Catherine: When Dr. Andrew Chan was a resident, he saw a lot of surgeries on complex spinal deformities: scoliosis, kyphosis, lordosis... And all of these surgeries were performed open. That is, with a substantial long incision down the spine– sometimes running all the way from the neck to the buttock. Patients would wake up, their spines aligned -- successful surgeries by all accounts. However -- due to the physical trauma of the procedure, they were often in pain. And in many cases, that pain would last for months. This is what Dr. Chan was used to seeing. Because this is just how spine surgeries were done.
And then one day -- Dr. Chan scrubbed into surgery alongside a colleague to operate on a patient with flatback syndrome, with the goal of reestablishing a natural curve to the lumbar back. Rather than one long cut, Dr. Chan watched as his colleague made several one-inch incisions on the patient’s side. During that surgery,
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they were able to realign the patients' spine without dissecting any muscle. The patient woke up, virtually pain free, with a beautifully curved lumbar. In that moment, Dr. Chan imagined a future where many spinal surgery patients need not endure the painful recovery of open surgeries. He knew that Minimally Invasive techniques were the future of spinal surgery.
THEME
I'm Catherine Price and this is Advances in Care.
Since that day in his residency, Dr. Chan has spent his career honing his Minimally Invasive practice and training other surgeons in these techniques. He is now the co-director of the Minimally Invasive Scoliosis Surgery Program and the director of Neurosurgical Spine Research at Och Spine at NewYork-Presbyterian/Columbia. I recently got the chance to talk to him about this innovative work. Here's our conversation.
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Catherine: Dr. Chan, it's great to see you. I'm so excited to talk to you about the work that you're doing.
Dr. Chan: And I'm so excited to be here. Thanks for having me.
Catherine: So to start, can you tell me when was that flatback procedure that inspired you to pursue minimally invasive surgery and research?
Dr. Chan: Oh, that was now, I want to say, eight years ago or so.
Catherine: Oh, so pretty recently though.
Dr. Chan: That's right. That's right. So really the heyday is now, and now we're finding out how to apply this to more and more.
Catherine: Gotcha – so can you actually define what we mean when we say minimally invasive surgery when it comes to the spine?
Dr. Chan: Yeah, so the big traditional open surgery is that long midline incision with all the muscular dissection. So broadly, minimally invasive spine surgery refers to anything that's less invasive than that. So it could be a little bit smaller or a lot smaller. That's why I tell the patient it's not helpful to really say minimally invasive spine surgery, but exactly what you are doing. Because somebody may say minimally invasive spine surgery and they just mean making two really long incisions on the side of the spine and to me,
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that's still a lot of muscle that's transgressed. That's still a lot of pain that you're gonna have. When patients say, uh, you know, “I'm interested in minimally invasive spine surgery” or “you're minimally invasive spine surgeon,” I tell them, “well, this is what I actually mean by it. This is what the procedure you actually have is,” and so they know exactly what you're talking about.
Catherine: So as opposed to the muscle dissection, what does it actually look like when you get down to the spine less invasively?
Dr. Chan: So what happens is I use a technique called tubular dilation. For example, if I'm doing a small decompression, I can either use a 16mm tube or an 18mm tube. So that means that the skin incision is just 18 or 16mm. Now what happens is I make that incision just at the skin level, and then I go through just the muscle covering that's called the fascia. And then what happens is then I can drop the smallest tube that's not 18mm yet, it's very tiny, that goes straight down to the area of bone that I wanna work on. And then I pass successively larger dilators over that tube. And so what you're doing is you're not cutting through the muscle, but you're dilating
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a circle up to, let's say 16 or 18 millimeters, and then once you've dilated up to that size, then you can use a microscope and you're looking right down at the bone of that area so you can see as opposed to, you know, cutting all that area, dissecting all that muscle with some cautery device, to, you know, stop the bleeding, um, you're just dilating through the muscle, so much less invasive. Um, but I think it's important to note that it's not like minimally invasive surgery is a total panacea for everything. It's not for everyone. And there's plenty of surgeries that do require open approaches. And that's why I think it's important to be evaluated by a surgeon who's actually capable of both sorts of techniques. So they aren't liable to the old saying that if the only tool you have is a hammer, then you're going to start treating all your problems like a nail. So that's why I think it's important that I have both a minimally invasive and open approach so I can give patients the best thing for them.
