This video demonstrates a Baerveldt Implant surgery in a 14-year-old boy with juvenile-onset glaucoma and presented with a high intraocular pressure of 37 mmHg. The other eye of this boy had only a light perception vision.
Surgery location: on-board the Orbis Flying Eye Hospital in Hue, Vietnam
Surgeon: Dr. Wallace Alward, Director, Glaucoma Service, University of Iowa Carver College of Medicine, USA
Dr. Alward: We’re going to show a Baerveldt tube shunt surgery that we did on the flying eye hospital. This is a 14 year old boy who has a juvenile onset glaucoma. His other eye has only light perception vision. This was done under general anesthesia, but typically we would do tube shunts with the retrobulbar block. Here we’re doing a fornix based peritomy. The Barveldt is a very large device, so we really need a lot of space. I’m using a Steven’s scissor here to spread very widely.
I like to loop the rectus muscles, the superior lateral rectus muscles. I really want great exposure to do this because I want this plate to be far from the limbus. People who are inexperienced, they’re putting in tube shunts often put them much too close to the limbus. I find in my hands rather than a traction suture to the cornea, I prefer putting a silk suture under the rectus muscles. So now I can put a lot of traction on this. I’m cleaning up some of the tenon’s because he’s very young and has lots of tenon’s tissue. And a move that I really like is to cut along the tenon’s under the conjunctiva parallel to the rectus muscles. And this really helps to open up this quadrant.
Remember that where we’re sewing this to is one of the thinnest parts of the globe. So we want a really good view. We don’t want to be passing a needle without great visualization. Here I’m measuring 10 millimeters back from the limbus. Put a mark there, I tattoo the mark a little bit, since I’m going to be doing cautery anyway, it just seems to help the mark stay there better, if I use a little cautery on it. Since the Baerveldt tube shunt is 350 square millimeters, to put it back in the orbit, I line up, those are the suturing holes and these four holes allow tissue to grow through and keep the Blab multiloculated, instead of one gigantic Blab. I line up along those four holes and push this very far back into the orbit and then place it under in this case, the superior rectus muscle, you can even bend the plate if there’s difficulty getting it in. And at this point, I want to grab the plate and move it around to make sure that it moves freely.
I have a 7’0 nylon suture here, very carefully passing through the sclera. Again, it’s a very thin part of the eye, very easy to perforate the globe. And this first side, I usually will put three throws, but not complete the tying down process. Thats because it gives me a little bit more mobility on the opposite side or the fellow side. In the end, we don’t want any of this tissue stuck in there. Now the second side, and you can just pass right through that suturing hole if you want to, if it’s easy or you can bring the suture out and then pass it through separately. Very important that this has tied down very tight and using a non absorbable suture here.
When I pull, I should be able to see the front of this silicone compress. I think if the plate is moving around and then the tube will be pistoning, in and out of the anterior chamber, I think that could make it much less healthy for the eye. And I’m going to go back and finish tying down this first side. And I like to rotate these knots into that islet there, just so there’s no suture ends that could poke through the conjunctiva. He has very thick tenon’s and conjunctiva. I doubt that that would happen again. I’m checking to make sure everything is firm, just to convince myself, I’m at least 10 millimeters in the limbus. Here I’m going to use a 6’0 Vicryl to tie off this tube. My assistant’s holding it tube, so it doesn’t dance all over the place. And I use a two, one, one closure. I think if I use three throws at the beginning, the knot becomes too bulky to close this off. We’re lucky here because there’s some air in the tube and that helps us to gauge that we’re absolutely tied off.
So this is really critical. And I’m going to test this and put some balanced salt solution on a 30 gauge canula and you’ll notice that that air passes through. So its a bit surprising to me that I didn’t do as good a job as I thought I had, but I’m really glad that I tested it, otherwise this could be a real problem. He could wake up with hypotony, as Vicryl lasts six or seven weeks and will just release on its own. By then the body will have encapsulated this plate. So no flow now, I’m happy. I am going to do a paracentesis, he’s phakic and young. So I want this too deep, but obviously I don’t want to be at near his crystalline lens, using sharp vannas, curved usually if I have access to them, I put a really striking bevel upward so that the Iris doesn’t get caught in this tube, inflate the chamber deeply. With the Baelveldt surgery. It’s really not easy to use viscoelastic because there’s not much flow and you just would make the pressure go up. And now I’m going to very carefully try to make this entry on the one hand, deep and on the other hand, protecting his lens.
When I pass this, I’m going to use one hand to hold the tube flat against the eye to keep it from diving so we can see I am passing it with my right hand here with the smooth forceps. The left hand is keeping the tube from diving. No, I think the tube is too anterior and that would be in the long run, especially for somebody who has many decades ahead of him, you don’t want anything that’s going to hurt his cornea. So I’m going a little behind that again with my 22 gauge needle. If I go close enough to my original entry point, the volume of the tube will occlude my prior entry point. Generally, I don’t need to tie those off. checking the depth here with my balanced salt solution canula and again, using two instruments to pass this, I just use the smooth forceps. It will just dive into the Iris.
So this is looking pretty deep, but the chamber is shallow some, I think I’m going to be very happy with this, once I get this chamber deep, kind of going nasally here a little bit so that when he ultimately needs to have cataract surgery, this tube is not in anybody’s way. Now I’m going to deepen the anterior chamber and you can see that the tube is in great position here. We need to cover the tube so that it doesn’t erode through the conjunctiva. Some people instead will tunnel into the sclera. This is pericardium tutoplast. Because his pressure is high preoperatively. I’m going to fenestrate the tube in front of where it is tied off. And so for this, I’m going to pass a suture, leave a suture and I find that if I just fenestrate with the needle, the pressure does not stay down for any length of time. But if I leave suture in, sometimes it actually works too well. So I’m doing this technique that I consider a releasable fenestration. So the suture goes through the tube and then comes out on the cornea and I’m going to make a little 90 degree turn here. So that right at that corner, we can pick up the Vicryl and pull it, should the pressure be too low, sort of the opposite of a releasable suture and a trabeculectomy.
And now I’m putting on the patch graft here, this is, as I said pericardium, one can use sclera. I typically use cornea that our eye bank, fins out for me to about 350 microns. It’s just a absorbable suture. You do not need to permit a suture for this. The patch grafts sometimes will melt a little bit, but they don’t go away. I’m going to make this a little bit more streamlined here at the limbus so that I don’t get dellen formation. And now I’m going to reach up and make sure that I pull the tenon’s forward, because I think it gets tucked a little bit by the plate and then bring all this tissue to the limbus. Easy in him because he’s not had previous surgeries, but many of these tube shunts are done in eyes that have had multiple prior eye surgeries. I have an anchor to the episclera too, so it doesn’t retract
Again this is a Vicryl, absorbable suture, the same suture I used for the fenestration and for tying on the patch graft. And just running this with a simple running suture, same thing at the other end, I want this patch completely hidden from view. So his pressure will stay down for a while because of the fenestration. And then at four to six weeks, hopefully this vicryl will release on its own. I’m injecting antibiotics and a steroid. This eye looks really good. So Baerveldt Tube Shunt surgery, this is one way of doing it. And I hope this has been helpful and instructive for you. Thank you.
April 8, 2020