We'll go over some things. Obviously, this is going to be about anti-approaches, both for deformity, but in general, anti-approaches and the issues that they are in. So we'll kind of touch base on this. And this is stuff that I guess if we have time maybe tomorrow in the lab, we can, if anyone wants to grab me, I'm happy to take them through a thoracotomy or sternotomy or something like that. Not that we do sternotomies for deformity. So here's a patient with a scoliosis. And the issue is that in most cases, I mean we talked about, I talked about coronal this morning, but obviously you can see by the next five speakers, sagittal really is the king in terms of disability. And I would say that corollary to that is that posterior approaches rule now. And they're not, so the anti-approaches for deformity are not as common, unless you're doing a minimally invasive lateral approach, right? Which is now one way to get that anti-approach without the fear of the exposure, of the approach. So the landscape is changing, and I gave this talk a few days ago, and I'd say it's even more, this is even more underlined in terms of, I made the comment years ago that the landscape is changing. Now it's pretty much changed where really posterior interpretation is dominant. But anterior access can be done less invasively. And so indications for the anterior approach, if you want to do a full discectomy, truly full discectomy, you can go from the front, like an A-lift approach, really get the, you can improve the curve correction. So if you combine it with a posterior approach, you can do that anterior as well. You can improve your effusion if you have a larger inner body. In the old days, we used to bring this thing up called a crankshaft, which is really when the implants, where the segmental fixation was not as rigid. And so as the patient grew, the anterior column would grow and the posterior elements would not, because you fuse in the back and anterior would prevent that but really with the type of instrumentation we use and how rigid it is, that's not really an issue. And then some people, they felt this was the definitive treatment for say, a single major curve, like a main thoracic curve where you could just do this all from the front without screws and maybe save some levels. All right. And then in the setting of adolescent hepatic sclerosis, some of these approaches that were used in the past, you could do things called epithysiodesis, which would really be stop the growth plate on one side, on the concave side, on the convex side, and then the other side would catch up with it. That was one thing. And that would allow excessive growth. That was probably the most minimally invasive way to do these approaches. But you of course required people to live a certain amount. So it was done on very young children. There's things called staples, intervertebral staples, where you can go in thoracoscopically. For small curves, these are curves that often we don't suggest fusions on. And for children who are very young, and you could do things like this, where you put nitinol staples in, you put the patient in a position that decreases their curve. So for example, their convexity would be up and you put them on a table and you put the staples on and it would be a fusionless stability. It would be a fusionless type of approach. And so here you can see some of this. But once again, you can argue that maybe you wouldn't even touch this patient in the first place, right? For the curve that's less than 30 degrees, just like that. And then as people started using the Lenke classification, they would say the main thoracic curves are really the ones where you can go in the front and maybe save a level instead of going in the back. So let's take a look at these. The reason that some people said that other reason to go in from the front is that there's potential problems going in the posterior. Untreated thoracic hypokliposis will go into that. Crankshaft, really not really an issue. And really more levels in the back. So if you go in the back and really wanna cover your cob, maybe you have to go a couple levels more in the back than you have to go in the front. And some people argue that it's not as big a case anymore. Maybe save one level at max if you're gonna save that. This has been looked at and if you look at all the studies that really looked at this, they're all older studies, okay? This is when people were really doing a lot of stuff anteriorly. So you're looking really in the 1990s when they were comparing surgeons who did both, both posterior and both anterior and saying which one's come out better. And they look at saying, hey, coronally and saginally, not much of a difference. Hammerberg said maybe anterior stays an average of 2.3 segments because he would try to cover his whole cob and go a little bit longer if he went in the back versus going in the front. And then we looked at some of these approaches. Now, the original thoracotomy approach to do a