Alright, so today we're going to do an exposure of the plexus with an approach and dissection of the supraclavicular and some of the infraclavicular branches. So there's basically two ways to approach it. It's certainly in the babies and where you suspect that all you need is a supraclavicular exposure, I think a transverse cervical incision is enough. You need to be able to get up to C4 and then down to the root so you can get to the lower trunk. If you suspect you're going to need to go below, then it's reasonable to do a top to bottom exposure. So I think that's going to be the more effective way to do this. So you're going to make a delta pectoral incision from here, something along the clavicle and then posterior border of sternum mastoid, something like that. That's going to give you a full exposure. As I said, if you're doing just a supraclavicular exposure, then something like a skin crease incision which is much more aesthetic than this sort of thing would be appropriate. We start with a posterior sternum mastoid incision. And bring it around, delta pectoral. And that allows you to do a clavicular osteotomy if you want to do that as well. You go through platysma and then elevate. So this is the platysmal layer here. We're seeing the start of the supraclavicular plexus just here, just there. And you want to keep moving at this point because there's a long way to go in one of these so feel free to ask any questions and I'll do my best or worst to answer them. So I'll leave the infraclavicular part for a minute, I'll just bring that to allow us to You're gonna get these jugular external jugular vein and I typically locate that with a Visceral rather than trying to burn through it because it always just continues to bleed and you'll have some of these perforators here so the next stage would be to Take down the external jug And come along the posterior border of sternum asteroid. You can see here The supraclavicular plexus and that's important landmark Because that's going to help you if you follow that down that'll take you to C4 So this is the supraclavicular transverse cervical branches Oh, I see, okay So is we just cut through that on this Now along the posterior border of sternum asteroid You're then not far away from and come down you raise this up as a adipofacial sort of triangular flat base posteriorly you know Inevitably I find You end up taking at least one of these supraclavicular branches of the plexus. So that's the other end of the There's another one there probably but you can see there's one here And you know to get an easy exposure And a good exposure you're gonna need to you can try and preserve those but I think it's pretty hard work So With this plane of dissection on the posterior border of sternum asteroid It gets difficult because you get involved in the lymphatic chain here along the jugular chain And I don't think you really want to get into that too much because it bleeds and it's a mess So you want to stay I try to stay behind that to some degree This will this will be this will be jugular chain In fact, there's some lymph nodes there You try and stay out of that the jugular is going to be internal jugular will be I'll just expose that in a second So just take this triangle now the next structure that you're going to come across Is coming into view here. This is the only hyoid Okay And the tendinous portion of it is there You can put a stitch in that and mark it so you can repair it later on but I'm not sure that that's a huge I'm not sure that I've noticed anybody having a significant omyohyoid palsy But anyway, so we'll do that So that that's formed that comes back in that part of that chain and part of this adipofascial flap We're going to go down now Raising this up And you're starting to see now the Under here is the the rigid prevertebral fascia and our Our plexus is going to be underneath that so just And the other structure that's going to come into view here in a second Is going to be the transverse cervical vessels And That's these ones here So these are the transverse cervical vessels and they're running perpendicular to the plexus Okay, so that's They just and they're a good dinosaur good set of donor vessels if you ever have to put flap up here. So that's them Okay At This point where this is prevertebral fascia, this is the start that's that supra transverse cervical Vessel now we're because that supraclavicular plexus or sorry the cervical plexus and its branch point that's giving us the top of our dissection okay so that it's not so clearly displayed there but there we are those nerves there are coming in and they're they are and the importance sorry they're emerging in the same cleft that the brachial plexus emerges from and the reason that's a good idea to find those is that you don't want to swing into here and without having some consideration where you're at because this is the phrenic okay so you need to of you need to know what level you're at in terms of this being telling you that you're at C4 and to be expecting as part of that group of nerves that you're going to come down upon the phrenic pretty quickly so that's the phrenic and phrenic lies on and you often see a contribution to the phrenic from C5 which is just directly underneath it but