30_min.mp4

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Speaker 1: [00:00:00] Slide, please. Gaetano. All right. And now we are back to our our main speakers for today. Again, as I mentioned at the beginning, our incredible fellow team the all have you know, a number of projects ongoing and have been presenting all around the country and the world. So we get to hear some of their recent work that was presented at the CNS. And Gaetano, I think you're going to be going first. Is that correct?

Speaker 2: [00:00:31] Yes, sir.

Speaker 1: [00:00:33] All right.

Speaker 2: [00:00:41] Let me share my screen. All right. Good morning everyone. So today I'll be presenting on our initial results of precision treatment of postoperative CSF leaks with ultrasound guided epidural blood patch. And this is a talk that I gave as an oral presentation at CNS in Austin, and really was the work of the entire spine team here at Mayo Clinic, Florida, as well as Doctor Clendenon and James West. I don't have any disclosures relevant to this talk. And as you know, incidental durotomy is a very well known complication of spine surgery. And if left untreated, it can lead to a persistent CSF leak or pseudomeningocele. The reported rate of incidental durotomy ranges from 4 to 16%, depending on the index operation. And if patients develops symptoms of persistent CSF leak. First line treatment is bed rest. Other options include oversewing the wound and placement of a lumbar drain, and there is the potential need of having to go back to the Or for direct repair. While epidural blood patches are routinely used to treat post anesthesia or post LP CSF leaks, they are not often used after spine surgery for durotomy repair. The problem is that the ultrasound is a great technique that allows radiation free and direct real time visualization of the pseudomeningocele, the dura, and the Tuohy needle. But its application in the spine is often very limited. That's magnified in the post-operative spine, thanks to the bone work that has been done by removing the bony anatomy and the ligaments there, which allows a window for the ultrasound and for the needle to be visualized properly.

Speaker 2: [00:02:38] So in our study, we did a retrospective analysis of patients that underwent the US, CBP at Mayo Clinic, Florida from 2009 to 2020 for symptomatic pseudomeningocele secondary to spine surgery. We collected demographic, procedural and outcome characteristics. The primary outcome of our study was ultrasound success, defined as a resolution of the initial symptom that brought the pseudomeningocele to clinical attention, such as postural headaches, incisional leak. So for our technique, patients are positioned prone. The ultrasound is used to localize the pseudomeningocele, and the color. Doppler can also be adopted to determine if there are any active sites of CSF. Leak of aggression under ultrasound guidance. A 18 gauge Tuohy needle is advanced into the Pseudomeningocele and the content is aspirated. The needle is then advanced into the epidural space, and about 30 ML of autologous blood is injected epidurally in 5 to 10 ML aliquots under continuous ultrasound guidance. Then, after waiting for 5 to 10 minutes to allow the blood patch to sit, the ultrasound is then used again to confirm the placement of the patch and the color. Doppler can also be used to confirm an absence of CSF egress if there was previously identified. So overall, we had 48 patients who Wonder when the total of 61 US IPS.

Speaker 2: [00:04:03] And you can see that the most frequent index operation was a Laminectomy 24.5%, and about 36.7% of these cases were revision surgeries, and also that the incidental durotomy was unrecognized during the surgery in about 22% of cases. You can see here that the median time from surgery to symptom development was seven days, and the most frequent presentation symptoms at presentation were postural headaches in 64% of cases and incisional leak in 26.5% of cases. Here, looking at the results of the EBP under ultrasound guidance, you can see the 51% of patients experience resolution of their symptom after their first blood patch, and you can see that the median volume aspirated from the Pseudomeningocele was 34ml, and also that another 20% of patients experience resolution of their symptoms after subsequent attempts of blood patches. We're talking about complications. We had about 14% complication in our series, and the most frequent one was wound infection in two patients, followed by meningitis also in two patients. Here is a couple of illustrative cases you can see here. Patient presented with a dural AV fistula. And here on the T2 sagittal MRI you can see a fairly large pseudomeningocele. After the patient had undergone the laminectomy and obliteration of the AV fistula, and then the patient underwent an ultrasound epidural blood patch. The contents of the pseudomeningocele was aspirated and a blood patch placed.

