We're going to talk about standard approaches to the thoracolumbar spine. I'd like to thank Praveen and Pat for inviting me. These are my disclosures. They should not impact the content of this talk. When you talk about your anterior anatomy, you really want to know your approaches. You cannot rely 100% on your access surgeon. A lot of times, if you go to someplace new or a different hospital, your access surgeon may not know what to do. They may not know how to get you down there. The other aspect is also consider anterior physiology. Look at the size of the patient, if they've had previous surgery, if they've had radiation. All these things you want to think about, whether or not you want to go from the front or from the back. We're going to go from the top of the thoracic spine all the way down to L5. At T1, you generally can get that through a standard ACDF approach. For the most part, you really can get that. Look on your sagittal views to see where the manubrium is. When you get to T2-3, you either have to do an upper manubrial split or you have to split the sternum. If the patient's got a really long neck or skinny, you potentially can just do a standard ACDF approach. T4 to T12 generally, a standard thoracotomy is what you want to do. When you get to L1, generally if you can do an L1 thoracotomy, a lower thoracotomy, T11, T10 with a diaphragm split, that's the general approach. L2-3, for corpectomies there, you want to do a lateral approach for those. And then L4-5, you want to think about going pure anterior. When we go through the anatomy here, they talked about this earlier. Left side, the recurrent laryngeal nerve wraps around the aorta. Right side, it wraps around the subclavian. If you're lost down here, so a lot of times if you're doing, say, some tumor at T1 and you're not comfortable and all you see is a bunch of muscle, what you can do is go higher. Go back up and find your SCM and find that plane where you do your ACDFs from and then work your way down. You want to be really careful when you get down to T1 because the recurrent laryngeal nerve is going to be flapping in the breeze. So, unlike in a standard ACDF where you barely ever see it, you're going to see the recurrent laryngeal nerve as you get down, down to T2, T3. It's going to be staring right at you. So, you really want to warn your patient that there probably is a higher incidence of hoarseness. I personally don't use the scissors or cut anything down here. Everything is blunt. If I do hit the recurrent laryngeal nerve, I've only dissected it and bluntly moved it. I've never actually cut it. So, just be real careful when you get down there and really warn the patient. The other thing to think about is when you do your visualization. So, if you look here, you can get down to this vertebral body, but you may not be able to instrument it the right way. You also want to think about not just seeing this space, but the angle. So, if you're trying to do a discectomy here, it's going to be very difficult to get that angle. You can do it here, but here it's very difficult to see it. So, you always want to think about the angle, think about the manubrium and whether or not you're going to instrument that patient. There are some cases in which if you were just to do a vertebrectomy and an expandable cage and all your instrumentation was from the back, that would be fine. This is an example of an osteosarcoma, T1, T2, going from the front. So, in this case, a sternal saw and then open up the sternal saw here. Your access searching can get you down here very quick. You've seen these sternotomies are very fast. So, if you look here, here's the specimen coming out. But if you look here, even though you've got this huge sternotomy, what's this structure here that's holding you up? Paul Ackerman. What's that structure? What's that structure back there? The anominate? Exactly right. So, no matter how big your opening is, the anominate is going to stop you from getting much, much lower. So, always want to think about that. And then again, you can see right here, this retractor is pushing, this is the anominate right here, pushing the anominate down south and then this is what it looks like. And obviously, we couldn't get a plate on this thing, it was just too much, but she was instrumented through the back. If you have to go through, Larry Ryan's wrote a nice paper doing a sub-anominate window. This is a really, really, really difficult thing to do. So, generally, most people would go through the back, but this is very hard to do this and there are a lot of structures. So, you can do this if you really have to, but I think most people would probably avoid this window. But just so you know, that is one option for you. So, when you do your standard thoracotomies, T4 to T12, again, this is for anterior thoracic pathology, generally requires a chest tube. It's technically very straightforward and you may or may not want to deflate the lung. Alright, so let's go with Ryan Grant. You want to go from the left or from the right? It's a general rule, your thoracotomies. You're going to go on the right? How come? What's your rationale for going on the right? So, you say that you can put more force on the aorta than you can the vena cava? Is that correct? It's more likely to tear the vena cava. So, you can