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Ok. Um Hello everyone. Um I hope you can hear me. So the the presenter is on our way. She's just logging in now and will be with us shortly. She had, she was having a bit of a connection issue. Um So I think the the shot the chart is open for the act is open for anyone that wants to do. I have any questions? Mm So, ok. Um Do you mind just letting me know in the charts if you can hear everything I'm saying clearly? Ok. Uh All right. Thank you very much. She's on our way. I'm just chatting to her. Ok. All right. Hello. Can I be able to hear me? Yeah. Right. Come here. You can't or you can't. Ok. Bear with me. Oh, wait a minute. I might just be me. I'm just gonna put some headphones in. Hopefully that will help. Can you hear me now? Ok. Yes. Can you hear me now? Is that any better at all? It is great. Uh All right. So how do I uh so at the bottom of the screen with that? I Yeah, there we go. Great. And can you see my presentation? Yes, we can. Perfect. Ok, so hello afternoon everybody. My name is Azia. I'm one of the Cardiothoracic registrars based in Southampton. Um I apologize for the delay. I've had a few connection issues based in the hospital, but hopefully I can take you through thoracic anatomy. Um It's quite a large topic. So, um I hope I will continue to have your attention through it. Um So just to quickly go through what the objectives are for today. Um So we're gonna talk through the Muin and the compartments, the transthoracic plane, the skeletal structures as as well as the muscular structures. Um the anatomy of the trachea, bronchus, lungs, thoracic duct and thymus, then go through the lymph nodes um and then the diaphragm and other organs. I um so again, as I said, it's a big topic. So I will do, I will do my best to try and get through everything. So, starting off with the mediastinum and its compartments. So originally, it was divided into four compartments. Um So superior and inferior um with the inferior compartments being divided into anterior, middle and posterior. But now actually, that's uh changed into a modern classification. It's now prevascular, which you can see in the CT scans here if you can see my cursor. So, prevascular hearing red and then visceral hearing, sorry, your slides are not moving. That sounds OK. Let me see. Let me try the, so present the internal screen steps. Is that any better. Yes, that's better, you know, that's better and you can see it moving. Ok. So if I don't change the full screen, you can still see me just dining in compartments. Yes, me compartments and he's seen it move to the next slide. Have you moved now? No. Yes. Uh It's not moving still. That's true. So can you see the next slide now? Yes, I can. Ok. So it might be that I just have to keep it in this for you then. Um Let's see. OK. So I was talking through the mediastinum compartment. Um So there was an old classification, but now we've moved to a new one. So the newer classification um divides the media dime into prevascular visceral and paravertebral. And you can see in the CT slides here that the prevascular is in red, visceral, in green and then paravertebral in yellow. OK. Let's move to the next slide. So what are the boundaries? So, going over the um previous four compartment model? So the superior compartment is bounded by superiorly, the thoracic inlet inferiorly, you've got the transthoracic plane or where the sternal angle is, which is around T four. Anterior, you've got the manubrium and then posterior, you've got um t 1 to 4 and then laterally, you've got the pleura and the lungs and the anterior can probably see here in purple. So bounded superior by transthoracic plane T four inferiorly by the diaphragm cos it goes all the way down to where the diaphragm is based here, anterior by the sternum and posterior by the pericardium. And then lateral, you've got the mediastinum pleura within the middle, this big yellow compartment. Uh We've got superior boundaries again, t four transthoracic plane inferiorly. We've got the diaphragm down here. Anterior, you've got the pericardium and then posterior pericardium as well. And then laterally is the mediastinal pleura. And then finally, in the posterior compartment, it can see T four as a superior boundary, inferior. You've got the diaphragm, anterior pericardium and then posterior T 5 to 12. And then laterally, you've got the pleura as well. OK. So the content, what is in the actual content of the mediastinal compartments? Um So superior, as you can see, the liner is demarcated in the superior and inferior mediastinum. And so superiorly, you've got the arch of the aorta and you've got all the head and neck vessels. You've got the S VC here on the left coming in. You've got the vagus nerve. It is, I don't know if you can see my cursor going over that, the vagus nerve on both sides, the phrenic nerve, which is a bit more laterally, which is here, the thymus, which is up here and then the esophagus which runs posterior to the trachea and the thoracic duct which you can't really see in the spider room. Then inferior mediastinum, as you said, was anterior, middle and posterior. And then everything else that you can see is within the inferior mediastinum being lymph nodes, being fat, being the heart itself in the middle mediastinum, pericardium with the making up of the boundaries, the cardiac plexus and um also part of the phrenic nerve because it courses all the way down through to the diaphragm. Uh posterior, you've got the thoracic aorta as it goes from the superior media, th ascending and then as it goes down. Um and this is eventually it's an aortic hiatus. It is in the posterior compartment. Um