Speaker 2: [00:05:43] And then you can see on the postoperative MRI, sagittal and axial cut that was done one month after the procedure. Complete resolution of the Pseudomeningocele. This is another case of a patient that Laminectomy. As you can see here on the CT scan on the level above a previous fusion construct, and there is an hyperdensity there, a collection fluid collection. There was also again identified under the ultrasound where you can see the star there, and then the color Doppler was used to identify the active CSF regression there. The Tuohy needle you can see here in white where this arrow is, is inserted. The content of the Pseudomeningocele is aspirated, as you can see in figure E, and then the blood patch is placed. And this is a postoperative scan that documents resolution of the Pseudomeningocele. So our study carries all the limitation of all single institution retrospective studies. Therefore, further prospective multicenter studies are needed to confirm the generalizability of our data. But our study is the first and the largest series describing the adoption of US EBP in patients presenting with persistent pseudomeningocele and CSF leak. Following spine surgery, we found an overall success rate of over 70% with a first attempt success rate of 50%. So this suggests that the utilization of US guided epi in expert hands may allow for targeted treatment of a large portion of symptomatic post-operative pseudomeningoceles. Thank you.

Speaker 1: [00:07:18] That's excellent work. Congratulations. It's a novel treatment for these not uncommon problems. One thing that, you know, I realized I never asked Doctor Miller or Doctor Clendenin. What's the consistency of the blood that you're using as the patch, and how long is it in between obtaining the autologous blood and actually injecting it?

Speaker 2: [00:07:40] I don't know about the time between the when the blood is drawn and injected, but most of them, I believe it may have been done in this at the same time of the procedure. Sir.

Speaker 1: [00:07:52] Yeah. But I mean, they they aspirate it and then immediately give it. Do you know, I was just curious about how thick the blood is. Maybe a. Iliad. I see. Doctor Who?

Speaker 3: [00:08:03] Yeah, I do some of these as well. Okay. Yeah, we go right away for the blood, you know. So it's right from an IV catheter into the epidural space. But, you know, the what's really helpful is the tisseel fibrin glue. So it's like an, you know, human fibrin blood components that we inject in that solidifies much, much quicker and is much more firm. So, you know, with the blood, it's thinner and can get into different crevices, while the fibrin glue is a bit more firm. So you try to get both properties in there right at the leak. So.

Speaker 1: [00:08:32] Excellent. Yeah. Thanks. Thanks, I appreciate that. Did you want to give I see your hand up there. Do you want to make a comment?

Speaker 4: [00:08:40] Yeah. Yeah. Sorry, I can't join on camera because I'm. I'm tied up in the hospital. But I would like to second those comments. I've done this a couple of cases. Doctor. Clendennen a lot of times what we do is we place an arterial line. So that way we can reliably draw blood right away as soon as access is identified with the ultrasound machine. And yeah, fibrin glue has also been something new. That's been very helpful for these cases. One question that I had and it's something that we always worry about is the risk of infection and meningitis. And it's interesting from the data presented, that was about two, I believe. Any thoughts on you know, looking at the data and anything that we can do to make things better or reduce that risk? Or is this contributed directly to the to the block itself? Or was there other circumstances on those two patients that got infections? Thank you.

Speaker 2: [00:09:40] Yes, sir. Excellent question. As you said, yeah. We had about two patients, about 4% for our series. It's a small series, so it's difficult to generalize if that's really a 4% for the procedure itself. But that was assumed to be related with meningitis. That seemed to be related to the procedure, not like a UTI or any other infections.

Speaker 1: [00:10:06] Let's see. We have a a question from Doctor Vargas about what, what about the presence of fibrous tissue after the procedure? I think.

Speaker 2: [00:10:18] Yeah. So these are usually done.