big thoracic scoliosis really was an approach that's been around for decades, for over 50 years. You can use a double lumen tube. I do not ask them to use a double lumen tube. When I do cases, they always ask me for thoracotomies, majority of which are not deformity-related or tumor-related. They always ask this. You don't necessarily need it. You approach the pathology on whatever side it gives you. However, there are landmarks in your way. So I'll ask people in a second. Last, often people use the 10th row approach and you can use a number of ways to treat this. So this is in general how you want to look at the 10th row approach in the chest for a lateral approach, okay? So when we say anterior approaches, we really mean anterolateral in the majority of cases, right? The only times we mean true anterior is up high, which is called a, when it's the here, midline sternotomy or some variation, or when we go midline down the bottom, midline laparotomy, which is usually retroperitoneal but can be transperineal. I just did a transperine until a few weeks ago because the guy couldn't get a retroperitoneal and they are more painful and you need an access surgeon. But in general, you're going to look at your rib selection really when you're up high, the ribs are pretty flat. So they match the level. And as you get a little lower, usually landing on a rib that's about one above the actual level. So you're hitting on T7 rib, but you're going at T8, for example. And then as you get lower, they can be even two more down. So you hit 10th rib might actually be on L1 or something like that, or T12. Okay, and this is the kind of idea. If you look here, you can see the ribs pretty flat. So if you were to take an L5 or an L4, I'm sorry, a T4 or T5, you're going to be close to that arterial level. As you go down, there's a slanting of the ribs. And so when you hit the rib much lateral, you're going to be much lower than you are at the corresponding. And these are the things that you got to think about, okay? So people always say, which side do you go on? You go on the side of pathology. And in general deformity, you're going to go on the side of the convexity in the old days. Now you don't have to necessarily do that with some of the minimally invasive ways we can do things if we can crack things open. But that's how it used to be done. And these are things you got in your way, all right? On the left side, the aorta was in your way. Up high, the arch of the aorta was in your way. Okay, as you go lower down, I always like going on the side of the aorta because you can push on that thing, okay? People say it's easier to repair the aorta than repair the vena cava. If anyone has been here with an aortic injury or vena cava injury, I'm on both, okay? I don't know what you're doing with this whole thing about it's easier to sew an aorta. I guess so. But if you look into a fire hydrant, it's not easy to sew anything. So in general, you want to avoid getting into either of these, but sometimes the aorta is easy to skeletonize and easier to rotate. That's the issue, not this whole, it's easier to sew. And the people who usually say that aren't sewing aortas together. Azagus is basically the vein that's contralateral to usually the contralateral to the vena cava. Sympathetic chain, I take it, and there's no issue there. Scapula, as you go above T7, you will hit the shoulder blade and that has to be mobilized above. And of course, the diaphragm comes on your spine at where the diaphragm inserts. So really, the issue is location of the primary pathology, usually convexity for deformity. Prior surgery, you go to the opposite side, upper thoracic spine. You're gonna go on the right because there's a big pump in the middle on your left side. The heart's gonna be in your way. And in general, as you get thoracolumbar, the liver's often in your way on the right, okay? Here you see some of the aspects of it. Aorta's on your left. Azagus is right next to the aorta below, and that's usually on your right. What you don't see here is the massive liver on the right, which cannot be retracted. So most of us go on the left side. And here you have people positioned. And this is the kind of incision that you make and you'd shoot an X-ray. This is a high postolateral thoracotomy versus a standard postolateral thoracotomy. This is a high one, meaning that you've gotta get close to the seventh rib, which is right at usually the tip of the scapula, sixth or seventh rib. And so if you wanted to take a rib resection that's up here, you would make a skin incision here and you'd use a scapular retractor and lift the scapula up and take the rib from under the scapular, take some of the rhomboids out, okay? That's if you wanted to go high. You take your latissimus dorsi, you take your rhomboids, and now you have this nice plane that you can even see on the posterior. You can run your hand all the way up, thoracic surgeons can run their hand all the way up and down the thoracic rib cage