Tethered Spinal Cord

Thank you. Just wanted to make sure we have that construction going on outside the building. Uh, it's interesting. Well, thank you so much. Um, uh, a warm thank you to Doctor Reddy and, and everyone here, um, in our division of urology, um, for the, the kind introduction and the invitation and opportunity to speak with everyone today. It's a sincere privilege. Um, we're gonna try to cover a lot of ground, to be quite honest with you. Um, one could go to a week-long conference, of course, like with many of these topics that are being discussed today, solely on tethered cord and really not cover all of the pertinent details. Um, so what I'd like to do is give everyone a broad overview of, of the most fundamental distilled down concepts of spinal cord tethering. Um, to give you a sense of how neurosurgeons think about tethered cord physiology. So that when your own local neurosurgeon reaches out to you and asks you for help in diagnosing a patient, um, you'll have a, a good sense of the conundrum that they're facing and, and trying to work through with the management of that patient. Let's see. I have no disclosures today, and we're going to talk about different types of spinal dystrophism associated with primary tethering as well as secondary tethering, review the pathophys of tethering, and then really try to focus on diagnosis and management of really common types of tethering and retethering that we see. All right, I was asked to put some questions in place, and this is the, the first poll question. I'll just leave this for the audience to look at the, the optimal timing of surgery to close this dystrophic defect that you see pictured there on the right and, and untether this patient, uh, would that be around 24 weeks estimated gestational age, so still in utero, um, the first few days of life postnatally. Um, at around 1 year of age, uh, when the urodynamics, uh, began to deteriorate, or at, either A or B. We can talk about that a little bit later. OK. You'll probably hear me use the word controversial, maybe a half dozen times during the course of this talk, and I apologize in advance, but really it's just to give you a sense that in many cases, the initial diagnosis of primary tethering or even a diagnosis of recurrent tethering can be quite murky. And I, I like to share these two quotes to sort of set the stage for this. Uh, the first on the left is from Sarwar and Bomani, uh, neuroradiologists from Yale. Who said, well, any well-defined syndrome or disease entity is characterized by generally prevailing coherence among its clinical manifestations, pathologic characteristics, and therapeutic outcome in a majority of patients. Uh, but such is not the case in the primary tethered cord syndrome, and, and I think it sums it up well. And then one of my own colleagues, the great Doctor Jim Drake, uh, who's at Sick Kids in Toronto and he's a pediatric neurosurgeon there, uh said few topics in pediatric neurosurgery generate, uh, as much controversy. Uh, debate or angst is the diagnosis of tethered spinal cord, as is often the case in surgery, the controversy is fueled by plausible explanations and strong convictions based largely on anecdote, and its intensity is all the greater because of a lack of good data. In many cases of alleged spinal cord tethering, surgery might almost be regarded as an alternative therapy, joining the ranks of craniosacral therapy, acupuncture. And cupping. Uh, so, Doctor Drake is never one to leave you wondering, uh, how he feels about in a given topic, but really it, it summarizes some of the controversy that we have. So let's start with the basics. This will likely be a review for most of you, but. The issue is that during gestation, our bony spine elongates much faster than the neural tube, and the spinal cord, so the conus itself will ascend over the course of gestation and early childhood, and that will elongate the phylum terminale, which is at the termination of the cord itself, and the lumbosacral nerve roots. And indeed this is how the cauda equina, the nerves of the caudaquia form as these nerve roots grow longer to accommodate the differential growth. And we know that in, uh, you know, approximately 345 months of gestational age in utero, the spinal cord extends all the way down into the sacral region and, and we call that a fetal cord position. But as pregnancy proceeds and after delivery, the conus continues to ascend to its more normal adult level at approximately L1 or 2. And during this process, the neural elements themselves, the distal spinal cord and the conus, are protected by the relative elasticity of the phylum terminale, which is pictured over here, right? So I normally tell families this is typically like a thin stretchy rubber band, and that's how we accommodate that growth. The term tethered cord uh was probably initially adopted by another neurosurgeon at Sick Kids, the great Harold Hoffman back in the 70s, when he described a pretty large series of patients with motor and sensory deficits in their lower, lower extremities, bladder issues, and imaging demonstrated a low conus, and their symptoms seemed to improve after they underwent surgery to section what turned out to be a thickened phylum terminale. And at the same time, uh, Doctor Yamada and his group in Loma Linda, uh, were working on the actual pathophysiology behind this process, and I'll, I'll tell you more about that in just a moment. And we're narrowing this down to oxidative metabolism at the cellular level and paralleling the, the metabolic and neurological derangements prior to surgery and improvement following surgery. So in general, we refer to spinal cord tethering as the neurological symptomatology that's correlated with traction. It's a traction effect or stretching on the spinal cord above the side of tethering and below the counteracting side, so the stabilizing ligaments that we all typically have, um, extending from the dura to our spinal cord. Along its length. Commonly this can be a thickened or inelastic phylum. Technically, we can have tethering anywhere along the spinal cord. So we have patients with cervical dystrophism and they're tethered at the cervical region, the thoracic region, or even in their brain stem itself. But most commonly, this is a process in the lumbar region. An injury to the spinal cord and the nerves themselves are exacerbated by just normal everyday movements, trauma, or in the case of our pediatric patients, just simple growth of their axial spine over time. So Doctor Yamada and his group at Loma Linda really looked at this, uh, in the 1970s and early 1980s, and they, they had a feline model of spinal cord traction, uh, to mimic what an inelastic phylum, uh. Uh, what effects that causes on the spinal cord and really all of their work can be summarized, um, here on this slide. What they found was with tethering over time, there is a reduction of regional blood flow to the neural elements, impaired oxidative metabolism in the affective cord, and oxidation reduction studies actually revealed that there is a derangement in the um cytochrome. Constitution in the mitochondrial electron, electron transport chain, uh, in these neurons, impairment of glucose metabolism, of course, and then ultimately deterioration of the normal in neuron action potentials. And so overall, these changes were similar to those that we see with trauma or hypoxic and ischemic injury. And in severe cases, the metabolic derangements become irreversible, and they correlate with persistent neurological deficits. So, when we think of the tether cord, what we're really talking about is the spinal cord and the nerve roots that emanate from it are attached to an immovable structure, whether that be a tight phylum terminale, a lipoma, as you can see here in this young patient. The bone itself, the skin, the dura. And that over time there's a progressive stretch applied to all of these neural elements with daily activities, but really, once again in the case of children, with skeletal growth. If you think about the spinal cord uh being anchored down at the bottom. And the bones growing over time, you will have vectors in opposite directions, of course, and