[Music] so let's take a look at some of these procedures that we do endoscopic third ventriculostomy is the most common one that you're likely to see um it's for obstructive hydrocephalus here we can see these cerebral aqueduct is obstructed ventricles are big floor of the third ventricles bow down and what we want to do is make a new hole can't get out here let's make one here let's poke okay when we get into the third ventricle there's some more anatomy we need to be familiar with okay um when we take a look we can sit here we can see the apex of the basilar artery through the thin floor x marks the spot that's where we're going probably don't want to go into the mammillary bodies or midbrain that's bad form and the dorsum cell or the back of really the back of the cell the clivis is visible here and what we want to do is poke through um we can see the clivis now the basilar artery um and this is what the hole looks like what's that look like in real time see if videos are gonna work here we go so we'll talk you through no we won't talk you through you may have to take your cursor and turn it off the laser pointer setting in order to get the video to play for you how do i do okay just do that there we go okay so now we're coming down through i'm going to talk quickly because we got to move through the foramen of monroe we can see this blush up here is the infinibula recess that's actually the optic chiasm at the top of the screen we're going to poke a hole through the floor of the third ventricle here here's our poke now we're going to want to make that ultimately bigger so we're going to go down through with a balloon dilate that up there are a lot of schools of thought in terms of how best to do this some people like to sort of dilate the whole um they're concerned that if you put traction back you can grab a perforating vessel always bad form but i will tell you it's what i do i've never had a problem with that personally um and we go down through and we take a look um and uh there's big red right there that's the basilar artery and the perforators probably leave those alone and that operation is very effective at treating obstructive hydrocephalus um we'll come back through with our endoscope we'll say yep fornix all those veins everything looks good and we're done it's a quick operation you can do this in less than 10 minutes once you get uh used to it um there are other operations that we do though here's a child who has a an arachnoid cyst sitting within the third ventricle um we want to pop that so that we can equalize pressures and reestablish csf flow this is uh not the world's greatest optics for this case but we can take a look at how there's the cyst within the foramen of monroe again we can see the septal vein chloride plexus as well as seeing the thalamus striate vein again um and you know the uh how we pop these is pretty straightforward it's cauterize the capsule and poke our way down through this this is not elegant or sexy surgery uh uh but it's effective and so and once we do that and we pop on through okay we can use uh really just traction and cautery to enlarge that hole you can see me sort of grabbing and enlarging it here pulling forward there we go and is that effective for us well it's certainly in this case sort of backing back out through okay now we can see that's down away from the foramen monroe we go we'll go through a septostomy here to look on the other side okay looks good that's retracted away from the other foramen and let's get out of dodge um and then finally you know grab there definitely are circumstances where uh pineal tumors are classic for this this will be uh something you'll talk about in your breakout sessions later on on today but if you've got an interventricular tumor you want to know what it is and you want to get that answer to guide treatment because there are circumstances where um some form of adjuvant therapy is a better way to go let's go in there and grab a piece of that we can do that in the anterior third ventricle like we do here okay this is a supercellar uh ultimately germ cell tumor and you can see again grabbing a piece of this in the third ventricle and bringing it on out you get small specimens but you get appropriate specimen for a diagnosis that's a very small amount of blood uh believe me you can you can see a lot more than that and ventriculoscopy and you just irrigate your way out of it there are also times where we can go back to the pineal region this is a low frontal trajectory you can see the blue trajectory here where it's a lower incision um to go through the concept is the same going up there and you'll see a pair of grabbers and you can imagine how that works keep pearls to this really important to keep your eyes on the screen at all times you take them away um you're not paying attention you're going to take that scope and you're going to have it somewhere like the brainstem you don't want to be the other thing is you can't always see what's going on that proximal scope so where you are okay up here on the scope as opposed to with the tip you can see what's going on here you won't see here and you can absolutely do a traction injury so be aware that the proximal scope can be a problem and then finally trajectory matters and the long axis that you the longest axis that you move through with csf the more maneuverability you have this is a diagram from peter and akagi um that's a great diagram illustrating that it shows the approach trajectory here gives you visibility of the vascular supply of this small tumor whereas if you're coming in from this trajectory from the top you can't see anything uh that you need to see so trajectory absolutely matters when it comes to uh neuro endoscopic approaches so in summary surgical anatomy the ventricular system we went over very quickly it's going to require some study on your part of reviewing this um that's okay and we've all been there we've all done it it's important work to do but this will give you some basics of the endoscopic uh set up in the room how we get in and then just thinking what do we do we poke popping [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