under the plane of the posterior shoulder girdle muscle. So if you do something like this on a, like I said, in more of an older way that we've done this, you can do this type of approach for a focal or a main thoracic curve, okay? As you get bigger and bigger, this is gonna be a much more larger procedure to do. So if you have a thoracolumbar approach, the curve is lower, it's not a main thoracic curve, it's something lower. You're thinking about a thoracolumbar approach, which means you gotta take down, what do you gotta take down in a thoracolumbar approach? What divides the thorax and the lumbar? Diaphragm. Diaphragm, so you have to take down the diaphragm in some way or deal with it in some way, whether you go retroplural and retrodiaphragmatic and retroperitoneal, but often it's much more, you usually don't have a nice plane that you can dissect there, but same idea. Usually come on a 10-through approach, you see a rib, you take your rib, you dissect it with any of your various elevators, whether it's an Alexander or a Doyen retractors here, here are Alexanders, here are your Doyen, pigtail elevators. You take the rib, you can use it as graft. You come through, classically come through the pleura. I don't, I try to avoid going through the pleura now. I actually try everything retroplural now, but this is at least the way that we used to do this or still do this in many cases. And then you see the lung and push the lung out of the way. And then you get a view. You don't get a view like this. This is the view you get if you go retroplural, where you see the segmentals, you see the sympathetic chains, and I think I have a picture on my phone that's not a great picture, but when you go retroplural, you see it look like this. If you don't, you often see something that's much more covered up with parietal pleura and you have to cut through that and find your segmentals. This is something like you see. You can kittener off this and you can get to the levels and do discectomies, inner bodies, cages, or vertebrectomies if needed, okay? And then you can close up your ribs with a rib approximator. In an effort to avoid these big operations, these big transcarotid approaches, people tried to use thoracoscopy for deformity specifically and this needed, you needed a number of set of tools. It wasn't just like taking a paraspinal tumor off the spine. It wasn't like doing a corpectomy where you just need a little access. You actually had to be able to manipulate the spine so you had to have a number of tools, which makes it harder, I think, thoroscopically for deformity. And a number of these authors published on this, but if you ask these authors, they really don't do this procedure anymore. So it's something that was shown to be technically feasible and done, but it's probably more work than a lot of surgeons are willing to do. So you do things like this, use fluoro, plan your cob angles, make ports, and you can have something like this cartoon where you have a fan for the lung, a suction, and then a number of other things, camera and such. And then you can do things like this. You can have certain bipolar cortery that they take the segmentals. You can put screws in the area and then you have all these different bayoneted type thoracoscopic instruments where you can align your heads and then you can drop a rod in. And then what's nice is they had these cool little segmental compressors that they could compress at each level. You can imagine the technical issues of doing this minimally invasive, which is just like any other minimally invasive case, you just gotta get used to it. But these were much more challenging. The contraindications to doing this type of thing were obviously if you had to work really high, really tough to work up high in the chest, you just don't have any room. So if anyone says, oh, I do a post-operative thoracotomy for a T3 lesion, people bring that up sometimes. I say, that's awesome. You must be able to dunk a basketball through your legs because I cannot do a post-operative thoracotomy at T3. Most of us are doing post-lateral in the back, costotransversectomy or sternotomy or just anterior. And if these patients are very kyphotic, you wouldn't go in the front because that actually creates more kyphosis in prior chest surgery. So when these were compared, you saw that, when they looked at this, they showed their pre-op, they showed their post-op, they were happy with it. Blanke and Kuklo were involved with Sukato-Newton-Betts. These are all big pediatric deformity surgeons and they found that they were happy with this. In terms of adult deformity, which is what most of us are looking at in terms of neurosurgeons in the group, we don't often see as much pediatrics. We do use anterior, but we don't do it the same way. We don't do it for main thoracic curves. We do it for anterior releases. We either do in combination with things that we're gonna do in the back, put a big plug in the front or release it so we make