Thoracic ducts is also in there and a sympathetic cane and ganglions. So, as I said that there was a newer classification of um the mediastinum um which is um done by the international Thymic Malignancy Interest group which um determined the boundaries by um sort of delineated by the anatomy um as well as using CT images. Um So you can see that the um as discussed before that the classifications are prevascular visceral and paravertebral and the contents are within on the table as you can see. Oh, so going again, prevascular compartment. So we talked about the thymus, the fat lymph nodes, brachycephalic vein or anonymous vein, visceral compartments. You can see the heart, the um vessels and then the pulmonary trunk. And he's also got the lymph nodes, esophagus and tracheia. Finally, paravertebral compartment is just the, just the paravertebral soft tissues and the spine. There's not much else within the paravertebral compartment. It, so moving on to the transthoracic plane. So it's level of T four. And so what happens at this level? I don't know if there's an opportunity for people to say the answers. So what structures are within T four? Um The chart is open so you can put your answers in. OK. So no answers just yet. But that's why we move on to the next. Um So many structures es essentially um within the transthoracic plane. Um So first off the mini sternal angle, so you've got a second costal cartilages, the trachea bifurcates into left and right. Main bronchi got the arter of the aorta pulmonary trunk that divides into the right and left a zygous vein that drains into the S VC left recurrent laryngeal nerve that hooks underneath the arter of the aorta thoracic duct ligamentum arteriosum and the cardiac plexus. So, lots of things happen at this claim, right? So looking at the skeletal structures within the thorax, so 12 pairs of ribs, what makes the true and the false ribs, true ribs articulate with the sternum as well as posteriorly with the spine and the costal cartilages and their ribs, 1 to 7, the false ribs are 8 to 12 and they indirectly articulate with the sternum by the seventh costal cartilage, but they don't articulate with the sternum directly. And then you've got 11 and 12 which are are floating ribs and that don't really articulate with any of the other ribs above and they just articulate with the spine. So the first rib in particular is quite um unusual as such. It forms a thoracic inlet and it's the broadest rib out of all the 12, it forms um within the head, it forms a groove and then going down to uh the articulation with the first cluster cartilage. There's a groove in which the subclavian vessels lie and also the scaling uh medius attaches and the scaling is important because of how it divides the subclavian artery, which I'll come to you a bit later. They're looking at the sternum itself. It's got three parts manubrium, body, xiphoid process important in stenotomus. You can see in the picture at the bottom. Um So the manubrium you can palpate on yourself really. So the upper jugular notch and lateral to this, you have the sterno clavicular joint. And as said before that, the facet articulates with the first rib with the costal cartilage. And then there's a Demi facet with the second costal cartilage. And then the joint between the manubrium and the sternum er body is where you then have the angle of L which is at T four as we discussed before and going over the neurovascular bundle. And they've got things that make all the structures that you're gonna pass through. If you want us to do a chest drain. These are the structures that you go through before you pop the drain in. So that's been skin fascia fat in the muscles, external, internal, innermost and between the internal and innermost, you've got the neurovascular bundle which lies infer inferior uh at the inferior portion of the rib and going through your innermost, you then have your endothoracic fascia before you hit your parotid pleura and then your pleural space. And within the vascular neurovascular bundle, it's vein artery nerve, so veins most superior than the artery, then the nerve and because the nerve is so um on the most inferior structure, this is prone to injury. And so partly the reason why people find chest pain, so painful. Um considering chest strains, I'll talk about in, in a second about the safety triangle and where we place them and they should be placed at the superior portion of the rib, so as to avoid the neo vascular bundle. And so as I said, the nerve is most likely to be damaged. Considering its most inferior, the anterior intercostal artery actually arises from the internal mammary. The posterior intercostal artery arises from the thoracic aorta and the descending thoracic aorta. The intercostal veins drain into the internal thoracic vein or internal mammary vein, um or the azygous venous system. And an internal intercostal nerve gives us the lateral cutaneous nerve before it then continues on as the anterior cutaneous nerve, as I said before, about triangle of safety and including chest drains. Um So the boundaries are anteriorly, you've got the lateral border of the pectoralis major here as you can see the green as the triangle even though it looks more like a four sided structure, but we call it a triangle. Um The base of it is the fifth intercostal space or just above the fifth rib. Um And then posteriorly, you've got the lateral edge of the lat Dorsi Latius Dorsi. And then at the apex, you've got the base of your axilla. And so this is to this triangle of safety is called the triangle of safety because you're avoiding all major um vessels and um nerves that you don't want to hit when