you will put progressively more and more stretch on the distal spinal cord and the exiting nerve roots, and that's what leads to tethering symptomatology. So I mentioned that this is somewhat controversial. What is the controversy? Well, the issue is that it's not often black and white, although sometimes it can be. There are a variety of different lesions that we can find by imaging and varying clinical presentations that sort of fall under the umbrella of potential core tethering. And in addition, because of this variety, there is really a paucity of high quality clinical data to provide guidance. And so I just provide to you here on this slide 4 different clinical scenarios to think about. Number one is very straightforward. A patient with significant spinal dystrophism that presents with overt clinical deterioration consistent with cord tethering, they obviously have a tethered cord and they need surgical repair. But what about that same patient that has documented spinal dysraphism on MRI but they're completely asymptomatic. How should they be treated? Or what about a patient with an incidentally discovered abnormality, so they present with scoliosis, a borderline lowconis, no visible tethering lesion. Should they be treated? And then lastly, and we'll talk about this just a little bit more, perhaps the most controversial, what if you have a patient that has tethered cord symptomatology but completely, seemingly normal imaging without any tethering lesion? Could they potentially have a tethered cord or what we refer to as the occult occult tethered cord syndrome. So the issue is plausibility does not equal causality, even if we have imaging findings that may suggest spinal dysfunction or a clinical exam. That patient may not actually have spinal cord tethering, and because of the lack of high quality clinical data, there is little consensus, especially amongst us as neurosurgeons, particularly regarding these controversial uh presentations such as occult spinal cord tethering. And really what we have to do is temper different philosophies, right? So, when should we pursue prophylactic untethering, which is indicated in certain cases versus advocating for treatment just to see if it helps. Versus observing a patient for many years, when in fact they're actually tethered and they're sustaining glacial neurological decline over time, but at a very slow rate. So in thinking about diagnosis, most of these patients are going to have spinal dystrophism, which of course you all remember is a malformation of the neural mesenchymal and cutaneous ectodermal structures or some combination thereof, and tethered cord syndrome is most commonly related to spinal dysgraphism, and this is what we typically refer to as primary cord tethering. The common features, uh, regardless of the type of dystrophic defect, uh, the common features they have are these three major causes of neurological impairment. The first is myelodysplasia, and this is, of course, static over the patient's lifetime, and this is really just reflecting that the neural elements, the neurons, um, did not form completely correctly, and so they do not function completely properly, and we can't do anything about that in this day and age, although there are various clinical trials looking at. Neural stem cell therapies uh for the myelodysplasia, neural compression, so we can have the nerves of the cord actually compressed with accumulating CSF, enlarging lipomas. And then tethering, our focus for today, which is a progressive process that worsens over time. And without treatment, of course, we see deterioration, we see chronic ischemic changes in the cord, as we already discussed, and these patients can have a rather insidious presentation, or we can have trauma at or near the point of fixation, and this can be a precipitous, almost apoplectic presentation. Um, and one of the examples that we sometimes see, fortunately not that commonly, would be, uh, someone that's been anesthetized and placed in the lithotomy position, so prolonged flexion at the waist in the setting of an undiagnosed tethered cord. Just as a review, and we're not going to discuss the, the specific embryological mechanisms behind all of these types of dysraphism, but we have open dysraphism, which is a disorder of primary neurulation, so this is the myelomeningocele population. Um, which you all probably see fairly commonly, and then we have closed neural tube defects, uh, which are disorders of secondary neurulation, and so these are very common. These are the tight phylums, spinal lipomas, including lipomyelomeningocele, and then less common variants, meningoceles, myelocystoces, which you probably are used to seeing in your OEIS population, split cord malformations, caudal regression, so on and so forth. Neurosurgeons will often talk about simple tethering versus complex tethering, so just to sort of um elucidate what that is, simple tethering is really just that. We're talking about a single point of fixation. This is a tight phylum, a fat infiltrated phylum. I have a picture of it here. You can see the end of the cord and the conus there on the sagit MRI. And then the phylum is nicely highlighted here because it's bright and so fat is hyper intense on this T1 weighted MRI sequence. So fibrous fatty tissue incorporated into the phylum replacing the normal glial tissue and pia and resulting in decreased elasticity. There's no scarring present in these patients and treatment is very straightforward. We go to surgery. We don't even typically have to remove bone. We simply go in between the vertebral elements, section the phylum. It's quick. There's a low complication rate and a low retethering rate. Complex tethering is really everything else, myelomeningoceles, spinal li. Patients that were already presumably untethered, but they have extensive post-surgical scarring, and these cases are not quick. Instead of taking 1 hour, these require many hours of microdissection under the microscope, freeing individual nerve roots from investing lipomatous tissue. So cases such as we see up here, this is a split cord malformation, and you can see the two hemicords, each in their own dural tube. And then this young child who has a very rare uh dystrophic defect, which is an asymmetric paramian myelocystocele with hypodevelopment of that lower ipsilateral lower extremity. From a clinical standpoint, the three symptoms that I always educate patients and families about back pain and to a lesser extent leg pain, lower extremity weakness and changes, we most often hear about easy fatigue with ambulation, children not being able to play for long periods of time, wanting to sit down and rest, toe walking is very common because of increased tone in the distal lower extremities, changes in bowel and bladder function, constipation would be the most frequent that we hear about. And then issues with incontinence, delayed potty training. Uh, recurrent urinary tract infections, and then we can see skeletal deformity. Such as progressive scoliosis, and issues with foot and ankle development, so a pescavis or a very high arch, as you can see on this child's foot here. One of the issues is though, constipation and toe walking are probably some of the most common symptoms and chief complaints that we get in our patients that are tethered, but they're also extremely common in the general pediatric population, and so these are really very non-specific complaints, of course. Um, scoliosis, I would just point out that about 25% of all patients with just a tight phylum will develop scoliosis, so it's a really common finding that we see, and most of these patients will always have a leftward thoracic curve as opposed to a right curve, which is more commonly seen in patients that aren't tethered but have idiopathic scoliosis. So this is something that we always have to assess for. Um, scoliosis is also very, very common in our patients with myelo meningocele. So cutaneous marker, something that we get asked about and called about quite frequently, uh, probably because it's really just so calm, and, um. If we look at all live births, 3% of normal neonates will have a cutaneous marker, such as a benign