it more mobile. And like I think maybe Praveen had shown somewhere, he'd done some inner bodies in the front and then did a deformity in the back. And this is kind of where we're staying with adults. And this is a slide bar from Mike Wang, who basically had this very simple cartoon. I said this really sums it up for me. And this is the comparison between peds and adults. In children, you basically have, if you imagine the rod being your lever arm, your ability to leverage on the spine. It's a pretty robust lever. You can put in screws into a kid and pull them to the rod, and they will just hold together. And they're flexible. So here you have a very strong rod. You can push on hard bone. And usually they're flexible, so the force you have to put is not that much. Where an adult, they're, yeah, that's right. Adult often has a lot more force you have to put on because they're rigid. Yet their bone is bad. So it really is the combination that makes it very difficult. So what does that mean? More releases, ligamentous and bony, more osteotomies in the adult than the child, who usually is flexible and has strong bone and can come right to the rod. So in light of that, anterior approaches for adults is usually in the form of a release or in the form of something to make fusion better, or in the form of trying to get a larger plug-in anterior to make lower doses of better things. So when do we use it? Ponti or an SPO with an anterior release, getting extra correction, extra fusion, extra support, less pseudo, and rigid curve. So here's a patient who had an anterior-posterior with a large curve in an adult. And this person was approached with an anterior release and then a posterior fusion to try to work on those. And these are some of the numbers. I think someone else will be talking about these. But the idea being that if one goes anterior, you can get more. So we always remember these numbers, PSO. And my fellows come in. I was telling some guys at the table that my fellows come in saying, we need 30 degrees. We need 50 degrees. We need a PSO. And I say, is the patient fused or not? No, they're not fused at all. Well, then why are we doing PSO? We're not doing it just for the measure. We're doing it for also how rigid it is. So if you can add an anterior, whether it's a T-lift or an A- lift or a lateral approach, with a posterior-compressive approach, you can get an SPO or a Ponti to turn into something more like 15 degrees. And if that's at the 5-1 junction, you can get 20, 25 degrees, potentially. And these are some of the lateral approaches. I think Charlie's going to talk about this. But you can take patients like this and do trans-PSOIS or dock on top of the PSOIS. You're still going to go through the PSOIS with most of these minimally invasive approaches, as opposed to pulling the PSOIS backward, like a standard retroperitoneal approach, and placing K-wires and doing monitoring during this process. And this is the exposure you have. And if this is what you want to do, do discectomies, this approach is fantastic. If you want to do corpectomies, it's a little more challenging and may require a little bit longer incision. So my incisions now are mini-opens for retroperitoneal to do corpectomies. But they're not true MIS, and they're not true what I used to do when I first was trained. And these are the types of things. Doing discectomy, I'm going to let Charlie talk about this, so I don't have to have to steal that thorn from him. But obviously, what he'll go into is that when you do minimally invasive anterior approaches from a lateral approach, it is going to be based purely on fluoro, or largely on fluoro. And you have to have everything lined up both laterally and anteriorly. And you have to have the ability to see everything through your fluoroscope. But this is the idea. You can do something in the front where you get a lot of lordosis at multiple levels so that you can fuse this gentleman without having to do a closing wedge osteotomy or pontes and maybe not get enough in him. Posterior supplementation, you can go anterior, and then you can stabilize, like I did on the last one. What to expect post-op. In general, if you're going to screw around with the psoas muscle as you go anterior in the lumbar area, you're going to have to deal with the psoas issues. Patients often will have some weakness of their psoas. That is usually just from tagging it a little bit, but they may not complain of the paresthesias. Going trans, that's if you pull the psoas backwards. If you go through the psoas muscle, you're likely going to have some sensory issues because we do not monitor for that. We're doing EMG, which is motor. So those patients, if you look at the data on the first papers that came on this, this was remarked as being very small, and what we found is that as we do more, we're finding that these patients are having issues that if you tell them, they're willing to accept potentially. Ephemeral weakness is a catastrophic weakness