Catherine: I'm wondering though, if you can tell me a bit more, some of the benefits you see to a minimally invasive approach compared to open surgery when it comes both to the short term and also the long term effects for the patient.
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Dr. Chan: Right, right. So I think, you know, the first big thing is the pain. Talking about that shorter incision and the less muscular dissection, we have the option with minimally invasive approaches to have completely opioid free surgeries. And of course, I don't need to belabor the point about the opioid epidemic and we certainly don't want to be potentiating patients for that. So, you know, there are several patients of mine that basically tell me, you know, “I don't want any opioids.” And so, and then so they can have these small minimally invasive surgeries that I do, and they don't need to take any opioids after surgery. Um, it's, it's quite remarkable. And, you know, I always tell my patients, for example, for the MIS decompressions I do, that actually about two thirds of patients wake up with no pain. They actually tell me, “did you even operate on me?” And then, you know, 20 percent just have pretty mild pain. They just say, “Oh, yeah, I feel the soreness back there,” but it's certainly not something that they would need to take pain medications for. And so you're talking about a whole group of patients that are avoiding larger surgeries
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that generally would need opioids, at least for some amount of time afterwards.
Catherine: Okay. Yeah. I was wondering how long a typical surgery would require serious painkillers for, compared to some of these techniques.
Dr. Chan: I'd say typically after a minimally invasive spine surgery, either not taking any opioids or you take it for the, you know, one or two days after surgery, as opposed to some of the open surgeries, you know. Some of these patients are taking opioids still at the six week follow up, sometimes even a three month follow up. So, you know, it's a big difference.
Catherine: And does it continue, like years down the line, is there still a difference in pain between the MIS and open patients?
Dr. Chan: If you study patients out to two to five years, you'll see that oftentimes the pain level is about the same for MIS or open at two to five years. However, there's the concept of the area under the curve, and that's the number of days spent in a high pain state. And so what happens is that's time that you're taking a lot of opioids, that you're not getting back to work, that you might be sour in
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your interpersonal state, and we know that health is a biopsychosocial state and so there's certainly long term effects from spending more time in this pain state.
Catherine: I mean, that seems so important to acknowledge. You know, that pain is more than just the immediate feeling. But apart from pain, what are some of the other benefits of an MIS approach?
Dr. Chan: One other important thing is we know with exposing different aspects of the spine, you're basically breaking up some of the natural anatomical support structure of the spine. So, things like the muscles that keep you in a good upright position, also little ligaments and joints that keep us in our position. When you do an open approach, there's more of a risk of getting into those structures, um, even with meticulous dissection techniques. So in the long term, the biomechanical strength of your spine that we want to leave as much intact as possible will be potentially slightly more compromised from an open exposure, as opposed to a minimally invasive exposure when you're really leaving as much of the native anatomy
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intact as possible. The other thing is you have less blood loss in the minimally invasive approaches as opposed to open spine surgery. And this is very important. This can help to avoid things such as transfusions that patients will need. And some patients with some religious objections don't want any transfusions as well, so sometimes they're not even candidates for some of these bigger surgeries unless you do it in a minimally invasive technique. So it allows some patients to even have surgery that wouldn't be, you know, surgical candidates.
Catherine: And speaking of which... I understand you recently performed a spinal surgery on someone whom other doctors didn't even consider to be a candidate because of his age.