not in this case so the phrenic on top of the scalenes, scalenous anterior and then below that we're now into the roots of the plexus just like that now you can make life easier for yourself if you're doing if you are in the position where you're you're doing a proximal dissection or dissecting the in the setting of a supraclavicular plexus injury this will be this will be quite scarred and will be plastered onto the front of a neuroma which will be sitting in here usually and you may have to do a fairly extensive dissection to peel the phrenic nerve off that and this can be a difficult area and what you can do to make life a bit easier is actually resect the lateral margin of the scalene to allow you to get more medially but we'll just leave that as it is for the moment so we're now on to we've got cervical plexus branches there of that phrenic nerve branch and then underneath here is C5 and then C6 so the jugular vein is going to anterior jugular is going to be underneath my anterior part of my retractor here and you want to be a bit careful don't stick a sharp instrument into that maybe we take you up here okay so scoliosis anterior plexus will complete the dissection of that in a minute so here's five here's six and seven will be further back so it's posterior emerging not directly out of the in necessarily in the same cleft that five and six are and then eight and T1 are lower obviously but you're starting to what you want to look for is some of these posterior branches as well so you'll see things like this one which with stimulation may well be dorsal scapula although it's a little tiny for that and also it's probably dorsal scapula here actually this one here okay I think that's probably not sure what that is that's probably just an accessory dorsal scapula if you never know what something is you just call it an accessory something so I think that's dorsal scapula and then we'll work our way down here but we'll try and find the serratus branch as well all right so let's go down so we've got five and six and it's good to get a bit of someone to put retraction on that and we'll just open that cleft up a bit to give us a bit more so I need to just expand out here and this is where it starts to get a little more difficult is this lower part of the plexus because well not so much today but this is where the if you're going to run into any troubles with bleeding etc that's where it's going to happens down low so you can see that if you come in here and resect do a bit of judicious bipolar and resect the lateral margin of the scalene that makes life a bit easier for you in terms of your exposure particularly distally but inferiorly all right so work our way down here so the next route we want to find is seven and seven so you can see the seven here is in a posterior plane relative to six so there's seven and it's further back you can see that there so five six up here and then seven is in a posterior plane and then keeping on that in that plane we'll head it down now to the next down to the lower trunk you got to be a little bit careful not only of vessels which are coming into view now but so this will be this will be vein sorry that's subclavian artery veins anterior veins going to be just let's see if we can show the vein just come out for a second so vein is at the end of so subclavian vein external jugular into subclavian and then subclavian artery and that's the take off of that vessel we clipped before or dealt with before but the other structure that you'll run into here will be a lymphatic significantly lymphatic and left or right side and that is a really bad thing to to damage it's difficult to control and you know a chile leak in this area it's just a significant issue so it's with trepidation you end up down in this area I think in the setting of the traumatic plexus injury in the adult this is pretty hard down here because there's a you know reasonable there's a reasonable risk of there being vascular injury and so that becomes that makes this area pretty scarred sorry I'm just going to change position here a little So from the top 5, 6, 7 vessel between 8 and 7 there's always a constant vessel which I don't know whether you can see or not. There's a vessel here between this the 8 and 7 you see that on the end of my scissors here. This naked first rib is on the end of my scissors here. so you can feel and see neck of rib there on the end of the faucet okay and then one this is one here coming up from below there to form lower trunk here so that's the prox that's the roots that's the sort of easy bit in some ways in terms of then moving on we'll come we'll just elevate this complete the elevation of this flap so we can open this up properly and then we maybe we can actually do a clavicular osteotomy and that can show you how much better the exposure is so um yeah or we might um so let's just sail on down through here so you can feel like vein coming into view here It's a delta pectoral groove, cavallic vein on the end of the scalpel. I might just complete this such gay abandon of slicing through these things without... So just completing this posterior flap, we're starting to see the anterior insertion, that's trapezius here coming around, so it's lateral or it's medial insertion I