sacral dimple. But in patients with spinal dysraphism, more than 80% will have at least a single cutaneous marker. Whether this is a midline dim dimple, a dermal sinus, a nevus, hemangiomas are very common. Uh, a tail, right, a vestigial tail with the lipoma, hair tufts, or gluteal asymmetry, um, in the top right here, this child has, um, a forked gluteal cleft, uh, which is a really common finding associated with, uh, dystrophism and tethering. However, most dimples are simply just benign sacral dimples. Um, the way that we distinguish dermal sinuses, which are worrisome, are usually large and don't have a clear bottom. They usually extend all the way down to the spinal cord by definition. They're often rostral to the gluteal cleft, and, and if they are, they're typically um pathologically abnormal. Benign sacral dimples are blind sinuses that terminate on the coccyx, they're always buried within the gluteal cleft itself, and these are harmless and really don't require any further evaluation. So here on the left we can see a blind dimple buried in the gluteal cleft. This is just a benign sacral dimple, and here once again we see a small dimple or a pit really, well above the gluteal cleft in the lumbar region in association with a forked cleft, and this is typically an abnormal finding. Just a moment to talk about spinal cord tethering in adults, um. In the pediatric population, we most often see a fairly slow progression, as I've been talking about, with symptoms exacerbated by growth of the axial skeleton and progressive foot deformities and constipation and bladder issues and lower extremity complaints. In the adult population, more and more we recognize symptoms of tethering, and it may be that they were tethered their entire lives and that there was a misdiagnosis, uh with slowly progressive symptoms, or it may be that they were actually asymptomatic, uh, in childhood, and that over time they've sustained increased fibrosis. In their phylum, as it's lost its elasticity, and there can be worsening traction on the neural elements later in life, even though they are adult size and no longer growing. We also see normal degenerative changes which can restrict the movement of the nerve roots of the cauda quia with lumbar disc disease, which is incredibly prevalent in the adult population. And so these changes can accentuate and increase the stretch if you already had a marginally fixated cord. And in the adult population, we more often will see a sudden onset of symptoms, so more precipitous than insidious, and trauma can be the initial trigger, whether that's a fall or a motor vehicle crash, excessive flexion of the spine, such as with sports, sitting for prolonged periods at a desk as a job. Um, changes in ligamentous laxity seen with pregnancy, childbirth in the lithotomy position, just being in the lithotomy position while under anesthesia for a different procedure. Um, back and leg pain is very common but may mimic just overall lumbar degenerative disease, and we will see quite frequently lower extremity sensory and motor changes, incontinence, and, and sexual dysfunction is of course, uh, prevalent in this population as well. And then bladder testing, and I really won't talk about this too much to this particular audience, but just know as neurosurgeons, we typically think of bladder testing as being quite helpful in unmasking subclinical bladder dysfunction, especially in young children that can't provide us with that history, um, if they're suspecting of of having a tethered cord. And we think that urodynamics can be a relatively good objective data point to follow pre and post-operatively, and I saw, I think that you're having a master class in interpreting neurodynamics a little bit later today. But so many of the other clinical symptoms that we see in our clinic, you know, you know, how long has your back been hurting, where is your back pain, how bad does it hurt? These are relatively subjective, uh, data points. But the urodynamics can be important for us to monitor patients that haven't been treated, but are suspected of perhaps being tethered, or can be a good early indicator of recurrent tethering symptomatology in patients with known complex dystrophism, such as our myelo meningocele patients and patients with spinal lipomas. So in terms of imaging, um, Ultrasound and MRI are what we use most commonly. Ultrasound is only helpful in newborns. By the time patients are about 3 months of age, the conus should be really no lower than mid L2 or the L2-3 disc space at the very lowest, um. Ultrasound is helpful in that it's performed in the prone position and it allows us to assess the cord and the cauda for pulsations and dependency within the fecal sac. We can screen borderline dimples very easily without the use of radiation and without the need for sedation to do an MRI. However, we do lose that ultrasonographic window at about 4 to 5 months of age because of bone growth, so after that time, it's not really helpful. MRI, as, as I'm sure you're certainly aware, continues to be the gold standard, and that it allows us to clearly delineate tethering lesions in most cases, shows us the details associated with the neural anatomy in a complex dystrophic defect. It allows us to easily see. Without any questions whether or not there's fat within the intradural space on T1 sequences, it helps us with operative planning, and also it's possible to use prone sequences on MRI which we'll talk just a little bit about here in the subsequent slides. Plain films can also be quite useful because most patients that do have tethering will have at least some bony abnormality, usually incomplete fusion of the lumbar sacral lamina uh that we can see on plain films. So MRI will in many cases absolutely make the diagnosis of spinal cord tethering for you and you don't really need a neurosurgeon and there's really no controversy. So here we can see on these selected images, here we can see this patient has a low lying conus and here is a very thick fatty phylum. This patient has once again a very low lying conus extending down to the lumbosacral junction associated with an intradural lipoma here, which is bright. That has an associated tailor tract which extends all the way through the subcutaneous tissues into the surface of the skin, and then this patient has once again a very elongated spinal cord down to the region of um uh the lumbosacral junction and a very significant intradural lipoma which extends all the way down into the sacral region. But what about this patient? You can see the markers here on in, in purple. This patient's conus ends at a level of L1, which is normal, and there's no overtly uh evident tethering lesion in the spinal canal. So could this patient be tethered? Yes or no? Well, for some of these, um, questionable cases, we use prone MRI which continues to be somewhat controversial, but here in our practice at Cincinnati Children's, we do tend to rely on it heavi uh hea uh heavily. And really the hypothesis that we're testing whenever we use prone MRI is that if we think cord tethering is reflective of traction on the neural elements themselves, then there should be a significant reduction in the free ventral translation if you flip a patient over prone in the MRI scanner, right? And so this can potentially assist us with decision making when we're encountered. With a patient that has tethering symptomatology, but really no evidence of tethering lesion on MRI, so imaging negative patients, the, the so-called potentially occult tethered chord syndrome as we've talked about. Prone images and its use in making this diagnosis is controversial. Early studies, including one from this institution. Really didn't find any value, but in the last decade, there have been several additional studies, um, both from North America and abroad, that have shown that in most cases, um, prone imaging can be quite helpful, particularly in patients that are looking at a new diagnosis. Its role in determining recurrent tethering is still not well known, and for, Reasons that I'll show you a little bit later, it does not really add any value in the setting of patients that have known major dystrophism, so