[Music] so i just wanted to take it through a case here this is a child that just had surgery about a little over a month ago for for hydrocephalus which initially presented two years ago with headaches nausea and vomiting and neck pain her parents took her to a local hospital but by the time she was imaged and transferred to our facility she was lethargic with bradycardia and a colleague of mine took her to surgery for a placement of an external ventricular drain she woke up immediately and felt a whole lot better her exam only was notable for papilloedema she had normal motor fine he's no other cranial neuropathy so she could see here she had this posterior of this large salamic mass that was obstructing the aqueduct we eventually performed an occipital transcentorial approach and sub totally resected the lesion most of it out but not all of it and it was a unfortunately a a3k 27m high grade diffuse midline glioma and uh she's battled that for the last few years with radiate radiation chemotherapy and a few different clinical trials but she returned recently with headaches and vomiting and this is the progression from january to march until now in may and she was having a frequent headaches and vomiting and you can see that that that here's the picture here on the t1 on the right there's this the tumor is growing back and it's now obstructing the the extreme aqueduct so we recommended um an endoscopic third ventriculostomy her oncologist wanted additional tissue like they always do so we also were able to use a flexible scope to biopsy some of the tumor for additional material but the primary goal of surgery the first thing that we did was that their ventriculosphere to deal with their hydrocephalus and it's going to take you through this so this is how again after the setup that i described this is a right frontal approach here in the residence and make the burr hole here in a second and then once once the door is coagulated and open um this is the stylet here from this navigation system in the peel away sheath and you can see this you know here we're tracking real time through the through the vent through the brain into the ventricle to get us into the uh frontal horn the right way the first time so that's that's you see a little drop of csf starting to come out we're just barely in the ventricle here um so that's that's how it starts the the obturator is removed the pillow sheath is open a little bit and then the scope is introduced sorry scope is introduced and this is kind of what we saw immediately so again we want to make sure that we're on the correct side she's got a very large thalamus triathane cory plexus the frame of monroe the septal vein is really diminutive didn't really see it very well but it's just not not really there but but we knew we were on the correct side and you can see here that we're going to enter the the third ventricle here in a second and really it's apparent very quickly you can see the mammillary bodies right here as we get things stabilized here's the floor the tuber scenarium infundibular recess that pink color right here optic chiasm the suprachiasmatic reflex and here's we're just looking back posteriorly to get a look at the the tumor there the little biopsy in a few minutes but this was just a quick look back there to see what it what it looked like so this was a flexible skill which you can take a look back this can also be done with the origin scope but again it can be difficult um depending on on where your burr hole is and some some surgeons have actually used two bur holes to do that two different trajectories to biopsy and also do the etv so the flexible scope gives you some added options there so again here's the there's the two percent there's the probe coming down the blunt probe the grasping force up you'll see a pop actually you can easily feel that but you'll see it too that kind of floor shutters a little bit of smoke there just a small bit of blood from the surface but that's really not much to worry about that'll often oftentimes stop with irrigation which is kind of running slowly in the background and then um sometimes if it's really going you may have to use cautery for that but it's pretty infrequent to do that or even tampering on that with the with the ambolectomy blonde here's the balloon coming down so you can see it pops through the uh floor and we're just going to dilate this up here one second and then lower the balloon again before we remove it and there's a nice opening in the floor but there's another membrane here that we've got to deal with so this is membrane olympus you can see that in the way there i think without i mean there's some smaller openings but we generally recommend opening that as well so i use the bugley wire without power just as a caught electric cautery wire but it's a little stiffer than the than the balloon and just made another opening which we further dilated just to ensure that we had really a nice free opening to the pre-pontine cistern as you'll see here in a second and that's the the ultimate view there that the pre-pontine cistern with the bowser artery pumping away the clive is here and you can see the neurovascular structures off the side so here's the surface of the pons right here and then when we're done here i don't show the biopsy but we kind of take a quick look when we're finished with the irrigation off and you can see the floor kind of pulsating nicely back and forth with