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Thyroidectomy (Cadaver)

Transcriptions

CHAPTER 1

So - so it's not going to be that easy to visualize the incision here relative to the - the sternum, but basically you want to find the skin crease that is sort of accessible to where you need to go, but you want to make sure that you’re keeping a sense of where midline is but… Make your incision just like every other. So you’re coming down through - you'll see platysma on the lateral aspects of the incision. Often, it’s dehiscent to the midline, so you won’t see it there, but come down and you'll start to see the anterior jugular vessels.

So then you're raising up the superior inferior flaps, and it's a bit different than your typical - you want it to be a little bit deeper right on top of the vessels. So you raise it in the super venus plane. Basically that limits the amount of tissue between the straps and your - there we go - now we come down here I guess. So that raises it just above the vessels. Doctor Sumad will talk about undercutting the platysma, which is a useful trick to get you some more exposure that’s wider than your skin incision. Let's see - pulling at your skin incision a little bit.

CHAPTER 2

So the next step is to divide the straps in the midline here. So divide the straps all the way down to the sternal notch, and you want to go up as well. There we go. So, what I like to do…

CHAPTER 3

Next, I separate the sternothyroid from the sternohyoid, which in this case it might be a bit difficult, and then I - I divide the sternohyoid in each and every thyroid. It just gives you a lot better exposure, and I don't think that the - the voice - there any voice decrements from it. But anyway I think it's probably got divided in there. The plane isn't very good but…

CHAPTER 4

The next thing that I do is to - is to find the airway in the midline. So you find your isthmus, which I can't tell where that is it all, but I’m just dividing the tissue overlying the trachea here and - and maybe that’s isthmus there - that's probably Isthmus there. So this just provides you with a useful landmark for the next part.

CHAPTER 5

So, once you identify the airway in the midline. What I do is bluntly dissected the straps off the thyroid gland inferiorly, pull the thyroid gland medially, and bluntly dissect inferior to the thyroid and find the nerve down there. And I think we'll have to dissect this. It’s not going to be very pretty otherwise. Got a nice size thyroid gland here. So typically you can bluntly dissect and find the nerve inferior to the thyroid gland, but if you can't find it, as is the case in this case, you come up to the superior pole here, and you dissect the sternothyroid from the superior pole, exposing the superior pole of the thyroid gland, which is right up in here, and then you get your tractor in there and…

So then what I do is identify the external branch of the superior laryngeal nerve, and this is the cricothyroid space that y'all heard so much about. And usually you can find - you can actually identify the nerve running in the fascia on the cricothyroid muscle, and that way you can you can definitively say that you haven't transected it. What a lot of people do also is just to dissect it very close to the capsule or within the capsule so that you're not going to injure it that way.

Then, once you've identified it you can take the lobe and retract it inferiorly and divide the superior thyroid vessels. And this is where you're going to find your parathyroid, your superior parathyroid is your - see, need to retract that a bit more here. You can walk it - walk the retractor along the - the superior pole. So, the parathyroid gland - I don't know if - I don't know how well it's going to be preserved in this kind of setting, but as you're dividing your superior pole vessels, it's going to be up near the joint and near the nerve. It's probably in this sort of fatty tissue right in here, and so this is where you want to be meticulous in your dissection in getting this off without disrupting the blood supply. I like to do this with a bipolar and a Kitner.

So once you've asserted freed up the superior pole, what you can do is you can start to retract the thyroid medially. Again if you keep your dissection along the capsule the gland, you're going to preserve your parathyroid, you’re going to protect your nerve. For thyroids like this where you can't find it easily inferiorly, I like to - to bluntly dissect along the thyroid gland after I divided the - the superior pole vessels, and as you pull it medially, it's going to open up that space, and you can find the nerve down in the trachea esophageal groove. Although on the right side, it’s often coming from a more lateral direction.