putting in a chest stone, namely long thoracic nerve that runs all the way down and supplies scapular, then you PCK major and lateral cutaneous branches of the intercostal nerves as well. Liver as well. You don't want to, you would definitely want to avoid that. Um And so the space is corresponds to um an area that is safer to put the chest drain in any lower than that. Then there's a risk of going through abdominal structures, then muscles of the thoracic wall um relatively important within thoracic surgery itself or more. So within um I'd say plastic surgery considering that the pectoralis major is the main one that we use in sternal reconstruction in pectoralis major flaps. Um And they also all these muscles helps to support the thoracic wall and also important in respiration. They got the pec major pec minors here. Cirrhatus anterior. So during a thoracotomy particularly a lateral thoracotomy, you go through the like do side, but then you spare the erratus and try and divide it and then go through um into the chest, the intercostal muscles um as described before, when we were looking at the neurovascular bundle. Um so the external is in the same direction as the ribs, the internal is actually perpendicular at 90 degrees and then the innermost is the same direction as the internal. And then again, uh another photo showing the muscles and then you can see a direction of the er of where the long thoracic nerve lies. And the cirrhosis anterior going on top and then other muscles that are involved are the transversus thorax as muscle, er which lies posteriorly in the um thorax wall. Ok. So going over rasa, as mentioned before, about the subclavian artery being divided into parts by the sle anterior. So the first part, er 2nd and 3rd part I unlike a mnemonic, er the one that I tend to use is called vit CD. So V being the vertebral artery that comes off first, then you've got your internal memory, then thyrocervical trunk and the second part which is posterior to the splene anterior um is the costocervical trunk, then lateral to the sle anterior uh muscle, you then have the third part of the subclavian artery and the branch here you've got the dorsal scapular artery. So VI TCD, it's a easy way to remember. Ok. So as it continues on in the arm continues as the axillary artery um terrace major is a landmark in which um your axillary artery starts and the subclavian vein is seen superiorly to the azygos on the right, the exit vein itself. Um So it goes through the aortic chiaus at T 12. It is um posterior, it lies in the posterior mediastinum on the right um and sort of posterior to lateral to the SBC and then ends and drains in the SBC. The hemiazygous vein is on the left hand side, azygous on the right. Um and then your accessory hemiazygous veins um descend to the posterior metin on the left. Oh ok. So trachea and trach bronchial tree. So going through the anatomy of the trachea. So it is ac shaped, you've got c shaped rings of cartilage that form the trachea. It's supported by the trachealis muscle and connects the larynx to the primary bronchi. Uh length wise is about 10 to 13 in males. Um and then lessened that in females and two rings of cartilage per centimeter um is approximated in terms of um layering. It's supplied arterially by um the upper cervical tracheal, lower thoracic trachea, um upper cervical tracheal supplied by the inferior thyroid arteries of the thyroid cervical trunk. As we saw earlier, which is a branch of the subclavian. The lower um thoracic tracheal is supplied by the bronchial arteries. Um And there's a direct um from the direct branch of the descending aorta and venous drainage wise, you've got an inferior thyroid venous plexus, the brachycephalic vein and then the epithelium, it's formed by pseudostratified ciliated epithelium and then goblet cells that form the lining that secrete mucus and then it's innervated by vagus. It's all the rhinal nerve and it's parasympathetic um action and then also sympathetic um supply from the middle cervical ganglion is from the sympathetic plexus. And I'll put a link at the bottom if you wanted to um find out more. So in Tokyo Bronchial tree, important um application within thoracic, particularly when you're doing bronch um to understand the anatomy cos it's very easy to miss all the branches if the anatomy is not clear. Um And so the ob bronchial tree is divided into sort of primary bronchi lobar, segmental and then subs submental. And in particular, you look um for the primary bronchi lobar and then segmental bronchi when doing a bronchoscopy because subs submental is difficult and it's not really helpful when doing a bronchoscopy. And so I've put a nice picture showing if we're going through doing the bronch. This is the vision that you'll see. First, you get to the carina and you have left and then right, right BB. And if you're going down the right main bronchus, um you then find that the upper lobe bronchus actually goes off and branches off quite acutely. Um And then you have the bronchus intermedius and then going down to the middle, dividing into the middle and lower, lower bronchus. So it's actually quite a nice picture depicting all of the um branches that you will see on the bronchoscopy. And then there's a really good link on youtube actually, um which was done by one of the consultants here in Southampton. Um and it's uploaded onto CT S net. So, mastering bronchoscopy for thoracic surgery and it's really good to understand the anatomy, but also understand what pathologies that you can find when doing um a bronchoscopy. So, moving on to pleura. So, pleura is a thin layer that lines either the viscera um or around the thoracic cavity. So