ESSSxAIM presents: An Operative Approach to Anatomy - Neurosurgery Part 2





Want to learn more about anatomy and its theatrical (by which we mean surgical) applications, but don’t know where to start? Watch the ESSS and AIM: An Operative Approach to Anatomy! This is the fifth webinar of eight and will serve as an introduction to the theatre and some of the key anatomy to look out for when observing (or assisting) in Neurosurgery.

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The following transcript was generated automatically from the content and has not been checked or corrected manually.

The most common type of pituitary tumor. Is it a or one prolactinoma to growth hormone secreting adenoma or three pituitary carcinoma? And, yep, but very rapid response this time, uh 92% of went for prolactinoma, which is correct. Uh Yep, that's correct. Approximately 30 40% of all pituitary tumors are prolactinoma. These can be managed in a multitude of waves. Um, and the other ways from medical management to surgical removal. And I guess on any bonus points. Uh Does anybody remember the type of medication that is normally used to manage for actinomma or if someone wants extra extra points, can they name the actual medication, the brand name? Oh, we've got dopamine as a dopamine agonist. Do you know the exact name of the drug? Oh, that's two. Usually there we go. Although I will butcher the name cap or bromo, I believe can be used, bromo. Yeah. So two of them can be used. Uh Usually capital go, usually use more uh just kind of due to expect in this is kind of the same as bromocriptine, but it's usually better tolerated than patients. But yeah, moving on. So the consultant proceeds to remove the tumor and seals up the exposed pituitary and dura, uh they then proceed to exit nose while using the skin flaps that they took out later on, uh to just seal up more exposed areas to try and prevent as much CSF leakage as possible. Uh Afterwards, they proceed to get an MRI to see uh for the patient to see if all the tumor has been removed, which is on the next slide. So to get the tumor, and as we can see from the first one, it has been mostly removed. So here we've got pituitary tumor and then we also on this side, we can now see that we can actually see both sides of the optic nerve now. So rather than the tumor, which was pushing up and compressing here, they now have a optic nerve which is decompressed and hopefully it restores the visual field. So moving on uh day one after the operation, uh you and your consultant go to see the patient to review them when speaking to the patient, they complain of a headache which gets worse when sitting up and better when lying down. They also state that clear fluid has been consistently coming out of the nostril consultant. And I should join the review because they are very mean like that. What is the most likely post operative complication the patient is experiencing? Is it rhinosinusitis? A CSF leak or meningitis? Oh, a lot, a few more votes come in. All right, we'll go with that. We've got 18 votes. Uh, and the majority are going for the CSF leak, which is ultimately correct. Yes, that's correct. The patient is experiencing symptoms which are classically associated with decrease intercranial pressure. So that is a headache. That is when they're sitting up, it gets worse. But when the lying down it gets better. And that's partly because with decrease the cranial pressure, when the patient sets up, the brain can sag a little bit, which can then cause the kind of headache symptoms. And then when they lie down, most CSF returns back to the brain and then helps to kind of normalize the pressure again, leading to them not having a headache. Uh We can also see the clear fluid as being continually released into the nasal nasal cavity, which could be CSF um again, as people pointed was uh rhino sinusitis. But again, although they might be clear fluid, if you don't want to do a very rough test, then if you get them to kind of wipe the nose, you find that Ritis will kind of like crisp up male CSF like won't really just b because one's mucus, one's fluid and that was that. So you have a sigh of relief. As the review finally comes to the end, the consultant mentions there's one other surgery that you will be interesting for you to watch and suggest you to other options. Either had the books and learn about spinal decompression surgery or go on the internet and learn about spinal decompression surgery. Either way you're learning about spinal decompression surgery, but just as take home messages, transphenoidal surgery usually should know your anatomical structures being the nasal cavity sinuses. And the, and the main indications are facial disturbance, headache, and hormonal dysregulation. And I will now pass you over to Jane. Thanks. Hi, Ron. And my name is Jane. I'm also 1/5 year medical student and I'll be going to a third case for today um on spinal decompression surgery. So, uh I'll just be going over what is spinal decompression surgery? And, and then I'll call a bit of the relevant anatomy to know for the surgery and then finally run to a patient case just to kind of tie everything together. Ok. So spinal deprehend surgery is when you're removing kind of part or partial or complete removal of like anatomical structures to help relieve uh pressure on the spinal cord or the nerve roots. And it's quite an effective surgical treatment option. Um And you've got different types. Uh but the main