Hello, my name is Tyler Kosky. I'm going to be giving a talk today on complication, avoidance, and adult deformity surgery. I work at Northwestern University. I'm an associate professor and the director of the Neurological Spine Surgery Program as well as the director of that Spinal Deformity Fellowship. Before we start, I do have a few disclosures. There are some device companies obviously on here. Spinal deformity is a device-heavy industry, but none of the complications or treatments I will be talking about today are in any way specific to any company, nor will any specific devices be mentioned. So when we talk about adult spinal deformity, we're talking about scoliosis, which can be de novo or degenerative scoliosis, which we all see quite commonly. Adult idiopathic scoliosis, which is essentially teenager scoliosis that grew up and now has degenerative changes on top of that, or iatrogenic deformities, which we certainly are seeing at a reasonable rate these days, kyphosis, and then sagittal plane imbalance. Commonly we see that as a flat back deformity, which can happen on its own as a result of some other conditions, or it can be a post-surgical situation as well. The reason we talk about complication rates in deformity surgery is that they are significant. Complications are definitely high. This is generally a large surgery, fusing many spinal levels, and has a high complication rate. I've got just a couple of quick papers to point out some of those rates. This is a study done on the National Inpatient Sample. Now it's a database query, so we all know that when you retrospectively look at a database, your complication rates are generally under-reported, but this was a large number of patients, 9,000-plus primary patients and 850 revision patients. They found a 47% complication rate in the primary cases and a 72% complication rate in the revision cases. These are all complications. Those numbers are high, but they're particularly high when you realize that those are likely significantly under-reported in that retrospective study. There was a very nice study done out of Vancouver. They looked at a 12-month prospectively collected registry. They had 942 patients. These are not just spinal deformity patients. These are all complex spine surgeries, however. It's a single center consecutive series, and 58% of those were elective. So there was a large proportion that had some trauma or tumor involved as well. So it was complex surgeries, but not significantly only a deformity series, but it does give us some ideas of what the complication rates can be. Interestingly, they looked at their complication rates for the year before. So they went back and did a retrospective study for the year prior and found a 23% complication rate. When they went and studied that prospectively, they found an 87% of the patients had at least one complication. They had 14 mortalities, intraoperative adverse events were 14%, so that number is quite high when you think about adverse events happening in the operating room. That is always a stressful situation, so that is significant. In their deformity patients, they had a neurologic deterioration rate of 5.3%. That's actually less than some of the larger studies that are coming out now are showing, particularly studies such as the Scholey risk study. And their dural tear rate was 4.5%, which would be consistent with what the literature would have previously told you. Now I always put this slide up in my deformity talks, and it's my steps to correct a deformity. I tend to think through things in a systematic way, and this is how I look at a deformity. Now oftentimes when I give a talk, I will go and talk specifically about a certain subset of these. Today we're talking about complications. So complications can arise from all sorts of areas, and we're going to touch on that. So this talks about the preoperative area where identifying the deformity, then planning your surgery, and some of the things you do intraoperatively to correct that deformity and get that patient to have a good outcome. So when we think about complications, where do the complications occur? Well, they happen in surgery, the intraoperative complications, or they happen postoperatively. But that's not the full story. Now if you look at the picture that we see there, obviously if you put a screw through the S1 nerve root, that's an intraoperative complication. No amount of planning or pre-procedural work would really prevent you from doing that. That's just a poor execution of the technique. That is a technical error and a lack of judgment at that time. Now a lot of complications, however, have their roots in a preoperative evaluation, whether that's an inadequate medical evaluation or a suboptimal surgical plan, and we'll talk a little bit about those. So really getting the patient prepped for surgery is the key to reducing your complication rate. So when we talk about preoperative complications, well, an inadequate assessment of the alignment, underestimating what you need or not planning a surgery correctly to generate the lordosis that you need is a big factor in somebody getting a postoperative sagittal plane imbalance like you see in the upper right-hand corner there. Inadequate medical optimization is another key, so we send patients for medical evaluation. Oftentimes people would talk about medical clearance. I'm never interested in medical clearance. I'm interested in medical optimization, and it really is working with your medical doctors and colleagues to make sure those patients do everything they can to get the best possible outcome. And then an inadequate evaluation of bone health is a big factor. If you look at that lower picture that I have there, that is a significant pseudoarthrosis on a patient that had a lumbosacral fusion. You can see they had a big iliac crest bone graft there, which when it comes to revision further complicates things, but those are