2024 Fetal Care Center Frontiers in Fetal Neurology Day 1 - Dr. Jesse Skoch

And so now, I'm going to hand this over to um Doctor Jessie Scoach. He's an associate professor of neurosurgery here at Cincinnati Children's, and he's gonna talk a little bit about surgical approaches to congenital aqueductal stenosis. Thanks, Doctor Venkatessen. Uh, thanks for inviting me. This is a, uh, awesome venue. Really cool to see how many different people from so many different countries are attending. Uh, I'm excited to talk to you guys today. Um, so I was asked to, uh, speak a little bit specifically about endoscopic third ventriculostomy. Uh, or ETV, uh, and even more specifically about the timing of the ETV procedure for patients with congenital aqueductal stenosis, uh, which I'm sure is a, um, frustration point for a lot of people, surgeons and, um, uh, other physicians alike, uh, because it's something that's not very standardized and there's not a lot of data to drive these kind of decisions. Uh, just a quick disclosure. Um, so, uh, as mentioned, um, the, the prevalence here, it's, it's a, a fairly rare disorder, but certainly not, uh, unfamiliar to this audience. Um, it's considered to be about 5 to 20% of congenital hydrocephalus etiology. Um, and then when you look at all comers for hydrocephalus, um, it's a, uh, A smaller slice of the pie for what we deal with in neurosurgery with hydrocephalus, but it is certainly a slice of the pie, and overall estimates in the US, at least about 600 to 1500 cases a year, just to give a general idea of the prevalence of this disease. Um, so, the little bit of history here, endoscopic third ventricular cisternostomy, or as we call it for short, um, uh, ventriculostomy or ETV, um, this was, uh, uh, a stem off of Walter Dandy's work in the 1920s where he did use a, uh, an endoscope, a crude cystoscope to, uh. or burn the choroid plexus with this idea that the choroid plexus was discovered fairly early on to be one of the major generators of the cerebral spinal fluid and that if we got rid of that in hydrocephalic patients, maybe we could get rid of their hydrocephalus. So this was a pretty novel idea. And it seemed to work well, um, at least in the one patient that survived the procedure. Um, the early neurosurgery is full of stories like this. Um, 24 out of 25 patients died of complications in this, uh, particular data set. Uh, not long after 1923, uh, Doctor Mixer is credited for what we consider the more modern version of the ETV procedure, uh, where there was actually a, um, fenestration of the floor of the third ventricle, and this was done with a smaller scope, a urethrascope, uh, still, uh, borrowing technology from our, uh, urology colleagues. Um. And then in 1936, um, there was a series published by Scarf al. um, and uh this was with um a special, more custom designed coagulation channel endoscope. Um, they published a series of 20 cases and 10 of them showed long-term improvements, so considerably better than some of the earlier work. Uh, 7 failed and 3 perished from, uh, immediate post-surgical complications. Um, This is kind of the relatively modern state of ETV technology. There's been evolution in cameras and technology um since the 1980s, but um, 1980s is when the camera technology and the endoscope technology really kind of reached its modern form. Things were pretty quiescent from the mid-1930s until the 1980s from an ETV standpoint, and especially in the 1950s when the VP shunt pressure regulated valve was invented. That really seemed to be a, a safer and more accepted procedure for hydrocephalus. And so we didn't see a lot of this, uh, ETV work. Um, here's a, just an example of, you know, one of these, uh, micro catheter, um, balloons. This is, uh, you can use a Fogerty catheter or there's other, uh, you know, custom neurosurgical catheters. This is just a, uh, uh, I believe a 3 French Fogerty catheter. Um, and this is in a, in a patient of mine with a, um, fairly narrow, um, Third ventricle and a small floor, but you can see that um kind of serial slow dilatation of these balloons after an initial ostomy is made um can successfully um open up the majority of the accessible floor of the third ventricle. Uh, OK. And then I thought you guys might like to see just kind of a, um, overview of the, the actual procedure from start to finish. Um, I'll go through this, uh, fairly quickly, step by step, but this is the endoscopic view, third. Uh, ventricle, we're using some cautery and opening up the floor there just to get an initial start. Uh, and you can use either a balloon as I showed, or you can use this kind of forcep technique to dilate and expand the uh cisternostomy. Um, and, uh, this is kind of just, uh, slowly and serially dilating. Um, then you can go in with the camera. You're gonna see a nice view. The PCAs, the basilar artery, that's actually the 6th nerve that you're seeing going across the screen there. Um, it's always an exciting view to, to look inside there. Um, and then, uh, some additional work to, um, extend the