Dr. Chan: Right. So, you know, it basically goes back to, to this notion that when you're in your mid eighties or your late eighties, sometimes people just think, ‘Hey, you're just too old for surgery. You know, you can't have general anesthesia. You can't have the heart risks or the pulmonary risks or even the cognitive side effects. And so it just wouldn't be worth it, and you will have your quality of life impairing spine problem, but you know, there's nothing we can do to fix it safely. So good luck the rest of your time.’ And it's a shame, right? I mean,
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now people are living longer and that means many years with a poor quality of life and that's not great. And so one of the things that's very neat about what we can do with minimally invasive spine surgery is that it opens the avenue for us to general anesthetic-free spine surgery. What that means is that patients can be fully awake during spine surgery, and we actually just leverage basically some IV anesthetics and also a spinal anesthetic. And then with those two, we're able to conduct full spine surgeries. So there was an interesting patient, um, who was an 87 year old gentleman and basically multiple people told him “You're just too old for spine surgery,” and he couldn't walk anymore. He said he had no quality of life, and what he needed was a three level spine surgery of the lumbar spine. And one of the issues with the awake spine surgery is that it has to be done approximately under three hours if you're leveraging spinal anesthetic because that's typically about how long it'll last and certainly you don't want to have any risk of you not being done with the procedure and, you know, the patient now being in pain because they're awake.
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So what happens for that particular surgery is I combine forces with another minimally invasive spine surgeon and we actually operate on both sides of the spine at the exact same time and then we're able to do that actually in two hours. Much under the three hours. And then this gentleman did fantastic after surgery. The best part of it was he sent us a photo of him riding his motorcycle again. So clearly he wasn't your, your 87 year old stuck at home, but clearly had a lot of quality of life to gain. So I was glad we were able to do that for him.
Catherine: Oh, that's wonderful. Yeah. I mean, it's, it's amazing enough to help someone walk again, but to help them get back on their motorcycle when they're 87 years old is a whole new level of outcome. I'm assuming you've now included that as a metric in your research of outcomes, you're like are they back on a motorcycle?
Dr. Chan: That's right, question 11.
Catherine: [laughs] So is there a misconception -- at least from the patient perspective -- about what these minimally invasive techniques can accomplish? Like, how you’re using these techniques on something like scoliosis?
Dr. Chan: Well, I think what,
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what most people think about is, you know, when, when someone has a bad scoliosis, you're going to put a lot of screws in, put in rods, and then, you know, straighten this person's back into straightened alignment, and we can also do that in minimally invasive techniques. So regardless of which approach you use, open or minimally invasive, your goals are the same. You're trying to reestablish a concept known as lumbar lordosis or the backwards C of the spine, realigning the overall global shape of the spine so that the head sits above the pelvis. So traditionally when people were doing that at the back of the spine, you need to make a lot of bone cuts at the back of the spine. Those are called osteotomies and those involve often a lot of blood loss. And then you straighten out the spine into the way that you want it to be or give it the proper curve and then have the global alignment be restored. But how you can do that in a minimally invasive approach now, is you can actually refashion that same shape, but by going to the front column of the spine, or where the discs are between the vertebral bodies. And how you do that is
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you actually need to go then with a surgical approach from the front of the spine. You have a small incision underneath your belly button, it goes down to your pubis bone. Um, and then I have a vascular approach surgeon, um, that I do these with, and basically he gets me down to the front of the spine. And so that when I'm ready for my part of the surgery, I'm looking at the front of the spine and all the vertebral bones and the disc spaces. Then I open up those disc spaces and refashion the curve of the spine, not by making bone cuts at the back now, but by jacking up the car space, like with a car jack with these discs at the front. And so, of course, those just in and of themself often, um, will not sufficiently hold the patient from a biomechanical strength standpoint. What you do with this one is you're still putting in screws and rods, but instead of going down to the spine, dissecting all the muscles, having that long incision, you're actually just making, I use a 3D navigation device to plan where the screw trajectories will be. And then I make small sub one inch incisions at each area the screws need to be placed into the spine. And then
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what happens is I place the screws down those little incisions and they go down to the bone like they would be, but without violating all that muscle that you typically would do in an open approach. So then I put the rod in. I actually do that underneath the skin, underneath the muscle, and just connect all those screw tulips together without doing all that dissection. And that way you're able to align the patient and hold them in that position that you've given them from that front or the side correction that you did before.
Catherine: And my understanding is that the vast majority of scoliosis surgeries are still performed open despite the fact that this is possible, so this is very much on the cutting edge.
Dr. Chan: Yeah, I think it is. I'm biased, though.
Catherine: You're like, I believe it is as well. And also you recently did an pretty innovative tumor resection that you'll be publishing on soon. So tell me the story of this patient and then how that relates to the overall challenges that come with treating someone who has cancer.