significantly haloed out screws, and when we did a DEXA scan on this patient, she ended up having a T-score of negative 3.0, so it's no surprise that she developed such a significant early loosening of her instrumentation. Now intraoperatively, positioning is something that is oftentimes overlooked, so poor positioning is oftentimes something you will see with inadequate correction. If you do a fusion like this patient is here on a Wilson frame, you should expect to lose some lordosis, and if you do a multilevel fusion, you should not be surprised when you end up with an iatrogenic flatback deformity. Positioning the patient on the appropriate table with their abdomen hanging free, with pressure points appropriately padded, with their nerves padded, you know, an ulnar neuropathy on a surgery that can take 6, 7, or 8 hours, if you don't position those arms correctly, you are at high risk for getting a nerve palsy, and ischemic optic neuropathy obviously is something that we all fear as spine surgeons, fortunately that rate is very rare, but we know increasing surgery time, prone position, and excessive blood loss are risk factors for ischemic optic neuropathy, deformity surgery has all of those, so you need to pay attention to that. Other intraoperative things, poor hemostasis is key, we know that blood loss leads to transfusion, and transfusion rates are directly tied to increased complication rates, poor tissue handling or leaving retractors on too long or too tight, leading to ischemic injury of the musculature, increases your infection rate, increases your wound dehiscence rate, malposition of implants speaks for itself, dural tears and spinal cord or nerve root injury are obviously significant intraoperative complications that can be technical errors, we need to pay close attention to those. Postoperative complications, inadequate VTE prevention is key, so having sequential compression devices in the operating room before anesthesia starts, using chemoprophylaxis, which at Northwestern we have a protocol that gives everybody, unless they have a contraindication, they get low molecular weight heparin starting on postoperative day number one, and early ambulation is probably the most important to reduce this complication in the long term, inadequate nutrition is something that we really don't focus on often enough in my mind, making sure the patients are optimized pre-surgically, and then after surgery making sure we're getting adequate nutrition in them is key to get those wounds to heal in a timely fashion, poor wound and drain management, obviously when we have issues such as drains disconnecting or leaking around drains and that not being paid attention to, that's something we tend to try and really teach our residents and fellows that we need to be very vigilant about wound and drain management, keeping things clean and dry, particularly with lower lumbar wounds, which can be easily contaminated, and then a lack of supportive services is something we don't think about very often, but we can manage the patient really well in the hospital, but if they have no support when they get out of the hospital, they're going to have a much much harder time and their readmission rate is going to be significantly higher and their complication rate is going to be higher as well. So how do we reduce these complications? Well I always think about it as what are the modifiable versus the unmodifiable risk factors? If I have a patient that's 78 years of age, I can't do anything about the age, but we can work on bone density, we can work on malnutrition, we can work on frailty, we can do lots of things to try and modify those risk factors to give that patient the best possible outcome. When I think about modifiable risk factors, patient selection is probably the most modifiable risk factor, so making sure you're picking the right patient for that surgery, the patient needs the operation you're planning and that you can execute that operation are really the starting point for all this discussion. But once we select those patients and think they would benefit from a surgery we can provide to them, we need to work on some other factors. So smoking status, we make everybody stop smoking and pass a urine nicotine screen. Mental health is key, it is overlooked, but it is well known that patients with untreated depression and anxiety have significantly more difficulties recovering from major surgery and their overall outcomes are lower when you look at their scores compared to the patients that have treated or know anxiety or depression. Bone health, checking bone density, using a CT scan and looking at Hounsfield units are something I do for every fusion patient, unless they are a low risk young male or something that would be unnecessary to check that, but it's something I'm always looking for. Working on obesity and their nutritional status, those are two things you can have, unfortunately both of those, you can be both obese and nutritionally depleted, so we need to make sure we're working on that as well. Mercy decolonization, we use Hibiclens showers or baths for five days pre-surgery and we use intranasal muporosin as part of our standard protocol for anybody undergoing spine surgery. We do not do a standard nasal swab and culture, we just treat everyone that's getting instrumented fusion. Surgical planning, the three column osteotomy is something that really came into favor over the last decade. The numbers skyrocketed and the complications went up with them. So I'll show you a little bit later some data where three column osteotomy has a significantly higher complication rate than smaller posterior column osteotomies and those are really only necessary if you have a fused spine. So if somebody has a fixed sagittal plane imbalance, three column osteotomies can do wonders, but they are not the appropriate operation in somebody that has a still mobile spine that you need a fair