Slides
Transcript
Thank you organizers and Scientific Committee for inviting me here and I’m really happy to have this opportunity to present our results from our new endoscopic surgery.
We have nothing to disclose except that I’m a neurologist and this surgery is performed by Dr. Kyunghoon Yang who is here in this hall. So please find this guy and take your opportunity to give very difficult questions to him, not to me.
So the background is that I opened the first CSF leak clinic in Korea in 2022 and I have encountered so many patients which were never addressed by the other patients. In 2023 I was very lucky that Wouter invited me to the Big Island meeting which changed a lot in my practice. So soon after the Big Island meeting I was able to start the ultrafast dynamic CT myelography thanks to Dr. Peter Kranz. He helped me a lot with this procedure and this addressed my diagnostic unmet needs.
However, I had so many patients so far, but although we became able to start the targeted treatments using the ultrafast imaging, so many unmet needs were left in terms of treatments because chronic SIH did not respond to targeted EBPs. So we wanted to find a neurosurgeon who does treatment for these patients but our neurosurgeons were so busy doing spine tumor surgery and they did not want to do the dural defect surgery because they think it’s way risky to do spinal cord manipulation.
So I was so desperate but I happened to collaborate with Dr. Kyunghoon Yang who is one of a few new spine endoscopic neurosurgeons performing thoracic spine surgery. Actually we knew each other 20 years ago in medical school, but we hadn’t seen each other for the last 20 years. All of a sudden we got a chance to collaborate. We discussed about this disabling condition and I was able to persuade him and he established the novel endoscopic — actually that’s not novel but it’s an existing technique — but we started to implement that to our dural defect surgery.
So today my aim is to evaluate the efficacy and safety of this endoscopic sealing technique in our patients with ventral dural defect.
So it’s based on my prospective registry ongoing in our hospital and we consider it eligible if patients with confirmed ventral dural defect which was unresolved by under 3 EBPs and they received the transforaminal endoscopic surgery.
In this particular study we analyzed the first 40 patients, but actually it’s ongoing and the case number is growing. We followed the patients more than one month. Actually the follow-up occurred immediately after surgery, at two weeks, and between one and three months to find a final radiological remission. So we considered it successful if the follow-up imaging shows complete disappearance at the extradural fluid.
So this is the surgical approach. You can see through this neuroforamen the endoscope can approach the epidural space by gently widening the foramen by drilling it, and we can press the ventral epidural space and there we can find the hole in causative calcification here and we first remove it by gently drilling it. We are confident that we completely remove the calcification because it’s an extradural procedure not an intradural procedure, and we place the sealing materials — first TachoSil and the Lyoplant—the artificial dura inside the dura and place it again in the extradural space like in a sandwich mandible, a double layered sandwich intradurally and extradurally. So there are artificial dura and TachoSil and in some cases we put some Gelfoam here.
To summarize the sealing materials used, you can see the TachoSil was used in all the cases, but we added Lyoplant which is artificial dura from our ninth surgical case, which we now consider it crucial to place our Lyoplant added onto the TachoSil. Gelfoam is not a mandatory procedure, but in patients who have very large extradural space, we put Gelfoam to keep all the sealing materials fixed in location. So it’s not a mandatory procedure, but it’s optional.
So you can see the video. Yeah, we can see the calcification and we dissect between dura and calcification and remove calcification and we can see the dural tear site and place TachoSil intradurally and Lyoplant as well, and do it again in the extradural cases. So artificial dura and TachoSil and in some cases the Gelfoam. So that’s it.
So let’s move on to results. The first result is the surgical findings. You can see most of the leaks were located in the upper thoracic regions and dural defect sites ranged between 1 to 15 mm with an average of 5.6 mm. We were able to find the causative lesions in half of cases. Most of them were located in the ligament, not the disc. So ligament calcification was causing little leak and cord herniation was noted in six cases. The sealing materials used included TachoSil, Gelfoam, and Lyoplant as you can see here.
