This is a surgery demonstrating the placement of a Baerveldt glaucoma implant in an 80-year-old female with primary open angle glaucoma. The tube was covered with corneal tissue.
Surgery location: on-board the Orbis Flying Eye Hospital in Can Tho, Vietnam.
Surgeon: Dr. Wallace Alward
DR ALWARD: Do I start talking to the audience, then? So this is backwards. That was weird. They have an inverter in it for retinal surgeons. So tell her we’re gonna start, and if she has pain, she should just tell us. So do we know if we’re broadcasting? Should I be explaining? So I’m gonna make a conjunctival incision. That goes a little bit past the superior rectus, a little bit past the lateral rectus, just so I have exposure. I spread. She’s not young, so her tissue is thin. And I like to make long cuts, rather than little tiny bites. And because her tissue is so thin, when I grab it, I don’t grab the conjunctiva. I flip it over and I grab Tenon’s, because I don’t want to tear her conjunctiva. And I spread on both sides of the rectus muscles. Stevens scissor, please. I’m sorry? Again, I’m gonna flip over, grab Tenon’s. And with this, I’m gonna make a space that’s gigantic. Because this implant is gigantic. And there’s a little pin in the scissor. I want to go about that deep. Like that. We can open the 350 Baerveldt. I’ll take a Gass hook with a suture on it, please. Let me see it again. I was looking right past it. Thank you. And a 0.5, please. Just put it through there. 0.5. That’s 0.12. 0.5. So as I talked about in our lecture, you don’t need to do these with a suture, but I really like it. Anesthesia, I’m gonna be grabbing muscles here. Just to let you know. So always tell anesthesia before you grab a muscle. You don’t want the heart rate to go down and then be surprised. So can I get some lidocaine/marcaine on a cannula? Yes. Thank you. Getting the Tenon’s cleared away here. She’s okay still? Is she better now? 0.12. And Westcott. So she’s having some discomfort from the superior rectus. I might try to do this with just the lateral rectus, and we’ll see how this goes. I’m relaxing Tenon’s now. I think we’ll be fine. Can I have a caliper on 10 millimeters? 10? Marked? So I’m gonna give her a little bit of lidocaine/marcaine. But I think I might just do this with only the one muscle, which would be fine. Is it marked? That’s good. A blot in there. A Weck. Down there, please. Thank you.>> Dr. Wallace, so why do we use a valve in this patient?
DR ALWARD: I’m sorry. I can’t hear you.
>> Why do we use a valve tube in this patient? Why don’t we use trabeculectomy?
DR ALWARD: I can’t hear you. Well… Okay. So I think the concern was that her conjunctiva was very thin. And so that’s why we’re doing a valve. A tube, not a valve. There’s no valve in this. It’s a seton. A tube shunt without a valve. So part of the reason we’re not doing trabeculectomy is because there’s no mitomycin available in the hospital. So I don’t like to do trabeculectomies much without mitomycin, and this is a technique that we want to learn. And her tissue is very thin. So the tube versus trabeculectomy study — these have equivalent success rates. And I think you could make a great argument for doing a trabeculectomy instead. So I just cauterized my mark there. So I know how far — I don’t lose my blue mark. But technically, you could do either one. I think you would be justified to do either one. Can I have the Baerveldt, please? And a smooth forceps? And another smooth… Yeah. So the Baerveldt, as you can see, it’s gigantic. It’s very big. So we have to be careful to get it deep enough in the eye. And what I try to do is to line up the dots with the forceps. Like that. And I’m gonna push straight back, and I’m gonna fold this and tuck it under the muscle. So I have it under both muscles. I’m doing the lateral last, because I have a great view of this muscle. The other one I don’t have as good a view, since she was uncomfortable while we were looping it. And now what I want to do is just make sure that this is very mobile. That when I put it somewhere, it stays there. It doesn’t want to pop forward. That means I’m not hung up on any tissue. I like that very much. 0.5 forceps, please. So to pass this, I think as we talked about in the lecture, this is a place where we have to be very careful. Passing this suture. I’m using my 0.5 on the rectus muscle, as a way of controlling the eye. So I want this to be — this needle to be flat. I don’t wanna go in with it bent in any direction. It needs to be flat to the sclera. And you want it to be enough of a bite to make sure that you have good tissue. You obviously don’t want to go too deep. For this, I’m just gonna put three throws, just to leave it here temporarily. I’ll take the other half, please. And this just gives me the chance to move this plate around, that I wouldn’t have if I had sewed it down tight to start with. And I’ll come back and sew that at the end. So for this, I want to be armed right in the middle, and twist it out just a little bit, so I can see that it’s flat. That’s better. Maybe under that Tenon’s. So it’s a little harder, because I don’t have both rectus muscles done, but we’ve got great help here. So again, I want this to be definitely thick enough to have strength, but not so thick that I damage anything. Yeah. That’s good. Thanks. I’m sorry? Actually, there is good. Thanks. Thank you. Just getting untangled here. I do 311. 311, yeah. Do you have a straight tie? A little wadded up here. Silk is sometimes a little weird to deal with. There we go. Do you have another needle holder I could use instead? Needle holder? So it’s important that this is on tight. And my tying forceps wasn’t holding well enough. So… This isn’t gonna hold at all. This really needs to be snug. Or else it will piston in and out of the eye, and it will cause inflammation. I’ll leave that a little bit long. Good, perfect. Can you go back? That’s great. Thanks. So that’s another mistake that’s easy to make, is to not tie this tight enough. I’m good there. Thank you. You can see I’m actually denting this plastic on the plate — or the silicone — because I really want this to not move. Ever, ever. A straight tie, please. 0.12?
