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Good evening everyone. Uh My name is Charles Senna and I'm the president of the FT SS East Midlands. Welcome to another session on anatomy revision. Today, we have Mr Salem here to, he's going to go through vascular anatomy revision and it's a general revision as well of anatomy. Uh I'm aware that this is not the last planned session of the series, er, because two of our speakers had to unfortunately postpone their talks. Er, but we hope you find this very useful and I'll turn over to him now. Brilliant. Um Thank you and thank you for that introduction and thank you for the invite to talk to you all today. Um So the brief I was given was just to do some basic vascular anatomy revision for the MRC S. Um So I just, I would just go through the various um components of how it's structured within the syllabus. Um, talk about some of the vessels, you'll find what are the probably the most clinically relevant ones that you need to know about. Um So I thought I'd start with the face. Um So again, apologies if some of this has been covered within the head and neck sections you've done. But again, it may just be an aid memoir for that. Um The main blood supply to know about for the face um is your external carotid artery. Um and the branches off. Um So the main blood supply that comes from the external carotid artery that supplies the face will be the facial artery. Um and the superficial temporal artery, um the superficial temporal artery uh uh I mice, can you see uh an arrow being shown? No, I'm not sure. Um So, apologies. So, if you follow the external carotid artery up, the super superficial temporal artery is the final branch. Um and you can palpate the temporal artery just in front of the tragus and in the temporal region. Um The clinical relevance of that is in those patients that are being potentially diagnosed um with um temporal arthritis. There are still areas and centers where you're doing temporal artery biopsies. Um And this is something simple that can be done under local anesthetic. I remember being asked when I was first doing it saying, oh, but if you're taking a section of the artery, what happens to the blood supply to that area? But the most important thing to know is that within all of these blood blood vessels that you can see that supply the the phase, there's really good um branches and collateral supply. Um So excellent anastomosis between all of these vessels, which means that you could easily take off a part of the temporal artery where you suspect there may be some inflammation, uh send it off for histology. It also means that the uh face is a really well vascularized area. It heals extremely well, but it also bleeds extremely well. Um One of the reasons that when we're doing uh operations around that area, we use adrenaline is that you get really quite extensive um skin edge bleeding. So adrenaline tends to uh vasoconstrict and, and prevent some of that. Uh the important thing to note that if you're using adrenaline with local anesthetic is that you don't use it in areas that are um and vessels over the tip of the nose. For example, if you were to use local anesthetic to do something around the nose, you can cause um quite significant necrosis. Um in terms of the venous drainage from the face. Again, it's a, it follows a similar pattern. Um mainly comes of either facial vein, which I'll, I'll, I'll demonstrate later on. Um this communicates centrally with the veins of the orbit and the um cavernous sinus. Um And that makes it kind of a dangerous area because uh infection can easily spread um centrally from the face uh upwards towards the brain. Ok. So, um again, you may have covered some of the neck again, from a vascular point of view, what are the important things that we really want to know about? So, uh and that will be covered within the exams are triangles. So there's the anterior and the posterior triangle. Um I was only really going to focus on the anterior triangle because that's the area that we commonly access as surgeons. Um They often ask you what are the boundaries of the anterior triangle of the neck? Um And the boundaries are essentially laterally, the anterior border of sternocleidomastoid, um superiorly, the infra border of the mandible or the jawline. Um And medially is the midline of the neck. Um And then we know that the roof of this triangle is covered by investing fascia. Uh and there's vissel fascia which covers the floor and what's important about this, uh this anatomical landmark. This knowing about this is that within it, you have the common carotid artery and it bifurcates into the external and internal carotid branches. Um Also found within this is the internal jugular vein um which is um responsible for venous drainage uh of the head and neck and the facial vein, which is the main vein that drains the face supplies, uh connects directly into the internal jugular vein within the carotid triangle. Um just carry on. Um So again, another a viewer of this anterior triangle of the neck. Um I've talked about the blood vessels that are in there, but there are also numerous cranial nerves that are located within the uh anterior triangle. Um Some pass straight through another gives rise to branches which innervate some of the structures within the, the triangle itself. Um The ones that are most probably again, commonly seen by ourselves and the ent surgeons are the uh seventh cranial nerves. So the facial nerve, the ninth cranial nerve being the glossopharyngeal nerve, the vagus nerve, the accessory nerve and the hypoglossal nerve. So 1011 and 12. Um so I don't have a way of demonstrating, but this yellow nerve that tends to run down underneath here, it runs uh underneath the uh internal, which I'll tell you which one is the long one here that branches comes across the external. So the yellow nerve is tends to be your hypoglossal nerve. Um And again, the, the clinical relevance of that nerve being so close to where we would tend to do an operation such as co endarterectomy is that if you damage your hypoglossal nerve, you get uh a hypoglossal nerve palsy which leads to um weakness and um you get a deviation to the side of the palsy. So if you're working on the right carotid artery and you either pull on it and you get a bit of neuropraxia or you damage it, um then you will find that when you ask the patient to stick their tongue out, the tongue will deviate to the right hand side. OK. So within the anterior triangle, there are actually many more other triangles, there are muscular triangles. Um But I thought I would just again, focus really on the ones that are important. So, the one that we commonly uh are interested in from a clinical relevance is your carotid triangle. Um And again, these have their own little borders. So the carotid triangle has uh their own boundaries. So superiorly, this is the posterior belly of the digastric muscle shown in green here. Uh laterally is the medial border of the sternocleidomastoid. So, remember sternocleidal mastoid has two hands of sternum and the clavicular. but the medial border uh is the lateral border of the carotid uh triangle and the inferior um border is the superior belly of omohyoid. So commonly, when we're making our incisions again, for the uh