Speaker 1: [00:10:19] Like, you know, scar, that sort of thing.

Speaker 2: [00:10:22] Yeah. So these are usually done right after the procedure is not too long. And that's why it's very difficult to do them anatomically guided. That's why the ultrasound. Ultrasound really helps to visualize the anatomy. And that's why we didn't have any issues as far as fiber going through fibrous tissue or the patches.

Speaker 1: [00:10:41] Great. Well, thank you so much. Gaetano? Yep. One a couple more points here. Doctor Dean mentioned would emphasize the need to make sure patient is afebrile and has normal white blood cell count prior to the blood patch. And I know that's that's part of the protocol And a good point. Some of these patients are, you know, immediate post operative. They have an immediate post operative status. So they might have an elevated white blood cell count just from surgery. But yeah, very, very good point. So. All right. So excellent work Gaetano. And we will go on to the next presentation. We have Doctor Garcia who is going to be presenting next.

Speaker 5: [00:11:28] Can you see this Doctor Fox.

Speaker 1: [00:11:30] Yes.

Speaker 5: [00:11:31] Oh it's advancing by itself. All right. So good morning everyone. Today I'm going to be presenting on Spect CT as a predictor of pain generators in patients undergoing intra-articular injections for neck and back pain. I think most of you already know of this project. It's a project that we did with the spine Group under particular mentorship, Doctor Abbott, and we presented it at Austin at the Congress of Neurological Surgeons. So as you know, low back pain and also neck pain, but there's a lot more literature on low back pain is one of the main leading causes of disability in general, and yet the identification of painful generators is still difficult. Despite of use of multiple morphological based studies, including X-ray, CT, MRI and also compounded by the fact that sometimes structural abnormalities are found on scans, have no direct correlation with the actual pain of the patient, which makes the correct identification of the painful generator difficult and therefore the targeted treatment for that painful generator also difficult and limited. With this in mind, there have been some interest in functional based tests like Spect to accurately identify those painful generators, and more recently, a scan has been developed which is called the hybrid Spect CT, which. At Mayo we have been fortunate to have available for a number of years and with good quality, as I'm going to show one of the examples scans.

Speaker 5: [00:12:56] So the idea here was to look at facet joint injections, target injections and see whether or not the hypothesis that injections targeted at positive sites of uptake would do better than injections targeted at foci without uptake. So to accomplish this, we designed a study with a single institution retrospective in which you compared both short and long term outcomes for patients undergoing facet joint injections for neck and back pain. Given the large sample size, I was able to do a propensity score matching to adjust for age, gender, BMI, hypertension, and multiple target injections and injection location. We did exclude sacroiliac joint injections, given that they are a bit different and they should not be grouped all the same with cervical thoracic and lumbar injections. So these were our main outcomes. We looked at immediate positive response change in Vas two weeks after injection, improvement in Vas above 50 and 70% after injection and need for additional treatment. Both injection and surgery. Importantly, at Mayo, we have people who do call these patients two weeks after the procedure who are not implicated in the research. So they're able to give us an unbiased feedback from the patient regarding patient reported outcomes, which allowed us to really objectify these outcomes. So as you can see, we have a large number of patients, 2849 patients that were evaluated with Spect CT within five years.

Speaker 5: [00:14:24] Out of this one, we had 3340 with facet injections within 150 days after Spect CT. Why 150 days? We had to choose a threshold. There is no a specific literature on the threshold. We just had to come up with a threshold that would allow us to look at outcomes that were associated with injection, not associated with something else that could have happened in the interlude. So we had a total of 140 surgical injections, 21 thoracic injections, and 207 lumbar injections. Importantly, 265 were uptake targeted injections. By this we mean that all the injections were targeted at foci of uptake, all of them. That was our definition of uptake. Targeted injections and 75 were non uptake targeted injections. So as you can see here just an example of a spect CT at Mayo. With in this particular patient the right l4-l5 facet joint having uptake that was targeted by injection. This is actually one of the cases that was included in this study. So here just some demographics and characteristics of the location and characteristics of the injection. As you can see, even though there's nothing that is statistically significant, it can always compound and have an effect, a confounding effect on the variables. Hence why we did the propensity score matching to adjust for all these variables.

