Slides
Transcript
Thank you for the opportunity to speak. Clearly, I’ve been having a wonderful time in Amsterdam. I have no relevant disclosure, unless Wouter and I find some LA Rams players on the football field that actually have a league active while we’re there. We keep looking, but we don’t have it. It’s been terrific to have the family in Amsterdam and to see where Wouter grew up and all this stuff. And John, you think that you were made fun of for your talk? I mean, my talk literally means, “Ray, I know you’ve caused a lot of leaks and how’d you fix them.” I mean, that’s the actual definition of the talk. I mean, my reputation has preceded me.
The other thing I thought when I was asked for this talk is that there’s some part this could be really short. I remember conversations about skull base CSF leaks. They never caused the CSF hypotension syndrome. So maybe I’ll just blaze through this really quick. We’ll get a really long break. And then people started to find other leaks. The good people in this room and others started to find ways to have leaks, and some of them are even the ones that Peter Kranz referred to, like there may be something different for pediatrics. If they can have enough decrease in CSF volume, they can create some type of leak syndrome—not the full CSF hypotension syndrome, but something—and they can have these interesting fistulas that can be repaired.
So maybe there is a role for us to talk about some of these different things and repairs. So I was going to break this down into different parts of the skull base, what we would call the anterior, the middle, and the posterior cranial fossa.
I, on the one hand, apologize for the anatomy picture. On the other hand, if on the break you go out there and you’re nauseated and you eat less cookies, welcome to the academic Ozempic—you’re welcome.
So for the anterior fossa, one of the things we worry about is the frontal sinus, which is cut off in this picture, and the cribriform plate.Those are areas that are common to find leaks that we will address. And so some of that would be an example of a case like this. There’s this 52-year-old woman. She had this progressive depression. She wanted to do less and less things with her family. Her husband was talking about divorce, and she was even being thought for electroconvulsive therapy. And instead they found this—it’s a little subtle—and you can resect the tumor, that’s one thing. And then actually this is more than 12 years out, and the family is still together. So it’s the family counseling part of my badge, but it’s the part of what do you do for all the reconstruction.
So the best access to that tumor is through the frontal sinus this way. That’s where the blood supply is. Then you have to reconstruct and seal things off, leak. So with that you typically exonerate the frontal mucosa. Some people prefer to really tear out all that mucosa, because in that future all that disrupted mucus layers can create a mucous seal. I think there’s a lot where I tend to push that down, to scrape it away but push it down into the frontonasal duct and try to block things off. We just want to have no residual tissue as the goal. An abdominal fat graft is important for that. And it’s nice to have a vascularized pericranial flap to help really seal, right? The nasal cavity and the intracranial cavity are not supposed to communicate.
And so in this you can see some of the fat graft in the sinus here. That’s what some of this material is. I swear this is not how I put someone’s head back together. That’s the recons. But you can see the fat graft and the sinus there. But it prepares you for other kinds of things, like this patient with a gunshot wound.
It’s always interesting when you have someone come to your hospital with a gunshot wound who’s actually talking because it’s just a little different than most gunshot wounds are ultimately fatal. He did decompensate while he was there at the hospital, but we were able to work on things. And so this is what happened to his frontal sinus.
There are programs where if you have a minor trauma like a blunt trauma and there’s almost any frontal sinus fracture, they may talk about repair for future CSF leak. But for this, you’re definitely committed to repair the sinus if the patient’s going to survive and to try and prevent leak and meningitis and things.
So when that bullet fragment comes through the sinus and obliterates and leaves pieces like this, that same kind of reconstruction that is performed for that meningioma is done basically, and hoping you can find enough vascularized pericranium to cover the defect.
And so here’s some of that reconstruction and again obliterating that sinus and all that stuff for the mucosa and everything. With our expanded endonasal techniques, once in a while we run across a patient from another hospital that has an issue. And it’s one thing if you have an intact skull base and a feeding tube placed, it’s a different thing if you have a big hole in your skull base and a feeding tube does something wrong.
So that’s one of those things that gets tricky with now transplantum and these other expanded transethmoid surgeries. We have to make sure we look at what we can do to prevent problems, and CSF leak could be a bigger problem than that, not necessarily that other thing.
And so this is that little bit of picture for the naoseptal flap. You can have a vascularized section of your nasal mucosa that you can peel off and rotate towards the middle. Dennis, when I get all this wrong just correct me later, okay. And then it can be another tissue layer to help prevent CSF from leaking out.
We already talked about tegmen defects a little bit, and we’ll talk a little bit more about that. Also, sometimes these are post-traumatic. One other example would be this patient who’s 70, had normal pressure hydrocephalus from Maui, and actually had a shunt placed, but he had an infection and then came to LA for revision. That all went fine, but he started to develop these episodes where every time he would fly he would get this spontaneous pneumoventricle and have an altered neurologic status for a couple weeks until the air absorbed. And what we started to notice is not just air in the ventricle but air down at the skull base, and we figured out that he had a tegmen leak and went and repaired that.
This is actually the same kind of repair as that superior semicircular dehiscence canal syndrome, but this is what we did for this. So you can have a bone graft or use bone cement depending on how close you are to ossicles. Obviously, bone cement and the ossicles for hearing are not really compatible, and lots of drill sealant stuff.
This is one of those dehiscences that’s to the middle ear where a patient had hearing loss and an effusion, and someone put in a PE tube, and then there was fluid and it leaked CSF. And so we do this with one of our neurotologists, and this is a part—these neurosurgical pictures are always upside down because you can’t sit on someone’s chest to operate.