fix the aorta more so than you can the vena cava, is that what you're saying? Yes. It's a rationale. The old historic thinking has always been that way. You've got to keep in mind when you're in the upper thoracic spine, though, the aorta is literally on top of your spine. So, if your aorta looks like this, you're not going to be able to see the spine unless you have a retractor for the aorta. And if you try to push the aorta aside, it's constantly pulsating and pushing back into your field. So, it's a general rule when you get to the upper thoracic spine, I tend to go from the right side if you see this. Now, if your aorta is more in the front, up here, more ventrally located, as you get lower and lower down, it'll be more ventrally located, then I think it's fine to do a left-sided thoracotomy. Ahmed, how many levels above your level in terms of your thoracotomy do you want to go? If you're doing a T9 vertebrectomy, what level do you want to do your thoracotomy at, Ahmed? Which rib do you take out? Ahmed? Which rib? Your question is, which rib? Yeah, which rib do you take out? T9 vertebrectomy, which rib do you want to cut? You want the one above? Yeah, that's right. About one or two above. Usually, two above as you get lower down, because ribs are sloping down, right? You don't want to go to the T9 rib. That's going to get you down to about T11. So, you really want to go one or two levels above. As you get higher, it's one rib above. When you're lower, it's generally two ribs above. The slope is much, much greater the lower you get down. I tend to use a plain x-ray to localize in the thoracic spine and not fluoro, because as you count, there's a lot of parallax and it's very inaccurate. Neurovascular bundle. Again, as we know, you always want to first dissect away above it, and then you go ahead and separate your rib from the pleura, and then you cut this out. Now, you do not have to do this, but it's great for us as spine surgeons to do this, because you get a great source of, number one, a great source of graft, and number two, your window is much bigger. So, if you've ever done this, it's a very easy operation to do, doing your own thoracotomies, and then you open the pleura. All you have to do is watch that neurovascular bundle. Talk to the patient beforehand and warn them about post-thoracotomy syndrome. They can get significant pain. Put your classic spreader inside. These are all open approaches, standard approaches, not MIS, not new technology. This is just the old-school opening, and then you deflate your lung, and then there's your spine, and then you reconstruct. So, when you do your thoracotomy, so here's your thoracotomy. So, you localized, right? So, you marked out the scapula, localized, and you go in, open your pleura, and this is what you see. So, Gerald O., what are you going to do? What do you see there? What's staring at you, Gerald? Solomon on Dama. What do you see there? That's the lung. So, what do you do, Solomon? Okay, so you tell anesthesia, deflate it. Okay, so, they deflate it. Now, what do you do, Solomon? You need to get down to T10. What is this structure here? Solomon? That's a diaphragm. So, what do you do next? So, your thoracic surgeon says, I opened the chest, see you later. There it is. That's it. Thoracotomy's done. Bye-bye. What do you do next? Bye-bye. So, the important thing is the retractors. So, deflate the lung, push it north, then you're going to push your retractors in. Now, these are the old-school retractors, so now we've got great retractors now, the table-mounted retractors, you can just use an omni-retractor to really hold everything back, but these are two chest retractors here at right angles, and then this large malleable is clamped onto the retractor. So, you're going to push everything, push everything ventrally, and then once you get in, all you see is pleura, and so the way to really identify what your level is, the first thing you want to do is feel the ribs. That's the easiest way and the safest way, because you don't know how ventral you are, so ventral is the safest way to get down there. Then you take your x-rays. Anish, what is this here? Anish? In the right angle. Can you tell? Anish, are you here? Yes. What is this? What's in your way when you do a vertebrectomy from the front? What structure? Melissa Stamatis. Viren Vasudeva. So, who knows what this is? Call it out. Segmental vessel, that's right. So, you've got to take your segmental. Why do you have to take your segmental? Number one, it's in your way. Number two, it's going to bleed on you once you start doing your vertebrectomy. So, there's a bunch of ways to do this. There's a bunch of clips here also, but the clips tend to fall off, so we just use the bipolar. And then again, the whole time, so when you do this vertebrectomy, the key is take off your rib head first, drill down the pedicle, and then you find your spinal cord. Once you find your spinal cord, then you do your vertebrectomy and everything is much, much easier. It's much more slow when you start in the vertebral body and slowly work your way back into the cord, because you don't know where the cord is, you don't know where it's soft, etc, etc. So it's much easier if you can identify the cord first, work your way from the cord out ventrally away. And then here's the reconstruction