And this is the typical response. This is – you can see a large organized SLEC which was unchanged over two years before surgery, and after immediately after surgery it has gone completely. We followed the patients and the disappearance of SLEC remained stable.
When you look at the further details of the responses immediately after surgery, we found a significant reduction or resolution of SLEC in 75% of patients. Half of them achieved immediate remission and half of them had significantly reduced SLEC. In these patients, even if they were not remedied completely, eight patients had ultimately remitted without any further additional procedures. But we wanted to see a very rapid improvement, so we implemented EBPs. You can see this orange bar. We implemented additional post-op EBPs and it helped. And this blue bar shows our redo surgery cases. In cases who did not show any resolution immediately after surgery, interestingly two of them showed delayed response and ultimately remitted, and some of them underwent additional EBPs or additional surgery.
So we wanted to see if this is really possible without redo surgery. So when you define the success rate as complete remission without redo surgery, you can see the first few patients, our success rate from a single surgery was about 60%. Actually at this time we wanted it was first in Korea and Kyunghoon Yang is a solo practitioner and this is very prone to medical legal issue in Korea. So we wanted to do it very, very conservatively. But we became more brave and we added the Lyoplant and we used larger Lyoplant which is sufficient to cover all the defect size. So now the success rate reaches about 100%.
We found a very interesting thing in a patient who received repeated surgery. This patient had a very long ventral dural defect and we replaced the TachoSil and Lyoplant as well, and after a few weeks we did a repeated surgery because he had remained a small hole here. So it was very easily sealed by the second surgery. But what was interesting was that you can see here the dura looked like a natural dura, and it was artificial dura replaced here, but you can see very little neovascularization within the artificial dura which may suggest some kind of dura regeneration. I’m not completely sure with this wording, but it’s really interesting and we were very thrilled about seeing this finding.
Postoperative complications do occur, but serious complications occurred in two patients and none of them left any long-term sequelae. Many of them were minor and transient. There was no permanent neurological deficiency. There were three cases of transient limb weakness which fully recovered after a few days.
To discuss efficacy, actually these numbers are from literature, but I know in this hall there are very famous neurosurgeons who do it more better than this literature. But we think our approach can provide comparable efficacy with the current state-of-the-art surgery with shorter time to remission and reduced operative time and potentially faster postoperative recovery because it does not require any laminectomy or durotomy.
The major complications were comparable between the two surgeries, and we used very minimal skin incision and minimized bone removal. No need to do durotomy or dural suturing, and spinal cord manipulation is minimized. So our method offers a safe and minimally invasive approach through direct access to the ventral epidural space. Some patients underwent additional EBPs, and it might have been unnecessary because there were some cases who showed delayed remission without EBPs.
However it may have a role because it may have facilitated the sealing effect by utilizing fibrins or fibroblasts in the blood. I don’t know, but whether it helped or not is not completely clear at this moment. So far we have 85 patients who underwent over 90 surgeries over the last 9 months. You can see the very big unmet needs which were never addressed in Korea. So patients are very willing to receive this surgery.
Among these 85 patients, 78 had thoracic ventral dural defect which was treated by the transforaminal endoscopic surgery, and redo surgery occurred in only eight patients and most of them were the first few cases. No redo cases occurred after our 23rd patient.
We have limited experience in cervical ventral dural defect which was not feasible to do by transforaminal endoscopic surgery and which was treated by ADR or interlaminar microscopic surgery. We have a few patients with post-dural puncture and some patients did not have dural defect but he worried thoracic calcification would cause a dural defect, so he really wanted to do the surgery, so he did it.
So the conclusion is that endoscopic sealing technique through transforaminal approach represents a novel safe approach for ventral dural defect with high rates of success. We think use of Lyoplant larger than the defect size is crucial for the success and long-term outcome, and the role of additional EBPs should be evaluated and are being evaluated.
I’d like to thank all of the collaborators in Seoul National University, especially Kyunghoon Yang for this surgery, and our Korean colleagues and international collaborators. We are working on the international guideline on the optimal peri EBP management. Thank you so much.