guess. And what we've got coming off the upper trunk. So we've got suprascapular nerve here and if you look for in the setting of trauma there'll be a neuroma here and this will all be quite often is pulled right down and makes this recognition of where the suprascapular nerve is quite difficult because instead of it sort of crossing the path like a textbook it'll be emerging from underneath the clavicle over here because it'll be dragged down underneath in a retroclavicular position and be running that way. So you know often you use the omoholioid to tell you where the omo is, tell you where the notch is and then you can find it coming backwards. So you can see they're both heading to the same posterior point, we'll have a look at that again in a second. So in terms of plexus anatomy from here we have upper trunk, suprascapular, anterior and posterior division and then middle trunk below it. So if we come down through the, leaving the difficult bit, which is the retroclavicular dissection, so we can take the There's always a series of pretty significant vessels crossing the delta pectoral groove. So subclavius, this muscle here, coming in here will be the thoracocramial axis, which was one of the structures we all know crosses the clavipectoral fascia, which is the sort of gap that we're going through at the moment. So this structure here will be the thoracochromial axis with its deltoid branch, pectoral branch, etc. So I'll leave the cephalic vein there for the moment for orientation. Okay, so coming into view is the tendinitic peck minor, just here, the coracoid, put your finger on the coracoids just in there. So, and then heading south down this way is the muscles of conjoined tendon, coracobrachialis, short head biceps. Okay, so if we take the one really nice dissection, one nice thing to do is to take the tip of the coracoid off with the muscles that are associated with that and now that really reflects everything down nicely but that's going to be a bit difficult in this setting, it's a bit stiff. So we'll just cut through this, normally you'd sort of step lengthen that or you put a step in it to make suturing easier. You'll see on the deep surface of peck minor down here somewhere, you'll see the quite often you see the pectoral branches coming through here. There's one there, that's probably the lateral pectoral, I think. Sorry, that's a vessel, so I'll mark that up. That's the lateral pectoral there. You can see the thoracoclavial pinnacle there is quite significant. So now we're down onto the subclavian artery again, or now axillary artery, sorry. And then above that will be the plexus, which is here. So this is our lateral trunk, sorry our upper trunk, which is branched gone through the divisions and now turned into cords, so this will be our lateral cord. And we might come in the other way. Here's the peck tendon here, part of the trilaminate pectoralis tendon, I'm taking that down to give us a bit more access. You can see here this is the coracoid, coracobrachialis. I'm just going a little deeper with this. So now heading north to south, so here we are again, cephalic vein, it's through the clavipectoral fasciae, you have the lateral cord of the plexus here. Maybe we should take that down to make the exposure a bit easier. After pre-drilling and pre-plating. Now, Mac just asked me how often I do that. Pretty uncommon really. There's morbidity associated with clavicular osteotomy, there's quite an incidence of non-union. Depending on the injury you can usually work above and below and you're not doing much in terms of posterior, but it's sort of nice in terms of exposure. So we'll just finish off that component there. I might just divide the cephalic vein here so as to make it a little easier. I would not normally do that. So thoracocromial axis, divide the cephalic vein, okay, so now we are starting to see, so this is lateral pectoral, I've divided the branch there, that's lateral pectoral Coming off our cord, lateral cord, so anterior division and coming into that from below with the anterior division of 7. so we're heading here to So am I getting my head in the way all the time? So, just trying to expose that musculocutaneous for you, make it a little clearer, so we got an unusual pattern here I think. You can see the, this is subclavian artery that I'm just on top of now, that'll be branched to the chest here, and you can see lateral root of median there, with the other root of the median nerve emerging from medial cord below it, sort of embracing around there. But then we have this reunifying down low here. That's a pretty unusual pattern, I think. I know people use the excuse of unusual anatomy to make up for a deficit in the knowledge of anatomy, but they do that on my side of the world as well. I think that's probably a branch to Coracobrachialis here, this thing. This is Coracobrachialis underneath the retractor. I'll show you the, so if we go back to the top again, so with this plexus stuff, when you're trying to work things out, it's always good to go to a point of reference and then work your way backwards. So if we go back to the top, we've got six and five, upper trunk, middle trunk. We've got suprascapular heading backwards here, towards the scapular notch, and there's