>> The eye is dry. The eye is dry.
>> Wet the cornea, he says. He says wet the cornea.
DR ALWARD: I’ll take a curved Vannas, please. That’s fine. So now I’m gonna cut this tube to length. Actually, let me do one thing before that. Can I have a smooth forceps? I have my marks here, so I know I’m far enough back. But I just want to grab the plate and make sure that it’s not wiggling. That it’s nice and solid. And curved Vannas. And I’m just gonna put this bevel up, which means I hold this flat on the cornea. And that will allow me to get a nice bevel. And sometimes it’s too long. You don’t want to make it too short. Better too long than too short. We can always come back and cut it later. Can I have that 6-0 vicryl? Just about 2 inches. I just need one piece. Thank you. That may be too short. Maybe a little longer than that. I’m sorry?
>> How long is the tube?
DR ALWARD: Well, I don’t really measure it in millimeters, because whatever we get here, it’s going to be different once it goes through the shorter course of the eye. But what I want is something that’s gonna come about — oh, maybe to there or there. I don’t want it so short that it could retract out. So to me, the exact length in millimeters is less important. This may be a little too long. But we’ll go ahead and try it and then see. You have a smooth? Just hold the — can I have another tying forceps, please? And then I’ll need the tube. Hold that down. So Dr. Tri is holding the tube for me. And I’m gonna just tie this off. Gonna do two throws, not three. Needle holders, please. And so if I put three throws, I think the knot is too long. And so it can make it not close as well as I would like. So I like two. I kind of put it over this bubble. And it needs to be very tight. And I always test it. If it’s not tight enough, then I do it again. Add another one. We had to do that on the last case, in the hospital. That’s okay. So having this suture release too soon is a really bad thing. Scissors. And I’ll have a straight and angled tie, please. Thank you. So I’m gonna put some air in this tube. I think for me, the only way I can be sure that it’s not flowing is if there’s an air bubble in it. So that’s what I’m doing here. BSS on a cannula. Smooth forceps. I think if it’s completely filled with fluid, you can push and it will look like it is occluded, but it’s not. But a bubble should compress when I fill this. And then release. And so I know that it’s completely tied off. Curved Vannas, please, and a straight tie. So to me, this tube looks like it’s gonna be too long. I’m gonna go ahead and shorten it, before I even try to pass it. Again, it’s important to have the bevel up. It’s easiest to cut it the first time. This actually turned out fine. 75 blade mark there — side port — paracentesis marked. I need it marked. 0.12? 0.12. So we’re gonna do a paracentesis. I always do a paracentesis. We talked about in the classroom — it doesn’t matter when. So this paracentesis, for this — sometimes for trabeculectomy, I’ll just make it down like that. Because if they’re phakic, and then we dilate them, I don’t want to be hitting the lens. But for a tube, I try to make it perpendicular, so that if I need to put a second instrument in, to hold the iris back, I can do that. BSS on the cannula, please. Just want to make sure it’s in there. I’ll take the 23-gauge needle. Does it have ink on it? So now I’m gonna enter the anterior chamber. And what I want to do is — again, I want to be deep. And this is a 23-gauge needle. Normally I use a 22. It doesn’t really matter. It’s a little harder to pass a tube through a 23. I was asked in the classroom about measuring, and I just don’t think for me that would make much sense. She has a chamber that’s really deep. She’s pseudophakic, so I can be — if I’m too deep, and I even hit the iris, it’s not gonna hurt her. So I’m gonna start here, and I’m gonna start the track up just a little bit and then go flat, and hope that I’m in the AC, which I am. Straight tie. So the tendency is to just try to push this in, but if the chamber is shallow, it’ll just go into the iris. So I use my 0.12 to hold this flat. So that I’m trying to approach at a flat angle, instead of pointing down. BSS on a cannula. So this to me is in a good position. It’s well away from her cornea. It’s high above her iris. We want it to be coming through her trabecular meshwork or ciliary body face. 9-0 vicryl, please. So you can see I still have bubbles here, so I know that it’s not flowing. I can see that there are bubbles in my tube still, so I know that there’s no fluid flowing. That makes me feel good. And now I’m just gonna suture this plate to this tube down, with 9-0 vicryl. Can you squirt the cornea? Yeah.
