Transcript
Question: What are the chances that a spinal CSF leak caused by a puncture is seen on MRI? I believe you covered this, but it’s the top question.
Answer:
Dr. Beck: Of course, and is a very important question. Unfortunately very low, in the range of 5 to 10%. So meaning that a negative MRI, be it of the spine or the brain, does not rule out post-dural puncture syndrome or post-dural puncture headache.
Question: Another question, again this was covered. If a patient’s symptoms started after a lumbar puncture and imaging is evaluated as normal, how can they go on to access the care that’s needed when so many physicians do believe that it rules out having a spinal leak?
Answer:
Dr Beck: We need to spread the news that imaging does not rule out PDPH. This is important, and of course this is our obligation by doing this, by writing papers, by going to conferences. And as a poor patient, you only can insist and say, “No, my life changed completely after dural puncture, I’m not able to function, I do have a headache, I need to lay down after a couple of minutes, and I need your help, that’s it, and please believe me.” A post-dural puncture MRI of the spinal cord or the brain does not rule out this syndrome, and probably you can even refer to your webpage or to our publications. And the paper by Charlotte Zander, I think, is an important landmark study for this. She presents clear numbers that all these patients have a normal Bern score, a normal MRI of the brain and spinal cord. So probably this helps that you get the care you need, the attention you need.
Question: Why are iatrogenic leaks so difficult to detect on imaging, and what’s the research ongoing here to address that issue?
Answer:
Dr. Beck: Good question as well. Probably the nature of the leaks are – I mean, we’ve been very lucky in the last 10 to 20 years that we have so much new findings in spontaneous leaks. But the nature of the leak is even more subtle and tinier, and the size of the needle is so small. So we do not have this big egress of CSF and the changes that we can easily detect on imaging or easily detect on lumbar puncture or CSF studies. These are more subtle changes. They are more difficult to detect, and these I think are the problems. And we do not have a biomarker for this at the moment. So it basically all relies on clinical grounds, on history, and the diagnosis cannot be confirmed or ruled out by any imaging or any other study.
Moderator: Thank you for explaining.
Question: Next question is, what can be done for a PDPH patient when multiple blood patches eventually fail over the years, but then again imaging cannot definitively confirm there is still a presence of a leak? And I think you addressed this a bit, that the presence sometimes just won’t be there – the confirmation on imaging just won’t be there. But when multiple blood patches are given and the same symptoms still persist, what then?
Answer:
Dr. Beck: This is an unsolved question, and there’s a real and unmet clinical need for what to do in these situations, and I don’t have an answer for that. But I can only tell you what we do in Freiburg, and first of all, this should never be a decision by a single physician, being a surgeon or radiologist or neurologist. So we meet in CSF board conferences, MDT discussions, and then decide together what to do. And probably some patients profit from surgical exploration. Meaning that this is not the solution, and I’ve given you the numbers. So after surgery, only like two-thirds, 50 to 60 to 70 percent, do profit, and one-third does not profit, and five to 10 percent are even worse. So there is no gold standard what to do with these patients. There’s one subgroup, I talked about it in my talk, when we find ventral CSF on the other side of the thecal sac, when the needle entered both dural surfaces, so to say. Then we would clearly recommend surgical closure of the leak because from this subgroup we know that the prognosis is quite good. Otherwise, individualized MDT decision.
Moderator: So what I understand you to say is really there’s no one-size-fits-all, as you’re still understanding the different dynamics at play and the uniqueness.
Dr. Beck: Yeah. And as a surgeon, I only cover a tiny little aspect of this disease. So I can only tell with my colleagues, “Okay, we go on with surgical exploration and hopefully we find something that we can fix.” But of course, you need a lot of care and support and rehab. So this is something my colleagues from neurology and anesthesiology and pain medicine take care of. But I only explore these patients once we have a team decision to do that.