they're known to have a myelomania, so these patients will always appear tethered on MRI throughout their entire lives, whether or not they're symptomatic. So here on these images on the right, you can see the patient is supine and the conus is actually laying dependently in the spinal canal, and all the nerve roots of the cauda equina here are just jumbled on the back, and here you can see all of the spinal fluid which is bright white, and then when we flip them prone, their spinal cord and conus flips here to the ventral aspect and once again all the nerve roots of the cono quina did so in a patient like this, you can clearly see. There is not significant stretch on the nerve roots, or else they would not move from side to side. And on these images here you can see a different story. This patient's conus is here on supine imaging and everything is resting dorsally in the canal, and when we flip them over prone. Well, the cord up here moves forward, but look at the conus, it's still fixated dorsally, as is the nerve roots of the caudaquius, so there appears to be some traction. And so we typically define. Tethering is any time the distal cord remains in the dorsal third of the spinal canal with less than 10% of movement of the total width of the canal when the patient's placed prone, and this can be quite helpful, right? Many times, um, children that are undergoing an MRI for a different reason may be found to have fat in their phylum, but they're not tethered and they have no symptomatology, and as I remind you down here, not all fatty, fatty phylums are bad. About 15% of patients that are not tethered will have a fat infiltrated phylum terminale, and it's a normal benign finding. And so in our practice, we use prone MRI and we find it very helpful in the setting of incidental imaging findings. Patients that have minimal indications by imaging or they have borderline indications on standard MRI or if we're trying to determine if they may in fact have occult spinal cord tethering. Which leads me, uh, again to the dreaded topic of occult, uh, tethering. And really the issue is, can a patient truly be tethered in the setting of normal imaging as we define it in this day and age with the imaging adjuncts that we have available to us, right? So if we have a patient with bladder dysfunction and a low lying conus and a thickened phylum on MRI, that's not a clinical conundrum, right? But take a patient with bladder dysfunction and a normal level of the conus and a normal phylum. And Here's where we get into issues about whether or not these patients could still have tethering, uh even in the setting of this normal imaging. And so this has been debated for decades, as I'm sure you well know, and you probably all see these patients at some point or another in your practice. Variable studies with variable results, but early on in the 90s and early 2000s. There was a prevailing sentiment, especially amongst pediatric neurosurgeons, that just snipping the phylum would often have a positive effect on neurological symptoms in these patients. Here's just a quick summary of many different studies that looked at that with varying rates of reported efficacy, all right? Um, but it has remained controversial, and so here's a, I always just show, uh, at any point in time at the American Society of Pediatric Neurosurgeons mean, you can be enjoying your coffee and then when we start the session on spinal cord tethering and someone begins to talk about occult tethering. Your mild mannered pediatric neurosurgeons may just engage in a in a barnyard brawl within minutes in in discussing this controversial topic because we have so little data to guide us really. And I'm sure you're all very familiar with this study, so I'll just mention it briefly. Um, Paul Steinbach and Jeff Pug, who are, uh, uh, uh, colleagues, pediatric neurosurgeons in, in Canada, um, spent many years trying to accrue patients for this, uh, prospect, prospective randomized study looking at urological outcomes, uh, with medical management alone, uh, combined with sectioning of the phylum terminale in patients believed to have, uh, occult, occult spinal cord tethering. They could not demonstrate any objective difference over the length of time that they ran the study and calculated that it would take many, many more patients and hundreds more patients and, and additional years to, to power that study. And so I'll just, you know, suffice it to say the controversy remains, more data is needed, and we typically will just make these decisions on a case by case basis. So in transitioning to management of tethered chords, really our goals are, are these, right? We hope to improve or stabilize neurological deficits in the symptomatic patient, and that includes relieving pain and stabilizing skeletal changes. And we hope to prevent future onset of deficits in asymptomatic patients, and so there is a patient cohort where we actually recommend prophylactic untethering surgery. And these two goals are predicated upon, on, on these points that we know that there is neurological deterioration associated with tethering, and that it's progressive over time if left untreated, and that once neurological deficits develop, they are very difficult to reverse, so you cannot always turn back the hands of time, as we say. And that for most patients with simple tethering, and untethering surgery, which is to say sectioning their phylum terminale, is quick and easy and carries minimal risk to the patient. So, really just to expound upon prophylactic surgery, right? Deterioration in these patients with tethering is very unpredictable. We can see fairly rapid deterioration during a growth spurt. I just recently saw a patient that I've been following who had new onset of symptoms, uh, because he grew 3 inches in about 14 months and, and led to onset of symptoms. Conversely, we can run into difficulties with those patients that have a more glacial decline. And so they will have slow onset of motor, sensory, um, urodynamic function changes over time, but. The parents become accustomed to this, um, they're lured into complacency because things are not changing very quickly over time, and, and the surgeons can be really duped into delaying intervention. But the issue then becomes, this neurological function, once lost, has poor potential for being restored. So ultimately, even though we know surgery is often safe and effective, the issue once again, is pretty complex and controversial because we have a broad spectrum of patients and um the waters can be quite murky on whether or not they're actually tethered to begin with, or if they've already had an untethering surgery, are they demonstrating symptomatology of recurrent or secondary tethering. So in thinking about those clinical scenarios that I presented just a little bit earlier, right, there's little disagreement. If we have a patient with spinal dystrophism and overt clinical symptomatology or deterioration, they require surgery, OK? These are not the patients that get sent to me for a 5th or 6th opinion. But what about patients with a significant dys dysgraphic defect that have a normal exam, they're completely asymptomatic, so this is a patient with a spinal lipoma. This has been debated for many years, however, Most neurosurgeons in this day and age agree that prophylactic surgery is indicated because long-term natural history studies have shown what I've already alluded to, and that is that these patients at some point in time will develop neurological deficits, and once they do, they're not easily reversed, and so we typically will untether these patients before onset of deficits. Patients with incidental imaging findings, plus or minus symptomatology, we typically will determine whether or not these patients might benefit from surgery on a case by case basis, and of course with occult tethered cord syndrome or suspected occult tethered cord syndrome, very controversial, and all I can say is that. Um, with these patients, um, there's often disagreement. They've typically seen 3 or 4 or 5 or 6 other neurosurgeons, um, before they, they come to see me, and we really determine these on a case by case basis. So, some