one that I'd like to highlight for uh today's talk would be a laminectomy and a discectomy. So if you look at the image on top here and that is a laminectomy where the lamina, sometimes the spinal process is removed as well, but usually you just remove the lamina um and preserve the spinal process and then the other main one to talk about is the discectomy. So if you look at the image on the bottom and that is where you remove any kind of like this, that's kind of bulging out of prolapse. Um And if you remove that, then you release the pressure that's um um compressing onto the spinal cord or the nerve roots. In terms of indications, you can kind of split up into an emergency and elective. So, uh the main one to mention for emergency indication of a spinal decompression surgery would be quina syndrome. So that's when you get compression on your ca quina and other things could be um due to trauma or hematoma abscess or tumor compressing on it. Um And then in terms of elective, uh one of the most common in common indication for spinal decompression surgery would be spinal stenosis. Um We will talk a bit more, a bit more in detail um in the next couple of slides. But first of all, let's look at some anatomy that would be relevant in helping us understand spinal decompression surgery. So, um if you look at the picture here, you've got your vertebra column. So uh we've got the three vertebrae in total, which can be split up into seven sevia, 12 thoracic, five lumbar, five sacrum and four coccyx. And the image on the right here just shows uh your what we column in a different view. So you've got your anterior view, posterior view and your electral view. Um And so, and the spinal cord kind of run through um in the vertebra uh kind of in the bra canal and your bra canal is what protects your spinal cord. Uh And in adults, your spinal cord ends at the L1 L2 level and below L1 and L2, you've got your quina, which is mainly just uh comprising of uh the remaining nerve roots. Um And then the next thing to talk about um is your individual vertebra. So, um your vertebrae is composed of your vertebral body and your vertebral arch. So, your vertebra, bro body is uh kind of makes up the anterior portion of your brain and it's the weight bearing component of it. And the lower down you go in your vertebral column and the larger the vertebral body becomes uh because um if you think about it, the lower down you go, then the more weight it needs to support. And that's, that's why the body is a bit bigger. Uh And then uh your vertebral arch is what forms the posterior part of your vertebra um of each of your vertebrae. And, and as you can see in the diagram, the vertebral arch has got a few bo bony prominences which I'll just quickly go through. So if you look at the image on the right, and you've got your spinus process kind of um protruding out posteriorly. And then you've got your process um kind of coming up laterally, um one on each side. And then you've got your lamina which connects your spinus process, your transverse process. Uh and then you've got your superior and inferior articular uh process and, and your severe and inferior articular process has got joints uh to help us with the adjacent vertebrae, which will look into more details. And so um this diagram here hopefully helps to highlight how your superior and inferior art facet joints are with the vertebra above and below and between your vertebral bodies. And I just want to highlight that there's your intervertebral disc which once again help with weight bearing. And the last bit of anatomy to go over is some ligaments which helps to support um the facet joints that um we've just gone through. So if we look at it from kind of going from anterior to posterior most anteriorly, you've got your anterior longitudinal longitudinal ligament which um runs through your entire vertebral column. And this ligament here prevents hyperextension of uh your vertebral column. And then if you go posterior to that and you've got your posterior longitudinal ligament, again, this ligament runs um all the way through your vertebral column and it prevents hyper flexion of your vertebral column. And then if you go even more posterior to that, we come to an important ligament to them. And so that's your ligamentum flam. And uh this ligament is uh it helps to support your facet joint and strengthen the joints and, and then your last two ligaments to know about kind of posteriorly. You've got your interspinal and supraspinal ligament, which kind of connect your um spinus process and adjacent spinus process together. Ok. So now we come to our patient. Uh for this case, we've got Mister John Wright, a 74 year old male who is presenting with back pain and has been ongoing and he's also got a bit of lower limb weakness and some numbness and tingling sensation. He's got a past medical history of hypertension type two diabetes and chronic lower back pain, but it used that the back pain he's currently having is kind of been quite bad and it's a bit different from uh his usual chronic low back pain and he's tried Ibuprofen, which did not help with the pain and, and in terms of regular medication, he's on Metformin and, and uh he lives with his wife. They both retired and both usually independent uh used to work as a carpenter. So, uh based on this presentation, uh Mister Wright um has been referred to get some investigations. So here we've got um Mister Wright's MRI and as you can see at the L4 L5 level, um