The ostomy, make it as large as possible. I personally think that's very important in these very young children, especially because one of the things we're constantly fighting against is closure of these. These ostomies in the growing infant. Um, And so I'll skip ahead just a little bit here. So we're going to move on. This is a plus minus portion of the procedure. This is the choroid plexus cauterization. I'll talk a little bit more about this at the end of the talk, but you can see kind of doing what I call painting the choroid plexus or carefully burning. surface of that with various different shaped electrocautery probes, moving on to the contralateral side through an ostomy in the septum pellucidum that allows us to get both sides through a single burr hole, and this is the final view. You can see all that kind of painted or torched. Uh, choroid plexus and as well as a, a zoomed-out view of the ostomy there. Um, but that's more or less what the procedure looks like. Um. So I think an important thing when we're talking about timing is kind of this idea of surgical success versus patient success. And what I mean by that is, over on the left here, you've got a patient a couple of years old. Um, this is a patient, uh, this is a very old picture, obviously, but, you know, if you, if you wait, uh, this patient's probably not going to do great. You can see some sunsetting eyes there, um, scalp veins, um, just not a great picture. But from a surgical standpoint, what a great candidate. You've got a nice, uh, easy view. The third ventricle is going to be safe and accessible. And uh you're gonna get a nice big ostomy and the patient's older, so it's not going to close very well. But uh are we really doing the patient any favors by making them wait that long? And then on the other side here, you've got a, a, a neonate, um, who, you know, the sooner we can probably start treating that hydrocephalus, the, the better to some degree they're going to do. But uh from a surgical standpoint, they're just a really poor candidate for, for good success in this procedure, higher complication risk, higher risk of moving on to needing other procedures. Um, so, Here on the left, you know, the risks of the procedure, hemorrhage, injury to the basilar artery, damage to the fornixx, which can cause memory loss, um, failure. So the ETV just doesn't work for multiple reasons, um, and that's where we turn to this ETV success score. You've probably heard of this. Some of you may have seen this before, but this has really stood the test of time and seems to, to hold up with the only thing really impacting this that's not on it being the cord plexus cauterization, which again, we'll talk about later, but Uh, you can see this is us in, in this aqueductal stenosis zone, um, and it's really the best etiology you can have, and that gives you 30 points. These points are really nice because they translate directly to percentages. This is the percentages of, uh, patients that are going to have a, um, uh, a good outcome, long. Term ETV success. And then the next thing we look at is age. And so this is a huge factor. So age trumps all. So, um, patients that are greater than 10 years old being the best, you add 50 points to your scale. So if they have aqueductal stenosis and you can wait till they're 10 years old, you're going to do great, 80% chance of success. Unfortunately, most of these patients we're dealing with, uh, with congenital, uh, operative stenosis are on this end here, that's less than 1 month, or maybe if we're lucky, this 1 to, less than 6 months. And so, we're talking about percentages of success in a lot of these patients that really end up in the 30 to 50% range. Uh, not a lot of surgeries that, uh, I will even consider offering, um, when we're in that range. Um, and the risks, uh, you know, the risks tend to get underplayed when surgeons talk about things or publish things. Um, but, um, there are real risks. Um, this is a, um, an example of one, so, This is, uh, again, similar case, um, except, uh, there's a little, uh, mishap here. That's the basilar artery. Basilar artery has been hit, um, and that's a big problem. Um, this was, um, you know, many hours of, of dealing with this, um, not a, a pleasant outcome. Fortunately, the patient Did do fine. We're able to get the bleeding controlled and to, to stop, but, you know, visualization is an issue, um, and certainly, um, this could have been, uh, much worse. So, uh, you know, I do think it's, it's, um, it's not a procedure to take lightly, especially in these, in these neonates and when you're dealing with these 30 to 50% success rates, it's, um, it's a big deal. Um, so, what does success look like? Uh, well, it's a little different, you know, we're used to seeing our shunted patients with smaller ventricles. It's easy. You get a scan and you can appreciate the change. There's no question about it. Uh, these are two patients that I have that are both doing really well with ETVs, um, but you, you, you know, you question if, if I did anything