amount of correction. Smaller posterior column osteotomies in multiple segments or the possibility of anterior interbodies will oftentimes get you the same result with a lower complication rate. Getting appropriate correction is key. Planning software is helping people to do some preoperative planning, but then making sure you get that appropriate correction in surgery is key. And then PGK prevention strategies are certainly important in adult deformity. Those are more long-term complications, but those are certainly key and multi-rod constructs have come into favor. I certainly am using three rods on all of my adult deformities. Basically that's to make sure we get the patient the optimal time for bone healing before they break down some of these constructs. Rod fracture, even with cobalt chromium rods, which we all thought were going to be a big improvement over traditional titanium rods or the previous stainless steel rods, really doesn't seem to hold true. They can fracture just like the other ones. So don't rely on the rods only. We need to get good solid fusion, but a multi-rod construct can help reduce the risk of rod fracture. So our Northwestern preoperative guidelines, all of our patients, we want a hemoglobin of greater than 11, BMI of less than 35, and that's a strict criteria, vitamin D of greater than 30, hemoglobin A1C of less than 7.5, and an albumin of greater than 3.5. The albumin is a lab screen, but there's some controversy whether that is really a value in a nutrition screen. So we have a low threshold to send them for a formal nutrition screen if there's any concern. Our patients have to be urine nicotine negative, and we want them medically optimized with the protocol we'll discuss in a little bit. We do a frailty screening, nutrition screening through that process on these patients. So some of the modifiable factors intraoperatively, you want to minimize blood loss. Make sure you have an experienced team. There's some data about two attending surgeons or making sure you have an experienced resident or fellow with you through the critical portions of that operation can make a big difference in terms of operative time. Anesthesia experience and managing blood pressure and managing coagulopathy is key. Transoxemic acid is a mainstay in some of the deformity patients. Dosing is variable, but something that we certainly utilize whenever it's not contraindicated. Minimizing durotomy. Durotomy slows down your surgery, leads to epidural venous bleeding, and really can increase your blood loss and your operative time, which increases your complication rate. Retracting the neural elements. That's some experience that's paying attention to everybody that's in the operating room Not just what you're doing what your assistants doing when they're retracting You're doing something else. You need to make sure you're watching what they're doing and protect the neural elements at all times using Multimodality neural monitoring is really a standard these days and infection prevention We know vancomycin powder and good Intramural irrigation to the procedure can help lower those risks as well And finally, did you accomplish your alignment goals? It is difficult to measure intraoperatively But so you really need to work hard to make sure you accomplish the goals you set out in that surgery to make sure you Did what you thought that patient? So in the post-operative model Modifiable factors make sure you're getting your medicine team involved early so they can be watching out for those medical Complications that you might not be so in tuned with DVT prophylaxis mechanical prophylaxis Definitely chemo prophylaxis that is still a little bit surgeon dependent Like I said earlier we start low molecular weight heparin on post-operative day number one And we have not seen an increase in epidural hematomas with that protocol And we have a study of over 4,000 patients that we've published on that early ambulation and then having a protocol So we talked about those alignment goals and I talked about making sure we can check them What do we try and do coronal we want to we want them balanced? We want a stable balanced spine. So there's c7 and s1 Line up so your center sacral vertical line lines up with with c7 that can be difficult to actually measure in surgery I personally scrub out and measure every x-ray to make sure I'm happy with the alignment before we Put the bone graft in and do a final closure Sagittal goals my goals are a c7 plumb line generally less than 5 centimeters You can't measure that in surgery so you can only measure the restoration of lordosis I want my PI Minus lumbar lordosis to be within 10 degrees. I am generally never shooting for over So if my pelvic incidence is 55 degrees, I'm shooting for between 45 and 50 degrees of lumbar lordosis That's generally where I want that to be For most patients the older the patient the more I want that in the 45 range over the 55 range Pelvic tilt we want less than 20 degrees and generally two-thirds of your lordosis should be from l4 to s1 That's something that really has come out of the gap score that I think makes a big difference in terms of overall There's a lordosis distribution index, which I do think is absolutely critical and that's how much of that lordosis is from l4 to s1 Getting it into the natural state With your lordosis where it's supposed to be makes a big difference in junctional kyphosis in my mind And then the relative spinal pelvic alignment is a general alignment goal using an angular measurement If you take all of those and you can score that full disclosure, I don't score this on every patient it is somewhat cumbersome To do but I think the concept is really sound and very good and some of their data When they show the mechanical complications and what they're showing here is if your lordosis Your gap score is is low. You have almost a minimal complication, right? these are mechanical