so that bit there and that bit there um that shows um ligamentum flaval hypertrophy. So, as mentioned earlier, um ligamentum flat 14 ligaments, the vertebra column. And what happens is that in this right case um it's become a bit thicker than what it should be. And and then this next MRI image shows that again. Um And then like lumbar, uh what we call them, you can see that there's this is kind of like protruding out and causing some compression on um the nerves. So, and based on kind of our findings there, and mister right has got spinal stenosis, which is when you've got narrowing of your spinal canal. And that can cause compression in your spinal cord, your nerve roots. And it's quite a common condition and it usually affects your lumbar like the spine. Uh and it's commonly due to kind of degenerative changes uh spine. So if you look at the diagram here and what happens in like degenerative uh changes would be you get thickened ligamentum flavum and your disc can kind of protrude out because of biochemical changes such as like cell dust and you like lose some water content, which um then your disc just kind of like starts pushing up. Um And that also increases the pressure on the joints and cause further degenerative changes. So usually your first line for managing spinal steno stenosis would be kind of con with conservative uh treatment such as kind of physiotherapy analgesia. Uh sometimes you can also offer epidural injection to help with the pain. Um and if all those fail, then you could consider surgical management. So, in this case, um Mister Wright has been uh listed down for a spinal decompression surgery. So I'm just gonna run through kind of the main steps that are involved in the surgery. So usually patient will be put under general anesthesia and, and then the surgeon will make a midnight incision uh and then pull off or dissect off the relevant layers uh until they get to uh the vertebra colon itself. And then they'll usually perform a laminectomy to remove the lamina And then that helps to kind of expose your duy and your spinal cord um and help you visualize the nerve roots as well. And then um if you remember cause mister right has got thickened ligamentum fla. And so you want to remove that and to help to relieve the pressure on the spinal cord and nerve roots. Um and then if the disc is protruding out, then you perform a discectomy as well. Um And then you do kind of like one final check to see if um adequate compre decompression has been achieved and then you close up, ok. In terms of complications for spinal decompression surgery, uh you can kind of divide this up into early and late complications. So for early complications, you can get things like 10 CCSS le uh left injury or POSTOP hematoma. Later complication that can arise include pseudo meningosis or infection and it's usually superficial infection. But if it uh if you get a deep infection, then it can lead to meningitis and sometimes there's inadequate decompression or you might get some instability of your spine, uh POSTOP and that would require further surgery as well. Ok. So now you get yourself to the, and you see the surgical team just about to start Mister rights and procedure. You introduce yourself to the team and the consultant asked if you know much about spinal decompression surgery. So you get a kind of sinking feeling that you're gonna be j with questions again. Um And uh the scop nurse kindly let you know that you might see things that you've not seen before and it it's fine for you a bit dizzy or woozy if you do feel so feel free to just uh pop off the, take a break and, and yeah, just take a break and just come back in whenever you feel ready. So now the consultant starts with a midline incision on Mr right back and he pulls through the relevant kind of layers and then starts drilling through something and, and as a consultant does this, you do you know what structure I'm trying to do through at the moment. So at the moment, we've got eight responses and 0 12 responses and we're going for a spinus process. Ok. So, um that is unfortunately not the right answer. Um So u usually in a spinal decompression surgery, you try and not cut through the spine's process. If you can. Um sometimes in certain cases, you would need to remove spinal and to get more visualization. But um usually what you do is you would try to do uh kind of remove the lamina first. And because removing the lamina itself can already need to start visualize the duy which contains the uh spinal cord um and your existing nerve roots. And so usually they're kind of like make that in work that you caught which and yeah, would be shown here. So they usually, if you can see kind of like um the blue line there, that's kind of your inward that you caught and where they cut through that and remove the lamina. Um Sorry, I'm just gonna show. Yeah. So this diagram here, um it's not the best diagram uh because in this diagram, it shows that the spinus process is removed, but usually uh they kind of like remove the and lamina. And then that allows you to visualize kind of the nerve roots and the spinal cord. OK. So after the consultant goes through the lamina and the consultant then ask you now that the lamina is out of the way. And what structure do you think? I'm gonna try and remove um him for this question is if you try and remember the MRI findings um of Mister right spine that might help you with this question here. So currently I see we've got 14 responses and