when you look at these images. And that's because we just don't see the same degree of ventricular reduction with this procedure, uh, but. Nonetheless, it's been shown time and time again that the developmental outcomes can be very good. Uh, I do like to see on the Sagvill image, you can see this jet stream, this black here. That's, that, that is CSF moving rapidly during the scan through that ostomy. It's just a nice thing to show the patency. You don't have to see that, but boy, it's reassuring to see that. It's just, it's different than what we're used to looking at with shunts. So why do these fail? You can have, these are the four reasons you can have the uh ostomy close, you can have it narrow or get close to closing, or you can have it be patent with other membranes that form anywhere along the, the third ventricle or the basil, basilar cisterns. Um, or you can just, it can just not be enough. It's just not enough CSF is going through that, or there could be some mixed element of communicating hydrocephalus these patients have, um, that is not, uh, treated by this procedure. And again, Uh, you know, this image here, I'm trying to grow here. It, it's, you're fighting against a brain that wants to heal, that wants to grow. You insult it by putting a, a hole in the bottom of it. Um, it's gonna do its very best to try to close that. So it, it's just an uphill battle in a growing, developing brain. Um, and again, that's been shown time and time again. This is, uh, one of the largest studies showing that, um, from the, uh, Toronto, uh, group, and you can see here that, um, this, uh, on this plot. The less than 1 month group just fares really quite poorly with um with their outcomes over time. 1 to 6 months is just a tiny bit better, but there's a big jump at that 6 month mark. That's kind of the magic number for this surgery. Here's another study by Mohammadi et al. and their percentages are actually a little bit better than most people report with their success, but nonetheless, it highlights the differences between the very young and even the, the, the slightly older. So, Uh, under 6 months of age here, you're really seeing that fall off. And then, um, You can see here, um, if there's a, uh, uh, a difference, if they're pre-term or post-term, um, that makes a big difference as well. And that's something that the ETV score doesn't really account for. Um, and there's, uh, not a standardized practice with that. I'm a big believer that you have to use the corrected age of the patient and take that into account in these premature babies. It makes a big difference. Um, so, uh, I just one thing I really want to emphasize with regards to timing and the different things you see or hear about, um, with the ETV. Procedure is aqueductal stenosis is not aqueductal stenosis. And so, uh, you know, Doctor Van Contessen alluded to some of the genetic outcomes, but this is really highlights some of these neurologic outcome differences. These are kind of artificial, um, uh, categorizations made by Rhodes at all, but, uh, I think it's a nice way of looking at this. So, congenital acute, so these are the kids with big ventricles right from the time of birth that are showing progression. They seem to have a, a better outcome neurologically over time with shun. than they do with ETV. Now, if it's a chronic, more slowly progressive hydrocephalus, that difference completely disappears. Uh, and then if it's, uh, you know, these adult cases, you can see also doesn't seem to make much of a difference if it's chronic or acute. But boy, the one that really stands out is that, that big ventricles, um, progression early on, those patients just currently don't seem to respond super well to, um, to ETV. Um, so, is this procedure safe? Um, Uh, yeah, it, it, it has its risks, as I showed you, and these are some of the numbers here. Um, and, you know, looking at this 2011 meta meta-analysis, um, there's permanent morbidity at a rate of 2.4% and a mortality of 0.2, uh, 0.21%. So, overall, I consider this a very safe, um, procedure. It's something that I'm willing to offer families if they understand, um, the risks and the, the limited benefits. Um, but, uh, what are we comparing it to? So, shunting, is shunting safer? Um, well, the in-hospital mortality is certainly lower, 0.3 to 0.8%. Uh, and the, um, uh, long-term outcomes, though, this is a, uh, you can only do this really in Norway. They have these really amazing longitudinal studies, um, 40 years or more of follow-up, zero patients were lost to follow-up. They have a mortality rate of 48% overall, and 8% of those were attributed to shunt failures and shunt. Related issues. So, the shunt is kind of the constantly ticking time bomb, whereas with the ETV procedure, if it works and you've got success at 6 months to 1 year, very few of those patients are going to have long-term delayed complications. I really like this quote. This is by Dr. Hal Rikate, a neurosurgeon, hydrocephalus guru. ETV is substantially more dangerous than a shunt procedure and substantially