Dr. Chan: This was an interesting patient. So she was a 38 year old woman and she had something known as adrenal cell carcinoma and she had unfortunately metastatic disease throughout her body and one of the areas she ended up getting metastatic disease was to the L2 bone
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uh, in the middle of her lumbar spine. The tumor grows into the bone, and then it starts eroding through the bone and then starts pushing on all the nerves and things nearby. So all her nerves were pinched nearby and she was very miserable from the pain, from the instability of that lesion as well. Now, the main goals of tumor surgery are that there's one component that is tumor control. So basically you need to decompress the nerves, take out as much tumor as is safe and that's something you decide with a medical oncologist and the radiation oncologist. But another goal of the surgery is to fixate the spine with screws and rods to help with that mechanical instability. Now, most of the surgeries for tumor surgery involve that big midline approach I told you about with a lot of muscle dissection, and the issue with that is these are a particular patient population, that has high wound risks because oftentimes they've had radiation to their spine beforehand, or they'll need radiation very quickly after surgery. We already know that a big incision is at risk, with someone with radiation, for poor wound healing because
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the tissues are not the same after radiation. And so there's already a risk of delayed wound healing or non wound healing. And so one of the issues is: What can we do to limit the chance of that wound complication or wound infection or wound dehiscence with these surgeries? Because one, at the least that may be another surgery, but two, it could delay the critical radiation therapy that these patients need right after surgery.
Catherine: And so with all of those restrictions, how did you approach your surgical plan for this case?
Dr. Chan: It was basically a piecemeal thinking. It was thinking, wait, I can do a full decompression of the spine with a tube. I can put in the screws and rods through these little incisions, I do that for the scoliosis patients. And all I need to do is shave a little bit more of the bone and take out the tumor beneath the spinal cord relative to my posterior view. Then why not? Why can't I do that?
Catherine: So how did it go?
Dr. Chan: So we accomplished the goals. I, I was able to get her nerves completely decompressed and the tumor basically removed down to the normal bone of that vertebral body. And then the other thing was
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I was able to fixate her spine with these screws and rods. Now the nice thing that we're now offering at NewYork-Presbyterian is the use of a carbon fiber screw rod system. One of the issues with, uh, tumor surgery of the spine is that traditional instrumentation involves titanium instrumentation. So anytime you're putting screws or rods by a tumor, you have a large metal artifact on MRI from these screws. And one of the issues is one, it makes it difficult to see what's on the MRI. It can make it difficult for a radiation oncologist to plan postoperative radiation therapy. It may actually make, uh, postoperative radiation therapy a little less, uh, effective. And then also, it makes it difficult in the long term to detect tumor recurrence, because if you have a small recurrence, but it's just in that shadow of where the metal artifact is, then you might miss that at a time that it might've been treatable in a different way and in a less invasive way. And so what you can do is what I did in this surgery is place these small carbon fiber screws right next to the tumor. And you'll see that basically
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there is no artifact from these screws at all. So the radiation oncologist can easily plan their radiation therapy and in case there's any recurrence for this patient in the future, we can really track in a timely manner, and that's possible with these carbon fiber screws now that we can now implement at NewYork-Presbyterian.
Catherine: So it essentially, it's almost like a ghost of a screw, like you just don't see it on the imagery. Why, why are these not being used more frequently?
Dr. Chan: So it's a relatively new technology. And the other thing is that there's a little bit of a barrier to entry in terms of cost. And so that's the nice thing I really appreciate about NewYork-Presbyterian because they know that this is the best for our tumor patients. That it really is in terms of long term care, the best for their radiation planning and their, and their tumor management. And so they, they've basically looked at that and said, “You know what? I know that this is important for our patients. We're going to let it happen.”
Catherine: And it also sounds like in the long term, if these screws are helping to prevent future surgeries -- then the cost-effectiveness would actually increase over time.
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Dr. Chan: That's exactly right.
Catherine: And how was the recovery for that patient?
Dr. Chan: The patient did great. Yeah, she's very happy. Um, she immediately stood after surgery and said her pain was gone and she was able to get on her radiation therapy in a timely manner.
Catherine: She, she, she stood up and said her pain was gone??
