Hi, I'm Sandy Lam. Thank you so much for the opportunity to participate in this forum. I am the middle part of this forum, maybe the surgical pause for thinking about why we're embarking on this journey. So the spectrum of thought could really be named controversies as well. So I'm going to review part of, you know, how we kind of arrive at when to operate and when not to operate. So the clinical presentation, as Dr. Roberts talked about, can be just neurocutaneous manifestations, or in terms of clinical symptomatology, they fall into buckets of typically urologic, orthopedic, or neurologic. So this is going to be the roadmap of what we're going to talk about. So the goals of surgery, like Dr. Roberts said, would be to protect neurologic function or to prevent a delayed neurologic decline. So you can see that there's actually a spectrum of management options. Even though we see a lesion in the patient, there is the option of conservative management or surgical intervention. Now, in the literature, for symptomatic patients, it tends to be a little less controversial, where if a patient is in trouble or having neurologic decline or already having neurologic symptoms, then most people would favor surgical intervention. However, when we fall into the category of perfectly, completely, utterly asymptomatic patients after a detailed workup, what do we do? So I'm going to present the rationale for all the camps of thought. So there are two vociferous camps of thought. And I agree, the nomenclature is rather confusing. There's a lot of different ways that people talk about lipomyelomeningocele, or when you look at the literature, I'm going to look at it as a body of spinal cord lipomas. So as you can see in a big series from France that was in child's nervous system in 1997, you can see that lipomyelomeningocele is part of this discussion in the literature for spinal cord lipomas. And then here's a depiction of the other classification, the Chapman classification for dorsal lipomas, caudal lipomas, or transitional lipomas. The transitional lipomas tend to have more of a rotational component and asymmetric presentation. Those in the literature tend to have a higher rate of surgical complications. So the other one not shown is the chaotic type named by Dr. Pang, where there's a more ventral component of the fat as well in addition to what you see for the transitional. So looking at what started off some of this thought was the French group reviewed a 22-year experience with almost 300 spinal lipomas. Some of these, a small subset were phylum lipomas, which were classified in the conclusions as a more low-risk and more benign type of lesion in terms of surgical intervention. And then of the surgical cases that were clinically symptomatic, patients tended to benefit from surgery. Now, leading into the controversy is of the asymptomatic cases, the long-term surgical results kind of depended on the anatomical types, as in the classifications I showed in that diagram. But when you look at about five years follow-up, only about half of the patients are symptom-free. So you're looking at a 50-50. So when we're looking at what does that mean? Are we helping people? When do we help people? Dr. Kulkarni, when he spent time in France with this group, actually looked at the conservative management of asymptomatic lesions. And this was the first time that, in the literature, that there really was a concerted effort to look at what happens when we choose to do conservative management rather than surgery. The asymptomatic patient cohort was compared to a historical asymptomatic cohort that actually received early prophylactic surgery at the same center. The mean follow-up was 4.4 years with statistical modeling to predict what would happen at a longer time frame. The conclusion was that the patterns of deterioration neurologically were actually similar between the conservatively managed group and the early prophylactic surgery groups. So you can see with the modeling there's actually actuarial risks of deterioration. And at nine years, it's about 33% for the conservatively managed group and about 46% for the patients who had had early prophylactic surgery without symptoms. So, you know, why look at this, you know, in terms of, you know, is it okay to manage conservatively? When we first look at this in face value, I think everybody in your individual practice has probably seen an older child come, you know, clinically symptomatic. So, you know, one of the thoughts in the literature is, well, you know, is this something that's been there a long time and is this progressive in nature? So if we just leave that, we're just leaving something that's going to actually cause neurologic problems. So does age have something to do with it and, you know, are more symptomatic patients presenting at an older age? So but what we actually don't know is that we lack natural history literature. So we don't actually know in the population what the rate of symptomatic versus asymptomatic patients are. We can't actually account for the asymptomatic patients that never come to attention. There are some autopsy studies that show that there are spinal lipomas that exist without having medical records to show that they've come to attention. So the rationale for prophylactic surgery, we've talked about the ideas of age at presentation and also the potential for progression and actually developing neurologic symptoms over time. So in the literature, one of the kind of big things that came out is Dr. Pang came out with a two-part series talking about the long-term outcome of aiming for total or near total resection of the fat in spinal cord lipomas and then radical reconstruction of the neuroplacode. So it's a 15-year experience with this technique with 238 patients with this aggressive resection of the fat with reconstruction of the placode. And the notion of the cord to sac ratio comes up, and we'll address that. The complication rate in this series is actually very low. When you look at the rest of the literature, the complication rates in aggregate are about 20 to 40% in terms of wound problems, CSF leaks, or a lower rate of neurologic complications. So the rationale from this kind of pro-surgery side is if you're presented with a disease entity that, you know, within 10 years there's a probability