to get access to the carotid artery, we know in general that the bifurcation lies somewhere between the two, but sometimes the bifurcation can lie very high and then we're having to go into the digastric or it can be very low and then we're having to divide omohyoid. Um And again, focusing very much into this uh carotid triangle. The main contents of the carotid triangle are the common carotid artery which again is the site of bifurcation, the internal jugular vein, um and the hypoglossal and vagus nerves. So those two really important nerves, both of which if you get damage to will have significant clinical effect on the patient. So, tongue deviation, difficulty in swallowing. Um Now, within this carotid triangle, most of the vessels and nerves are quite superficial level, access quite easily from surgery um, it is quite interesting because, you know, we had a patient in a true story overnight, came in last night who tried to stab himself directly almost at the site of his carotid uh triangle. It's actually very difficult to harm yourself or set off, harm yourself when you're stabbing yourself because you naturally turn to do it and your sterno kind of mastoid comes directly and protects your um important structures. Um So very rarely actually do we see uh harm to the carotid artery from uh uh from deliberate self harm like that, often you'll get damage to the internal external jugular veins. And that's where patients that um have difficulty or bleed, right? Um within the carotid triangle as well. Um something to know is the carotid sinus. So this is a dilated portion of the common carotid and internal carotid arteries and it um it's where the barrow receptors are now, barrow receptors detect stretch. Um And these are a um a measure of BP. So they negatively feedback on BP control. Um and the glossopharyngeal nerve is also um directly related in um sending uh or innervation of baroreceptors to the brain and regulating BP. Um And therefore, in some people, the baroreceptors, like I said, because it's relatively superficial um can be very hypersensitive to that. Um external pressure on the carotid sinus can cause a bradycardia can cause a hypotension or drop in BP. Um The results of which can lead to a um drop in flow and perfusion to the brain and a an episode of syncope. Um So that's why if somebody's particularly sensitive, we all say don't try to palpate the carotid artery when you're thinking about uh assessing pulse, for example, because some people are particularly sensitive to that um in terms of the carotid arteries themselves. So the carotid artery um on either side. So, on the right hand side, the carotid artery is a direct um extension of the brachiocephalic or innominate artery, uh which comes off the aortic arch. The innominate artery then divides um or bifurcates to the right subclavian artery and the right common carotid artery. Um And this is about the level of the right sternoclavicular joint. Um the left common carotid artery. And I'm gonna show you a picture in the second of the aortic arch comes directly off the arch. Um And again, this um goes directly upwards. Um The common carotid arteries on either side, don't really give off any branches. Um They run laterally to the trachea and the esophagus um at the level of the superior margin of the tracheal cartilage. So around about C four is the site of carotid bifurcation. Um Like I said, this can be variable and certainly when we do our carotid arteries, um we will often uh carotid artery, endarterectomies and dissections will often go on duplex findings and our duplex um results and our scientists will tell us if there is a low or high bifurcation because that will tell us if our approach is gonna be difficult. But in general, it is about the level of C four. All right. Um The exter, that's right. So the external carotid artery, um once it bifurcates, it has lots of branches that tend to supply everything extracranial. And as you can, you can see in this picture, the red internal carotid artery has no branches and goes directly to the brain. Now again, the clinical relevance for that is that when you're doing a, an an operation and you, you know, you've identified the common carotid artery and it's bifurcating and then you need to know right. I've got to dissect into the internal car and you've got two vessels that look identical and you need to know well, which one is the internal, which one is the external? Because they don't always lie as they do in the textbooks. Median and natural. Sometimes they lie uh uh anterior and posterior. We know that the one that has branches is your external carotid artery. And the one that has no branches is your internal carotid artery. And again, from a clinically relevant uh in place, the important thing to know is that internal carotid artery, stenosis is what can lead to strokes and tias and therefore disease within this portion is something that needs to be treated. Um If somebody was to have an occluded external carotid artery. Actually, that doesn't really have many uh many effects. And that's because there's just excellent crossflow growth on the other side. You may get asked, what are the branches of the external carotid artery? And it's um not unusual that you may get asked that. Um The first one that we see is always known as is always the superior thyroid artery which goes directly despite the thyroid, there's the lingual artery, the facial artery. Um there's the ascending pharyngeal artery, um occipital artery, uh posterior auricular artery. And then as I said, the final branch of the external carotid goes to be the um superficial temporal artery. Um There are uh the maxillary artery also uh interestingly enough, like I said, the external, it's, it's interesting on this because the external carotid artery supplies everything within their face and neck, but not into the brain except to the middle meningeal artery, which is a branch of the maxillary artery. Um And the maxillary artery does come from the external carotid and again, from an exam point of view and what's clinically important, what's clinically important about the middle meningeal artery is that it can be damaged by direct trauma um to the head at the weakest point of the skull. You may have covered this when you did head and neck. Uh anatomy, uh known as te direct trauma will tend to um cause damage to the middle meningeal artery which can lead to um subdural hematoma right. Um What do I need to tell you? So I just thought I'd go through the common approaches and why is all of this important this important? Because if you're doing an operation, um so we do this, the ent and head and neck surgeons will do extensive neck dissections. Our a common approach to the, the carotid triangle and the anterior triangle is an incision directly anterior or medial to the steno mastoid. We tend to go through skin, subcutaneous tissue um through the platysma, we stay just in front of stom mastoid. Um And then when we get through stenocladum mastoid, we get this kind of a picture which has been demonstrated here, we get in picture. Number one here shows um is that showing um the internal jugular vein, uh the main branch of the internal jugular vein is the facial vein and the facial vein tends to be again, your gatekeeper to um