complications and if you're in this 11 12 or 13 range, so the highest Mismatch in terms of what your gap score is. They had 100% rate of mechanical complications in those patients So that's a high number that is certainly significant as I said before Confirming that you achieved your goals can be difficult. This is an example of a preoperative and then a intraoperative Long segment scoliosis film that we do in our institution Getting that film allows me to break out and actually measure that but again That is difficult an on-table x-ray is much harder to measure than an than a standing x-ray in the outpatient clinic But I scrub out and measure that each time myself to try and make sure I think I got everything I was trying to in order to limit it or so limit So when we talk about opportunities for some of these complications, we talked about things we can do to try and modify them Well, we have for the positioning. We have the exposure with poor technique and dissection and and that can be particularly easy to get into some really strange complications and really deformed or highly Or spines that have a lot of previous surgery where the anatomy is simply not What you would expect Screw placement is a whole other talk I could talk about but getting screws into deformer spines can be difficult and is certainly a Place where you could get into trouble But for the sake of this time in this talk, we're going to leave that out Because and unfortunately, I think the screws are actually the easy part of that Osteotomy is we know Add to surgical risk there's bleeding nerve injury and durotomy the more you do the more that risk the more complex They are the more that risk rod placement can lead to malalignment Or if you are overworking your rods with in situ contouring it can lead to construct weakening Arthrodesis poor technique or poor graft material or just poor bone quality in the patient all lead to the long-term risks of sclerosis When you look at some of the complication rate in terms of osteotomies, this was a review the scoliosis Research Society M&M database again It's a retrospective collection. So it's not As good as a prospective database, but they looked at a large series with both PSOs Vertebral columnar section and posterior column osteotomies or what we sometimes will call Smith-Peterson or Ponte osteotomies If you look at the posterior column osteotomies They had 28% complication rate versus 39% in a PSO versus 61% in the vertebral column or section So the more complex the osteotomy the higher the complication rate So if you don't need the more complex osteotomy choose the the easier less Risky osteotomy that's really clear. That's really clear This is a nice study of a single center looking at 237 patients going through complex spinal reconstructions with osteotomies pedicle subtraction versus VCR the PSOs were done in different regions of the spine So they had a greater preoperative disability generally a flat back deformity And but had significantly higher complication rates and you can see some of that Data here with their complication rates major complications in PSOs being 33 Which is 38% versus 22% in a VCR minor complications 53% in the PSO versus 28% in a VCR So this is a little different data than that SRS database But both are showing a fairly high complication rate in complex osteotomies PSO had greater correction of the SVA in this series which makes sense as these were lumbar operations versus VCR is generally done in the thoracic spine and some like major complications were age Length of surgery age is not modifiable length of surgery is depending on some certain techniques and medical comorbidities So the medical really can see when we talk about medical risk We always talk at Northwestern about the cardiac pulmonary hepatorenal nutritional and psychosocial Those are the hallmarks of what we call our high response protocol. This is published a long time ago back in I believe 2007 and Or it was published in 2010 started in 2007 But the Northwestern high-risk spine protocol grew out of an adverse event like many of these things do it 2005 with we had a root cause analysis and then went through a quality improvement project and it ended up developing this protocol protocol And what we have is we had to find what was a high-risk case So we thought anything greater than six levels of fusion greater than six hours of surgery anything that was anterior posterior stage or at an age greater than 80 Automatically triggered our high-risk spine protocol. We had It was a comprehensive pre intraoperative and post-operative management Strategy to help reduce complications. We had the surgeons who would identify the complications. We had a whole host of medical risks including Significant coronary artery disease congestive heart failure cirrhosis dementia emphysema Renal insufficiency pulmonary hypertension stroke or that age greater than 80 all of these were automatic triggers to the high-risk spine protocol So the surgeon could designate that but if the medical doctors doing the workup found these they could trigger the protocol as well as well We would have a collection of data and evaluations then have a pre-operative Conference with our anesthesia team our medical team as well as the surgeons to discuss each other case each other case I won't go too deep into this as this is always readily available in the literature We protocolized some of the pre-operative testing even OR temperatures or discharge any criteria We worked through when we would collect data. What would be documented? What our communications would be when we would Do neurologic testing our transfusion management was a big part of this where we realized that fresh frozen plasma really led to increased edema and decreased extubation so we switched to cryoprecipitate with excellent results with that We protocol our our pathway through the ICU before discharge care and some of the lab values we