of the most common types of tethering that we see, the type phylum, which can either have fat in it or no fat within it. Um, from an embryological standpoint, really the easiest way to think about this are primitive streak, uh, precursors that fail to migrate to the proper position during secondary neur neurulation. So for the fat cells, which you can see pictured here, instead of being in the epidural or subcutaneous space, they're actually incorporated into the, to the phylum themselves and attached to the conus. We often will speak of these patients uh that just have a tight phylum as having spina bifida occulta, which is an old term, and really the true incidence of these patients is still not known, um, however, it is rising over time as, um, more and more patients undergo MRI screening, um, for symptomatology or for completely unrelated, um, reasons. About 20% of patients with spina bifidaculta will have no cutaneous marker, and so they often will not be referred to us during early childhood. Uh, they may present with pain, uh, when they flex at the waist, they can have, uh, motor, more commonly than sensory deficits. And we can see relatively simple tethering, which is what this is, in otherwise, uh, complex patients, so patients with vocctoral and OEIS imperfect anus. In fact, that's the most common type of tethering that we see in patients with imperfect anus. The so-called corino triad with sacral deformity, a pre-sacral mass and imperforrate anus, and then so-called occult tethered chord, as we've talked about. Here are just some intraoperative photos. This is a very common scenario here. Um, you're looking at, uh, the caudaquina. The dura is pinned up on these sutures here, and there's the arachnoid, and up in the forceps, I have this thickened and fatty phylum. You can see it's much thicker than the nerve roots. And so what we do is we isolate it and we cut it, and I would just point out here you can see the phylum in here I've already cut it, but I'm holding on to it and then this next photo you can see how far it will actually migrate rosterally once you section it. So these phylums are always under significant tension, and once we cut them, they will actually then retreat in a rostral direction up and out of our field and it it's very gratifying when we untether these patients. The outcomes with simple tethering are quite good. Um, I would just point out in red that the retethering rate is not zero%, depending on which series you look at, it's anywhere from 2 to perhaps 8%. So we tend to follow these patients for many years as they continue to grow, and often we'll quote families an average, um, retethering rate of about 5%. And then myelomeningocele, um, of course, probably, uh, the, the patients that you, you see the most, these are very complex patients. Almost always with neurogenic bladder dysfunction, just as a reminder, spina bifida is the most severe form of neural tube defect, and it represents a failure of the caudal neuro pore to close. It's an issue related to primary neurulation. Uh, there is dysfunction of the distal spinal cord and nerve roots which often do not develop normally. And we still see in the United States about 2000. Live births each year, uh, children with myelonemia, so. The overall mortality in this patient population is quite high unfortunately and approaches about 20 to 25% by the time they reach their 21st birthday. In those undergoing postnatal closure, standard postnatal closure, about 80 to 90% will have hydrocephalus requiring treatment, and survivors have significant issues with lower extremity function, scoliosis, bowel and bladder dysfunction. Here I have a fetal MRI just showing. Caudal descent of the hindbrain, so this is the Chiari2 malformation with the cerebellum actually entering the cervical spinal canal, and here you can see the skin terminate in the actual neural placo, the distal and the spinal cord as it projects out into the cyst inside the uterine cavity. For children undergoing postnatal closure, we typically will pursue this, uh, within 72 hours, and we need to recapitulate. Yes, this is, uh, your colleague here, Brian Vanderbrink. Yes, I just wanted to share with you the results of your question. Yes, to, as you're, uh, transitioning to kind of see what the audience. Um, so, what you had kind of showed was a, uh, exactly what you're talking about here, an open spinal, uh, dysgraphism. And basically, just so you know, we got about 36% that are favoring a prenatal and 38% in the first few days of life. So, exactly, probably. What, uh, you might find in, uh, or, or what you were hoping to instigate some uh debate. And they're both correct. Um, as of 2021, uh, prenatal closure has not supplanted postnatal closure. Not all moms and fetuses will, um, be good candidates for prenatal closure. So both A or B were correct answers. Um, regardless of when you close the defect, um, the idea is to finish closing the neural tube, right? So we have to cover and protect the distal spinal cord, the nerve roots of the cauda quia, and, and recapitulate the fecal sac. So thank you very much for that, Doctor Vander Brink. Prenatally, we perform this surgery in the same way, but we typically do it at about 24 to 26 weeks of gestation, and that does, um. Yield some benefits for the child in terms of being able to reverse the hindbrain herniation as you see here and reduce the incidence of, Hydrocephalus, of course all of you are familiar with the MOMS trial, and I won't discuss that here, but just recall that enrollment was stopped early in 2010 due to unequivocal efficacy of prenatal surgery and achieving the primary outcome measure and reducing the incidence of hydrocephalus and need for shunting, but it also achieved its secondary outcomes on final analysis of improving the number of children who were able to independently ambulate by 30 months of age. So here's some just some photos. This is an open intrauterine repair. You can see we've just opened the uterus and here is the fetus in a large myelomeningocele which we just close in standard fashion. Here at Cincinnati Children's, uh, we more typically close these, um, in an endoscopic fashion. So instead of making a large hysterotomy, we'll just place, uh, 2 or 3 working ports and, and place a camera down and just as you might perform laparoscopic surgery, uh, we will perform this endoscopically and you get a great view of the defect. You can see us closing it here in primary fashion. I would just like to, to make everyone aware that in 2019, um, uh, the WANS, our, our governing body, assembled a task force to, to look at best management practices a myelomeningocele, and, um, just to review this with you, there was level one data to show that prenatal surgery does reduce the risk of developing hydrocephalus. And level 2 data to show that it does indeed improve the ambulatory status of these patients, but you should know that there is evidence, and the mechanism has not been clearly elucidated just yet, that prenatal closure does increase the risk of recurrent tethering. So we do see in this patient population, a higher incidence of symptomatic retethering. Um, that we have to look out for. The clinical symptoms of myelomeningocele, um, and you could see, uh, recurrent tethering, you know, back pain. Uh, we see it in about a third of patients. Um, we typically will use urodynamics, uh, to help us make this diagnosis. Um, at surgery, what we find is you can see the distal spinal cord here and we open it up and this is the neural plate code and it is just scarred to the dura circumferentially and so we have to establish our planes, identify all of the nerve roots which you can see exiting like sort of the branches of a Christmas tree here. Here on the dissector I have the sacral nerve roots. So these are the ones that are most important for bladder and bowel function, of course. And then when we're done, the spinal cord and the placode has been completely released on all sides. Most patients will improve, especially if you can get to them early, but about 13 will require repeat operation for untethering. And so finally, I'll just end, uh, with just a couple minutes here, um, I'm talking