tend to be your gatekeeper to the carotid bifurcation. Now, um again, such a big important vein, but we routinely divide it and you know, again, in trauma situations, whenever you need to, you can without really much effect, you know, ligate these big veins because the collateral blood supply and venous drainage is so good. I mean, obviously, you never do anything you don't need to, but we divide the common facial vein. We bring the internal jugular vein laterally which you can see um being done in number three, which exposes the common carotid artery and its bifurcation. And then normally you can see signs of plaque within the internal carotid. And just up here, you can probably see a branch coming off which is the superior thyroid artery. Um And finally, the nerve that's running across here. Um There is a nerve, sorry, a a nerve that's running on picture four right at the top is your hypoglossal nerve. And there is a branch called your aneris, which runs down it, which can be again divided um again, from a um clinically relevant point of view. What's the importance of knowing this? So that when you're doing your dissection, there is the module mandibular branch of the facial nerve which um supplies the mouth and damage to that during dissection through aggressive retraction, using your retractors can lead to a neurapraxia. And again, that might lead to um a inability to fully form a smile, a droop or um patients often complain of drooling, which can be sometimes last just a few hours to days or can last longer depending on the damage that may have occurred to the marginal mandibular nerve branch of the facial nerve um moving on to uh the thorax. And again, I know this is a um something that you've covered already. So I'm only gonna go really through the vessels and the important vessels through the um thorax. So the most important thing being the aorta, there are three real parts of the aorta in the chest. There's the ascending aorta uh which arises from the aortic orifice from the left ventricle. It ascends uh to become the aortic arch, which is about five centimeters in length, uh traveling with the pulmonary trunk within the pericardial sheath um within the uh ascending aorta. Um at its origin, there are left and right aortic sinuses which give rise to the left and right coronary arteries that supply the myocardium. Um going on to the aortic arch. As I said, we kind of briefly went through it, but there are three main branches that have this configuration. The first branch is your brachiocephalic or innominate artery. Um that uh tends to bifurcate um into your right, common carotid and right subclavian artery, you then have your left common carotid artery and then your left subclavian artery again, which come off directly from the arch. And then you get down beyond that to the descending aorta. What are the clinically important things and diseases that can infect this area? So, obviously, most of the ascending aorta and arch are dealt with by the cardiac surgeons. But any um dissection would need immediate reconstruction. That's a type a aortic dissection if it affects the ascending and arch, if it affects the descending aorta beyond the left subclavian, that's a type B aortic dissection, which we would often manage medically unless there is um complications such as end organ uh ischemia. Now, again, one of the important things to note is this aortic isthmus, it's just beyond the left subclavian artery. Um Now, the arch is still relatively well connected um to the pulmonary trunk by the ligamentum arteriosum, which is a um embryological remnant or fetal remnant of the ductus arteriosus. Now, you might be thinking, oh, why am I telling you that? And what's the importance of that? So again, where I work in a, in a big trauma center because of the way that the arch and the descending aorta are fairly free and mobile, but the aortic isthmus and the arch is fixed in that one particular place just beyond the less subclavian. What we see is that if you have people in road traffic accidents, so acceleration, deceleration, rapid injuries, the aorta tends to move very fast forwards and then very fast backwards. Um but it's fixed in a specific position and that can lead to a significant aortic injury. Uh So we might call that a blunt uh aortic injury. So not a penetrating but a blunt aortic injury um of which there are various classifications, but it can lead to a complete transection where the two ends of the aorta are just completely uh detached. And you might think, well, how is that compatible with life, but actually with a bit of adventitia holding it all together and hematoma it is, but they're the the kind of cases that need immediate um immediate treatment with stenting. And again, often in those conditions because of the location of the left subclavian to where the uh injury happens, we stent across the left subclavian and very rarely do we ever have to um revascularize the left sub, the left subclavian gives rise to the entire blood supply to the left arm and the vaginal artery to the left posterior aspect of the brain. But because of the really good collateral blood supply in the brain from the circle of Willis and in the arm. Um actually, even if you occlude the lesser flavine artery, very rarely do patients get symptomatic, right? Um I just thought I would talk about again. It's just to let you know, we're gonna talk about the abdominal aorta. The abdominal aorta is um is divided really into three parts. Uh Certainly the mesenteric vessels, uh the celiac artery, the superior mesenteric artery and the inferior mesenteric artery. So, these are the non paired branches that come anterior off the aorta. And um the relevance of this is that the celiac artery when you look at a four week old embryo and how the embryological development of the aorta is the celiac artery supplies the forgot viscera. So the forgot viscera include the spleen liver, stomach, the superior mesenteric artery supplies the midgut viscera, which tends to be most of the small bowel, the um cum um ascending colon, transverse colon and part of the descending colon. So, part of the splenic flexure and the inferior mesenteric artery is um responsible for supplying the hind g crier, which include the descending um sigmoid colon rectum. Um Now there is again a good collateral um blood supply between the two. And that's why often you can lose any uh one of these. Um But as long as you normally have one out of three, then through their collateral blood supply, you can, um you can safely uh continue and certainly people who have peripheral arterial disease will see them maybe lose their im or their celiac. But if you've got a good sma, you tend to be fine, uh supplying all of the major um viscera within the abdomen and within the retroperitoneum. So, uh when you go do this, so the aorta uh the descending aorta runs down and it goes through the diaphragm at T 12. Now, that's important that the cable comes through at T eight. And again, they love asking questions um about uh the various structures that pass through the diaphragm. And at what level? So at T 12 is where the um the aorta comes through um to become the abdominal aorta and that's where you get then the abdominal branches. Um Now the main branches like I said, that