because patients cannot lock their, if they cannot lock their knee up, they can't stand. So when I give a different talk on on blocks and I say, what nerve roots can you take? I was at Double Nest and I gave one, and someone raised their hand and said, what are you talking about? You're a neurosurgeon. What do you mean take nerve roots? You're not supposed to take any nerve root. I said, wow, I guess I'm not going to do any post-op thoracotomy, the cost of transversectomy approaches without taking thoracic roots. I guess I can't take a C2 nerve root to take care of someone's, so the issue, I didn't say it that way, but I'm just saying that the issue is that there are more, we can take nerve roots with impunity. You cannot take C8, C5. You cannot take CAT1. Patients can get away with a C7 nerve root probably. L3, L4 in the lumbar spine is catastrophic. Can patients walk with a foot drop? Yeah. Can patients walk with plantar flexion weakness? Yeah. Do a total sacroectomy takes S1 roots? For some reason, they still have plantar flexion strength. So the issue is that if you go trans psoas and your motor monitoring is off, and I don't want to take Charlie's Thunder, that is huge because ephemeral neuropathy is something where patients often have problems walking. So the lateral is becoming more familiar to most spine surgeons, and there's less need for an axis surgeon, but the problem is traditionally cannot approach the L5-S1. There are a number of companies that are now shifting their lumbar lateral to a little bit more anterior so they can have L5-1 from a lateral approach, and that's being more of, it's almost like a modified ALIF. And then ALIF is great, and I think Tyler showed a case where he gave a lot of lordosis back to a patient by going at L5-1, and that's a huge workhorse for me. So this is the kind of approach you'll see. This is actually a transperitoneal approach because you're seeing guts and omentum. But in general, what you're gonna do is classically go retroperitoneal on these, and if you go transperitoneal and you don't have an axis surgeon, just set your stopwatch to that hernia or whatever else you're gonna get that is gonna come and they're gonna say, why don't you have help? So if you go transperitoneal, I think unless you're generally surgery trained, I don't think it's a good idea. Retroperitoneal, we do ourselves regularly. But this is a great axis, great size graft, great discectomy, and if you have preoperatively looked at your vessels and you have access to the discs, you can do a great deal. Here's a patient, a 56-year-old lady who was treated at an outside hospital for AIS as an adult, so as a 54 or whatever, and she had some improvement in her leg pain, worsening back pain, and a surgical site infection, and then broke her rods, and she's got some rods broken here, and she's got some positive sagittal balance there on her standing films, and the recommendation by the treating surgeon was to extend and put more screws in the upper thoracic spine to help her balance. What, you're shaking your head. You don't like that plan? He said, if we go higher, we'll be able to pull you back with the, did Dr. Smith teach you anything, or what do you think? Tell me what's going on. That's exactly right, my friend. She's got a lumbosacral kyphosis, so in your mind's eye, for me, it's just in my, I haven't asked anyone this, if you were to create a patient with a good plumb line on this patient by going up higher, I can't even conceive, maybe you can conceive what they'd look like after you did that. I mean, what would they have, a VCR up here, and then you'd pull them back, and they'd be positive, and they'd be negative? I mean, it would really be, if you actually obtain that, it would be very, very challenging to obtain, and then if you actually achieved your goal, it would not be ideal, right? So just like you said, it would be a lumbosacral. So you look at this, and this person had biologics used, and they had this massive macho infusion from basically T10 down to the L5, and then had a pseudo, like you said, and the rod was broken right next to that. So if you look at her numbers, her PI is 65, which is broken down to basically a 20-degree slope, and a pelvic tilt of 45. Pelvic tilt, 45, good, bad, okay? Not good. Not good? Like how not good? Like not good, like B plus not good, or like F? Yeah, good. So pelvic tilt of 45, and that's strong. That's strong work. That's strong rotational on the pelvis. Now, her lumbar lordosis, back to, I think, the original comment, I think, that maybe even Bob brought up about just how much lumbar lordosis is normal, maybe even pervene, 32 degrees. Maybe that's pretty good. That's pretty good for most people. Maybe it's in some range. Not with a PI of 65, right? So she's a mismatch. Now, if you look at her L5-S1, like you said, sir, she's actually kyphotic at L5-S1. In general, what's a good amount of lordosis? What's a robust disc in a lot of people? What's the range of a robust