about. Recurrent tethering, um, we refer to this often as secondary tethering, and so it can be seen, uh, in patients that have arachnoiditis for various regions, uh, reasons they might have undergone multiple lumbar punctures as a young child, as we used to see with our leukemia survivors, uh, trauma at some point during their lives, uh, evidence of meningitis or intradural, uh, emynema at some point, an abscess. Um, and then recurrent tethering in patients with dysraphic defects that have already undergone prior and tethering, and we can see this in up to 50% of patients depending on the complexity of their dysraphic defect. Our actions have consequences, and I thought I would have to show a, a group of urologists that at this beach apparently if you urinate, they're going to record you and place your video on YouTube, and, and so too our actions at surgery have consequences when we untether these patients at surgery, uh, we do increase the risk that they will have recurrent tethering over time, particularly those with complex defects, so. Nearly all complex cases will demonstrate radiographic retailing, so all patients with myelomanningia, so even, you know, at any stage of their lives, if you perform an MRI, it will look as if they're tethered, even though they have no symptoms, OK? And the rate of symptomatic retethering is higher in complex tethering than in simple tethering. And any patient that has lipomatous tissue investing in the nerves, that's a strong predictor of recurrent symptomatic tethering over time. Once again, I always counsel families and other physicians to, to remember the holy trinity of recurrent tethering, back and leg pain, gait changes, and bowel and bladder changes over time, and, and you all can be very helpful in monitoring bladder function over time, uh, to help us make this diagnosis in a timely fashion. At surgery, For patients with recurrent tethering, we have to lice all of the adhesions and we try to enlarge the fecal sac. Here's a picture of the patient, and this is the distal cord, and this is the end of their spinal cord. It looks like just a big glob of fat, and you can see some nerve roots. This is not always a, a pleasant day for us. What we have to do is trim all of this fat. Here you can see I've trimmed all of the distal fat and I'm identifying these all-important sacral nerve roots, and you have to keep trimming everything down and freeing up the nerve roots until at the very end, you're gonna have normal appearing spinal cord and just the small plate code with all of the exiting nerve roots. You're not done until the distal cord and all of the nerve roots are free floating in the spinal fluid, um, really, really like a raft floating in the ocean. Um, and here's a patient with a lipoma and recurrent tethering. You can see the lipoma is adherent to all of the dural edges, and at surgery we just have to go around all of the circumferentially, identify and preserve all of the nerve roots which are, are pictured here. And this surgery can take several hours. It's one of those procedures, as I'm sure you're aware, you're not done till you're done, until it's completely free, however long that takes. So I have a second poll question here at the end. And that would be which of the children pictured here that show up to your clinic should be referred, uh, either for an imaging study or to your friendly neighborhood, um, neurosurgeon. We have one, we have a, a dimple here, and then this patient up at the top seems to have this small appendage coming off their lumbar spine. Here we can see a hemangioma, here we see a rather luxuriant tuft of hair coming out of the upper lumbar spine, and then here we have a patient with a, a pit and an atypical. Uh, gluteal cleft. So which one should you refer to the neurosurgeon? All of them 2 through 53 through 54 and 5 only, 2 and 4 only? So I don't you look at those for a moment. So, in summary, there are still many controversies uh surrounding tethered spinal cord, right? Timing of surgery, when is prophylactic intervention indicated, and it often is. Um, what about a phylum terminality that has fat in it, but the patient's asymptomatic and they have a normally conus. When is a fatty phylum just a fatty phylum? What about a low lying conus with no tethering lesion? What is normal and how low is too low? Once again, what about patients suspected of having occult spinal cord tethering? Really, I don't have anything else to add to that. And how long should these patients be followed? After they've reached skeletal maturity and they're 1718, 1920 years old, what is the risk that they may develop symptoms later in life? Do they need to be transitioned to an adult neurosurgical provider, an adult neurological provider to continue to look for this in the decades to come? And in conclusion, you know, the time of onset and rate of progressive decline is unpredictable, it can be fast or slow. We do recommend early intervention, even in asymptomatic infants when they have known tethering lesions, because early surgery can be effective prophylaxis against later, sometimes irreversible neurological injury. Tethered cord uh remains very fascinating for us. Uh, there is continues to be much debate and uncertainty. There's a lack of good data and the onus is on us to, to continue to try to produce that data. We have many challenges ahead of us in trying to identify these patients and predict which are at risk for symptoms and which require surgery and, and which really wouldn't benefit from surgery. And resolving these dilemmas will be dependent upon better information, uh, both from the laboratory as well as from prospective clinical trials. And then, um, finally, I would just add, this is, um, one of my partners that I've worked very closely with and I'm privileged to do so. This is Doctor Brian Vanderbrink, a urologist extraordinaire. Um, I've been working with him in our multidisciplinary spina bifida clinic for many years now. He trained in New York and as many of you probably know, he's, he's a, a superstar, celebrity, media sensation. I remember seeing this ad from our local newspaper, the Cincinnati Enquirer, a few years ago. You know, congratulations, uh, Brian Vanderbreen for pleasing 15 women and for an entire day. We were all exhausted and very satisfied, and we look forward to next year. I mean, This is the kind of star power that Doctor Vander Brink brings to our spina bifida clinic, and, uh, he's been a wonderful colleague. Um, uh, I'm very um grateful for all the collaboration over the years. Although I would point out that the editor of the paper, uh, did apologize the next day, um, for the innuendo, and, uh, I would also point out in defense of Doctor Vander Bringing that this was pre-COVID, so really no concerns about any, um, violation of social distancing regulations and restrictions, so. Even though, uh, most pediatric neurosurgeons, uh, don't live in the public eye as much as, uh, Doctor Vander Brink, if you ever see any patient that you are concerned may be demonstrating tethering physiology, please don't, uh, hesitate to, to reach out to us, and I'm sure we'll let you know that, uh, we can probably untether that. Thank you for your time and I'm happy to entertain uh any questions. And once again, thank you to all my colleagues in urology uh that have been so helpful over the years, particularly with our intrauterine surgery program and helping us follow and maintain good outcomes, particularly bladder outcomes for these children, uh, over the years as they grow and develop. Thank you. Wow. Thank you, Doctor Stevenson for such a uh educational video, except for the last, uh, you know, two slides, but, uh This is how we have fun here and, uh, exactly, as you've alluded to my New York roots, you know, the baseball season's starting, so I have to uh try to celebrate the other cross-eyed bear besides the spina bifida clinic is rooting for the New York Mets baseball team. So, um, try to stay off of page 6, please. Yes, exactly. Anybody can be a Yankees fan and uh I'll let our esteemed colleague, Doctor Masseri, uh, later on talk about that. Um, there are, as you can imagine, a lot of questions with some interplay