we need to know about are the celiac artery and the celiac artery give rise to the hepatic artery, left gastric and splenic. So, supplying the, as I said, most of the stomach, uh spleen and liver, the superior mesenteric artery comes again anteriorly Um And these are roughly at around about T 12 L1 level. Um And then there are paired renal arteries on either side again, around about L1 L2 always slightly different. Some people will have accessory renal vessels. Um But the vast majority are around about L1. Um And then further down, you have the inferior mesenteric artery again as an unpaired branch which comes out and supplies most of the hindgut. Um That's around about level L3 and just one lumbar level down at L4, the aorta bifurcates into its iniac vessels. Uh the surface landmark of which is the umbilicus. And so when you're palpating for the aorta or such as an aneurysm, you want to make sure that you're slightly above the umbilicus and slightly to the left. Um If you are uh palpating an aneurysm below the umbilicus, then it's likely that there is a iliac artery aneurysm. Um And so that's the, these are the surface landmarks, the important things to know about because again, this is what they like to ask in questions uh within the exams. Um just briefly in terms of some of the clinically relevant anatomy. So a an any vessel becomes aneurysmal when it becomes 50% bigger than its normal size. So the normal aorta is two centimeters once it becomes three centimeters, which is 50% bigger than normal. We class it as an aneurysm, we don't tend to fix aortic aneurysms that are three centimeters, but we do want to keep them in surveillance because they are liable to get bigger. And at some point cause symptoms such as rupture, thromboembolism occlusions, et cetera. Um in terms of the venous drainage of the abdomen. Now, that's quite, there's two separate systems that you need to be aware of. There is the systemic venous system, uh which essentially transports all of this deoxidation blood back to the right atrium of the heart. And that's mainly through the inferior vena cava. Um Now, the inferior vena cava um forms at the confluence of the two common iliac veins, your left and right, uh which is just uh slightly higher than where the aorta part gets around about uh sorry, slightly lower. So around about L5, um as I said, the CAVA goes through the diaphragm at T eight. So the cable hiatus. So, one of these questions, they love to keep asking what structures that go through the diaphragm and what, what levels they are um Now, so that's your systemic venous drainage. And, and that's also comes uh additionally from lumbar veins and the renal vein, uh the gonadal vein. So all of these systems uh drain into the cava. Um The relevance again from that is that you can get varicoceles uh in the scrotum. If you've got something higher up, um when we're approaching the aorta to repair, to do an aortic aneurysm repair, we need to be aware of, as you can see here, where does the left renal vein cross? Um because it's coming from the left kidney to the cava on the right side of the aorta. So is it crossing in front of the aorta or is it crossing behind the aorta? And that's important because if we're not, if we're not aware from preoperative imaging where it is, it's very easy to damage the left renal vein. If you're dissecting the aorta and you hit it from behind. And once that happens, I mean, you're really in a, in a bad place, you're in a, a disaster zone because you can get excessive bleeding with very difficult ways to control it. So you want to be aware of all of these things. Now, um again, one of the other things which I was just gonna point on the clinically relevant anatomy, we talk about um a May Furner syndrome. A May Furner syndrome is where you get an extensive DVT because of compression of the left common iliac vein. Now, the left common iliac vein tends to be um compressed often by the right common iliac artery because that's what crosses it because of the way that the configuration of the cava and the aorta. If you get compression of the artery on the vein, you can get a significant DVT uh very painful swollen leg. And often it won't respond to just anticoagulation alone or venoplasty, you often need to stent it to give it that radial force to keep it open. Um I did explain that the within the abdomen, there is a completely separate um venous drainage system and that uh is your portal venous system. The portal venous system carries uh again, venous, the oxygenated blood, but it's nutrient rich blood that's come from the gut to the liver to be processed. Um The major vessel of that is the portal vein which is a confluence of your superior mesenteric vein here and your splenic vein shown the green, inferior mesenteric vein. Again, is something that we would we try not to do anything routinely. But if we're having to do a dissection to the aorta, we can routinely divide it and there's a very good collateral blood supply. So there's very little effect from doing that. Um So the, as I said, the superior mesenteric vein and the splenic vein form the um portal vein. Um and that ascends towards the liver. Now, there are um lots of uh crossflow. So portovenous systemic shunts to be aware of. Um now, what's the relevance of these and where do they occur? So, this is something you would probably remember from me four times, but there are esophageal rectal retroperitoneal and uh paraumbilical portosystemic anastomoses. Now, the relevance of that is that if you've got portal hypertension, something like liver cirrhosis, um and you've got poor flow through that system, you're gonna get engorged veins, uh um engorged flow through these areas of anastomoses. So you're going to then get um dilated veins and varices, which then can lead to significant bleeding from these areas. So, again, commonly, we we know about esophageal varices leading to upper gi bleeds or rectal varices leading to lower gi bleeds. Um both of often which will need treatment uh in the presence of a bleed. Um We had a patient who was in ICU yesterday, uh significant variceal uh esophageal varices, bleeds, uh who had to have a tips procedure, which is again a kind of a vascular end of endovascular procedure where you um try to shunt um within the portal venous system to try and reduce the uh resistance and outflow. Um So that's that um within the pelvis. Um again, as I said, the abdominal aorta, uh bifurcates at L4 into your common iliac artery, uh the common iliac artery then bifurcates further deep down the pelvis into your internal and external iliac arteries. Um The external iliac artery will go directly down to the um to the beneath the inguinal ligament into the leg and, and literally the same vessel changes its name. It's a continuation of the external artery which then becomes the common femoral artery and that supplies your lower limb. Your internal iliac artery has a number of branches that supply everything within the pelvis. Uh going in a clockwise direction. You can see some of these named vessels in your lateral sacral, superior gluteal inferior gluteal, internal pudendal, middle rectal, your inferior vesical which will supply your bladder, superior vesical bladder obturator, an internal IAC which is shown as the main