Dr. Chan: Yes.
Catherine: So I see this is why you're drawn to this field, huh?
Dr. Chan: Yes, yes, and you know when those patients get their quality of life back and they're smiling in an immediate, you know, time after surgery, which of course oftentimes there's still a little bit of postoperative surgical site pain, but that their initial pain that they came in for was so disabling that even immediately it feels like you flip the switch on it and it is very rewarding to see them very happy.
And so that's why quality of life is very important to, to, to assess. And I think spine surgery has done something that's been really great recently because, um, we've realized that the patient is the final arbiter of success, right? There's nothing–it doesn't really matter if I show you an x-ray and you're my patient, I say, “hey, your spine's perfect,” and if you're still sitting there in pain,
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it doesn't matter what your x-ray shows. You're the only person that matters. And so there's this notion of something called the patient reported outcome metric. And these are basically a bunch of questionnaires that we ask patients, I get them on all my patients before surgery and after surgery, and I diligently track these outcomes over time. And we get them to answer questions in several domains. But the most important thing is what actually makes our patients satisfied? What actually makes our patients less disabled, have less pain, or improve their quality of life?
Catherine: That also seems like a good segue to ask you more about some of the research that you've done about the outcomes from minimally invasive surgery versus a more traditional open approach. Can you tell me a bit about that?
Dr. Chan: Yes, of course. So, you know, as with most things, you know, one of the issues in spine surgery, you know, more than a decade ago, let's say about now, is a lot of the research was really just a single surgeon, often at a single center, just publishing, “Hey, I did this surgery 15 times. I did it this way. Patients did great.” And you would try to make practice changing judgments from a study like that.
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Well, that's tough, right? There's so many variables there. The surgeon's idiosyncrasies, the center's idiosyncrasies, so many things that may not apply to your local center or to your surgical skill set. We want to make sure that we're actually using real world data to prove that this works and not just sticking our finger in the wind and thinking, ‘Well, I think it works. It looks great.’ But, you know, now we have so much rich data of how patients do with different techniques. So I can answer real questions like, okay, we know minimally invasive approaches exist. Are they actually better than open approaches? Or which type of minimally invasive approaches are better for our patients? And these are all important questions that then help me counsel my patients better and then also select the best surgeries for that given patient in front of me.
Catherine: What are some of the things that you found?
Dr. Chan: So the interesting thing was, for example, one of the procedures I do is called a minimally invasive transforaminal lumbar interbody fusion, or a TLIF as we call it. And what this is, is basically let's say there's a
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single level of the spine that's very degenerated, maybe has a slip called a spondylolisthesis, and all the nerves are pinched at that level. Um, they are patients that could benefit from a fusion, and so what I was able to do is actually one of the studies I was lead author on at both the two and five year time point is assess and compare these two procedures. And the interesting finding that at two years, so the first long term time point after spine surgery, that actually the minimally invasive approach was associated with a higher quality of life when associated with an open TLIF approach for those patients. And then the five year time point basically was interesting as well. So it seemed that there was no longer any significant benefit for the MIS group, but that actually both groups did well at five years as well. So it's very interesting to see that, you know, basically what the study said at five years is, you've got to take in the whole host of factors, such as patient specific factors, surgeon specific factors, you know, different radiographic characteristics so, yeah, it does depend
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whether I apply a minimally invasive to you or open to you.
Catherine: It sounds like you have a very personalized approach to your patients.
Dr. Chan: Yeah, I think that's important. I think that's when you have the happiest patient.
Catherine: Speaking of happy patients, let’s talk about the Quality of Life outcomes database. First of all, what is it? And second, you were recently awarded a grant, right, so tell me about that as well.
Dr. Chan: Yeah, so that's, that's one of those spine registries which several spine surgical centers across the United States have combined their outcomes data. So they basically have data on many patients that were operated for a given spinal pathology, their baseline characteristics, but also their postoperative outcomes. And then this allows us to have just such vast real world data on our patients. You know, what I can do now is I can actually build predictive models to assess when patients do well, when patients don't do well. And, and one of the interesting things is I've actually been able to use this large data set, use some machine learning techniques to actually identify different clinical phenotypes of patients.