vessels there. Now the other part of the upper trunk is here, and that's going to course down, post you to the vessels, and give us our auxiliary. so posterior division of upper trunk there traced up to our part here and that is heading to the oil accounts should be heading to quadrangular space here watch us come through here to make that a little more easily so that thing I've just gone through is the super is this circumflex scapula just there so that's not something you'd want to replicate necessarily yeah you would you would be aware of that step yeah and you would have a sort of moment of audible hemorrhage so there's the axillary nerve here okay so that's and you know grafting an isolated axillary nerve lesion does it always do better with nerve transfer or not I think there is a you know there's plenty of evidence that a dedicated graft for that is not such a bad thing I'm just going to take these deliberately just to make it a little easier so that's that's our axillary nerve there now coming down behind that is going to be our the rest of our posterior cord here that's going to be heading down to the triangular space as a as our radial nerve and branches that's going to be the profunda vessel there okay so the only other part of it really that we haven't seen so well yet is the medial trunk so we should go looking for that just to make it a bit easier so before I destroy it that's the lateral pectoral branch coming off fairly approximately going around the thoracochromial trunk which is here and again you wouldn't do that in real life obviously I'll just do a bit of inter vesicular dissection Now the medial cord is going to be in front and below the vessel, so let's just try and tack that down. Remember 5, 6, 7 and 8 lower trunk is here, sorry the lower part of the lower trunk is here. if we just get you back up in here for a second, so a subclaving artery, insertion of scalene onto first rib is there, sorry scalenous medius, scalenous anterior here, but this is scalenous medius here, artery there. The T1 is not a big nerve root, you know, the C8 is a much bigger deal than T1. So again 5, 6, 7, 8 and 1 is below that, artery is here, ledial lower trunk in this guy is sort of confluent almost, it's not quite anatomical but that's lower trunk, this is middle. The confluence of divisions and then we're into lateral cord, posterior cord, medial cord. I'll just isolate that. medial cord, lateral cord, posterior cord, axillary, radial. So from the top, so from the top cervical plexus which is our first landmark we found that got us onto phrenic that took us to C4 which meant that we could then find C5. We resected part of the lateral part of the scolinus anterior to give us a better look at the proximal roots. C5 and C6 are in the same plane but then C7 is more posterior, it's further back as is 8. So C7 is here, sorry C7 is there. So 5, 6, 7, 8 and then 1 is pretty hard because it's small and it's back a long way. And you're generally in trouble if you're down that far, potentially. But it is this lower part of the lower trunk. So then coming laterally out over the scalenes. Upper trunk is always pretty easy and you've got this suprascapular that tells you where to go. Then 7, 8 and T1 are often pretty confluent like they are in this guy and it's almost artificial to divide that between this being middle trunk and that lower. But if we follow that out we get our divisions here, anterior division from upper trunk and middle and that's contributing to our lateral trunk, lateral root of median and musculocutaneous but there is something a bit unusual. This is a big musculocutaneous nerve and I think we'll have a look down here in a minute and that will explain what's going on there. Posterior trunk, sorry posterior cord here with axillary and radial. Suprascapular is really a posterior cord nerve root which is not really surprising when you think about what it does. So it's quite, you can see how it's related to the posterior cord. And then medial cord here and that's all above, above where it joins the artery and then we're onto the artery and we embrace the artery so to speak with our lateral root of median joining up with our medial root of median which is this structure and I think that's our, I was talking about medial pectoral before, that's our medial pectoral just here and I reckon, if you just come out of that for a sec. This is pec minor, just relax for a sec mate. Oh, I didn't mean to do that. Yeah, that didn't work. That's thoracocromial trunk there and the cephalic I've divided just for access. This, I think that'll be just the pectoral branch, unnamed, the artery of Higgins perhaps. Yeah, that's all you need to do. So that's to there. So medial here but I'm sure that'll be medial pectoral here and that's useful to know but I think you've better, the easiest way to find that is to reflect your pec minor forward and it's the one going through it. Now what's a bit unusual about this guy is, I'm just going to take a little bit more vascular destruction. There we are, so there's median proper and then there's appearing below us is ulnar. So this is medial cord, that'll be ulnar nerve and there is medial cutaneous nerve, probably of forearm because that's a bigger, that's a pretty big