branch. Now, what is the relevance of all of these? Again? Um The relevance is that they all supply different parts of the pelvis if they've become occluded through direct trauma, uh that can be iatrogenic. Sometimes we have to embolize the internal IIAC for various um episodes of bleeding in the pelvis, uh or through peripheral arterial disease. And that can lead to impaired blood supply to the important structures and particularly the your biggest muscle in your body, your glut, your glutes. If you have impaired blood flow, you can get severe buttock claudication. The reason that often doesn't happen when we do this because we do embolize and occlude off these vessels routinely is that there is really good cross uh collateral blood supply from the contralateral side. Um Again, you know, the gynecologist when some of the difficult patients are bleeding, um will arrange for um selective embolization in trauma, patients will do the same. So we had a chap who's in it at the moment. You know, you know, he's had a really horrific injury, 34 years old road traffic accident, motorcyclist come off his bike, he split his pelvis in half. He occluded off his external artery, but he had major bleeding uh from his veins and from his various arteries which had been embolized and the vein was packed. Um And so the, the pelvis in particular has such a rich collateral system of veins that um it's very difficult to actually get control in a deep dark area. So then in trauma situations, the best thing to do is just to pack it all, pack, pack pack and come back and actually you can get quite good he spaces um very quickly. Um Now, the venous drainage system, which I'm starting to allude to follows their named kind of IAC artery. Uh sorry, follows the named arteries. So the femoral vein drains into the external IAC drain, which drains into the common I vein. Um I talked about the, the significance of getting a DVT and DVTs we often commonly think about in the leg and they're the ones that are managed medically with anticoagulation. But when you have an extensive DVT and it's normally, you know, it can be secondary to an underlying cancer or pelvic compression, uh, tumors. Um, as I said, it may then, then because you're, you're talking about the main outflow of the leg, that's where you get significant s um, symptoms. You can get your post thrombotic syndrome where you get real pain, swelling, discomfort, ulceration, et cetera. Um The other thing to say is there is something called pelvic congestion syndrome. So, in the same way that you can get varicose veins in the legs due to um, valves that don't work. The same thing can happen in the pelvis. Um if you then get dilated torto veins, it's very difficult to treat them in the same way that you would treat the varicose veins in the legs. Um So this kind of uh di dilatation and congestion can lead to significant pain um in women and it's something to be aware of. And the treatment is uh embolization against selective embolization from um doing a selective catheter venogram really, right, moving on to the lower limbs. So the lower limbs. So from again, an anatomical point of view, the things to be aware of that they like to ask in, in exams and in questions is um about the femoral triangle. Now, the femoral triangle is important because it contains the major neurovascular structures that supply um the leg and certainly the anterior part of the leg. So the femoral triangle has its borders from Sartorius, um a ductal longus medially and um inguinal ligament uh superiorly. Now, what are the contents within the um femoral triangle? So we know that we have the femoral nerve, the femoral artery and the femoral vein. Uh And finally, and if that's going from lateral to medial and family, the femoral canal which contains deep lymph nodes in some vessels. And there's a bit of space between the vein and the canal to allow uh expansion. But that is a site of where femoral hernias can occur. Um Again, so that's the important thing to know it is that it, it is vein, artery, nerve, medial to lateral, um, nerve artery vein, uh lateral to medial and again. Wh why is that important? So, if you're doing any kind of procedure, you're taking a blood gas or you're, you know, you can't bleed somebody and you're taking a femoral vein stamp. How are you gonna identify that? You, you identify it from palpating the femoral pulse and whether you palpate the femoral pulse, the femoral pulse is palpated, mid inguinal point which lies between the anterior suprailiac spine and the pubic symphysis. It's not where the inguinal ligament lies. Uh the inguinal ligament lies between the anterior superior spine and the pubic cubicle. That midpoint of that is your deep inguinal ring, which is where you get inguinal hernias. But your mid inguinal point lies between your aces and your pubic symphysis. And if you can find that point, what we, you know, we always teach our students is that you will always be able to find the femoral artery there bearing in mind that lots of our patients have occluded, aortas, occluded arteries. Um and if you can't palpate it at least, you know where it is and you know where to place your fingers. Um And then if you need to do something like a, a venous tab, you know that I just need to go medial or if you're doing a, a nerve block, you know, I need to go lateral. Most of this is done ultrasound, guided, but um it's good to know the anatomy. Um Right. So, within the leg, the main branch, like I said, is the common femoral artery. That's a direct extension of the external line artery. Once it goes under the inguinal ligament, it quickly branches off to become the profunda femoris. Um And then the superficial femoral artery which lies just under sartorius. So, in this diagram here, you've got tensor fasciata most laterally, you've got your big rectus femoris muscle here, your sartorius which has been divided, but normally it lies subsartorially. Um And again, you've got your adducta muscles here. So you've got gracilis, adducta, longus, pectineus right at the top there. Uh There are various branches that come off um including your external pretend or your circumflex vessels of the common femal. Um The profunda femoris artery is a really important artery. It serves as a savior for so many patients that have superficial femoral artery disease, you know, smoking peripheral arterial disease, they get that, you know, they keep walking, they keep going because their profunda femoris uh keeps things um well vascularized. Um So your superficial femoral artery uh continues, like I said into the anterior aspect of the thigh and it goes through your abductor canal. Um and various branches will supply the anterior thigh muscles, most of which I just um uh which I've just described to you um in your um a ductal canal, sometimes known as your Hunterian canal. Uh and once it comes out through there, it becomes your popliteal artery. And again, the clinical relevance of this is that your common femoral artery in your femoral triangle is a fairly superficial. I mean, if you're very big, it's going to be a bit deep. But for most people, it's a fairly superficial structure. It can be damaged easily in trauma, but it's your site of access. Obviously, we use it in vascular. But when you're doing