it's parietal pleura, it's made up of mesothelial cells. Um The visceral pleura is around the lung and it's supplied by afferent fibers. Parietal pleura is supplied by somatic fibers and obviously because it's around the thoracic cavity, it uh lines the media of like the um costal er cartilages. It all allow the diaphragm and then the also cervical pleura you've got as well. Um But the cervical pleura, you've got intercostal nerve supply, costal pleura, you've got also intercostal nerve supply, mediastinal and diaphragmatic pleura. Um same nerve supply as the phrenic and the pleura comes together around t five and seven at the hilum and then that's where you then get uh a connection down to the diaphragm which then forms the inferior pulmonary ligament um which I'll come back to a second. So going again through the anatomy of the pleura. So the pleural cavity itself um is just a space between the two different pleura and the serous fluid that is secreted um allows the air to then slide. Um This creates surface tension and allows the pleura to be together. But if air enters then, so extension is lost and you then end up with a pneumothorax. Um intrapleural pressure is negative. So, uh less than the intrapulmonary pressure and the course of the pleura itself. So again, a bit more like surface anatomy. So considering it's 2.5 centimeters above the mid of the clavicle and they meet together at around the second costal cartilage and on the right, actually. So going in the midclavicular line, one way I tend to remember is above the apex, midclavicular line, um sorry above the uh above um the clavicle in the midclavicular line. Um You've got the apex going down to the second costal cartilage, then down to six, then down to eight. So 268 in the midclavicular line, then if you go around the um the axillary line, mid axillary line, you've got 10 and a posterior, you have 12 as the lateral border of the rib um and the lateral border of the ecto spine as well as well. The left pleural actually leaves the midline at the fourth costal cartilage, but on the right is 268, 10, uh laterally 10, posteriorly 12. Well on the left, you then have 24 going laterally and there's the same on the going laterally and then posteriorly, then, as mentioned before, the inferior pulmonary ligament is a double cereal layer. Um, and then, er, it goes from the pulmonary hilum to the diaphragm. It's important within lobectomies, but I'll come back to that later. So the lungs itself, so got on the left, two lobes on the right three and the segments itself are 10 on the right and nine on the left. Arguably, you can say there are eight, considering that the apical posterior is counted as one rather than two separate um segments, then this picture on the left. Um So if we're going through the right lung and all the segments, so one being apical, two posterior, three, anterior and a middle lobe, they see four and five, you got the lateral medial and the lower lobe got the superior. Then actually, in this picture, you can see the me basil is a bit better s shown here in gray eight, you've got anterior, basal, nine, lateral, basal, 10, posterior, basal. Then on the left again, as I said before. So one and 2, 10 are together. So apical posterior, um so sometimes they counted as one segment. But actually, um in reality, they're counted as two. And that's important when calculating postoperative F EV one in patients that you're doing lung resections on that's one and two. Then three, you have anterior and you've got the lingula rather than the middle lobe equivalent on the right. Um And you've got the superior and inferior lingular, then you go down to the lower, left, lower lobe. So six being the superior, it's like a complete mirror of the right, essentially 7/8. You have anterior basal, just seen here. Then eight. Again, you can see at the front but seven eights altogether, then nine lateral basal and then 10 is posterior basal. Again, you can see a cadaveric image of the lung. This is the right lung, um y oblique fissure coming down here and then horizontal fissure dividing into right, upper middle and then lower lobe and the right hilum structures. So on the right hilum here, it can go from the bottom, whichever way works for you in terms of remembering. And that's helpful for me to start from the bottom and going to the top. So on the bottom, you always have the inferior pulmonary ligament, which is coming up here, which then lead it leads up to inferior pulmonary veins here. And you've got an inferior pulmonary vein, you have a superior pulmonary vein and then continue going up the hilum. We've got pulmonary artery which lies anterior to the main bronchus. And you've got a bronchial archery that sits behind there and then there's a groove on the right and this groove is for the Zygus vein and at the left. So the, the features here, again, you can see, as I said, following up, starting from the bottom, going to the top and the inferior pulmonary ligament, which leads the inferior pulmonary vein, um which you can see better in this one. And then you have inferior and then superior. And then the closer picture actually in this one is better to show you the bronchus and the pulmonary artery. And another way that I tend to remember is left pass. So pulmonary artery is superior, pa S pa is superior on the left, on the right is pa, so pa is anterior, it's just a nice, easy way to remember then, in terms of the groove. So you've got a nice big groove here for the aorta that's on the left. And then the phrenic nerve then passes anterior and the vagus nerve passes posterior to the hilum and the pericardial artery, uh cardiophrenic artery and vein