mark these. And then under the microscope, we'll put the fiducials on there.
OK. So these are markers that we use for radiosurgery. They are carbon fiducial. They show up really well on MRI scans. So when they do the MRI scan tomorrow, they'll be able to nicely localize this tumor. So this will define the infratemporal corner of the tumor. Yeah. You can see this is right at the border-- the medial border of this superior rectus insertion.
OK. So what we're going to do is make a little trapdoor here. So you want this about-- this flap at about 60% to 70% depth. All right. So we'll make a small incision here through. So we're in the tumor there.
OK. We have a specimen. And we're just closing the flap door over the biopsy site. So right now we've got three stitches in there, one in each corner and one in the middle.
[MUSIC PLAYING]