CHAPTER 6

So at this point you can - if you're going to find it up in here - you want to go layer by layer right on the thyroid gland, and the nerve will make itself apparent. If you want to find it like I do, down inferiorly, than you can bluntly dissect. So when you're coming along the lateral aspect, you're going to encounter the middle thyroid vein, and that may be it there. You just want to stay within the capsule of the gland. Divide all that stuff - that - is that nerve there? That may be parathyroid here.

So it’s a bit hard to teach the method I usually use since it sort of relies on it being on stretch and finding it inferiorly, but the nerve is a bit more constant up in its position up at the - at the joint, which is why some people advocate finding it superiorly. Looks like a tubercle there maybe. So it’s helpful if you can find - identify some landmarks like the carotid, which is difficult in this case. So as I was saying, I usually find it with some blunt dissection. It makes it a lot harder when it's been cut, but that may be it there actually.

CHAPTER 7

So once you identify the nerve inferiorly like this, when I - in a thyroid that’s not this large - I find it inferiorly and then takedown everything off of the inferior pole and connect it to what I had exposed before with the trachea and the midline - so take down all this tissue - and that typically will preserve your inferior parathyroid gland. So you keep - just keep your nerve in view, and you connect those two. You have to control the - there's some bigger vessels down here that can be a bit pesky, so you want to make sure that you're controlling those as you go. Where’s the airway there - there it is.

Alright, so once you identified the trachea and cleared everything off the inferior aspect, you trace the nerve up, so there - there's a nerve right there.

CHAPTER 8

Trace the nerve up superiorly into its insertion into the larynx. So up at the - up at the joint, it becomes pretty adherent at the Berry’s ligament, so you have to be cognizant of that. And also you want to - especially on the right hand side - you want to be cognizant of how much you're retracting medially on the thyroid. There it is - there’s nerve there. So when you're coming superiorly, if you found the nerve inferiorly, you want to make sure that you're staying on the gland cuz there can be - the superior para can be right around that tubercle of Zuckerkandl, and the nerve can go often go right under it.

And again, the thyroid gets pretty adherent to the trachea up here, and there's some big vessels that are - that will always run in that general vicinity too. Cut that. I don’t like to clip because if you're going to get any subsequent imaging in central neck, then it's going to be - you're going to have a lot of artifact from that. So I use the harmonica a lot or the bipolar, and if it's too big for that, I like to tie.

So here is the nerve here, going up into the larynx. It’s obviously not on any tension, so we’re - it's usually not - there's not this much laxity on the nerve, but what I do is I come up along trachea and get the thyroid basically pedicled on Berry's Ligament.

And you’re starting to see - you can kind of see some of these vessels in here, and these are really bothersome if you don't control them, or if kind of - if you dissect really forcefully through here. But you want to stay along the gland as well and try to preserve that vessel as much as you can cuz it is the blood supply to the - the inferior and superior parathyroid glands generally. And once the nerve is sufficiently away, which I kind of think it is, you can be a bit more aggressive and coming through this tissue. But oftentimes down in this - gets to be a little crotch area where the nerve comes up and Berry’s Ligament is - you can distinguish yourself maybe from your - from other colleagues who do thyroidectomy by being very meticulous in this area and getting all of the thyroid tissue out. It's easier to come across and leave a little bit of thyroid tissue at that area, but I think if you get it off of the trachea and get it pedicled on that - that may be thyroid tissue there - get it pedicled on the Ligament of Berry, then typically, you can take all of that tissue out pretty easily. I like to use the bipolar again in that area.

This is the Berry’s ligament here that we’re coming through. See the knife. It's easy to leave thyroid tissue in here. You want to make sure you're getting all the way down into that crotch. The other place that's it’s easy leave thyroid tissue is at the superior pole, so that's why - you have to be - you have to be good at identifying the tissue planes up there and - and retracting inferiorly to make sure you get all of that. Another place where it's easy to leave it is at the pyramidal lobe here, so when you're coming up, bringing it medially, you know, be cognizant of that and watching superiorly since you can include the pyramidal lobe in your dissection. So here we’re on tracheal rings. There there we go.