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And I'm actually using this data to tell patients in the clinic in front of me, “Hey, you're actually in that group with the slightly worse outcomes, so, you know, this is what we should do next,” or “You're in the group with very good outcomes, this is what we should do next.” And that's the nice part, to actually use data, the studies that I've published to help our patients.
Catherine: I mean that must make your patients feel so much more comfortable with their treatment plan, you know, if they can see themselves in the data.
Dr. Chan: Right, you know, you’ll ask my office staff, I'll actually print out some of my papers, um, often they apply to the patient in front of me and they love reading it, you know, and this is very neat to be able to do that and give them the evidence from this high quality study group.
Catherine: And also it really sounds like you really honor your patient's intelligence, you know, you don’t want to make assumptions that they’re not going to be able to understand or that they’re not interested.
Dr. Chan: Yeah, no, absolutely not. And in fact, it's funny every so often I'll have a patient that starts to apologize for all their questions and so for being so inquisitive and I tell them always in fact, “Not only do you not need to apologize, I am so appreciative that you're asking all these questions
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because what it means is that you're totally invested in your health and it means that when I give you postoperative restrictions or I tell you how the next year or two years after surgery are going to look, you're really going to listen to me,” and I think that is the best sort of patient because then they have the best outcomes. And so when I see that, I actually love that.
Catherine: That's great. When I first was approached to host this podcast and I was talking to my husband about it, he's like, “You've literally been kicked out of doctor's appointments for asking so many questions. Like you obviously have to do this.” And so this whole thing has been a dream for me cause I get to ask all the questions. So thank you for being someone who wants their patients to do that. It makes such a difference.
Dr. Chan: [laughs]
Catherine: Anyway, I know you're saying there are cases in which the open approach is the right one, but it also seems like there are many, many benefits to minimally invasive approaches. So I'm wondering if you can talk a bit about some of the barriers that you see in terms of getting minimally invasive techniques and procedures more widely adopted.
Dr. Chan: So one, from a practical standpoint, some surgeons just aren't trained on it. And even if you are trained on it briefly,
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there's a big learning curve, which for some may be insurmountable, and unless you have a high volume practice, you might not ever get to a state where you feel very comfortable with this, so… It’s, it's this skier versus snowboarding conundrum. When you go to the slopes in winter and let's say you're a lifelong snowboarder, are you going to want to waste your trip learning skiing? Or you know, both of these can get you down the mountain. Um, well, you're just going to do the same thing you've done, right? So I think it's sort of the same thing. You know, it's not like our open surgeons are having a bunch of terrible outcomes. No, they have great outcomes too. And so if you're having great outcomes, you're going to be hard pressed to want to change, especially if you've been doing it this way for 20 to 30 years. And there's other practical standpoints too, right? There's, there's the, I, I told you about how I actually have an approach surgeon to bring me down to the front of the spine safely, and so some centers don't have that. You know, NewYork-Presbyterian has an excellent approach surgeon that gets me down to the front of the spine. He's fantastic. And if you don't have that, if you're at a smaller center, then you're just not going to be able to do some of these approaches. And so these are some of the barriers to entry. But I, I'm hoping,
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you know, I'm up here at NewYork-Presbyterian now so I train a lot of residents and hoping that now that they have the exposure to this technique, that they'll be able to disseminate this as they move across the country. So I think, you know, some of these barriers are there, but I think they'll, they'll gradually, you know, fade away. And I think this is really the future that we're talking about.
Catherine: That seems like a fantastic note to end on. Thank you so much for making the time to speak with me today about your work. This was absolutely fascinating.
Dr. Chan: Thanks so much for having me.
THEME
Catherine: Huge thanks to Dr. Andrew Chan for sharing his work in minimally invasive spinal surgery.
I’m Catherine Price.
Advances in Care is a production of NewYork-Presbyterian Hospital. As a reminder, the views shared on this podcast solely reflect the expertise and experience of our guests. To listen to more episodes of Advances in Care, be sure to follow and subscribe on Apple Podcasts, Spotify, or wherever you get your podcasts. And to learn more amazing stories about the pioneering physicians at New York Presbyterian, go to nyp dot org slash advances
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