nerve. Medial cutaneous nerve of arm is usually a lot smaller. So taken down, this is completely taken down, his pec major now, that's gone. And we've got our conjoined tendon with coracobrachialis and short head biceps. So actually I'll just get that out of the way for a sec. So this is a slightly unusual pattern in the sense that his median nerve joins back with his musculocutaneous. I'm presuming that's what it's a low, so again lateral cord. You would think to that level you would say oh that looks pretty typical, there's musculocutaneous, this is median, that's all fine. But then we're seeing contribution back to here. And this is going down pretty low, this is a low, normally the musculocutaneous is at this level, it's pretty high in the axilla. So that would make doing a, because we're here at his elbow, we're not that far away from the midpoint. So that would make looking for an oblon transfer in this guy a little more confusing I think. There we have the musculocutaneous nerves. Well that might just be nerve tachoreca brachialis actually, and then we're going to have a low innervation. We'd have to just work that out. You were anterior and then inferior to the spinal accessory. So spinal accessory, if we go back to that, this is always a challenge to stay out of its way and then to stay to find it if you're doing a transfer from the front. As I was saying before, go from the back more typically now, but if we just try and, so let's just stay a little more superficial and I think the thing to do is to get onto the muscle to get onto trapezius and stay out of that. So try and stay relatively superficial here in the posterior triangle so you're not in amongst this fat because that's where it is. I think we'll probably find that's it there perhaps. And I just go down to the muscle, lift up the anterior edge and then dissect down until I see it. And I reckon it's there. And it's usually the squiggly one, the one that's got not as much tension on it, but I think that was it there. So that's accessory. Has it already given the branch to the sternum mastoid? Yeah, I think so. The sternum mastoid branch is really high. That's really high. But that's how I would find it from the front. And I think the trick is not to, I have, when I was a fellow working in England, I did one of these during the approach, but I was in too deep. I think you want to stay suppletismal with your skin dissection over this entire flap and then you can make an L-shaped flap and that makes sure that you're well away from that. And then when you come to find it, it's a matter of identifying the anterior border of trapezius and tucking over the front of it and then you'll find it. The other thing which we haven't sort of really shown, and so in terms of doing transfer from here to from the front, you just go down as far as you can to the branching point and then flick it through this adipofascial flap and tuck it onto this, which is suprascapular. So you've done that a lot. From the front. Yeah. Can you show us how far you dissect down and when you would feel comfortable that you were distal enough on the SIN that you were not de-nervating? In other words, what's the modification point? Because getting it through there and making it reach, it's sort of an issue. It would be easier if you cut the SIN up high, but obviously you don't want to. Well, you want to go down as low as you can. So here we are at the point where it's already starting to branch. At that level, this part of it, this bit is already innervated. So this nerve, I would take it down to about this level, and it's usually when you start to get bleeding, which is convenient, but the point where you're starting to get bleeding is where you've got the vascular hilum and the nerves going into the muscle at that point as well. So that's about, at the point where I have to jam a gauze down here to stop the bleeding, that's about where I start. That's a good signal. Okay. So, but to be clear, you would cut it then here and then mobilize it. I would cut it there, say, just for what purposes, do that, and then I would do something like that. So I think this is a bit different experience than the last case, meaning if you were trying to preserve branches that were as far distal as here, and then you're sort of digging stuff way down here up, and it doesn't give you the mobility. And then you're tethered here, and you can't be careful. Right, absolutely. Well, that absolutely was our problem. I don't know if you guys remember what I'm talking about, so really, your last innervation is here. And especially, you know, if you're doing the gracilis transfer, your nerve, your vessels are here, because that's where the thoracochromia pedicle is, and your tendon is here. So your nerve, you can dissect your nerve on your gracilis up as far as you can get. So yeah, you are constrained by your pedicle position. You can go a long way on your gracilis, and I'll try to hit up, you know, my trapezoid innervation. But I think that, you know, for that, doing at that level, that wouldn't worry me too much in terms of trapezius innervation. Right. Well, I think that's the kind of thing when you don't see somebody with experience dissecting it, you would say, okay, you're reading the text, and it