Question: Speaking of that, can you talk a little bit more about the success rates of dural repair surgery in the case of PDPH, and if those rates differ when there’s a bleb involved? That was the next question.
Answer:
Dr. Beck: Yeah. And this is always the key question, and I can only repeat the numbers. To give you, this is a very important point, to give you rough numbers: improvement can be expected in only 60 to 70% of the patients after surgery, and this is increasing once we find a bleb. The success rate is a little bit higher, but not 100% in patients we find a bleb on imaging before surgery. And we do now very high-resolution spinal MRIs in our patients, so the chances that we find these tiny little blebs are getting better and better, and the chances of a benefit from surgery even is increasing further if we find ventral CSF. So these blebs on the other side, so to say, with ventral CSF, then we have a very high success rate.
Moderator: Thank you for explaining that.
Question: Is there currently research taking place to look at why some patients with blebs get, as they called, healed and sealed, and some do not or even get worse? Seems to be great variability of how patients recover. Can you speak to that just a little bit more?
Answer:
Dr. Beck: We of course do research on that, but currently I cannot give you any clear identified risk factors for the ones who profit versus the ones who do not profit. We are not successful in finding the ones that profit versus the ones that do not profit. Maybe we just miss a bleb. As I’ve shown you in many many instances, I find two, three, four needle holes, so to say, beneath the membranes, and probably in the patients that do not benefit I miss some. On the other hand, we are not really clear because we are trying to stay extrathecally and only remove the membranes and to cover the dura. Why patients get worse, and we do have patients that get worse after surgery. So 5 to 10% of the patients do get worse, but no clear risk factors at the moment. Sorry for that.
Question: Another preconference submitted question: when a patient has repeated history of relief from patching, and this is similar to a question we’ve already asked, but there’s no area of leak identified other than that initial procedure, is exploratory surgery again considered?
Answer:
Dr. Beck: Yes and no. It is when the risks and benefits are clearly explained to the patient, and we can say, okay, we can explore this suspected site of the leak, and you have a 60% chance of getting better, but you also have a 10% risk of getting worse. And if the suffering is so strong and, for instance, an affected patient cannot really cope with daily life, cannot really go to work, then probably it’s worthwhile. And if the symptoms are subtle and, okay, I have to stop running after 20 minutes, probably it’s not worthwhile doing surgery. So this is an individual decision based on our group discussion and based on the level of affection, if you want to say, how the quality of life, how severely affected a patient is, and then we have to do an individualized decision for that.
Moderator: Thank you.
Question: You noted that lumbar infusion and other testing does not turn up clear evidence of CSF leakage in cases of PDPH. We saw the images you showed in surgery of weeping dura and the like, which seems like evidence of CSF leakage. Would you say that in PDPH there is CSF leakage, but sometimes it’s too small for existing technology to detect, or it’s taken up somewhere else in the body and that we just don’t currently understand?
Answer:
Dr. Beck: This is a wonderful summary. This is a wonderful description. I think this question really summarized it. There is no gross egress of CSF. There is no gross, no large egress of CSF that we can detect on imaging or on CSF infusion studies. But if you have seen in surgery, it’s still kind of what I called in one slide oozing or increased reabsorption. And it’s also a very clever question because what is the next step? Is it just a tiny little amount of CSF? Probably not only, because there’s also probably another pathophysiological little thing happening, meaning these membranes are forming, and these membranes are very vascularized and reabsorb the CSF. The tiny amount of CSF that is oozing is immediately reabsorbed by the vessels. This is probably the other mechanism why this is escaping being seen on imaging. Okay, first only a tiny little amount, and second, these membranes and vessels just eat the CSF up immediately, and so this is why we don’t see it.
Moderator: Is it kind of like wicking it away essentially?
Dr. Beck: Exactly. Exactly. And even if you remember the weeping dura imaging, this only happened after I removed the membranes. When the membranes were still in place, there was no weeping. Only after I removed the membranes, I probably tear off the connection of the vessel with a bleb, and probably the CSF is going like a mini tiny micro CSF-venous fistula induced by a spinal needle. This could be one possible explanation. But all of that is current speculation and is escaping our modern imaging paradigms.
Moderator: It’s really fascinating. It’s exciting to know that there’s still so much that can be learned about what exactly is going on, and yet it is a little scary as a patient sometimes when we’re not sure exactly what to make of everything.
Dr. Beck: But this is probably very, very, very important also for the patients and the affected, that there is really so much we need to learn. It is not that we are very secure on the physician side, on the treatment side. Oh, we need to apply strategy A, B, or C. We are still learning every day. And this is something that also the patients need to understand. We don’t do surgery on purpose or not on purpose. We just do not know better. We are trying to get better with the help of our patients, with the help of our scientists, with the help of the registry of prospective studies. This is not fully understood at the moment. It’s difficult for the patients, but also for us, for the physicians, on what to base our treatment decisions.
Moderator: Yes, thank you.
Question: Someone asked, “Given the patient variability of dura mater, is pushing the bleb back in and suturing it always best for repairs?” Basically, they’re asking about, I think, resecting and pushing it back in. And then they go on to ask, “If the patient experiences increased low pressure after being sutured, would it be advisable to remove those or try a different approach?” They’re wanting to talk more about the dura stability it sounds like.
Answer:
Dr. Beck: Yeah and the technical aspects, but also excellent questions. In the beginning, when I started doing this years ago, I pushed the bleb back and sutured it. But when you suture the dura and you look very closely under the microscope where you put in your needle, your stitches, there’s always a tiny little bit of oozing. So these days, I usually push the bleb back and I shrink the dura a little bit with the bipolar and cover it with TachoSil and fibrin glue and reinforce it. And the results are basically the same, probably a little bit better with not suturing it. If I have a larger defect, like in spontaneous intracranial hypotension, sometimes these defects are a little bit larger. I still suture it. So it really depends on what I see during surgery. And since I do not see this in advance, the decision is always done during surgery intraoperatively. And to put it in simple words, if I have a tiny little bleb, I reduce it and I cover it. If the bleb is a little bit larger, I reduce it and suture it depending on the specific anatomical findings during surgery.
Question: Someone asked that you’ve mentioned in prior talks about some leak repair surgeries where you’ve applied autologous platelet-rich fibrin. Have you seen success in this technique for chronic PDPH patients?
Answer:
Dr. Beck: Yes. Good question. And we do use this more and more often. This is a technique where we withdraw blood during surgery from our own patients and prepare it and then reinject it. So this is an epidural blood patch plus during surgery, and we can even make tiny little fibrin patches which are solid and even suturable with this procedure, and we use this more and more often and with slightly better results. It still is not the breakthrough, but it’s getting better and better, and one piece in the puzzle is using the patient’s own fibrin. So I have good results with this. Not the breakthrough, but getting better and better.
Question: Do arachnoid blebs occur spontaneously or is it only iatrogenic in cause?
Answer:
Dr. Beck: I have seen them only iatrogenic. These tiny little typical blebs, I’ve never seen spontaneously so far.
Moderator: And how often have you found that they are successfully sealed with patching or is surgery usually or always required?
Dr. Beck: Tough question. I don’t know any good literature, and the patients that approach me for surgery all have many, many blood patches, so up to 15 or so. So from my perspective as a surgeon at the end of that chain, blood patching doesn’t help because otherwise they wouldn’t have come to me, but of course this is a high selection bias, and I’m not aware of a good study answering that question.
Question: Are all blebs visible on imaging?
Answer:
Dr. Beck: No, unfortunately not. But since we know that we are looking for these blebs, we do very good anatomical solution imaging. Probably Andrew can elaborate on that with specific parameters for the MRI. So imaging is getting better, but still sometimes we find we are looking for one bleb and we find a tiny little other one just next to it. But imaging is getting better and better. But I think Andrew, for instance, can elaborate on that about the progress in imaging.