disc? Justin just said, don't measure to the bottom of L5. Measure the top of S1. Why? What's a normal, healthy-looking disc? Yeah, you could get 15 degrees, maybe even more. So the issue is that this patient's positive eight degrees, and maybe she live in, before that was 15, she's maybe 20 degrees off or more just at one segment. So basically, from an anterior approach, you look at this lady and say, does she need a PSO? Well, she's all fused to that. That's an option. Or you can go anterior on this patient, right? So the goal is really to obtain a fusion of 5-1 increased lordosis by 30 degrees to make the match. So what we did is I did a three stage where I went in the back and took all this stuff out. And then I did an A-lift. And then I saw how much I got. And then we were able to do without very much in the back. Go for it. Yeah. When you went from the front, were you able to get it fully loose? Yes. I find the challenge on these, when you're trying to do the back, front, back, is getting it loose enough from the back that when you go from the front, you'll be able to get it correct. I did my ponties at that level. I did fascitectomies, whatever was there, just to loosen it up because I was fearful of that. So then when you went to the front, you were able to kind of crank it open? Right. And I'll show you what we did. And the thing is, she also had this infection. So she had this ID doctor who had said, I'm gonna be on lifelong prophylaxis for the infection around my hardware. So I just went in the back and changed everything out quickly. Took out and worked at the bottom, loosened it up, and then did an A-lift. And for A-lifts, I use femoral autograph and I take an oscillating saw and I cut it. So back to all these measurements, is I plan, like you're talking about measurements. I say, with that almost surgery mapping type way, I wanna make a wedge and then I just, I make it happen. So far, so good, where you kind of plan. So here's what she looks like with a marking pen. You can see the staples on the back with a marking needle. And then you get this, you can see this kind of mortised femoral. So you go down to your bone bank and they have femoral struts there that are like 100 bucks. Or you get the one fashioned by the companies who are very thankful for you coming here, which by cutting them for you are orders of magnitude higher. I don't know if that's an issue, but maybe. So anyway, you get the femoral strut, you cut it and you slide it in. And then you can put some little, a little plate over it, or these are also cheap cause they're just little frag screws from the ortho set. And then you put that in. And then now you look there and you say, okay, she's got this other stuff going on above. I guess I took everything out. Wow, I must've left her out, yeah. And then I went back in the front. So she's still, I did not change her coronal here because I would have to break through this. So I said, let's see how you stand. And her coronal balance was actually good and she's super happy. But if the key, the key is because the lumbar lobes end up being pretty darn close to what we shot for. And we went to negative 25 here, which was in positive AP4. So I really did no other deformity maneuvers except an anterior approach. So although we're getting really good at doing posterior approaches and a lady with a fusion who has one level that's bad and it's at the bottom, it's a huge multiplier, right? Go to the bottom, you can get as much as you want. A-lifts in my practice are a nice workhorse to supplement. So I have a lady coming up, I'm going to do an A-lift and then I'm going to do a PSO because she needs like 50 degrees. But I'm going to get a lot of that A-lift. So these are the kinds of patients that, that anterior approaches may be good in an adult setting. So you take someone like this, you do an A-lift and you get them back just from that. There's no other, there were no other maneuvers done to shorten her spine from one A-lift. So the anterior approaches can be nice. The lateral approaches can be good, although we talked about them being often very good for chronal and maybe not as good until more recently for sagittal. As we get more lordotic segments, you may show those. Those can also give you some lordosis. So the summary of anterior procedure deformity, you should be familiar with them in general, okay? If you're, especially if you're a complex spine surgeon, you've got to take care of pus or tumor or fractures. You should be familiar with these and have a good access surgery if you don't do them yourselves. They're used less and less with AIS. I showed you for historical purposes, but really not being done much. They're using a lot now for Degen. And as you know, as you raise your hands, it's really in the minimally invasive way to do lumbar lateral approaches, but A-lifts are great as well. Thank you.

deformity

general surgery

thoracotomy

minimally invasive lateral approaches

complications

anterior approaches