says, get the spinal accessory, go beyond the distal innervation, and cut it and bring it up. But that's where I've taken it there. That is the point at which, so if we go back up on those, I've probably made a mess of it up here, but there will be branches off this, up in this level. And they're going to be branched through, and they're going to be innervating this. Right. And so that, that preserves this shrugging and shoulder tip elevation. So we're talking about innervation of the proximal trapezius, there are branches here at this level, which are innervating this upper border, which is the part that has the acromial attachment, it's going to give you the shoulder shrug and give you some scapular rotation. So the lower part, you know, the sacrifice of this means that you can't use your lower part as a tendon transfer potentially for external rotation, which may be an issue. But it's, it's really, you know, if you think about what the lower part does, it comes around the spine and scapula and, and probably has some mechanical advantage, it's a strength of shoulder. There's a lot of these guys aren't going to reach above their head. So you know, are you, for the greater good, are you sacrificing function that's really important? And perhaps not. But I think your point is, it's, I mean, this is so important, and I just love the fact that you guys are watching, and I'm pretending I'm not learning anything here, but I'm just for their benefit, is that if you mobilize this like this, it makes it a lot easier to reach and hopefully, you guys are all nodding your head and remembering, we just did this chrysalis transfer. Yeah. Like I said, we were struggling because this thing was coming up here, we had a long obturator nerve going through and more than us doing a coaptation here, and you can imagine. And it's, you know, you're doing a coaptation there. That is enlightening. Yeah. Around the corner. Yeah. I want to be doing it up here. It was. It wasn't. Yeah. Thanks for reminding me. I'm sure you made it look easy, but. Oh, yeah. For me, that would be a walk in the park. Yeah. And then for your typical use of this is a- Suprascapular. Suprascapular. But as I said, these days, I would preferentially do it from the back so that I can get a look at the notch, because getting a look at the notch of your suprascapular notch is hard. It's all the way back. Way back there. You can actually feel it. If you put your finger in there, you can feel this little divot. What you've got your finger on is the superior border of the scapula. So it's actually a long way back. Yeah. Right. And in the setting of a real live bleeding patient, that's actually pretty hard to work back there. Yeah. So pretty frequently, you're seeing injury to the nerve. Yeah. I think you see it more often than you perhaps, you know, expect. And I think that my feeling with this from the front was that results were, you know, okay, but not great. But I suspect that some of that is due to the fact that we weren't sort of really seeing the whole thing, not getting close to the muscle, second level injury. And you know, there's a lot of, if you think about adult plexus patients, you know, there's a significant number have glenoid injuries, scapular injuries, you know, there's a lot of pathology that happens in the shoulder that we don't perhaps give credit to. Right. The only other thing that I thought it'd be worth seeing if we find is the nerve to serratus. It's a long thoracic. So it's usually off the back with contributions from five, six, and seven, I might just do that. So you always take it off the clavicle whenever you do this dissection, right? No, not, only for the, in the lab, in the lab. I don't, there we are, that's, it fixes that all the way up. So I think, there, what have we got there? So the serratus nerve is generally posterior, I'm just going to cut that, I'd love this cadaver work, it just. The stakes aren't very high. Well, I'm being filmed, I'm feeling. You are filmed, that's true. I'm feeling, you know. But this I think is going to be a, actually I'm not sure, that might be dorsal scapula, a little bit distorted here. I normally don't use my finger quite as much as this. This bit looks a bit inexpert, doesn't it? I might have been able to fool you for a while, but now the true colors are coming out. So I think this is going to be, the thing I was dissecting here is the long thoracic nerve. Right there, okay. That's heading. Dorsal scap here. No, that's suprascap. I think dorsal scap might be. Okay, it's coming off, yeah. Yeah, it's usually pretty high and posterior. It even emerges, whether this thing here is it, and roughly dorsal scap, it's pretty small. All right. Let's take a break. This is a great dissection. And so we are, we've done the complete plexus. You reviewed the spinal accessory nerve transfer option. And I think what we'll do next is go down and do a little bit in here for Oberlin. Yep. And then before we're done here today, hopefully wear you out and get a politicization. Yeah, we can get a politicization. It's easy. Okay.

plexus exposure

supraclavicular branches

infraclavicular branches

dissection of plexus

landmarks

nerve branches

spinal accessory nerve

nerve transfer options

long thoracic nerve