Speaker 5: [00:15:41] And what you can see here is that both on a univariable analysis and a multivariable analysis, we did not find statistically significant differences between non non uptake and uptake targeted injections. But when we did look at patients who already had a failed injection before the Spect CT and in which the the surgeon or procedures was able to change the target page based on the information of the spect CT. Here below what you can see is that in those patients we do have a benefit. And the benefit was particularly greater if there was any change made on the target. So that is very suggestive that for a particular set of patients with adequate patient selection, you do see a benefit with Spect CT to guide a facet joint injections. So basically our conclusions seem to support that a pending adequate patient selection spect CT has a benefit in guiding a facet injections. There are limitations, of course, with our retrospective single institution study, but we did use a propensity score to match for confounding variables. We have a large sample size, but of course future directions would have to be prospective, multi-site, hopefully double blind clinical trial to accurately discern the impact of Spect CT in routine clinical practice and I'll take any questions.

Speaker 1: [00:17:08] Excellent, Diogo. Really fabulous work. And I think this is you know there's so much potential applicability to using imaging biomarkers for better delineating patients pain. You know, and this you know, even with the precision of these Spect studies, it shows how challenging it can be to figure out pain generators in the spine. And I think this is incredible work with a lot of promise based on what you've seen so far, who do you think? I mean, do you think this should we should be doing this more or less, or do you think people should have have this upfront? I mean, how do you recommend we use this based on your knowledge of the technique in our everyday practice?

Speaker 5: [00:17:54] So the patients that I did see have a benefit where patients in which there had already been an attempt at an injection. So because my understanding is that Spect CT is sensitive but not necessarily specific. So it's difficult to figure out which of those facets are lighting up are the ones that are actually causing pain. So when we have the benefit of having a patient that already had a procedure that failed, we do know which of those joints did light it up, but they're not the actual painful generator. So we can take those out and pursue the next ones. So I do see spect CT not as a necessary first line for any patient that has a first procedure, but for a recurrent facet injection. For a patient who has not benefited from a facet injection, I would definitely see benefit there. But of course, I think to actually make a recommendation would have to have a double blind clinical trial so we can make a recommendation hopefully coming. Hopefully.

Speaker 1: [00:18:47] So yeah, and we'll continue to learn more about these imaging biomarkers, which I think will be very helpful. Doctor Dean makes a great point in the comments as well that we have extremely high quality spec studies at Mayo, which, you know, I completely agree. At UF, we didn't do this at all. So this was this was something novel to me. Seeing here and very impressed with the quality of these studies. So excellent work. All right. I think we can move on now to our next presentation. Doctor Vivas Buitrago, who is going to be speaking about super marginal resection impact on overall survival for ID h wild type glioblastoma.

Speaker 6: [00:19:29] Perfect, sir. Can you hear me now?

Speaker 1: [00:19:31] Yes. Yes. Thank you.

Speaker 6: [00:19:34] Let me share the screen here. All right. Are you seeing my slide?

Speaker 1: [00:19:40] Yes.

