Aortopexy for Innominate Artery Compression of the Trachea

INTRODUCTION

I’m Walter Chwals, the chief of pediatric surgery at the Floating Hospital for Children in Boston, Massachusetts. I’m here to discuss today an aortopexy. The procedure is usually done in a child who has tracheomalacia. Tracheomalacia is usually associated with other anatomical variations that are congenital in nature. For instance, tracheoesophageal fistula often results in tracheomalacia. The cartilage of the trachea is poorly developed, and during expiration, when intrathoracic pressure increases, the trachea collapses as a result of the improperly formed cartilaginous tissue. This can lead to feeding difficulties in children who have tracheomalacia or - in more serious circumstances - can lead to cyanosis and even airway collapse with respiratory embarrassment requiring intubation and resuscitation. So it's not a trivial issue in many clinical situations in which it exists.

In understanding the way that an aortopexy works, it is important to understand the anatomy of the aortic arch as it is associated with the trachea itself. The trachea lies behind the aorta - aortic arch, and the rationale behind doing the aortopexy is to elevate the aortic arch by attaching it to the underside of the sternum and in so doing elevate the trachea along with the aortic arch, which is being elevated. So when one elevates the arch, one pulls the trachea behind the arch up along with the arch itself.

CHAPTER 1

I’m trying to stay out of your way. I'm trying to stay out of y'all's way, too. The procedure begins with flexible fiberoptic bronchoscopy, which is performed through a laryngeal mask airway. Here we’re at the level of the carina, and as we move more proximally, this site of the prior tracheoesophageal fistula, which has been closed, can be seen. More anteriorly, we reach the height of the aortic arch and the innominate artery, which is causing compression. Tracheomalacia can be seen here posteriorly. The cervical trachea demonstrates normal caliber, and as we move more proximately into the subglottis, this airway is clear. The vocal folds appear normal.

CHAPTER 2

Just biases the lower part of the incision, right over here. Incision is made in the anterior aspect of the chest wall, overlying even - the third cartilaginous rib or the fourth cartilaginous rib. Can we go fifteen-fifteen? I prefer the right side. Many prefer the left side instead. It’s a matter of individual surgical preference. In either case, the thymus, which overlies the - the aortic arch, should be least partially removed. And this is to create a space between the aorta and the underlying sternum. We knew about where this was because of imaging that we'd gotten both from the endoscopy as well as some plain films. So I think that the important concepts of this are first to gain adequate exposure. Second - to remove a portion of the thymus to create the space. Though it’s a mistake not to remove some of his thymus. The problem with that is the thymus may get squeezed in between the aorta and suture, weakening the aorta and the sternum - weakening the suture line. Or you don’t get adequate elevation.

Alright so, we’re still in the mediastinum now. Now we’re going to get the thymus and a portion of that thymus and do a la - lateral thymectomy - a right lateral thymectomy. We’re gonna go up on the underside of the sternum now and free that. Just going by feel there? Yeah. I’ll stick my finger in it eventually. Do you have a rib spreader now, please? So you can see the medial margin of the right line and the intact pleura. The approach to the mediastinum involves blunt dissection of the right or left pleura away from the field without entering the pleural cavity, so a chest tube is not needed. And generally speaking, drains in the mediastinum are not needed either. There’s the thymus. Okay. Just want to get the pleura to go back as much as possible. And then we’ll take the thymus out.

You can now see the lateral border of the thymus coming into view. I hope you won’t tear the pleura. That’s thymus. Yeah, you just want to make sure the lung and the pleura are intact. This is where you can easily tear into the - yes. You can now see this - the thymus coming into view pretty nicely. You just want to remove that thymus to create the space between the aorta and the posterior margin of the - sternum - of the sternum. Now there’s a - Do we have those silicone-guarded retractors? The malleables? So the inferior thymic vein that comes up here, and then there is an arterial branch off the internal mammary. Probably not, let me just - this is just counter traction - traction - kind of traction trying to develop, but these kids have big thymuses. Yes, particularly at this age.

Sort of posterior aspect in the thymus down there. You can see that now. We're developing that up now we're get - we’ve gotten to the lateral border. And there’s a little vein coming in there. Well that is the phrenic nerve. Where do you see that nerve? Right there, overlying the - oh there, I see it. Yeah, great. I was seeing the - the vein coming up lateral to medial. So there’s the phrenic. There’s the phrenic nerve, and now we’re on the SVC. And you want to not get into the pleura if can - you know, and there’s a pleural cavity if you can avoid that. You can do a lot of this with just blunt dissection - yep. Now careful blunt dissection. I’m just going to stay on the superior vena cava here. You just use that as your margin.