that you and I have multiple text messages, emails, Epic, EMR, and, um, some of my colleagues from Indiana and, um, Chicago, who, who are in the trenches too with the spina bifida clinic and pediatrics, as well as everybody else. So, I, I figured, Doctor Reddy, it might be just easier as I've been trying to reply on there to Jump in here. Um, one of the questions, which happens a lot, and I'm sure it is up there with the, uh, occult tethered cord, uh, a lot of people like to get MRI's on these patients. And as you, uh, I think, uh, exquisitely showed us the painstaking nature, especially in this, uh, myelo meningocele population of what does a secondary detethering look like. One of the questions was, uh, what do you do with the spina bifida patient who is urologically normal, they're caffeine, everything looks great. And then they said, has a tethered cord. So, my question to that person was, well, how do you know they have a tethered cord? Well, somebody got an MRI. And then our radiology colleagues are taught to, why don't you just put down what you see? And then they're gonna tell you this six year old spina bifida patient has an MRI consistent with a tethered cord. The parent has read this in their MyChart, and they go, Doctor Stevenson, my son has a tethered cord. What are you gonna do about it? So perhaps, I know you touched upon it. Yeah. Uh, we as urologists in this hypothetical said there was nothing clinically wrong with the patient or urodynamically. What do you usually Tell people in those situations. Well, it's a wonderful question and it's a common question, and it comes up on a daily basis for those of us who are, are treating this patient population, and this is where our, our colleagues in neurology can be so helpful. Just as a reminder, any patient with a myelomeningocele is technically tethered at the anatomic level. 6 months after you perform that closure, or 6 months after you do any repeat untethering surgery at any age, if you were to go back in and look, they have formed arachnoid scar around the neural placode and the nerve roots, and they are scarred down. So on the MRI they are going to look tethered 100% of the time. But that's really not the issue. Really, all we care about is the advent of symptoms, right? So, even though we know they're scarred down. Are they under stretch, right? That is really what comes into play. Over time, as they continue to grow, is the amount of scarring around those nerves such that as they continue to grow, will they exert more and more traction on the spinal cord and the neural elements and become symptomatic. Otherwise, their MRI will always show that they're tethered, whether they're 10 years old or they're 55 years old, and it really doesn't matter. What we're really looking for is that clinical diagnosis, so the bladder changes, or the changes on physical exam, or the symptomatology that I reviewed. And so the imaging in that case is not really that helpful, and I didn't go into this, but we can sometimes look for. A new development of the syrinx or we just use the MRI to, to guide, um, operative planning, right? But not in actually making the actual diagnosis. Doctor Stevenson, uh, Bob, before, so just a quick follow-up to that question, what if the patient has a bladder augmentation where the urodynamics is probably not gonna be super helpful, um, in your decision making? So then we just go on their clinical exam, right? So, progressive scoliosis, worsening changes in the lower extremities, symptoms of back or leg pain. Chuck, uh, how often do you use, uh, manual muscle testing as an adjunct to, uh, MRI? So, uh, we use here and, and not all centers use this, but, but we use, uh, manual muscle testing very frequently, um, really all that is, is a neurological exam looking at each individual muscle group and the lower extremities, uh, in terms of the strength and the range of motion, and, um, we have our physical therapists, they're, they're trained, um, to perform this, and they usually will follow these patients in a longitudinal fashion and so. Um, it's really a third party exam, right? So that the actual clinician is not really, um, biased in any way, shape or form. We'll, we'll have these therapists continue to, um, follow the exam over time and when they see, um. Changes in the actual strength over time, um, they will alert us to that, or increasing spasticity in the muscle groups. And so, really it's just, uh, having someone else follow the neurological exam over time. I'm not sure if that answers your question. Yeah, no, I, I think it's just, uh, I was just trying to bring that up, that that's a useful adjunct when the urodynamics and the MRI may be not as useful using, uh, uh, uh, you know, the manual muscle testing as another objective measure. Absolutely. So then the question comes up, you have, you have a child with myelomeningocele who is already wheelchair-bound. Who has a bladder augment. What sym what further symptoms may they develop that would require you to do something surgically, even if they do have a tethered cord? Like, at what point does that tethered cord become clinically not so significant for you? I'm sorry, what was the question again? So you have a, uh, 16 year old who's almost done growing. They, they have significant myelomeningocele with, uh, lower extremity, um, uh, um, papyresis, so they're non-ambulatory patients. They have a bladder augmentation. So the urodynamics are not gonna help us. Even if this person does have a tethered cord, when is it no longer clinically significant that you would worry about having to go and retether them? When would you say they're OK, they're not gonna get any worse clinically? Well, it's a wonderful question, and, and that's really why, um, There's a lot of discussion, um, in this day and age about transitional clinics, right, because we think that although it's a minority of this patient population, that there is a definite percentage of them that can experience decline later in adulthood, from a neurological standpoint and so simply graduating them from your clinic. When they're 18 or 19 or 21 years old, it's probably not sufficient, and they probably do need to be followed, um, as the decades go along, there's some data that would suggest that we can see, uh, kind of another peak on this bell curve of symptomatology in patients in the, the late 20 and early 30-something age group, right? So. Uh, either continuing to follow them in your, in your pediatric institution, or having a transitional clinic that they can establish care in because there is a risk of decline even later in life, although it's not nearly as commonplace as while they're still undergoing, um, growth of their vertebral column. Perfect. And I know, Chuck, you talked about the use of ultrasounds early on. Uh, but how do you reconcile the fact that during the 1st 3 months, there's still some differential growth, and so the conus might still ascend if you do an ultrasound on a 32 week preemie, and you, you know, you see a cutaneous markers suggestive of tethered cord, you get an ultrasound like, uh, it looks tethered, but then do you repeat that closer to that 3 to 4 months? Sorry. Absolutely. I'll usually just wait as long as I, I think they can, um, in terms of their, their bone growth, and then just repeat the ultrasound. And then, you know, if it's somewhat indeterminate, then I'll just follow them clinically over time, and when they're a little bit older, get an MRI probably with prone images, just to show that there's no traction on the distal cord. Doctor Stevenson, Bob For again, I, I don't know if you saw the results of your last poll, but about 1/3 of the folks said all of these, and about 1/3 said 2 to 5, and my comment on that is one of the best pearls I ever heard from you is if you actually have to peel apart the gluteal fold, and you see the pit, then it's usually of no significance. And so I think, um, you want to comment on the, on the poll results? That's right, uh, I think the The answer is, anytime you have any question, please just reach out, uh, or order an imaging study. Uh, but choice A, uh, was just a benign sacral dimple. You can see that you're opening the gluteal