we're going for the ligamentum flavum. OK. So yes, that is correct. It is the ligamentum flam. Um So yeah, as mentioned earlier, um it's quite common for people with um kind of degenerative changes that's causing spinal stenosis to have a thickened ligamentum flavum and causing the compression uh just to quickly go through the wrong answers. So, it's not your supraspinal spinus ligament. Uh because if you remember your anatomy and this is the ligament that kind of attach your uh spinus processes together and it's not really anywhere near your spinal cord nerve roots. And so it won't really be causing compression usually. And similarly, with an interspinous ligament, it's also not quite near where the, you find your spinal cord and your nerve roots. And so this ligament usually wouldn't be the one that's causing compression. And so this is just kind of a diagram to hopefully help better visualize what is going on. So, um this is kind of before when you can see your ligamentum flam is a bit thickened and causing compression. And then what happens after um you cut off the lamina and the ligamentum fla, you can see that um your duract is no longer being compressed. OK. Now that we've removed the ligament and se what structure do you think we can see here? So we've got 14 responses and 50% are going with posterior longitudinal ligament. Mhm OK. So it, it is not the posterior longitude ligament. And so again, this diagram here shows uh kind of where your, each of your ligaments lie So if you remember, um because when you're kind of doing a spinal decompression surgery, you're coughing, you kind of like you the ligaments that you visualize first would be your most posterior one, which would be the ligaments here because uh this is kind of how your you would be looking as you cut into the spine. So, and your posterior longitude ligament is this ligament here. And if you remember you've removed the kind of like ligamentum flam. But then you need to remember as well that your spinal cord and nerve roots kind of run bet between kind of this area here. So actually, before you, uh you get to the posterior long ligament, it would be the nerve roots uh that you'll be seeing first. Um And so the correct answer is your nerve root. And uh again, just something to highlight is that in adults because your spinal cord ends at level of L1 L2, everything that's below, that would just be your nerve roots. Um and then to quickly go through why it's not anterior long ligament again. And if you look at this diagram here, your anterior long ligament is quite anterior, like it's the most anterior ligament in your um vertebra column. So you, it's if you are kind of operating, it will be quite a deep structure and you won't really be seeing it just yet once you remove the ligamentum flam. OK. So now um the consultant then moves on to kind of check for any other structures that may be compressing onto Mr Wright's um spinal cord or nerve roots. And so given Mr Wright's age and his previous occupation as a comp, um do you know what structure the consultant is looking for? And again, him for this question would be um if you remember the, the MRI findings of Mister Ryan and hopefully that will help. So we've got 12 responses and 75% are going for intervertebral disc. OK. Yes, that is correct. Uh So it is the endo disc and it's quite common with like increasing age. And also, especially because Mr Wright used to have like quite a manner job or like quite a physical job and it's quite common to have a disc prolapse that's bulging out and it can cause compression. Um So it's not the panicle because the pedicle is a structure, a structure that um connects your wper body to your transverse s and it's not your vertebral body because again, um as mentioned earlier, your vertebral body would be, would form the anterior portion of your vertebral column. So it's not quite um where do you expect it to be? So, um because Mr right, this was found to be kind of herniated out and causing compression as well. Um The surgical team then proceeds with discectomy as well. Um And before they close up, they perform a last check just to ensure that everything has been decompressed. Um And then once they help you with that, they start closing up and Mr Wright is, then we off the recovery and you look at the theater list and realize that that was the last case for the day. And so just to summarize our third case on spinal decompression surgery, and we spoke about how the most common types of spinal decompression surgeries are your laminectomy and discectomy. The common indication uh for the surgery would be spinal canal stenosis, usually secondary to degenerative changes. Um and then, um definitely know your anatomy that will help you with understanding um how the procedure um works and things like that. Um So the important anatomy to know for a spinal decompression surgery would be your vertebra column, know each individual vertebrae itself and the joints and ligaments. I'll now pass it back to JJ just to call the last bit of our talk. Great. Thank you very much Jane, uh Claire Sue and Anton to round up the session. We're gonna have a few MC Qs one from each case. So I hope you've been paying attention uh and starting off, we're gonna go with question one by Claire Sue. Ok. Um Which CT image is most likely to be indicative of an extradural hematoma or Ed H um Bonus point uh for identifying the diagnosis of all of the other ones as well. Um So you can just answer um in the