This is a part that’s a mastoidectomy, a limited mastoidectomy, and this is subtemporally after a craniotomy. You can see this defect, that these two spaces should not connect, and you can lay down a dural graft. You can lay down either autologous bone or bone cement depending on the scenario, and a dural sealant, and try to reconstruct these things.
On these CTs, these two are coronal views. You can see these defects in the cancellous bone, right? You should have harder bone everywhere, and you can fashion a small craniotomy, and sometimes you can use a little bit of a split-thickness graft off that and have a little piece of graft here to cover some of those defects and scar over that thinned area.
And there’s another case that someone reported that had actually spontaneous pneumocephalus and a CSF hypotension syndrome, but it actually turns out we think it was more the CSF, like a fistula, more than the pneumocephalus and the tegmen defect.
For that superior semicircular syndrome, people tend to have vertiginous symptoms more than dizziness. Sometimes they have some hearing loss or aural fullness and weird sounds. This is a 27-year-old that had those kinds of things. Her heartbeat was louder than normal and things. And again, you see some of this defect in bone down here on the coronal view. For this one, her temporal bone is thinner, so we actually fashioned more of a full-thickness autograft and just put some mesh on some of the craniotomy to cover things up.
In the posterior fossa, there are fewer spontaneous pathologies. I mean, you could always have trauma. Actually, there was one of our colleagues that had someone in LA who got stabbed in the back of the head with scissors and that kind of thing. But some of these are really post-operative or things related to Chiari malformations.
So this kind of syndrome would sound kind of familiar. I will not take credit for this tumor resection. Surprisingly, this is actually resected by a neurosurgeon out in Temecula. It’s like a little wine country area east of San Diego. But I will also not take credit for this pseudomeningocele. It’s there, slightly subtle.
In the waiting room, the nurse is like, “She’s got a big mass in her neck. I think she’s in the wrong clinic.” It was awesome. At that surgery, I can totally understand if you don’t have terrific dural edges for closure, but all they did was onlay some DuraGraft and that’s not really going to cut it for most of these scenarios. I was talking with Angelique Tay and apparently there are some neurosurgical programs who still debate whether watertight closure is required in the posterior fossa. I mean, we’ve been doing it that way for 20 years, but apparently some people are not attached to that idea.
And so at re-exploration, I needed to suture as much as I can. There are some areas where the dural edges were eroded where I anchored the dural graft into the bone. A multi-layer closure, kind of like if you had a big endonasal opening and you need multi-layer closure to seal things off, obviously layers of tissue glue. And then for that one, I used acetazolamide for a month and tapered her off. I guess the question is whether I should be using topiramate more than acetazolamide. We’re gonna have to try that out.
I’ve seen people where they have a leak in the posterior fossa and they don’t immediately repair and they go straight to a lumbar shunt. I feel that’s usually not the best idea. This is one of those tricky things in medicine. Every medicine we test is tested well, like a randomized control trial. But so many of these procedures aren’t. You can’t actually recruit people for a randomized trial of surgical repair of a leak versus a lumbar drain, lumbar shunt, because most of us would say I don’t have equipoise and I couldn’t put a shunt in somebody if I can avoid it. Right? But people do. Most of the neurosurgeons in this room have taken out someone else’s lumbar shunt that has caused a leak. It literally causes a CSF hypotension syndrome. Right? It’s literally the cause.
This is a different patient that had posterior tussive headaches and some tingling in the hands that has this Chiari. And so at a Chiari malformation, we have to deal with the CSF layers. In general, there are a few neurosurgeons still who would do the bony and ligamentous decompression of a Chiari and ultrasound, and if the cerebellar tonsils move well enough, they might say that that patient’s probably okay. I think for most people it’s become that standard of wanting to reoperate less, like I don’t want to leave stones unturned. Sometimes there are membranes in there, and it’s better to free up all the CSF flow.
And so this is an example of that where a small craniectomy is done and there’s cerebellar tonsils and opening all these arachnoid membranes to make sure there’s good CSF flow down to the spine and a sutured watertight dural graft closure with a sealant. There are people who talk about lots of interrupted sutures here but it’s hard to really get that watertight closure. It’s the tension of pulling that really gets that watertight closure typically. And so I remember when I was an intern, we had this one rotation. We rotated with a private group out of St. Paul and one of the first things I did was oversell a Chiari decompression where clearly they didn’t have a watertight dural closure and they closed with staples, which I don’t understand. Also not watertight. It’s just friendly stuff.
And where else would I be if I didn’t talk about a Chiari and talk about someone who had some other finding on the scan? Sometimes I use this with oral boards preparation cases for our former residents and make sure they notice other things on the scan, other things that are subtle or not, and try to take them through attacking the syrinx versus attacking the Chiari. And I want to make sure Marcus Stoodley is paying attention, I had to show him a syrinx.
So in final, that skull base defects are generally reparable. We can fix these leaks. Watertight closure I think is very important when it’s necessary. Vascularized tissue grafts can be very useful. We know tons about dural grafts and dural sealants. We tend to use a lot more acetazolamide than lumbar drain placement, but everyone can vary with that a little bit. And to us, most of the time shunt placement should be a last resort. I have been asked to place a ventricular shunt in someone who had multiple lumbar surgeries that started outside hospital to repair a CSF leak and by the time there was a different repair level, there was essentially no dura. But in general, shunts should not be where we go in the beginning.
I want to thank everyone for the opportunity to speak and it’s been great taking the kids to the Van Gogh Museum and the Rijksmuseum, but I didn’t know all I had to go was to Pancakes Amsterdam. You just got to pick the right bathroom and you can see all the art you want. Thank you.