Speaker 6: [00:19:42] Perfect. Good morning everyone. Thank you for attending this lecture today. So I'm going to present our study that we presented in October this year in CNS. The title of this study is Supramarginal Resection Impact on Overall Survival for ID blastoma according to their Cell density distribution infiltration profile. This is a mathematical model. So we have no disclosures for this lecture. So a bit of background regarding the extent of resection of glioblastoma. We know that not long ago the most common surgical recommendation for glioblastoma was to perform only a biopsy. And this was not only in the United States but worldwide. But since the 2000, we started seeing very important studies from Doctor La Cruz, from doctor McGurk, from Doctor Sanai, from UCSF, with Doctor Burger, and from Doctor and Doctor Quinonez. With this data from Hopkins that all of these studies were in favor of a performing more Extensive surgical resection on patients with glioblastoma, and the results were pretty much homogeneous, identifying that resections above 78% of the contrast enhancement in T1 were really were associated with a significant improvement in overall survival in patients with GBM. But furthermore, we see that the gross total resection is the is a, is, is this complete surgical resection of the contrast enhancement component of the tumor that you can see up here. But what about the flair component, the T2 sequence that we have now and for, for a while already that there are infiltrated GBM cells within the brain tissue that most of the time is not being taken care of, of, or resected because of The infiltrated behavior of these, of these cells within functional brain tissue that if you resected it, you can cause a deficit in the functionality of the patient.

Speaker 6: [00:22:09] So we aim with our group and Mayo Clinic to start looking at the extent of the supramarginal resection beyond the margins of the contrast enhancement tumor. And we have seen that regarding this topic, that is that it has been influenced by the results from the, from, from their good results from extend beyond the margins in low grade gliomas. We see here the very important papers from the MD Anderson, from Hopkins, from Cleveland Clinic and from UCSF. And not all of them have homogeneous results, as we found before in the, in the gross resection for the T1 contrast. So we wanted to give it a shot. And thanks to all the all the data that we have at Mayo Clinic with all the with the high flow of patients, we were. We were able to do this study in which we identified more than 800 patients. And we selected only those patients that were ID H mutants, which is the most aggressive type of GBM that has a a less overall survival in total. So we only selected those patients with that had a gross total resection of the contrast enhancement and that they did present before the surgery with some degree of preoperative flair. So in total, we included 101 patients. We we perform all volumetric analysis on all the sequences in the, in the contrast enhancement in the necrosis part and in the flare for all the patients. And we did find the univariate and multivariate analysis that increasing SMR as a continuous variable for the first time we can show that is that is statistically significant for an increase and improved overall survival in our patient population.

Speaker 6: [00:24:18] And furthermore, when we perform a threshold analysis, we found that those resections above 20% and less than 60% were the ones that were related with a significant increase in overall survival. So to summarize our findings, we did this illustration that just shows that, you know, in the green part, in the green portion are the are the percentages from above 20 and less than 60% that were related with an improved overall survival. And we didn't find a significant benefit in those resections above 60%. That is the red portion of the figure here. So now we know that increasing smear is beneficial for the for for for the for an improved overall survival in our patients with ID h type wild type GBM. But we know that there is also a high variability in the radiological presentation of our group in general in GBM, but also in ID as well. So we partnered with the mathematical Neuro-oncology Laboratory at Mayo Clinic, Arizona, with Doctor Christine Swanson to try to further personalize the, the, the, to try to be more specific and with using a specific patient characteristics from the radiological data. And we can see that following our hypothesis at the center of the, of the, of the, of the lesion, the, the one that is in close proximity with the contrast enhancement part has a greater tumor burden cell concentration over there. And once you are going to the periphery, you see that the low density that the density of these tumor cells is, is, is lower.

Speaker 6: [00:26:09] So this is the the formula that was used in our patient population. In summary, for the interest of time, you can see that in the T1 with contrast the volume was approximated to a to a spherical shape. And we saw that the. This part this portion has a greater cell density compared to the cell density in the T2 flair. So with these results, we classified our patient population in three groups that were nodular, moderately diffuse, and highly diffuse according to their to the, to their, to their tumor cell density and distribution profile. So this is a representation from some of the patients that were selected and classified and included in these three groups. You can see here in the note where they have more contrast enhancement than flair. And see in the model diffuse, you see that there is a some more flair in the patients surrounding the the post-gadolinium T1 and in the highly diffuse you see that the flair is, is is greater than in the other groups. So for this in the univariate analysis, we saw that this was significant, statistically significant only for moderate and diffuse and highly diffuse. