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Transcript
Thank you for these excellent talks. And now, if you don’t are successful with the epidural blood patching, send them to a surgeon. I don’t have the answer, but I can show you more riddles and what we find during surgery for post-dural puncture headache. And I completely agree that we probably need to rewrite the basics, that we do basic science and need to define this disease better.
Ian Carroll taught me that we really do need to look at the needle size. It is important. It took a long time to accept this. It is important. And chronic post-dural puncture headache—what is it? It is not really defined in the International Classification of Headache Disorders. There’s a stop at 5 days and there’s nothing spoken about chronic PDPH, but it does exist, and it is clearly to be separated from spontaneous intracranial hypotension. However, the clinical signs and symptoms are quite similar. I don’t go over that, you all know that.
And the bottom line again is it’s a severe disease, it’s not benign. And these very few patients—probably concerning the high number of lumbar punctures or inadvertent dural punctures—but this is a severe problem for these patients, and they all lose, again, their lives and their partners and their job.
Very highly biased data. This is since we started to do surgery on these patients a couple of years ago. We have higher numbers now. Just our patients, 60 patients, were over one year of sick leave and hospitalized over one month due to chronic post-dural puncture headache. And this is a series with the colleagues from Vienna, and again highly, highly biased. And this study was mentioned already—it’s an internet-based study, so it’s biased—but in this group of patients only 12% did work full-time in their job.
So one consequence could be, probably not during labor, but during a diagnostic lumbar puncture in neurology, if we have such a severe disease afterwards, why not document where you stick in the needle? I mean, every, every, every anesthesiology note reads lumbar puncture PDA was done at four or five. It’s never there, never ever, and you do not document it. And of course, you cannot document it during labor, but probably in a stationary setting in neurology you should even consider taking an X-ray. Then you know what you do and where you are, or do a photograph, and of course follow these patients.
Coming back to our experience now in Freiburg, these 40 patients—we do minimally invasive surgery. We started 2-3, because it is never at 4-5. We start at level 2-3, go even up to 1-2. A lot of punctures are done way higher and go down to 3-4. And now you see some findings. Of course, the most famous finding is the so-called arachnoid bleb, you mentioned already, and this is how it looks like during surgery—minimally invasive approach.
And now you have the first finding. It’s clearly pathologic. You have these sticky membranes. It’s like a foil over the dura. It’s very sticky. It’s vascularized. And only if you open it, you find this bleb. And then you see CSF oozing out because it’s washing the blood away. This is collecting next to the bleb. So there’s clear CSF oozing out. But this is not a high-flow state. It’s clearly oozing out. But this is not a high-flow leak as we see in SIH. And who knows what I did by removing the membrane. Probably I open it only. So easy to close, easy to handle. But you have clear findings. This is one of these sticky membranes. And if I push a little bit on it, you see they are vascularized and you see the vessels elongated. And only after you remove it, you see here is a clear—you can cut it. It’s clearly there. And this is never there in plain spine surgery for lumbar disc surgery or anything like that.
Then you have the bleb and CSF is oozing out. We called it the weeping dura and maybe that’s the origin. Maybe not. These patients get better, but not all of them. Then this is another bleb. It’s even more obvious. So all of the sticky membrane is removed, and there it’s a bigger bleb and there’s more CSF oozing out. Probably this is a case you all suspect. Is this just a CSF problem? A low volume, a low pressure problem, more likely.
How to handle it? This time we sutured it and packed it with TachoSil, and this might be the same mechanism as we have, for instance, a natural leak. So we have a tear in the dura, we have a hole, and the bleb is again the arachnoid or some membrane that is trying to seal it. It’s a physics thing, a fluid thing. So there’s something oozing out, probably not as much as an SIH, but it could be.
Other things we find or other solutions we have. This is another opening, so to say. It doesn’t look like a bleb. Probably this is—you see several holes here and without really a bleb. Probably this is a different form of healing. And since we had several—one, two, three, four, five, six puncture holes—we decided to go all around the thecal sac to do a 360 patch with some dural substitute to take care of the holes. This time, with the already seen non-penetrating — this comes from heart surgery — non-penetrating clips. Again covering the dura with TachoSil, and then holding this collar together, applying slight pressure, and adjusting it with an aneurysm clip—not, of course, clipping the thecal sac but only the collar—to make it watertight. This is another solution for this.
What we see very often, which is very thankful for treating, are these through-punctures to the ventral side, and in almost all our cases that’s clearly discernible from the rest because there is a ventral SLEC—very tiny, but very often in the penetrating leaks there’s a ventral SLEC. So this makes it easy for us. We know where to operate and we know what the reason is.
We have quite some numbers of ventral leaks now done by puncture through both duras. So again, this leads to formation of these sticky membranes you never see in plain lumbar surgery. Then you see after dissection of these membranes, you see the dura and you see probably how a healed bleb looks like. The blood is identified, it looks a little bit different, and there is no oozing out, there is no flow, there is no weeping. And since we know there is a hole on the other side of the dura, I cut open the dura and then you see, and this looks like a typical ventral leak in the thorax with transhole funnels that keep them open, leading to a SLEC again.
And this is then easily sealed by the same way we do it in SIH, meaning putting a sandwich patch with TachoSil and even suturing it at this site. You have plenty of space in the lumbar spine beneath, next to the root, so you can easily suture it.
This is just a detour. Brain imaging is really not something we rely on in post-dural puncture. Of course, we need to do it to gather data to make registries: how often is imaging positive and negative? Other imaging signs are the dinosaur tail sign, which we don’t also really know how to handle, how sensitive, how specific it is. The bleb sign again—sometimes there are really big blebs. So this is how it looks like in surgery, the big blebs.
Another video and a new finding I didn’t show you in Aurora last year is the vein on a bleb. So we have even a combination of the pattern mechanisms you saw with the lateral leaks in SIH. This is a very interesting case a couple of weeks ago. We found again sticky translucent membranes. And how can you patch a leak, Tim, when you have a foil over the hole? You can glue as much as you want to, but this is really a barrier. And I don’t think that in chronic post-dural puncture headache a blood patch really is able to seal the leak if there are these membranes there. And now you see there’s a vein. There’s indeed a vein here. I can move it around. I can cut it. It’s filled with blood. And underneath, when I cut the vein away, there is then the bleb. What does this mean? Has the vein drained the bleb? Is this a reabsorption phenomenon?
I can just show you the findings, and anytime we find these findings we’re kind of happy because the chance of the patient getting better is way higher, but not 100%. Even still, probably 75% or 80%.
Then long-term—meaning long, long, long-term chronic post-dural puncture, decades or so—you find even more crazy findings. Again, a real bleb on highly T2-weighted MRI. And during surgery, we have now a distinct second layer. You see there’s a whole space filled with CSF as it looks like on the MRI, and then you open it. It’s oozing out, of course, and you have these sticky membranes. And if you peel it away, then you see underneath these membranes there is a hole that is then, once I removed the membrane, is oozing, and there’s a real fountain of CSF – a jet.
But on the other hand, there was also a space filled with CSF. So in this case, it is very likely that it is a fluid phenomenon that is really leaking and not only some kind of reabsorption or any other mechanism. You can easily suture this, and this patient gets dramatically better.
You can even have herniation like you have in the spinal cord, in the thorax. In SIH you can have herniation of the rootlets down there, of course lateral, dorsal, ventral. This is a case where there were nerve roots herniated to the leak after lumbar puncture in the dorsal space, also covered with neo-membranes in a second space, in the neo space.
So it’s never oozing out like in the sacral leaks, for instance Niklas found. And there you also can see that you can easily misdiagnose the dura with the membranes. This is not the dura, these are the membranes, and only underneath you find the space where the rootlets have been herniated to. And then you find the real dura, and you can reposition the rootlets into the thecal sac and easily suture it, and even can use the second layer, the neodura, as a double cover for sealing these patients, these leaks.
Again, my most favorite paper in the last couple of weeks, 1918, probably this is really important. Why so many lumbar punctures and nothing happens, and in this small subset of patients it happens? It might be chance that really both layers need to be affected: the dura and of course the arachnoid underneath it. And only if both holes, so to say, are at the very very same spot, the membranes can be invaginated and the hole stays open and is causing all these problems.
To summarize some of the findings, there are plenty more findings, and we’re trying together with Wouter — the plethora of findings we see in surgery and the plethora and the mentality we have for handling these lesions.
There is no standard, and unfortunately the outcome is not always good. But we have sometimes clear blebs, weeping blebs. You have only puncture holes, probably these are sealed, and there is nothing going on anymore. A clear entity that is very, very good to operate on are the ventral leaks, and you almost always see ventral SLECs in these cases. So then you can be happy and say, okay, I can help you.
I don’t know what to do with the sticky membranes. I don’t know how or how many levels they are going. When we explore three levels in many patients, they are most prominent in one level, and this is the level with the highest likelihood of finding a pathology underneath it. But it sometimes spreads one, two, three levels above and below, and probably this is a huge factory. Again, I don’t know that I know it any better, but this is a huge factory again for any metabolic syndrome, for anything that changes the system of these patients without having a fluid problem with autostasis. And I think we haven’t considered this enough.
What is the contribution of such a third system, base membranes, to the pathophysiology of this disease? It’s clearly not normal. And strange findings also in long-term patients with herniated fascicles, a wild formation of membranes, and also sometimes very prominent vessels where you can have the impression—it’s just what I see, it’s just the impression—these vessels do suck out CSF through the dura, for instance. I don’t know, but you can explain to me what it is. But it’s clearly pathological and shouldn’t belong there, and we find it in almost all patients.
There is one thing I cannot account for: all, all our patients in Freiburg have gotten many blood patches before surgery. So I do not know what’s the role of blood patching in inducing these membranes. I do not know. And many blebs, puncture holes, and penetrating holes, penetrating ventral holes, are very good to operate on. These patients do get better.
So you mentioned it already, Dr. Schyns, is it at all — what is it — chronic post-dural puncture? I mean, in the early phase, in the first five days, it’s probably very straightforward. But there are reports from the 50s and five years ago that it’s probably not a pressure or leak problem at all.
And the paper is accepted. It’s under embargo still in a good journal, so we were lucky. And I think in 15 or 20 patients we were able to convince that we do infusion testing in chronic post-dural puncture headache, and none, none of this had low pressure or any change in RCSF out. So is it really a fluid problem at all? Very interesting. Is it rather a leaking, oozing, weeping, reabsorption problem? Is it a metabolic syndrome induced by these membranes? I don’t know, just some thoughts for you.
Currently we try to focus on what we do first. First, we only operate on these patients after a long multidisciplinary team discussion. This is nothing you should let your neurosurgeon loose and operate on—thousands of patients with chronic headache. Don’t do this. It’s every time a very long, repeated seeing these patients in outpatient clinic, and then we decide together with neurology, with anesthesiology, with neuroradiology, okay, we explore these patients. I think this is important.
And then we have three rules. Resect the pathology—we think neo-membranes are not good. Restore the anatomy—try to build a kind of a new good dura. And also, I think, do not only respect the dura, also respect your arachnoid. I think it’s very important. Thank you so much.