Let me have the Metzenbaum scissors. And usually once you get this started with a little incision, you can sort of chase it down, but you just keep working down and down and down on the thymus until you get the inferior margin up in your face. And here, you know, the parietal pleura is still trying to sneak into your - your - I mean, it's almost like it wants to get cut. And it’s not the end of the world if you happen to get into the pleura by the way, but stay outside his spine. I always use the SangLy’s for this just cuz they're less traumatic. Alright, now we're at the medial side of the superior vena cava. Try not to molest the phrenic nerve as much as possible. We’re sort of lifting up and off the - we’re lifting the thymus up and off of this area, trying to get behind it a little bit. So sometimes I'll just take out a portion of the thymus and then go back and take out more if I need - need to.

There we go. We finally got the inferior part free. Yeah. Now just Bovie that. Stay on your upper jaw. Go right between them. We don't remove the rib, but you can - you can - if you have difficulty in achieving exposure, you can remove the cartilaginous portion of the rib and allow for greater expansion of the tissue within the wound space, and then we leave the pericostal rib intact for the new cartilage. It really does mobilize quite nicely once you get it up. Just have to be patient. SangLy please. I’ll take this right about here. Go ahead. Bovie. That’s just the - right side of the - left side of thymus there. It might be the left lobe. Yeah, it’s just - as long as we can push that back and create enough space here, we’re all set. There we go. Can I have a right angle now, please? Thank you. Creating enough space for elevation of the aorta is the purpose behind removing about 50% or so of the thymus because that allows for the space for proper elevation of the aorta. These children have huge thymuses. Right on the front there. Right here, yep. Right on the prong. Okay. Alright, let’s see a Schnidt.

Alright, let’s have the ligature now. Show me the underside of this. Alright, let’s try that again. Okay so, that’s the right thymus - so there’s SVC - lobe. And now, see if we can expose the aorta a little better. Take out the shunt. Can I get another retractor under there? We’ll have to take out a little more of this. So here's - here’s the innominate vein right there, and we're gonna have to get up into this area. Right over here is the innominate vein. A little lymph node. So I will chase a little more of this thymus now. There’s plenty of thymus left, so let’s get a little more of this out. And that's what I mean by - you know, you take out the thymus that’s in your face, and you can see much more about what you need to do next.

There's the pericardial reflection. Right up - right there. I don’t know if you can see it - yes - but it’s right there. So, take off a little bit more of this. And again, same thing - we try to move the thymus up off of the aorta from inferiorly to superiorly to try to get that inferior margin. You can see, as we continue to do this, more and more - more of the lobe emerges. And I think this is about all that I really need to take is this area cuz the rest retracts enough away from - right. Okay, that’s perfect. Ligature back. So that’s still some more. Yeah. More thymus. It's the last part. Okay. Here is the aorta and aortic trunk. And here is the superior vena cava. Here is the branch of the superior ven - vena cava and the innominate vein. It - the innominate vein is right here. Superior vena cava is right there. This is the - we’re retracting back the lung, and this is the - the phrenic nerve right there, intact.

Okay. We’ve removed a substantial portion of the thymus on the right side, and at the base of the aorta here, you see the reflection of the pericardium coming up on to the aortic face right there. We’re about to open that in a transverse fashion right over here. Okay so here, as you see, we’re opening to the pericardium. See that? Yes - right there. See the pericardial fluid coming right out? Suction? Thank you. Now I’m just going to open this up a little bit on either side. Alright, that’s exposed. So that’s our aortic root? Yeah, exposed pretty well. Alright so - I see how we couldn’t really do that with that intact because you wouldn’t be sure you have the - right. You want to get - have Andrew come in, and what we'll do is lift up the aorta and see whether or not - can we get Dr. Scott? You have a better sense of where… Okay so now, we are exposing - oh there we go - nice. See the base there? There’s our innominate. Yeah, so I think we’re where we need to be for all this. Very nice. You have the stitches ready?