any form of lines, if you're going to do any kind of percutaneous access, uh the cardiologist routinely use it. Our radiology colleagues can routinely use it and then the superficial femoral artery lies quite deep to the muscles. So in the thigh, it's not as easy to get to. Um, you certainly wouldn't consider doing anything percutaneous to the superficial femoral artery. And why is that? Because when you're doing percutaneous access on blood vessel, when you want to then get hemostasis and control, you need to be able to press it and compress it and compression only works if you can compress against a solid structure. So when we're, when we are accessing the femoral artery, we know and we look for the femoral head um of the femur and we compress against the femoral head. If you can't compress, you're never gonna get hemostatic and you're gonna end up with a false aneurysm. Um And so if anybody needs access to the superficial femoral artery, it's often a cut down, uh through the tissues, uh below the sartorius muscle. But then your popliteal artery which comes through, uh, the abductor canal, Hunterian canal, um, is a place that's quite accessible. And again, it's, these are the sites that we think about doing our anastomosis onto when we're doing bypasses, uh, which I'll just show you shortly, um, when you get to the, the top of the knee, behind the knee, like I said, the artery becomes your popliteal artery. Um very, I mean, it's quite a posterior structure. I just did a uh a popliteal artery bypass on a patient and having them prone. So head down made it quite easy to access the popliteal artery because of its location. Um It lies very close to the tibial nerve, which is an extension of the sciatic nerve, uh branches of which go to the common perineal um and to the heads of the gastroc anemia. So when you're doing your dissection, if you've got a patient and you may have covered this already, but you, you may need to know the orders of um the popliteal fossa. So your heads of your gastroc gastrocnemial semitendinosis, you remember? No, that's where your uh popliteal artery lies. Um The way we normally do it is we make an incision directly in the midline. We find the short saphenous vein which tends to then go directly to your safa pop or junction, your venous junction and there lies your artery. But these important nerves can be damaged through stretch, through careless dissection. So you have to be really um particular careful when you're doing it. Um because that can have a, again, a devastating effect on the patient. Um The Popliteal artery uh has three parts of the above knee in the popliteal fossa and be and below the knee. Uh P one, P two, P three. And then it goes, and it bifurcates into a tibioperoneal trunk and a branch that goes to your anterior tibial artery, your tibioperoneal trunk, then bifurcates and then you therefore get three vessels. We call them cru vessels, tibial vessels, whatever you want to call them that go down to the foot, your anterior tibial artery, your posterior tibial artery and your perineal artery, which is sometimes known as the fibrial artery, which lies in close proximity to the fibula. The fibular artery or peroneal arteries tends to stop at the ankle. Whereas the posterior tibial artery and the anterior tibial artery will continue into the foot. Create a foot arch, the anterior tibial artery in fact becomes the dorsalis pedis artery, which you can see on the right hand picture here and the dorsalis pedis is one of the pulses. You can feel on the top of the foot, just lateral to extensor, hallucis longus. And your posterior tibial artery is another pulse that you can feel just um between your achilles tendon and your medial malleolus. Knowing where you can palpate pulse is important because examining and knowing where the pulse is in almost all patients pulses and arteries always take the same course. So they're always in the same area. If you can feel it great. And if you can't feel it, then you know that there's probably a problem with flow. Um And this, when we do CT S or Mr S is the kind of images that we get, um you can see the flow in the pelvis and then coming down through the pelvis, your branch to the profunda, a nice superficial femoral artery which goes laterally to anterior tibial and then in the midline goes your perineal and then goes your posterior tibial medially and the clinical relevance to all of this. So most of our patients have got peripheral arterial disease from one form of another. But getting bypass, you know, getting a good bypass to work means a number of things. It needs a good inflow vessel, healthy inflow through bug and healthy outflow. So that might be AAA graft as you can see here, going from the femoral artery to the above knee popliteal or it might be going below the knee. Uh In this case, it's showing a femoro posterior tibial bypass, what we call a femorodistal bypass using the vein. Now, the vein which we often use, which I'm going to talk about is your great saphenous vein. We use it, we can reverse it because of the valves or we can keep it in the same position and use a valvular tome. Uh So these are the clinically relevant. Uh And, and the nice thing is with almost all of these vessels, they are accessible through one form or another through open surgery. Um or we can use do endovascular techniques through the femoral artery or through the uh dorsalis pedis uh keyhole. Uh very quickly, we talked about aortic aneurysms. So popliteal aneurysms are less common than aortic aneurysms. They don't tend to present with rupture and bleeding very rarely. What they do is they can cause compression. So people will describe a very painful lump. Uh First presentation may be a painful swollen leg which is a DVT because of compression of the venous outflow. Um And uh one of the presentations of teal aneurysm is acute limb ischemia because they tend to be thrombus lined and that thrombus can shower off down into these three vessels which I described earlier and taking 12 or three of them out can lead to acute limb ischemia. Um So that's again, just to be aware. Uh and the popliteal artery a bit like the femoral artery and your dorsalis pedis and poster tibial is a an artery that you should be able to palpate. Um You may have covered this when you did the lower limbs, um lecture earlier, but I just thought from a certainly from a vascular point of view. What why do we need to know about compartments of the leg. So we need to know about compartments of the leg because often ischemia, trauma, um burns, any of these can lead to compartment syndrome. And if it's not recognized and treated, it can have devastating effects, it can lead to limb loss, amputation, et cetera. So, there are three blood vessels that supply the the lower leg uh be beneath the knee. But actually, there are four compartments. And that's because the anterior compartment shown in blue here is supplied by the anterior tibial. The lateral compartment is supplied by the um perineal or fibrillar artery. And the posterior compartment, which is supplied by the posterior tibial has two compartments. There's a deep posterior and a superficial posterior, really important to recognize this because if you don't, and again, I've seen really senior people do fasciotomies