>> Professor, why do we need to stick the tube through the sclera? Because we will have the graft above it later?
DR ALWARD: I think probably this may not be necessary to do. I sometimes leave it out. I don’t think the graft will prevent it from retracting, but this is probably extra work for not much help. I’ll need that vacuum. Can I have the cornea, please? I think it’s fine to leave that step out. Some things we do just because we’ve always done them, which isn’t so smart. This is a cornea. Preserved in glycerin. Dr. Richard Lee was nice enough to send these along. But we can use Tutoplast, or we can use sclera. 9-0 vicryl, please.
>> So we’ve got an American cornea in a Vietnamese eye. That’s cool.
DR ALWARD: It is cool. I assume it’s American. It’s Florida. That’s almost America.
>> Why this cornea is too cloudy?
DR ALWARD: Well, there’s no endothelium. It’s just the corneal stroma. And so we don’t care if it’s cloudy or not. Cornea just is really nice for this. At my institution, when they come from the Eye Bank, they’re tapered, which makes it really easy to sew on. Because this is a little bit thick. And so what I’m gonna do is just grab the anterior border of this, with this pass. So you don’t want it real thick at the limbus, because you don’t want her to get a dell-formation. And it needs to be a little bit anterior to where the tube enters. Because sometimes it’ll move a little bit or shrink a little bit.
>> Professor, some people asked: How do we release the tube in the future?
DR ALWARD: So there are ways to do that. To me — I’m glad you asked that. Because one thing we could do, if her pressure was high, is we could fenestrate the tube right here in front of the suture pass. But since she’s elderly… I’m struggling with my chair here. Excuse me. Stepped on the wrong button. My chair went down. Since she’s elderly, I would rather have a high pressure — and her preoperative pressure was not very high — I would rather deal with a little bit of a high pressure than have too low a pressure. Because she could have a suprachoroidal hemorrhage. All sorts of problems. But I’m not gonna fenestrate her. I know Dr. Richard Lee did. And I sometimes do. But I’m not going to on her. I’m sorry? Oh, okay. But that didn’t really answer the question. So the question — you can either — for some people, we’ll put a suture through the tube, and have it come out under the conjunctiva. Or else have a way to release it. I don’t like this position. I’m gonna swap this out. Have a way to cut the suture with the laser. For me, having the suture release too early is such a big problem that I just wait until this goes away. And if I need her pressure lowered sooner than that, I could fenestrate the tube or use an Ahmed. But I don’t like to do the ripcord techniques, because I don’t wanna be releasing this at 3 weeks. Even if her pressure is high. Because I don’t want a pressure of 0. So I replaced this switch, because I had pulled it too far over. That’s why I didn’t like that first stitch. The graft wasn’t centered. Next I’ll need a Westcott scissor. Oh, he’s got it?
>> How do you manage strabismus secondary to (inaudible) this device?
DR ALWARD: So how do I manage strabismus? Thank you. So a lot of times people have transient strabismus. And that will just go away from us looping the muscles and from the block. So I would wait a while. Do we have tetracaine drops? They had some earlier. Yes, thanks. But if they have strabismus that’s… We just… Yeah. If we have strabismus that is… I need the 9-0. Yeah. If it persists, which is thankfully not real common, then I would have the orthoptics or strabismus doctors take care of them. Usually with prisms. Very uncommon that they would need surgery. But I would wait for a long time to let it resolve, until the tube is open. 0.12. Was that a question?
>> Professor, some people asked about the cornea decompensation after implantation of this (inaudible).
DR ALWARD: I think cornea decompensation should be very rare, if you put the valve — if you put the tube in deep enough. If you put the tube in superficial, then you will get lots of corneal problems. So the key is to be deep in the anterior chamber. And I think that corneal decompensation is not common.
>> A question about how to put the tube in, in case of no scleral donor or pericardium patch.
DR ALWARD: Can you cut this one? Can you cut this for me? Yes. So yeah. So people who don’t have access to grafts sometimes will make a long tunnel, or they’ll make a scleral flap. And that seems to work fine. I think this technique really goes back to Dr. Molteno, and it has worked well, so people have tended to stick with it. But I know people who don’t have access to grafts can do fine with a tunnel or a flap. So this does not have to be watertight, because it’s not flowing. I just need to get it closed and have the patch covered. I may have covered it more than I needed there. Curved Vannas. It’s all the way over there. Just gonna trim this a little bit, because I got a little carried away covering this. BSS on cannula. Again, I don’t use any viscoelastic in this, because the tube is occluded. And I think this looks good. The tube is a little, maybe, more anterior than it often is, but it’s still far away from the cornea. So I think it’s gonna do great. Injections, please. 0.12. Give it some antibiotic and steroid. Hope it doesn’t smear it too much. That’s all it is. Can I have one Weck-Cel? The pressure is good. It’s not too high.