accompany the phrenic nerve, then going over the pulmonary artery branches themselves. Um So on the right anyhow, on the left. So going through, there's a nice picture showing all the branches. So we've got the right main pa and then your truncus anterior then giving off the branches to the upper lobe and apical and anterior segment. The posterior segment is actually supplied by a branch that tends to come off. Um the either inter lobal artery depending on the anatomical variation or the main pa A and then if you carry on, you've got the middle lobe artery coming down and then the lower lobe artery that's giving you all your basal segments, segmental branches on the left, the left pa A um we have branches that are going all the, all the segments, each individual segment, including your lingular segments as well. And then the basal arteries um continue off the left main pa A going down here. So left lower lobe artery. Oh so right P has explained. So truncus anterior giving branches to the anterior and right upper lobe, um bronchus. So essentially um your anterior and um apical er segment branches. Then the posterior segment of the right upper lobe, as mentioned before, in terms of the variation on in the anatomy, interlobar artery then runs between the bronchus intermedius and the superior pulmonary vein and it runs of the interlobar fissure. So it's just um giving off the right middle branch, which is quite important because again, in doing lobectomies, um sometimes people do a fissure last technique, er which also means that as they're trying to find um the bronchus intermedius um and the superior pulmonary vein, they take it all in one staple rather than actually dividing, dividing them up, then lower lobe arteries. Um So you got the apical segment of the lower lobe and the remaining basal segments as mentioned before. Um with the lower lobe artery then on the left. Um So it arches over the left main bronchus. So I remember it was the third left pass. So PA is superior. Um and then 3 to 5 branches of the left pa supplies the upper lobe and lingular and the left lower lobe, it then branches off to give off the segments to each. And then this is just explained that the VC IVC goes to RA uh Tricuspid via the tricuspid valve to the right ventricle and then to the pre monitoring arteries. But that's just a revision. We all know that I say CT imaging. So again, looking at where the PA S are. Um So this is on the left, you know, your left main pa A and you've got left upper and a left lower. So it's actually quite a nice image that you can see here on the CT and then on the right, you got the right main pa A, then you have the right upper and then you've got a middle that's coming in here. Um But this is so the interlobar which then sits um near the bronchus intermediate and then you've got the right lower lobe artery that's coming off there. And again, another CT image to show you um the main PA A and the left and right pulmonary arteries in relation to the pulmonary veins. It's quite nice to see in this image on the left that the pulmonary veins just sit here underneath. Yeah, good. And again another um image to show a CT image here in this one showing the arteries here and in the veins are sitting underneath the arteries. And you can see in this 3d recon that are pulmonary arteries, anterior and then the veins are posterior. Ok. So when doing uh lobectomy, as explained before I said I was gonna come back to it. So going through a right upper lobectomy usually ports in um and one lung down and initially going through with the arterial dissection uh or vascular er dissection. So first off going through the vein, then the artery, then the bronchus um and you can see in this with the right upper lobectomy, they've identified the upper lobe vein and then have divided it with a stapler, er, found the upper pulmonary artery and then who divided it as well. You can see they've identified the truncus and then interno then they divided truncus anterior and an upper lobe. Bronchus identified afterwards after identifying the division of the anterior trunk, which helps give you access to the bronchus. Er So the fissure last technique uh essentially where they divide the fissure at the end um to help remove the lung, which you can see here. No. Oh. So going through venous drainage. So the right superior pulmonary vein drains the right upper and middle lobes. You can see here and then the right inferior pulmonary vein drains the right lower lobe and the left, the superior pulmonary vein drains the left upper lobe and then the inferior drains the left lower lobe. See there are many variations. Um And the common one that we tend to see is on the left, you have a common pulmonary vein. So, rather than giving you a nice left uh left, upper and left, lower um pulmonary vein, you then have a common vein before you have a left upper, lower, important is the linear before doing um a lobectomy on the right. Oh, sorry, on the left. Um Because if you take the um what you think is the left, upper bone is actually a common um middle lobe or common pulmonary vein. Um you may end up um requiring the patient to end up having a pneumonectomy. This doesn't get OK. So let me just start the lymph node stations themselves. So this is uh actually quite a nice photo that shows where they're located and what the indications are er and implications are and most importantly within lung cancer, lung cancer staging. Um And it's important to know what they are. So particularly with N one N two and N three disease, N one disease. Um I mean it also in this diagram that it's from lymph node stations 10 to 14. Uh However, N two is all the ipsilateral