of deterioration of 33% to 43%, isn't this this grave problem that you actually should intervene on when you have the chance? So the question presented in his papers is not really do you treat or not treat, it's actually what technique would you do to improve the natural history of the disease? So to remind you of the embryology, this could be a primary neurolation defect or a secondary neurolation defect, depending on if it's a lipoma or a lipomyelomeningocele spectrum. Now he actually, in the second paper, he compared his own surgical experience where earlier in his career he did parcel resection of the fat. And then later in the career he moved to this very aggressive fat resection with reconstruction of the placode. So when he constructs his survival curve in terms of progression-free probability to time to development of neurologic symptoms from tethering, he actually has an 82% progression-free survival at that 9 or 10 year time frame. So this is very different from the conservative management group. However, when you look at the partial fat resection, you actually have a 34% progression-free survival. So when you look at it the other way, it would be a 66% chance of actually developing neurologic problems over time. So how do we put these two very divergent camps together? So when you look at early prophylactic surgery for asymptomatic patients in other reports in the literature, Dr. Cochran here has actually pulled together different papers in the literature and plotted it out on the same survival curve. So he describes this pattern of continued late deterioration with actuarial risks plateauing at this 8 to 9 year time frame of 20%, 40%, or 70% depending on the paper that you're looking at. So there's actually four colors on here and one more color. So it's Chicago, Pittsburgh, Vancouver. He extrapolated the Connecticut series as well. And then there's BC in the graph. So for example, as one of the papers that was in that graph, the Pittsburgh experience was 94 patients. Medium follow-up time was 58 months. About 20% required 28 subsequent surgeries of these 94 patients for symptomatic retethering. So the median time between the first surgery and the reoperation was about 52 months. So you need that long-term follow-up. And then transitional lipomas, as we mentioned before, had the highest risk of perioperative complications versus the dorsal or the caudal classification. And then of note, there was a small subgroup of patients, six of them, who had repetitive symptomatic tethering that was increasingly difficult to treat. So there's this notion of every time you go back in to do a redo surgery, you're actually kind of starting your stopwatch for when they're going to retether next. And this was in this small subgroup of patients, six of them, included in these patients who required symptomatic untethering. So when you look at other, you know, comparing the literature to what I presented with Dr. Kulkarni's paper, Dr. Kulkarni, when he looked at his conservatively managed group, actually shows this kind of decline over time as well. So when you're watching patients over time, a certain number of patients actually develop neurologic deterioration over time. When you look at authors who have tried to do what I'm doing in this very quick 10-minute talk, so Dr. Walker, when he looks at the spectrum of thought and the treatment options, their suggestion of, well, you know, it doesn't have to be black and white. You know, you can actually say, well, you know, I know in the literature there's the transitional lipomas have a higher perioperative risk. So maybe the dorsal lipomas, if in my hands I can operate on with low surgical morbidity and I have a rationale for this, maybe those are the ones that I can choose to operate on. And then the ones that I think, you know, do carry something more compelling in the risk-benefit ratio towards risk, then you may choose to watch that. But with either treatment strategy, conservative management and watchful waiting over time, or upfront early prophylactic surgery, close serial multidisciplinary follow-up is essential, because as you see, you know, patients can develop symptoms over time. So are we – have I convinced anybody one way or the other after showing kind of the important papers? You know, are you kind of more towards conservative management now or more towards early prophylactic surgery? Because we know that patients, you know, are probably going to need another surgery at some point. So Dr. Cochran actually recently had this nice, elegant study. It's small numbers, but I think this shows this interesting concept of the treatment options were actually made by shared decision-making with the parents. So the parents were actually the ones who chose if they were going to have prophylactic untethering or if they were going to have observation over time. And this is for asymptomatic patients. And you can see that it's actually quite similar in terms of what happens to them over time. And the patients who kind of needed repeat untethering were actually quite similar to what is described in the literature from before. And then the mean time to repeat untethering is 98 months in the prophylactically untethered group. And then when you look at the initially conservatively managed group, their mean time to initial detethering if they develop symptoms was about 88 months. So are we dealing with, you know, kind of like all fruit and you can choose what you like? Or will you be swayed by what Elias is going to tell you next when he shows you a whole series of challenging cases? So because Dr. Roberts shared his institutional experience, I can tell you we looked at our institutional experience. And it is actually quite in keeping with what's described in the literature. In the past five years, we've had 15 lipomyelomeningoceles. As a group, we tend more towards conservative management and operating if the child develops symptoms. And our rate of wound issues or CSF leak is about 25%. So we understand that these are very, very challenging cases. And we want to do it for the right reasons. And I'm not sure that we have the right, that we have the answers. Then something that we need to strive to do better. Thank you.

Sandy Lam

controversies

spinal cord lipomas

surgical treatment

conservative management