chat for what you think the other ones are and then for the poles, um, just use the, um, uh pole that just came up. Ok. Um Oh, we've got a few more people answering. Um So, yeah, almost unanimously we've got D which is the correct answer. Um Yay. Um Does anybody know what A B or C are? I will go through them very quickly? Um, ok. Uh Yeah, essentially. Um So a is a subarachnoid hemorrhage. Um And sort of you can tell because the blood is in the subarachnoid space. So it can flood around to the brain and kind of seep into the sulci or the little bump sort of in the brain. So that's why you can see sort of the white that's going around and sort of the star fruit sign that Jingjing was talking about earlier. Um B is a cerebral abscess. So that is also pretty correct. Um Just as a note, um pus comes up as dark on CT and blood is bright on C uh CT. So you can see the sort of hypodense area senior. So like the black area surrounded by a bit of white. Um The white is sort of like a little capsule um that the abscess forms and the black on the inside is the pus on the inside. Um And then C is subdural hemorrhage, which is correct. Um So the blood is between the dura and the Arachnoid and it forms this little banana shape that you can see. Um and then d is our extradural hematoma, which is the correct answer for this question. And it is the classic biconvex lemon shape. This one is uh frontotemporal um extradural hematoma. Usually it's in the sort of temporal parietal area, but this is also pretty common. OK, great. Thank you very much Clare Sue moving to question two by Anton. Uh So my question is, what structures do the motor nails within the cavernous sinus innervate? Is it the muscles of facial expression, the muscles of mastication or the optic muscles? All right, I will call it there. So you find at fault, 70% are saying that it's the optic muscles, which a correct answer. So basically, as you remember in the cavern sinus, uh we have the ocular motor trochlear and abdus nerves which run through, which are the main muscle are the main elevators of the eye. Uh For facial expression, there is there was no kind of facial nerves that run through the cavernous sinus and in terms of muscles of mastication. Uh although the trigeminal uh sorry, although there was two branches of the trigeminal uh BV one and V two, they are actually only sensory elves only. Uh the muscles of mass medication is controlled by the mandibular branch, which is the free, which does not pass through the cavernous sinus, which is why it was optic muscles. Thank you very much Anton and moving on to the final question. By Jane. Uh So my question is which of these structures lie between the superior and inferior articular process bilaterally at each vertebral level that should say level, sorry for the typo. So, on my screen, I think it takes a little while it's buffering a little bit, we've got uh 11 responses and we're going with the pars interarticularis. Mhm uh Yeah, that is the correct answer. Um It is a bit of a cheeky question because I didn't really mention the structure in um my case. Uh but the past the artis is um the structure that lies between your superior and inferior ocular process. And then just to quickly run through again, your ligamentum flavum is the ligament that uh connects your uh that extends between your lamina of your adjacent vertebrae. Your pedicle is the structure that connects the vertebral body to your transverse process. And your transverse process is the lateral kind of bony prominence that's coming off your vertebral body. And your laminar is the structure that connects your TRS process to your spinus process. Much Jane and thank you so much, everyone for attending. I hope you've learned a lot today and to summarize each case, uh the key anatomy to look out for in a craniotomy is the scalp, skull and meninges. Um The main indicators for a craniotomy are brain tumors, hemorrhage, uh or hematomas or aneurysms and abscesses. Transsphenoidal surgery is often used for pituitary tumors. Um for example, if they're having visual disturbances, headache, uh hormonal dysregulation and the key anatomical structures to look out for are nasal cavity. The sphenoid and cavernous sinuses. The sella t the pituitary gland and the optic nerve. And finally, spinal decompression involves laminectomy and discectomies. And the common indications include spinal stenosis and disc prolapse. And the key anatomy to know is vertebral column, vertebra, joints, ligaments and the spinal cord and nerve roots. Um Thank you so much, Jane, if you can go to the next slide, um Here's our references if you're interested. And thank you very much for listening. Today. We have another session on ophthalmology and ent surgery next week at 7 p.m. on the first of February. So stay tuned for that and make sure you register on me all. Also, please do fill in our feedback form. You all being sent an email, but I'll send it again in the group in the chat. Um It's really important for us to know how we can improve our teaching. Thank you so much for sticking around even though it ran late. I hope it was enjoyable nonetheless. And remember that you are eligible for free R CS student affiliate membership if you attend six out of eight of our sessions, if you have any questions, do pop them in the chat, but feel free to leave if you don't have any and do feel free to reach out to any of us through either the aim or ES S social medias or emails. Thank you very much, everyone.