tested there So the question is did it work are we maintaining it should it be updated updated? Well, we published it in 2007 This was the first time we put that in the literature. So we had we started in 2007 Excuse me And we published it in 2010 after we had an evaluate ability to evaluate and realize we were doing quite well for us We published another paper looking at well, we have a protocol, but are we following it? I thought this was an interesting paper and that despite having a dedicated neurospinal anesthesia team Everybody knows that there are breaks that are taken There are cases that go beyond normal hours and you get other people coming into your cases so we had greater than 30 attending anesthesiologists and greater than 100 residents in CRNAs and when we looked at the The intraoperative portion of protocol we only had a 2.6 percent protocol breach and there are many many factors that are on that protocol in terms of What they're giving how they're giving it what they're documenting when we're checking labs. So a 2.6 percent breach We thought was fantastic That meant our protocol was not onerous and was easy to follow even for somebody that wasn't on our dedicated neurospinal team We found signs that we have clear improvement with decreased post-operative edema patients simply when you turn them over aren't as swollen As they once were we had early extubation we've had early identification of medical Complications our communications been improved and importantly we have decreased transfusion rates, which really is very important so Starting to wrap things up here when we think about things to think about again starting with is this an appropriate patient for your surgery? That's the number one way to reduce your complication is to pick the right patient for the operation Make sure you have solid indications And I tell my patients that I only operate on adult deformities for three reasons and that is pain that has been resistant to non-surgical techniques neurologic deficits due to the deformity that need the deformity to be corrected to open up that space and then radiographic progression and Pain resistant to non-surgical techniques is the great majority of those patients It is rare that you see a radiographic progression without pain or other disability that leads you to operate on an adult Notice that there is no Number in there. There's no 45 or 50 degree criteria like there are an adolescent andopathics and adults I tell them all that that's a Number that you use in an adolescent that is trying to predict the future and it's a preventative maintenance surgery Once we have an adult we are living the natural history. We are going to see what happens over time there is no longer a significant benefit to a prophylactic operation in that in that group and Making sure the patient that is medically and socially appropriate for the magnitude of surgery making sure their bone is good enough to heal Because you can do the greatest operation if it's plants start to pull through that bone Nobody is going to be happy with it. Do the patients understand the loss of motion and do they really understand? When I think about level selection, how high do you need to go how many levels do you need to fuse the longer you fuse the more motion restriction the Greater the Difficulties with fusion and adjacent segment problem sometimes and if you're stopping at the sacrum pelvis You're really stiffening up that construct. So you increase your risk of some junctional disease, but oftentimes in adults It's important and then what is your PGK prevention strategy? We did talk a lot about that today But proper alignment is key Getting the lordosis where it's supposed to be is key and a transition of force and whether that is using some type of tethering technique using hooks a Variety of different things good soft tissue management are all important things that I try to practice on a daily basis So when do I say no to these patients? I say no if an appropriate operation is not possible Just because somebody has pain if I don't think I can do the right operation for them I do not think it is a value to try and do something smaller just because you don't think they're a good candidate for the bigger operation that almost always leads to a situation where now you're Stuck with a patient that you've operated on it's failing and now you're having to put them through that operation which you didn't think they were a candidate for in a harder riskier setting if the medical risk is too great and Cardiac and pulmonary risks are significant renal and hepatic risks are significant If somebody has liver disease beware of that patient Their complication rate is high if you think the risk of the surgery would have to do is too high from a neurologic standpoint or other And if the patient's psychological Comorbidities are too great or they don't have the right support system That is something that can really cause a problem in your recovery process And don't forget that medical clearance is not the same as medical optimization. Like I said up front I don't want medical clearance on my patients. I want medical optimization Oftentimes we put people through our anemia clinic where they're getting iron transfusions or they're doing some prehab with a conditioning program I've gotten many patients on weight loss programs and smoking cessation programs Trying to meet our criteria so they can go through that surgery and when we get them through their process our results are better We have a big impact on the preoperative medical workup and optimization. We can reduce medical complications We reduce our readmission rate and we reduce our likelihood of stay all of which our metrics were judged by the standard age So with that I will finish and thank you very much for your attention today

complications

adult deformity surgery

complication rates

patient selection

surgical planning

patient outcomes