cleft, and on exam, if you could look at that more closely, you would see that it's, it's just a blind dimple and the base is easily visualized. And so those, those are just benign findings that require no additional workup. Uh, many times these children will go on to get an ultrasound just to show that it's normal, but really they needn't. If we see them in our own clinic, we just tell the family that it's a, it's a benign incidental finding and that uh there's no additional evaluation necessary. That's great. You're absolutely correct. I had one other question. Uh, you know, we see a tremendous number of patients in our healthy bladder clinic who have urinary incontinence, fecal incontinence, and caprisis, um, may or may not have any other, uh, neurologic findings. Do you have any sort of thoughts on when we should start to think about a spinal MRI in our massive cohort of these patients looking for a tether cord? All right, back to history. Yeah, I would, yeah, I would say history, and then if they have any other symptom, and, and that's really why, uh, it's important to keep some of those in mind, and so, really, when we, we think about that, that triangle of, of tethering symptomatology, so if you start to see some of these issues and then the patient has any other complaint, if you just screen them for back pain or any changes in the way that they've been walking or any activities that they can't do anymore that they used to enjoy doing. Um, really, I think, um, in that case, just image early, uh, right, um, with MRI we're getting better and better, uh, doing shorter sequences, uh, trying to avoid any sedation, of course there's, there's no radiation involved, and so I would say. Image early if there's any significant clinical suspicion, and there's really not a right or wrong. Doctor Stevenson, uh, this is Rosalie Masseri, I'm one of the pediatric urologists over in Indianapolis, and I had a question for you. In kids with refractory voiding difficulties, at what point do you decide you're gonna do a total spine MRI in lieu of, instead of a lumbosacral spine MRI? Cause our, our reflex as urologists is always to do the lumbosacral spine. Um, but in some cases, it seems like a full spine MRI has been more, has been useful in, in that small group of patients. Right, to assess for uh a syrinx or some other lesion more rostrally. Well, that's a wonderful question. Um, and so the, the default is, um, you know. To be complete, the total spine MRI is required. I would just say that's not a decision that I, we often have to make because really we just speak to our, our radiology team and so anytime we order a lumbosacral MRI they also include um a very quick single sagittal sequence of the entire neuraxis for us. So, it adds, I think, 45 seconds to the total scan time. So very quick, but it's a T2 image that shows us the posterior fossa so that we can assess for um a Chiari malformation, low lying cerebellar tonsils, and then we view the entirety of the cord, um, and so it is enough with that one sequence for us to identify any intradural mass like a lipoma, uh, you know, occult dystrophism, a spinal cord syrinx, and so. Um, that's kind of the, the cheating answer I know, but really we, we always have a view of the core just because we incorporate that one single screening sequence, and, um, uh, perhaps if your institution does not utilize that, you could just simply ask your neuroradiologist because it is very fast, but it gives you a good view, and if there's anything suspect there, then you can of course focus in on the MRI, but. But you're right, I didn't really talk about cervical tethering and thoracic tethering is beyond the scope of this discussion, but if the symptomatology is concerning and the lumbar images are, are normal, you're not really finished looking until you visualize the entire spinal cord. Uh, but thank you for, for that point. Thank you. Elizabeth, do you have a question? I, I did. Um, good morning. I'm Elizabeth Yerkes. I'm, um, one of the pediatriologists from Chicago. I enjoyed your talk. Um, the, uh, question, I, I appreciated your comment about placing patients in lithotomy and having them have an acute, um, presentation of tethering. I'm wondering what recommendations you give to your patients as they graduate from you, um, as they may move into reproductive years and be in lithotomy or, um, maybe subject to other operative procedures with lithotomy. Do you give them, uh, any instructions or how do you educate your colleagues on that? It's a wonderful question, and it's a, it's a big issue, right? Um. In general, what I counsel the patients themselves as, as well as the family members they have with them is, um, really just to let the physicians that, that are treating them as they continue to grow older or if they're gonna be having some procedure, um, to let them know if they've been having. Any back pain or any difficulty with bending over, flexing at the waist, so, is it uncomfortable when they lie in certain positions when they go to bed at night, or when they bend over to pick something off the floor, right? Or have they noticed any other changes? And I, and I really drum that into them in terms of that, that triad of symptomatology, um, typically. A good screening tool is if one of those patients is able, if you just have them bend over and touch their toes in your office, and they can bend over and reach down and touch their, their shoes for 30 seconds without any discomfort, then there's really not going to be an issue with lithotomy position, even if they're under anesthesia. And so I really just kind of, Always talk to them about that and usually I just encourage them if they're having back pain or whatever just to contact me so that I can um direct that evaluation if necessary. Chuck, I think, um, last question from the audience is, uh, at what point, uh, are you using somatosensory what potentials in your assessment of patients with tethered cord? Um, so we do not use it in the extra operative setting, so just using it as a diagnostic tool, um, we don't tend to do that in our practice here. However, for every single patient that has been diagnosed with tethering, that, um, is taken to the operating room, we always use, uh, intraoperative neuro monitoring to guide the untethering. So we're uh performing somatosensory evoked potentials, although those are not always helpful. No child or adult with a myelo meninguso will typically have somatosensory evoked potentials in the lower extremities. So we're using transcranial motor evoke potentials as well as free running and triggered EMG so that we can identify all of the functional nerve roots. And then we're typically trying to assess for bulbocavernosis reflexes. We can assess that pathway too if we're running total IV anesthetic because it's very susceptible to inhalational anesthetic. So we don't tend to use it as a diagnostic tool in the clinic, but we use it, um, every time to, to guide our untethering in the operating room. Thank you, Chuck. That was uh, a phenomenal lecture and thank you for answering all of our questions. You, my brother, are a true frontline warrior. Thank you. Thank you for being part of our workshop and, um, really appreciate it. Well, thank you so much. Oh, go ahead, sorry. No, I would say thank you, uh, once again. Um, you all, uh, help us take good care of these patients, and we're so grateful you've, uh, um, I've been here now 12 years at Cincinnati. Children's and it's been a real pleasure to, to work with all of you. And so, um, thank you on behalf of myself and, and all of my partners. We appreciate it pleasure and privilege is all ours, Chuck. Thank you, I, I, I also thank you for using an earlier photo where I was less folically challenged, so. At, at this juncture, I think we're gonna be directing everybody towards that bio break as we approach, uh, Doctor Maceri's lecture starting at 10:30. Yup. So, uh, we'll kind of take a little break. We have that social lounge to find people. Uh, please look at some of the videos that were submitted for the fellow bowls. And, uh, once again, uh, thank you for our morning speakers and, um, We will see each other back here at 10.