stations from 2 to 9 and then N three is contralateral lymph nodes or supraclavicular lymph nodes. And I'll go through the uh TNM classification in a, in a moment. So, in terms of what you can see here in the CT images where they've identified one are so high menin lymph nodes as well as upper paratracheal and then prevascular and retro er tracheal lymph nodes. Then again here on four lower peral lymph nodes and then two are that they've got here actually. And three and then six pa will take that they've identified him on the CT and A five is another one to note, don't often uh go for five. but subaortic lymph node as you can see station rather is here. Oh, so they said I was gonna come back to TNM stage and really important to know the lymph nodes and identify them um preoperatively as part of preoperative planning. Um because arguably er N two disease um we don't operate on for anything. N one and below we do. So N two is all is debatable whether they need new chemotherapy or immunotherapy. Um But that's a topic, separate topic for another day. Um But going over the tumor characteristics, particularly with N 12 and three disease defined by the lymph nodes that we saw in the previous slide good. So surrounding vessels and I'm also short on time. So I'll quickly go through the rest of these. So, mammary arteries, which are important within more so within cardiac than in thoracic. But in terms of um our anterior intercostals, they come from the internal mammary um branch of the subclavian as we discussed before. And the terminal branches are as seen here, the musculophrenic and the superior epigastric running down and the artery that supplies the phrenic nerve is the pericardiophrenic artery as you know, that runs alongside laterally to the heart. Oh, and there's another photo showing uh the internal memory, the vessels are here. And then the right phrenic is just running down laterally. S VC. They can't really see the IVC, the diaphragm and then the pericardium that they've dissected out here. Good. So claiming after branches just brought that back in again to D rediscuss, but we've gone through all the branches. And I remember vitamin, vitamin CD or VIT CD um as the mnemonic to used to remember the divisions and the branches. Oh, so esophagus, so anatomy of the esophagus itself. Um So it's made up of mucosa submucosa and connective tissues. Let me try and bring this forward if you can see. So the mucosa submucosa, the muscularis propria and then adventitia and within the muscle itself, um it's made up of striated and then smooth muscle. And then you've got striated and smooth together. It connects the pharynx to the stomach and descends between the trachea which lies anterior to the esophagus and then posterior to the esophagus. See how the vertebral body is. It starts at C six and then ends at T 10 where it enters the diaphragm with esophageal hiatus and it's lined by stratified squamous, nonkeratinized epithelium and also the innervation of the esophagus, I'll come back to in a second, but you can see a nice picture showing the layers with the mucosa submucosa. Um So muscularis propria, which is a circular, muscular and longitudinal and an adventitia on the top and carrying on with the blood supply of the esophagus. So rule of thirds. So if you divide the esophagus into three, then it's supplied by different things. So the upper third um is supplied by the inferior thyroid artery, middle third by the esophageal branch of the descending aorta and the lower third by the left gastric artery. We can see here, the venous drainage pretty much the same. Um So upper third is inferior thyroid vein, middle third, azygous, lower third, left gastric vein, then the lymphatic drainage um can rule of thirds. So upper third is deep cervical, middle mediastinal and the lower is celiac lymph nodes and then the nodes that run alongside the left gastric supplied by, as shown in the first photo with all the layers of the esophagus by the upper, upper third of the esophagus is um sorry, upper half of the esophagus is supplied by the recurrent laryngeal. And then the lower half is supplied by the esophageal plexus, which is from the vagal trunks and the sympathetic trunk and then indentations as you know, from the aorta as well as um the left main bronchus. Yes. So I just wanted to briefly go over esophageal trauma. Um So it's quite important because um more recently, I've had a few referrals of patients that have come in with subcutaneous emphysema. Um And then people always forget about the esophagus. So thought to intro introduce this or briefly go over this. So, esophageal trauma can be genic or non nitrogen. Um and you can have spontaneous rupture. So non nitrogen is quite rare, especially um with stabbing injuries, um not impossible but rare. And you can have spontaneous ruptures and will go over um later and then foreign body and caustic ingestion or even malignancy as a way of um causing trauma to your esophagus, spontaneous rupture, um, common in mallory rice tears, er, where you have a longitudinal tear in the gastric mucosa above the gastroesophageal junction and then it develops or presents with upper gi bleeding, usually self limiting of all houses when people are vomiting, um, or straining severely. Um, and that causes the spontaneous perforation of the esophagus from the increased intraesophageal pressure. And then the lower part of the um esophagus is often affected within spontaneous rupture. Um, and this is goes mostly untreated, all right. So JIC um not uncommon, particularly after O GD. Um, and unfortunately, with perforation after O GD, it's um actually quite life threatening if it's not caught. Um