CHAPTER 3

Now we’ll take - let’s see how I want to do this now. Okay gentlemen. Let me know when you’re in there. You got it. Alright, well why don’t you go and pull up a little bit and see if you can get any. Alright. How about right there? Yeah, that’s impressive. That says a lot. Okay, is that better than - give me like a number one and a number two. Okay, here’s number one. There’s number one. Here’s number two. Both of those are equally efficacious. And - you’re going to need to go more superior - wait a second. And here’s number three. Yeah, number three is the money. Okay, and that's right on the brachiocephalic trunk. Okay that helps us. Alright, let’s have a stitch.

CHAPTER 4

Pediatric otolaryngologists are - are very helpful in visualizing the trachea in the collapsed and the expanded state to see that the expansion, which we've achieved through placement of these sutures, is adequate. The sutures are placed using 4-0 Prolene. You can also use 4-0 silk if you prefer, but the Prolene is less reactive for the vascular wall, especially. And we pledget those Prolene sutures to try to avoid further trauma to the aortas. Okay, table up. Turn the table away from me. Not anymore, yeah. Can I give you that back, Janice? More. That’s good. Make sure that the interrupted mattress sutures - I put in two rows of those - are - are adequately placed over a broad enough area to elevate the aorta. A better thing even would be to sort of move the aorta up against here, so you can get more surface area involved. Hold that, James - just get it taut, yeah. Total of six horizontal mattress sutures we place in this particular case.

These suture should not be taken full thickness and are instead taking through the adventitia an - and the media of the aortic wall, bearing the intima. The sutures can be interrupted or equally spaced. I usually take them in two rows - three sets of sutures up through the anterior aorta to the branching of the brachiocephalic artery from the aortic arch. Let’s see. Now, let me have that for a second. You have to feel yourself going into the cartilage on that. Another stitch. Okay now to use the pledget ones. Down farther please. Table down farther. You have the needle driver - you try to bend it? Yeah. What - what size needle is this? BB. Can I have the vein retractor again? That works. Wait, wait. Let me just see if I - can I have a Kittner ready as well? Yep, all set. I’ve turned the vein retractor just like that. That may work. We’re almost finished here. Can I have a rubber shod? Can I have the other needle driver, please? So you all - so - so what do you guys use? Prolene or something? Yeah, 4-0 Prolene.

Table down please. Sure, coming down. And you get a good as hunk of periosteum basically? Yeah. The trick is getting the needle in and out at the right angle. Right. And the same thing - suction. Too tangential. Right. Do you - do you overbend it? Yeah. Sort of have to bump off the periosteum instead of skiving? That’s it. Alright, now another vein retractor - yeah. Vein retractor please. As you lift the aorta anteriorly, you lift the trachea with it, and the posterior aspect of the trachea is still also attached to surrounding tissue against the anterior surface of the thoracic vertebra so that, when you lift the aorta up and it pulls the trachea up with it, it also expands the trachea because the posterior aspect of the trachea, which is attached to the vertebral bodies, where the soft tissue associated with the vertebral bodies stays in place. So in effect, you are expanding the tracheal lumen by lifting the aorta.

Okay now, I will take a pledget. And let’s see, there’s another needle up here somewhere. And we’ll put in one more stitch, and then we’ll have Andrew go in and - watch while we tie. Yeah. Well, first we'll pull up. Alright, let’s have the shod - shod, shod, shod. Okay, one more stitch. Pull driver. You have good - this is the last - exposure? Yep. Good exposure. So we got the last stitch going in.

Postoperative complications include not only bleeding from sutures, which erode through the aorta, or sutures which have been inadvertently placed into the aortic lumen and erode through but also infection and finally recurrence. And recurrence is more frequently associated with sutures which are inadequately placed. Ultimately the sutures which we place are only as strong as the tissue we put the sutures in, so it's important to get good tissue bites on the periosteum of the posterior sternum and adequate tissue bites into the adventitia and medial aspects of the aortic wall. And again pledge reinforcement of these sutures will help to avoid erosion of the suture through the aortic wall, but it is important to get adequate tension and purchase of the aortic wall over a broad enough area so that the trachea is adequately expanded.

Okay let’s have the needle driver and the pledgets. Okay. Thanks. Alright, Andrew. are you ready to go back in? You ready? Yeah. And we would like him to get - be in a hundred percent just before you - great - lock block the tube. Yeah, I’ve got about two minutes, so a hundred percent away. Push the trachea. See how - how flexible it is? Yeah, because it’s so… Okay. So give us the word when you want us to pull. Alright, give - give a pull. Wow a lot of resistance now. Now, sir. It won’t be long - much longer. Alright - okay, now relax. Okay, now pull again. You can see how it passively opens your fistula too. Now relax. Good. And you feel good about all those sites? Yeah. It looks great. Alright, I’m a gonna - tie them away. Yeah, I’m gonna tie them. Yeah. Great. Alright, so - go ahead and ventilate, Paul. Just cut one - here this one.