Question: Is it better to proceed directly with surgical approach after a lumbar drain leak rather than trying to blood patch first?
Answer:
Dr. Beck: No, I would always blood patch first.
Question: Some complex patients have reported that after multiple patches and surgeries, they’re told it just must be something else. But most of these patients were, you know, “normal” prior to the puncture procedure or the incident that led to the leak. Any thoughts on that conundrum?
Answer:
Dr. Beck: It’s a conundrum, and probably there is another piece in the puzzle we are missing. Probably with this arachnopathy or duropathy over time, we have some metabolic changes, some kind of inflammation that happens in the CSF system that we cannot cure by surgery or by blood patching. And we are still not allowed to forget the central desensitization mechanism in all chronic pain patients, and so probably it’s a mixture that the longstanding changes induce a metabolic syndrome that we currently do not understand for instance.
Moderator: It’s still complicated and unknown, it sounds like.
Dr. Beck: It is.
Question: “Dr. Beck, could you please discuss how you would like to see chronic PDPH classified with respect to the overall spinal CSF leak umbrella? Is it best described maybe as a hidden leak? We know that it is distinct from spontaneous intracranial hypotension in that it’s not spontaneous, but it’s ultimately the result of fluid leaking.”
Answer:
Dr. Beck: Most likely, but probably oozing tiny little amounts of CSF leaking in combination with this duropathy. I think we are not in a state, we do not have enough evidence and numbers to base a new classification on solid grounds. I’m sorry. I cannot answer this question sufficiently. Sorry for that.
Question: Do you see a correlation with the size of the bleb or the defect and the severity of the symptoms?
Answer:
Dr. Beck: Nope.
Question: What is the best practice when getting a lumbar puncture in trying to accurately log where it is done exactly? It sounds like documenting the location is important. Do you have any thoughts on that?
Answer:
Dr. Beck: I have the same thoughts. This is an excellent question. We should document the site of the lumbar puncture. In case we do a myelogram or a CT myelogram and we do it under radiological guidance, we should make an image, a plain X-ray, where the needle really is. But this is only in rare circumstances. It’s not done in general practice or during PDA, so it’s difficult. Maybe we could take a photograph and mark the spine at the iliac crest or something like that. Sometimes patients come and they bring a photograph where there’s still the site on the skin visible next to a mark on the skin, for instance. These are some hints that we know where to explore. This is a good question, and probably we can use a photograph, for instance.
Moderator: That’s interesting. After any myelogram or blood patch I had, there were always the Band-Aids left on the back, and I always had someone take a picture. It was my form of basic documenting.
Dr. Beck: Yeah. Excellent, Jen. Better than not doing the photograph. Yeah.
Question: Again, someone’s asking about long-term prognosis. I think you spoke a bit in your talk about that timing matters. Getting treatment as soon as possible is better. Do you want to speak a bit about looking forward? This will probably be our last question.
Answer:
Dr. Beck: Again, from the perspective of the surgeon, I cannot answer that question, but we should clearly build a community where we take care of these patients that are post several epidural blood patches, post-surgery, and still not getting better. What to do with them? And they need to be taken care of, and I know several patients that are still kind of bedridden after many, many blood patches, after surgical exploration, and I don’t know how high this percentage is, but this is still not sufficiently solved, of course. And luckily we can help some patients with blood patching. We can tremendously decrease the number of post-dural puncture headaches with using the right needles, small needles, and reducing and marking the site where we enter the spinal thecal sac. But at the moment, there are many conundrums still open, and I cannot answer all these questions, but we need to do better, clearly.
Moderator: Well, thank you very much for your time, Dr. Beck, and attempting to answer all these questions as best you can and showing all the insights that you shared. We really appreciate your time.
Dr. Beck: Thank you so much, Jen. Thank you so much to everyone for having me.