with the cage and then a plate. So now we're moving down. So L1. So L1, Robert Scranton, are you here? What's the right for L1? And why? Any idea, Robert? No idea? Well, it would be left side. And what's your rationale? Avoid the liver. Avoid the liver? Okay. Jonathan York, do you agree with that? Yeah. You agree? Raise a show of hands, who says right side? Who says left side? Everyone agrees with you. All right, so yeah, I think it's a reasonable thing. So the key is to look for, once you start to get down here, you've got the aorta, you've got your segmentals, and what's the structure here, this number 2, Joseph Spinelli, spleen. So it is much easier to do, especially if you have someone who's got an alcoholic, cirrhotic liver and large liver, it is easier, it tends to do it on the left side, and I think most people do it. But you can do it on the right side, just so you know that. For whatever reason, there's previous tissue, previous scar tissue, on the left side. You can do it on the right side because of the liver, but it is easier to do it from the left side. So when you do your L1 corpectomy from the left, the standard, traditional, historic way to do this is T10 or T11 thoracotomy. And why T11 versus T10? T. Ryan Owens. Any advantage to T10 versus T11? What's the difference? It's exactly right. So when you have a floating rib, it's much more difficult to reconstruct the thoracobdominal area. So if you do a T11 thoracotomy, you really want to make sure that when you do it, you preserve the structure. Remember, it all converges anteriorly. So as you follow that rib head out anteriorly, the points converge. The diaphragm, chest cavity, and anterior abdominal wall all converge in three points. So if you go in and take out that whole T11 rib, you've got to be real careful to put it back together. T10, not so critical because, again, like you said, it's not that convergence of all three points. So if you do a T11 thoracotomy, we tend to leave the anterior tip intact, that very little tip is a convergence of the chest, the diaphragmatic cavity below, and the anterior aspect of the abdominal cavity. So again, if you want to be safe, just go to T10, don't do a floating rib. If you're comfortable doing a floating rib, go ahead and do the T11 thoracotomy. Split the diaphragm. The cruci, remember the cruci inserts into T12, the diaphragm inserts into L1. Always keep that in mind. So if you see the top of the diaphragm, you see the top of the psoas muscle, then you know you're at L1. So this is a standard thoracobdominal approach. Now this is the old-fashioned way that we used to do this. We almost never do this operation anymore. It's extremely morbid, and it opens basically the entire cavity. This is a lady with a 55-degree scoliosis we did many years ago. You can see here's the opening from the chest wall to the abdominal area. When you split the diaphragm, where do you want to split it relative to the chest wall? Osama Kashlan. Where do you want to split the diaphragm relative to the chest wall? Catherine Hoes. Close to the chest wall. How much of a cuff do you want to leave? About two centimeters. And why do you want to leave a cuff? Sew it back together. That's exactly right. So it's really critical. The other thing you have to keep in mind is your phrenic nerve. You see your phrenic nerve is very close to the midpoint. That's why you don't want to split your diaphragm here in the middle, because you'll take out the phrenic nerve. So you're going to split your diaphragm, stay near the chest wall, leave a little cuff, and then remember it's a circular muscle. So you're going to start out here and you're going to split it this way and you're going to come in this way. So you don't want to split here where your phrenic nerve is. So this is, again, you can see right here the retroperitoneal space is exposed. This is all exposed here, and again, very morbid operation. This is the antithesis of MIS here. Spine is exposed. You can see right here, ALL removed, discs removed. In the old days, you used to use these small little cages just as little pivot points, and then we'd stuff bone inside these little cages and then do all your corrective maneuvers from the back. But then again, you can see everything is exposed here. So you've got the chest cavity, the abdominal contents, so everything is exposed. Pretty morbid operation. So now with the newer technology, with a lot of the knowledge that we have of really releasing these spines all posteriorly with MIS techniques, I think that we really don't do this sort of stuff anymore. So L2 and L3 corpectomy, so you're doing a lateral retroperitoneal approach. This right here is the gunjun goel, you hear? So this is cephalad, this is caudad, this is posterior, this is anterior. So you're doing your L2 retroperitoneal approach. You're going to reflect the psoas away from you. Are you going to reflect it dorsally or ventrally? And why? Ventrally. Ventrally? Who agrees with her? Who disagrees with her? Why do you disagree? Lumbar plexus runs through it. That's right. So the lumbar plexus runs through it. So if you take this psoas ventrally, you're going to take all the nerves with you, right? So you're going to destroy the lumbar plexus. So you really want to push everything back. So when anybody's done any direct lateral