to release the compartments and not adequately release all four compartments. Now, it's important to know obviously which muscles lie in within the compartments. So knowing that your anterior compartment uh contains tibialis anterior and your extensor hallucis and longus. Um your lateral compartment contains Peroneus, longus and brevis. Um your deep compartment is really again, your flexor tibialis posterior and your superficial compartment is your the big calf muscles that we know as you being your castros and your celeus um and associated nerves that go with them. So when you're doing fasciotomies, knowing that you potentially may damage the nerve, but you know, you can't really uh not do a proper fasciotomy. And how do you do a four, you know, a four compartment fasciotomy. So, the common way is through two skin incisions laterally and medially, the medial uh incision will get you to your posterior, deep and superficial compartments and your lateral compartment should get you. Lateral incision should get you to your lateral and anterior compartments. And sometimes we see it where if one of the blood vessels is gone, say the anti tibial is acutely uh occluded, you'll have nice, soft, healthy muscles within your posterior and your lateral compartment for your anterior compartment will have uh nonreacting dying muscles. So it's really important to recognize, to know it and to treat it quickly. Um I thought I'd talk a bit about amputations. Uh amputations are a couple of levels. We do transfemoral uh transtibial and uh we don't really do the um through ankle, we have it. We tend to do transmetatarsal. And that's because if you try and do an amputation through the ankle joint, when the prosthetist and their rehabilitation team take over, they say you don't really get a good fitting prosthesis. So if somebody has, you know midfoot disease, we won't often do a um a Symes amputation through the ankle will often go directly for below the amputation. Um moving on to the venous drainage of the leg. Uh We have superficial veins and these are important because of varicose veins, but they're also important, you know, because we use them as conduit for bypass. The cardiac surgeons use it as conduit for coronary artery bypass grafts. So you have a short saphenous vein and a great saphenous vein. Uh they both ascend uh one ascends posterior to the short saphenous vein and enters into the uh deep system via the sa popliteal junction. Your great safa vein, which is uh a collection of the dorsal foot arch runs anterior to the medial malleolus, superficially goes with the um saphenous nerve up towards the uh groin into the cribriform fascia, the groin through the cribriform fascia and joins the femoral vein at the snof fe junction, the deep veins um tend to follow the names of the arteries. So you've got your femoral vein, popliteal vein, poster tibial fibula and anterior tibial veins. And any of these veins which become damaged can lead to deep vein thrombosis or deep venous insufficiency, which again can have significant impact on patients. Um For us, if we are ever having to do major reconstructions of the aorta, sometimes we will strip the femoral vein um to, to reconstruct and to create the aorta. It's probably one of the best vessels. You can't use a great silus vein because it's just not a big enough vein. Um but normally the venous outflow is good enough from the Great sappers vein and the profunda vein. So there are options and again, in trauma situations, if you have to, you can ligate this. Uh although the impact is quite significant. So we try not to and we try to keep as much flow as possible through these veins right the hand. So this is the last thing that we're gonna cover or towards the end of time, the hand um is supplied, as I said by the subclavian artery. On each side, the left subclavian artery comes directly from the aortic arch. The right subclavian artery we talked about comes from the brachiocephalic artery. Um Now, the subclavian artery has three parts. They love to ask this, I don't know why, but there are three parts of the subclavian artery and each part has a um a number of branches. Now, the way that somebody always taught me to remember some of the branches of the subclavian artery is vit CD, Vitamin C and D. So the first part of the subclavian artery has the vertebral, the internal thoracic and the thyrocervical. So that's the vit the second part of the subclavian artery, uh which is in relation to scolen anterior has the costo cervical trunk, which is the c and the third part of the subclavian artery has the dorsal scapular artery. And then you can see the relationship with the scolen anterior in the first rib. Now, I think I saw in one of the lectures that you had on upper limb. There is something about the thoracic outlet, the relationship between the subclavian artery and subclavian vein and the brachial plexus in this region. And if you have any compression in this area, then you can either get uh ischemia. Uh you can get venous thrombosis or deep venous thrombosis. Or you can get um uh neuropathic symptoms, paresthesia, numbness, weakness. So, that's the clinical relevance. And then beyond the first ray of the subclavian artery becomes the uh axillary artery. So the axillary artery um again lies deep to the pectoralis minor. It's enclosed within an axillary sheath, which is a fibrous layer that covers the artery and some of the cords of the brachial plexus. Again, it can be divided into three parts. Always try and remember three parts of the arms, three parts of the uh subclavian, three parts of the axillary artery. Um and they're divided in three parts based upon its relationship to Peck minor. So the first part is proximal to peck minor. The second part is posterior to peck minor. And the third part is distal to peck minor. And again, each of the parts have a number of branches. The upper limb compared to the lower limb has a really rich uh network of collateral blood supply, which is why I explained a bit earlier on that, you can occlude the subclavian artery and the patients will have no symptoms whatsoever. Um But there is the superior thoracic artery that comes from the first part, the um thoracoacromial artery and lateral thoracic artery from the second part. Um Again, I wouldn't, it's just to be aware, I don't think they'll ever asked you about all of this in detail, but there is a subscapular artery, anterior and posterior circumflex arteries um that come from the third part. Um and these wrap around the, the neck of the humerus. Um And the clinically relevant importance of that is that if you were to fall on your shoulder and get a neck of uh humerus fracture, you can easily cause a lot of bleeding. Um And then at the lower border of the terra major, the axillary artery then becomes the brachial artery. So the terra major is just shown there and that's where the brachial artery starts. Um Again, just showing you this um routinely as a vascular surgeon, we're asked to provide access or we may use the axillary artery as an inflow. If somebody's got an occluded aorta and they can't have a laparotomy. We may do a axillary femoral bypass and we will dissect the normally second part of the axillary artery out. Uh going that's a deep to peck minor. Um Being