Okay, here’s your needle back. You got it? I do. Alright. It’s a little wet. Alright. Real vasculature. Sure. Don’t you love a little positive feedback? Doesn’t that - I know, yeah. That’s like me rubbing your back, basically. It’s true. In a very like collegial, non - non-threatening kind of way - professional way. That’s an attaboy. That’s a surgical attaboy. When you’re tying, do you try to get it totally up to the sternum. Yes, I do - yes, I do. Alright, let’s have scissors. Do you have Metz for the next time? Here's your other needle back. Sure. You got it? Yep. Okay. Okay, so we can just cut that one off, right there. See now, how that you're pull right up - there's no dead space between the sterile periosteal and the… That's a really nice stitch. You can see it beautifully incorporated. Great. After we’re done, I’ll get you to look in there with a camera to show everything. Well I think the camera is - is going right now. I mean - yeah, but dropping your head to kind of look under to the side.

Alright, scissors, please. Metz. Here’s your needle back. See I think, normally, you would put one down here too, but - okay - I don’t think we need to because this is high. And that's why we had to go up here in an area we don't normally have to go. Here, let’s cut this - give me a needle. Can you cut that off? You got it? Yep. And the key with this - cuz you’re using 4-0 - is not to break the suture. Yes. It’s not the knot. It’s the jerk at the end. Yeah. You can cut this off too. Here’s your other needle.

So, table up please. Sure, coming up. Alright, that's enough, thanks. So let me have a right angle retractor please and the DeBakey. Now, what would be nice at some point - if you guys are up for it - would be to - we might need to angle this camera a little bit - try to get an LMA in there. So right here is - we can do that after you close - are the stitches. Can you look up a little bit? Attaching the aorta to the sternum. And here’s a lung. Pull it up a little - tilt you head up just a bit. Just to adjust - there you go. So pretend like you’re looking at the superior aspect - the - the medial aspect of the wound instead of the wound itself. Alright. Focus up here - there you go - because your camera is angled. That’s beautiful. That’s great. Alright so we see the sutures in place with the pledgets in place - the lung and the parietal pleura coming up into the wound here. I don’t see a lot of air in there. I think we're gonna just leave it alone. Yeah, as far as our tube. Yeah. Yeah, there’s very little - there’s a little bit of a tear, but I think it looks like it’s managing well. Alright, good. Good. Let’s take the table down now, please.

CHAPTER 5

Okay, gonna hold this back a little more - okay. Please come and give us traction on this for me. I’m holding it. Got it? Okay. Gonna pull back a little more. So are you gonna try to get a pericostal or not even bother? You know, I’m not going to bother because - I don’t know. Let me see about this. I don’t know if we can get it easily. It’s a pericostal on the - Paul, do you want to see your - your handiwork? Okay, yep. Wow! Okay. That - that's good. Is he on positive pressure? Or a peak? Yeah, take off some of your peak. Oh, that’s good. That’s good. You can see the fistula there too. That’s great. Alright, excellent. Alright. Yeah, so the pericostal kind of go on repair too. See, this is costochondral. This is the - this is the chondral portion. That’s not - you don’t - I wouldn’t put a - around the rim. Yeah - a pericostal on that. What you’ll just do is get the fascia of the pectoralis and close that.

You guys got that last bit? Great. Alright well, that’s great Andrew. That’s good - good pictures. Nothing can get above that, right? There’s no - no sense going higher on the anomaly? No, that - the problem with that is - because you’d have nothing to sew it with. No, it's the fact that you would then crimp the innominate vein, which is lying right over the top. You want to do this? Yeah, I can do that. So the next one, you - you do it, and I’ll - I’ll assist you. Yeah, that sounds good. I - this - this way I can even see this one. You needed to just get it. It was not easy. Well, you know, once you see them - yeah, I’d never seen one before, so I needed to know what to do. I appreciate you coming up. It was a pleasure. Thank you. This worked out well. So tell Jeremy - oh yeah. At the end of the case, after they do their nerve block, we're going to put an LMA in again and get an identical shot to your pre-op. I think that’ll be nice bookends.