Transcript
Question: Yes, thank you once more for the really interesting lectures. I had two questions. One of the last part, one of the part before the break. Starting with the last part, the Chiari malformations. I’ve now come across two patients who had a decompression for a Chiari malformation and sometime after that, some months after that, developed acute orthostatic headaches. They were referred to me to rule out CSF leaks, spinal CSF leaks. We did extensive spinal imaging, myelography, found nothing. We rechecked the pre-operative imaging to make sure that these were real Chiari’s and not pseudo-Chiari’s that had been CSF leaks spinal all along, and we found nothing. Is this something you have come across, and is this something with a change in dural compliance post-operatively, or what is your idea about this and how to treat it?
Answer:
Dr. Chu: I’ve come across that uncommonly, and the brain imaging was fine. Sometimes the question of it’s a pseudomeningocele leaking just low. Oftentimes on these Chiari’s are a little bit lower. Where you do a C1 laminectomy, some of that actually ends up being in the cervical spine that drop, but not there. Huh. Okay. Yeah, it might be a compliance issue. I haven’t really seen that a ton.
Question: My other question was about the obstetrics that were talked about before the break. My question is related to that. So pregnant women with spontaneous leaks. I get quite a lot of questions from gynecologists and anesthesiologists about some, I think four patients we’ve seen now, who are pregnant, have a spontaneous leak. Can they have a spontaneous delivery? What with all the pressure happening around there? Can they have epidural analgesia? So there’s not a lot of literature about that. Some case reports show that’s usually fine. But what’s your experience with this?
Answer:
Dr. Leffert: Does anyone have any experience with this? Yeah. I mean from an anesthetic standpoint, I would say I would feel comfortable doing a small gauge pencil point spinal anesthetic on them for sure. The issue of Valsalva—if they’re symptomatic already, then they might not want to have a Valsalva delivery, vaginal delivery.
But in your opinion, it’s not a clear contraindication, like a medical contraindication, right?
Dr. Leffert: Not necessarily. I mean, that would be a perfect time for a multidisciplinary discussion, and that’s what we actually do, because we have all kinds of different sorts of fascinomas that show up when women come to deliver, and we have a multidisciplinary discussion about what are the relative risks and benefits.
Unknown Speaker: Yeah, we did as well, and in the end they delivered spontaneously, and they were all fine. So, in my humble opinion, very small. And it’s safe. But I was wondering if anyone else has more experience with this.
Dr. Urbach: But what I learned from your presentation is we all have our patients in bed for two to four hours after the blood patch. And just for me that never made sense. And now you showed, yeah, okay, they get better when they—or they get worse when they lie for four hours. And the problem, or why I’m not convinced so far, is because we want to have the blood getting distributed along a long distance, and that is not if the patients are just lying flat and do not move. So they have to move, and for us it could be a paradigm shift change, but we can send them immediately home. Any comments from the audience too?
Dr. Kranz: I mean, there’s what you think is going on and then what you know is going on, and I think a lot of times these recommendations are based on what we think is going on because we don’t have hard data. But I think one of the ideas is that when you’re laying down, you’re decreasing the CSF pressure in the lumbar spine. So if you’re trying to seal a leak by putting a patient flat or even in Trendelenburg, you’re decreasing the CSF pressure in an attempt to prevent—sort of like putting a lumbar drain in to get a cranial leak to heal. You’re decompressing the system. So whether or not that has any real effect or not, that’s sort of the…
Question: I have a question for Dr. Beck. The neomembranes that we all see during surgery. I always thought it was an inflammatory reaction to the epidural blood patch because it’s reminiscent of the subdural intracranial membranes with the chronic blood mixing with the CSF causing an inflammatory reaction there. Do you have any thoughts on that?
Answer:
Dr. Beck: Could be. I don’t know for sure, but I personally think it could be an inflammatory reaction, but I rather think it’s a reaction to CSF in the epidural space when we do revision surgery. Unfortunately, we haven’t analyzed the cases without any epidural blood patch before, but we do a lot of revision surgery after spinal cases, disc herniations, fusion surgery, and there are no membranes. And of course, there was always blood in contact with the epidural fat in the epidural space. Thinking to the analogy in SIH where all these membranes form, so I believe it’s rather a reaction to extrathecal CSF. When CSF comes into contact with epidural fat or space there’s something going on — inflammatory yes, but not due to the blood, rather to the CSF. But I think [inaudible] has an idea.
Unknown Speaker: May I comment on that? I’m pretty sure it’s not the effect of the blood patch, the membrane formation. This was what I thought at the beginning as well because it seems so logic, but we see the same membranes and even the same amount of membranes in patients with SIH that didn’t have one blood patch before. So it could not be the blood patch. It must be the CSF that’s the problem, that causes the membrane formation. For me, it’s like the try of your body like healing and patching itself, in a simple-minded way of speaking.
Unknown Speaker: Also from a blood patch perspective you would suspect that the blood spreads, which some data has shown, over several levels, and the membranes are usually formed at the level of the post dural puncture hole and adjacent to that, and then they stop. So that would be an argument against this as well.
Dr. Beck: The third argument in favor for not being the blood is that usually the leak is never where we suspect it to be. It’s almost always higher. So if the anesthetist—I don’t know what’s the mechanism, at least in Europe or in Germany—he says he did a puncture in neurology at L4-5 or so, it’s almost always 1-2 or 2-3. And this doesn’t fit as well with the blood patch [inaudible], hence no proof.
Unknown Speaker: As a response to what’s happening in the epidural space, we often consider the epidural space to be a very simple space. It’s not a space, it’s a compartment. And we think it’s filled with a sort of random array. At least we anesthesiologists — sorry, maybe I shouldn’t tell this in this esteemed audience — but as anesthesiologists, we often think it’s just randomly filled with substances like fat, etc. But recently there were some papers that actually there is a sort of paradural membrane, and that the whole epidural space has a sort of synovium-functioning response to friction and whatever. So maybe the membranes are a response of this epidural environmental damage.
Unknown Speaker: Seems like a good question maybe for an animal model. I don’t know if anybody has capabilities in doing that, but that might be a good way to answer this. You could do blood patches and take a look, or yeah.