less dangerous. than a lifetime of shunt dependency. And this is the conversation that I try to have with families when we're talking about the ETV procedure and the timing of it. And so much of this just depends on, uh, a really, I think, a discussion with the family and their risk appetite. Um, you're looking at the neurologic signs, um, you know, if you're seeing these risk factors, um, then you, you just need to intervene. You can't continue to wait and hope that this is going to be one of those uh Rhous type 2 or chronic progressive, um. Uh, situations. Um, if there's early monitoring that's not showing these excessive fussiness, these jumps in head circumference, um, fontanelle changes, the child's really doing well, I think you can kind of hang in there and monitor the patient closely and see if they're gonna be one of these more chronic patients that might make it to, uh, you know, 3 months or hopefully, again, that magic cutoff of 6 months where we see a big jump in success. Um, you know, there's no guidelines for this. My personal recommendation is if there's no early red flags, um, I would watch these patients for 1 to 2 weeks, uh, preferably inpatient with very close observation. If, um, you're not, if you're not moving comfortable, uh, if you're not comfortable moving on with the patients to an outpatient setting with at least a 2-week, uh, gap in follow-up, uh, That's my, that's my red flag warning sign that, you know, that patient, if you can't let them go for two weeks without seeing him with another ultrasound or something, you got to bite the bullet and, and shunt that patient, in my opinion. Um, and then can the family deal with the expectation of failure. So, we're dealing, if we're talking about a 50% success rate, um, you know, with one of these procedures, that's if you, if you can get. You know, we're, we're close to that six-month mark, even, um, you know, you, you, you're doing worse than Vegas odds here. And so, I, I think that, uh, you know, setting a family up to, to understand that is really important. Again, if, if you understand the lifetime risks of dealing with a shunt, in my opinion, that might be worth it, but that's not really for everyone. So it's just really important to have an informed discussion about this. So, can we do better? What's, what's in the future? Um, Stented ETV. This has been tried in multiple studies using some kind of hardware to hold it open and fight against that closure. Um, and this just hasn't really seemed to pan out very well. Um, just like shunt failure, when you put some kind of hardware in there, it's a foreign body. You get a foreign body reaction that can happen at any time in the patient's life. It's still kind of that ticking time bomb of, of just waiting for it to, to close. Um, and it looks like I'm running over time. I'm gonna try to, I wanna talk real quickly again about the choroid plexus data. So, Uh, what about this cho plexus cauterization? Obviously, I showed you that video. I do do it. I like to do it. Um, I want to believe in it. Um, and, uh, this is going full circle back to Dandy's original trials, um, and adding that procedure to the ETV. It's not enough by itself. ETV maybe is not enough by itself in some of these patients, but can we improve it? So, the big data comes from this, uh, sub-Saharan African study from Doctor Wharf, um, showing a 30% improvement. So it's just an instant. Plus 30 on that ETV success score scale. However, unfortunately, some further data has not really been able to replicate that. Looking at a meta-analysis of other published studies on it, it seems like that benefit is somehow exclusive to Dr. Wharf's population, either from surgeon factors or patient population factors remains unknown, but we're just not seeing those same kind of numbers in the larger data sets. Um, so, uh, just, uh, real quick, what about converting to ETV? Uh, if we start with the shunt, can we just buy some time, use the shunt as a temporizing measure? Um, a lot of, uh, complications that come along with that as far as the timing, when is the best time to do it? Is the family ready to go from a working shunt to a, a questionable ATV? Procedure, uh, as far as the outcomes, um, it, it's a little bit difficult to, um, to get that to fit into the patient's lifestyle, so to speak, um, but it's certainly an option. It's certainly something, something that can be considered. But in my practice, um, most families are not really interested in doing that once they've kind of bought into the shunt. Um. Just want to do a quick plug. I don't make any money off of this. Um, this is just, uh, for patients with hydrocephalus that I, I know the majority of you see. Uh, this HydroAsist app, um, from the Hydrocephalus Association that I've helped develop, um, is a really nice tool, regardless of whether it's a patient with an ETV or a shunt, um, this can help, um, track them, especially if they're mobile and moving around to different centers. Uh, thank you guys so much. I apologize for going over time.