surgery, this is the stuff we're talking about. This is where people get all their nerve injuries and palsies, etc., because the plexus is inside here, right? And the plexus originates from the neuroforamen back here. So you always want to pull it laterally or dorsally, not medially. You can see this is the classic old-fashioned big exposure. Open everything up. Do your vertebractomy. You can see the nerves coming out this way. So the whole plexus is behind this retractor. So you can see after this surgery, the patient's going to be weak from taking the psoas off the muscle, from pushing on those nerves. It's going to be expected the patient's going to have some weakness after this. So again, when you do your vertebractomy, you always want to see the contralateral nerve root to make sure you've done enough of a vertebractomy. So you want to see all the way to the other side. Put your cage in and then rebuild it. And then again, you can do spondylectomies through this also and then take them out on block. So again, this would be done first from the back, released from the back, and then you pull it out on block from the front. But same thing. You want to push the diaphragm posteriorly and not anteriorly. So the last one is going to be L4-L5. So why would you not want to do this in the lateral position if you need to do vertebractomy here? Bartos, Grobelni? Pelvis? What else? That's a good answer. What else? Any other structure that's in your way as you come laterally here? Great vessels. Are there great vessels there? What else? Who could help him? Plexus. And what else? Iliacs. And then what's this big? How thick this thing gets here? So it's just massive down here, right? So when you get down there, that thing is so huge, right? So it is unwieldy. So you really want to think about when you do these anterior approaches, once you get down to L4-L5, and you're going to do a full vertebractomy, not a discectomy, not a direct lateral interbody fusion, but a full vertebractomy, you also want to think about doing this in the anterior position. So you're going to do a full vertebractomy, right? So you're going to do a full vertebractomy, not a discectomy, not a direct lateral interbody fusion, but a full vertebractomy. So you really want to think about when you do these anterior approaches, once you get down to L4-L5, and you're going to do a full vertebractomy, not a discectomy, not a direct lateral interbody fusion, but a full vertebractomy, you also want to think about doing this in the anterior position. So again, do you remember the arcuate line from your anatomy first year of medical school? What happens below versus above this line, Prayaj Patel? The arcuate line for your abdominal wall. Veeran Vasudeva. Chun Po Yen. That's exactly right. So what happens is, remember, you've always got to keep in mind the rectus sheath is split. The rectus sheath is split above this line, and then below it's not. So when you close your abdominal fascia, if your vascular surgeon, like my vascular surgeon, leaves the room and says you close it up, when you close it, are you going to get the anterior or the posterior rectus sheath? Where's the strength? Andrew, you. Anterior. Anterior sheath, exactly right. So it's really important. You've got to go back to these fundamentals. So you can't rely fully on your axial surgeon. Again, when you talk about the L4-5 anterior spine, again, the big problem is the iliolumbar vein. That's the one thing that's going to prevent you from moving everything aside. When you go to L4-5, really make sure that L4-5 iliolumbar vein is taken. So this is an example here. Again, perimedian skin incision. And again, same thing. You've got to know your anatomy here. This is the anterior rectus sheath. We're going to dissect out and we're going to find the retroperitoneum. When you push the retroperitoneum immediately, does the ureter go with the retroperitoneum or does it stay back along the abdominal wall? J. Kevin Cooper. I think it goes with it. That's exactly right. So the ureter is going to go with your peritoneum. So make sure you know that so the ureter will be swept with your peritoneum. And then again, you can see your iliac vessels here. Again, this is an L4 vertebrectomy. For L4, you want to work above the bifurcation. And then right here, here's an L4 corpectomy. You can see you're working above the bifurcation. And you can see this psoas muscle here, which you would have had to deal with if you did a lumbar lateral approach. You don't really have to deal with it. It's really just the vessels. So if you do a full vertebrectomy, you get a beautiful view from a direct supine position go all the way down to dura, rebuild the spinal column. This is L5 here. This is the sacrum. This is the L4, different case. So you can see right here that you're right below the bifurcation. Just like doing a 5-1-A lift. Very, very straightforward. And then go all the way back to the neuroelements and then reconstruct the spinal column. So in conclusion, standard anterior approaches vary depending upon the level. Knowledge of the anatomy is critical even if you have an access surgeon. And preoperative planning is important to ensure proper access. Thanks. Any questions? ??

thoracolumbar spine

anterior anatomy

anterior physiology

ACDF

thoracotomy

corpectomy