the cardiac cycle just gives you a good idea so that's generally a good sign that things will will work um so most of these children will go home post-op day one or two um she did very well was discharged the next day her headaches and vomiting resolved very quickly and this was four weeks later so you can see there has been a considerable reduction in the size of eventually which correlates with her improved symptoms unfortunately she still has a battle ahead of her with her tumor but her hydrocephalus for right now is not a part of that so other post-operative considerations number one imaging you know some some get that i typically get a ct scan easier tonight just to make sure but i'm not always um just to make sure there's no bleeding but typically when we're finished we inspect the third ventricle the lateral ventricle if it looks pretty quiet then then i'll oftentimes skip that you need to watch urine output you are making some manipulation of the hypothalamus it's rare but they can have some transient diabetes insipidus permanent endocrinopathy is very unusual antibiotics are continued for like a day some surgeons use dexamethasone to try to limit inflammation around the ostomy for a few days to let that kind of prevent it from sticking if you will again most kids are discharged home the next day or a day day after complications are pretty rare infection is very low less than two percent um hemorrhage again is also uncommon it usually stops with irrigation or tamponade um but significant bleeding if it happens can be can be cauterized but if not then the procedure generally would be abandoned and an evd placed just for external drainage the thing we worry about the most which is fortunately very infrequent is an injury to the bowel or artery so less than 0.2 percent and a permanent endocrinologist i mentioned is pretty infrequent so in terms of outcomes if you look at all all comers the failure rate of two years is about 35 percent but most of those happen within six months of surgery and success really depends on a few factors age is critical and also the etiology and this was really an important paper that was published in 2009 describing the etv success score it's a very simple thing this is something that you should on a neurosurgery service keep in your hip pocket if you will keep take a picture of it and keep it on your phone but it takes into account the age etiology and whether or not the person had a prior shunt or not and you see just essentially simply add up the points so in a 15 year old boy like this with a technical mask never had a shunt before he gets 50 points for being 15 years old he's got aqueductal stenosis that's 30 points and see since he never had a shunt add that all up that's a 90 chance of success so it's a very high likelihood that that would work as long as the other anatomic features like technically you could you could do this as long as the pre-fontaine cistern is sufficient it's not dangerous to try that it's not contraindicated and this this score has been validated by other groups and it really is a helpful adjunct to predicting responses so generally for less than six months the results are not as good at least fifty percent of those kids under six months of age will fail and certain ideologies like myelomeningocele there's a history infection or intraventricular hemorrhage again are much less likely to work but in conjunction with chord plexus coagulation these generally may have a better better outcome and again the best case scenario is a kid with a technical tumor a pineal tumor or aqueduct stenosis where up until the point in time when the things finally closed off their circulation of csf was normal so if you can restore it restore that circulation into the subarachnoid space then then it generally will work so if you're over two the failure rate's pretty low um if it does fail you can repeat that and it can be successful in more than 50 of the cases and late failures can occur this is not a this is a child that died of a another had a tumor but died of oncological issues a few years after etv but this was autopsy you can still see that the ostomy was was open at the time of her demise so again etv is an ex really an effective treatment for hydrocephalus it's important that you must identify the relevant anatomy before proceeding and keep in mind that it's a deep procedure you have a instrument deep inside the brain so small movements and general a gentle touch is necessary because you really don't want to be whipping that scope around inside the head and this is another patient it's the cory plexus you can see nicely you need to maintain control that endoscope at all times and you don't want to be advancing instruments beyond your your field of views if you know instruments you can't really have that in there if you can't see the tip again if there's a small pre-pontine sister and if the anatomy is otherwise distorted then it may not be a good case and this is just going to go through this quickly but you can see the tuber scenario here very nicely the infantibular recess here's the here's the floor and eventually once that fenestration is created um get a nice view of the pre-pontine sister in there phasor artery we're just a little bit off to his left side [Music] hey everyone ryan rad here from neurosurgerytraining.org if you like that video subscribe and donate to keep our content available for medical students across the world