careful of the brachial plexus, we use it as a uh an access vessel when the cardiologists are doing t so uh transaortic valve implants who people who can't have major open heart surgery uh as a treatment for severe aortic stenosis, it's been a complete game changer, but we will, if they don't have access from the femoral arteries, we will do a surgical cut down onto the axillary artery and use that as an access. Um going down beyond terrace major. We did explain that the axillary artery, the same vessel becomes the brachial artery. Um And again, the brachial artery, it's important just to know that there is a really good rich blood supply that comes off it if there's damage to it, uh you will see somebody routinely have a pink normal hand. So this can be all sorts of trauma uh in Children from your supracondylar fractures to major trauma. I had a patient uh I was on call last week who was bitten by a pit bull XL American bulldogs. One of those dogs that had been banned, she was their owner, her dog attacked her, took a great big chunk out of her. Uh arm, took the brachial artery. Um didn't actually divide the brachial artery, but the trauma of it caused bruising and contusion and damage, which meant there was an occlusion there. Um We had to resect the whole thing on block and do an interposition graft. I mean, she had very good flow, but the reality was she's a young lady and as soon as she starts to use her arm, she would have got ischemic symptoms. So we made the decision to reconstruct that immediately. Um So as I said, we know that if you're, for example, elderly, you have acute embolus sitting at the brachial artery. It's your non-dominant hand with anticoagulation alone. Heparin often you get away with it. Uh But for the vast majority of people, um even with a good anastomotic supply, um good collaterals rich network, um ischemia can lead to um necrosis, fibrosis of the muscle fibers. Um And that characteristic flexion deformity, you may have heard of it called a Volkmann ischemic contracture. They're the really clinically relevant point that you need to know about. Why do we need to know about it? What's the damage that can cause? How might that impact the patient? Um through the cubital fossa, you get bifurcation of the brachial artery um into its uh radial ulnar artery. And there is this common intraosseous artery and again, really similar to the lower limb. It almost matches it where we get the anterior and posterior tibial arteries and a a perineal artery that stops at the ankle. There's a anterior artery that stops at the wrist. Um This bifurcation can happen anyway, we normally say it's around the anal fossa below. It sometimes can be a very high takeoff and a high division. Um I've had a prisoner who had stabbed himself multiple times in his arm. Divided his, what I thought was his brachial artery soon found out that his brachial artery divided very high up and it was actually just his radial artery. And thankfully because it divided very high up, he had a very good blood supply via his own artery. Um And again, the clinical relevance of all of this is that usually you only need one or two, sorry, one of the two arteries, one of the radial own arteries. So, when patients get repeated um cannulations of the artery and you get thrombosis or damage or pseudoaneurysms. As long as you've got, you know, we talk about um testing this before you do a blood gas to make sure you've got a uh a decent own artery, um and a uh a palmar arch. So, um that leads us very nicely into the palmar arch. The palmar arch is extension the same as the foot where you've got the dorsal and plantar foot arches. Here, we have palmar um and dorsal arches that are, are direct connections of the radial and ulnar artery. Uh again, give a rich supply to each of the fingers with the digital arteries. Um The last very, very last thing, when was that time to cover was the uh venous drainage of the arm. Again, very similar to the uh the leg. We've got superficial veins, the cephalic and baci vein and the median cubital vein, which tends to be the, the vein of choice when people are doing cannulation of the antecubital fossa. Um from a perspective of surgery. Um We think about using these veins as conduits for bypass. If you don't have good uh leg vein, you know, if you're having to do a bypass and it's a choice between using arm vein or using prosthetic any day of the week. We'll use arm vein because we know it's more durable, more uh less prone to infection, et cetera. So, the cephalic vein and basilic vein are often marked out. It's also the site of um AV fistulas when you're doing uh transplant work, or you're creating a arteriovenous fistulas for dialysis thinking about a radiocephalic or a um a basilic um C or uh fistula. So just knowing where these are marking them, knowing the sizes being aware. Um and again, an anatomical description of that and finally, there are of course deep veins uh similar to the leg that match their arteries. So your ulnar and radial veins and brachial veins. Um and that is the venous drainage to the arm. I think that's all I've got to say. Um I'm sorry, that was a really quick one hour run of everything vascular. I hope I've just gone through the main uh anatomical and clinically relevant things. Um If anyone has got any questions, I'm really happy to answer them or happy to be emailed or anything. Really? Thank you very much, Mister S for excellent talker. If there are any questions, please do, put them in the chat and we'll read them out will just allow a little bit of time for people to put any questions they may have. Yeah, it's interesting, you know, we do anatomy so early and then we start doing operations. So, you know, you'll see more and more kind of cadaveric um courses learning anatomy. Um when people are doing convex operations haven't done a lot, we will still wander down to the anatomy room. Uh So it's not uncommon to, you know, keep trying to refresh ourselves on most of this. Bye bye. We have no questions as of yet. So we'll give it one more minute if that's ok. Of course. Yeah, no problem. So, like I said, I'm happy to, um to be contacted later If anyone wants to go through, if anyone wants to go through things in the operating theater as well, you know, we always say that theater five is open to everyone, really our emergency theaters. Um literally just email us and if you ever wanna come and see anything in particular, we can try and let you know when that's happening. Um do get involved. Like I said, part A is a lot of theater but part b you know, just being in the theater is, makes such a difference, I think um if there are no questions, I think we'll call tonight then. Thank you so much. No, thank you. Thanks for the invite. Um Thank you for organizing. It's really good. I hope you don't mind. I shared it with other people who told me they're sitting Mr S and um some of the other videos you've done have been as well. We're always happy to welcome new people er, for everyone who's interested attending today, we put a feedback, a link for a feedback form in the chat. So please do fill it out. It's very useful for us and the sp speakers to know how we can improve the future. Uh So please do fill it out otherwise. Have a lovely evening. Thank you. Thank you.