And so the relative risk factors of people that end up getting uh perforation is if they've got diverticular um, or if they have er, peribronchial er, traction or strictures or even malignancy and it's diagnosed by er, symptoms that they present with uh chest pain, abdominal pain, um subcutaneous emphysema, as I explained before, um difficulty swallowing or a change in their voice, um whether they become short of breath, tachycardic household versus or septic picture. Um and then Mackler triad is another um sort of definitive um way of diagnosing being vomiting, chest pain and subcutaneous emphysema. Well, so diagnosis and managing esophageal perforation. Er so imaging wise and assessing the injury score scale and then being able to manage that depending on um what you find. So chest X ray being the main um thing that people start off with with chest pain presentations. Um then ct helps to um identify any mediastinal air er or pneumomediastinum and a water. So, water soluble contrast is helpful um as well to identify where the er esophageal perforation is located. Um endoscopy potentially is another route to diagnose. But considering the patient's already had an O GD that caused a perforation, probably other measures are preferred before going to endoscopy. Um bronch or Lagos copy potentially bronchoscopy, not so much um as more as a ruling out any other cause of pneumomediastinum um rather than as a diagnosis of esophageal perforation. Then the s injury score scale being grades 1 to 41 to 5, sorry. Um So 1 to 3, it all helps to guide in terms of um whether a fistula has developed um and how to control and how to manage it. Um So more conservative management in 1 to 3. However, grades 4 to 5 is more serious and requires a patient to um either have esophagectomy or even staged esophagectomy if the patient is too unwell. Uh And so the general management esophageal perforation um would be sort of a at e assessment and managing resuscitating that way. Uh, early surgery if needed or sometimes conservative measurements or measures including putting an endo VC, um giving antibiotics, antifungals and then closely observing them. But if they deteriorate, then they would be for surgery. So some things are related to the esophagus. So, if you injure the esophagus, what other things can be injured? Um So anteriorly or the bronchus, um so you can get a pneumothorax and trach a bronchial er tracheoesophageal fistula. Um you could get bleeding as well with the bronchial anxy veins posteriorly aorta, which is, you know, catastrophic patients don't often come uh make it to the hospital immediately. Um patients get a pneumothorax with the pleura being injured and then a chylothorax with the thoracic duct being injured um when it's on the right and complications from um injury to esophagus, as mentioned before. So, abscess media, stenus, uh Neom mediastinum um which is difficult to treat. Um and then tracheoesophageal fistula with the mortality is actually quite high. Cool. So, going back to the thoracic duct. So what is the function? Um So it transports lymph back into the circulatory system, it starts at the upper aspect of the cisterna Kyla, which is down here at T 12 L1 and then it passes through the T 12 aortic hiatus in the posterior mutum and then goes from right to left at T four and ends between SBC. Um and the er sorry, left internal jugular and the left subclavian vein confluence. If it's blocked, people can develop uh develop chylothorax. Um and that's usually diagnosed by sending off um free fatty acids or um Chylomicron diagnostic test by sending off some of the pleural fluid, then diaphragm going over that. Um So the apertures are cava esophageal and aortic and another mnemonic to try and remember um what goes through. So, voice of Africa V OA VB vena cava uh which is at T eight esophagus at T 10 and aortic hiatus at T 12. Um Within the cable hiatus, there are a few structures other than just the vena cable that goes through. So the right phrenic nerve goes through again. T eight T 10, the esophagus left gastric artery and vein and vagus nerves also go through then T 12, the aorta thoracic duct and the zyr vein go through him in terms of the attachments. So several attachments of the diaphragm. Um So you've got the zip, zip sternum alip process anteriorly, the costal margin of the thoracic wall, the ends of ribs, 11 and 12. And then on the lumbar spine itself, um you've got the ligaments attaching to L2 and um L2 and three and then arterial supply of the diaphragm, you've got the inferior and phrenic uh so sorry, superior and inferior phrenic arteries, musculophrenic and pericardiophrenic arteries um coming from the internal mammary drainage wise exactly the same um from the arteries to the veins. Uh and then innervation as we all know is the phrenic nerve and phrenic nerve itself. So it originates actually at the lateral border of the anterior scaling muscle. And then it passes deep to the prevertebral layer of the cervical fascia and then runs behind the sub a subclavian vein. The right passes anterior to the subclavian artery and it enters the thoracic inlet and then passes anterior to the hilum and then courses along the pericardium um in the right atrium through the diaphragm of the cable opening. Um So that's t eight in the left phrenic itself. Um It passes anterior to the left subclavian artery descends anterior to the left um lung hilum and it crosses the aortic arch and then um runs on the pericardium on the left ventricle and then it pierces the diaphragm as well. Uh It has sensory and motor functions for the diaphragm. Ok. So, coming to the last few slides, so, thymus and sympathetic trunk. So the thymus gland um particularly important within thoracic because we do thymectomies often for patients with myasthenia gravis. Um So understanding um where it's located, um the previous function that it had um within childhood is important. Uh So it lies within the anterior mediastinum and it has two lobes and it is also p midden shape. Um It's lymphoid tissue. Uh so it's immunological. So it produces and matures immune cells and then secretes thymosin which helps to make T cell lymphocytes. Um again, as I said, it becomes a bit more red, red in uh adulthood. Um And so it's easily removed during a steno. Um but also in patients who have um mycena gravis, the arterial supply from the internal mammary, as well as the superior and inferior thyroid arteries, venous drainage into the brachial phallic and then also internal mammary veins. It also develops from the third pharyngeal arch if you remember back to your embryology days. Oh, so sympathized to trunk, the series of right and left paravertebral ganglia connected by post ganglionic fibers. So there's 12 of them and then it runs, it's quite a long length that it runs within the posterior mediastinum and then the cervical thoracic ganglia. Um it's made up of the stellate ganglion and you feel cervical ganglion. So, as I said, it was quite long. So it runs 22 all the way down to 12 and it communicates to the ventral primary um ra by ramus communicans as you can see here, not here. And then it supplies the thoracic viscera. Um and it also gives off splanchnic nerves and these consist of presympathetic fibers um that don't synapse within the ganglia, but instead pass through the ganglia um through the career of the diaphragm and then synapse at the preaortic ganglia. And then you can see there's a great Islamic nerve that's done here. ST 5 to 9, the lesser splanchnic nerves at T nine and 12, uh sorry, T nine and 10. And then the least splanchnic nerve at T 12, it say very quick whistle stop tour of thoracic anatomy. Um So we reviewed the mediastinum and compartments and included the new classification of um the mediastinum. We looked at the transthoracic plane and T four and the structures that lie there. We also looked at the musculoskeletal structures of the thorax good in the neurovascular bundle and how that was important um in relation to getting in chest strains, we looked at adjacent and relevant vessels. Um So the subclavian artery, the various branches, the zygous veins, hemiazygous veins, the tra tracheobronchial tree. Um And then I also provided the link to the bronchoscopy. Uh looked at the pleura and the relevance to pneumothoraces and understanding um the um pleural pressures. And then also looked at the lungs from the hilum, the lobes, the segments, the arterial venous supply had a look at um uh right upper lobe, lobectomy also had a look through the lymph nodes and the TNM classification and the lymph node stations. Then also the other organs in the thorax with the esophagus and then associated trauma. Uh the thymus and relevance in mycea gravis and thymectomies, thoracic duct and then the diaphragm and then finally ended with um the re nerve and sympathetic trunk. So hopefully, all of this is giving you sort of an overview of the thoracic anatomy and I hope you find that helpful. Thank you very much. Um Yeah, we value the feedback and um I believe that forms will be sent out to you if you need to get the certificate. I also like to credit um Miss Giani who helped me with the presentation um for this, yeah, Thoracic Anatomy presentation. So thank you very much. Um Thank you very much for that. It was uh quite informative. I'll see. I'll say it's such a, you know, anybody who's not taking the MRC S is probably ready to take it right now, to be honest, we did. Uh Yeah, it was quite informative. Um So, uh the chat is open, anyone that has any questions and, you know, and unfortunately, I think we have quite a poor attendant. Uh I think we had more than 20 people sign up and here I can only 12345678 people in here. To be honest, that's fine. I think they, now they are ready for the Mr here. So, all right. Um Any questions that you have any concerns anything you'd like us to address. And I like the fact that you also put uh y you know, the um the pneumonics to essentially, yeah, to make things easier to remember because sometimes it is so much to remember the way you want, but also, you know, doing it over and over again, you kind of like you, you expect once in a while you tend to come across that the, you know, the normally and things that go outside the C mm, you know, but are you primary cardiac or thoracic? I remember with thoracic. Yeah, that's the thing I'm doing. I'm currently doing cardiac at the moment. So counting my days, II II definitely do understand what you mean. To be honest. I understand what you mean. Um So he doesn't, I don't think anyone's got any questions. So what I would do is I will send out the feedback forms. Uh Do you please do your best to um fill them out so that we can all, you know, be able to send, I'm sure that we can all get our um certificates and then we can send the certificate to the present as well and if you have any questions, anytime you can put it on the whatsapp Group chat. Um and uh yeah, and then we'll address them also. I was wondering if there, if you've got any, you know, any availability later in the year. I think there's someone already for January. Uh but any any availability later in the year, just let me know and we'll set it up. Ok. This is something that should run all year. Ok. Mm. Thank you very much for that. Thank you for the invite. All right, take care, take care. All right, bye bye.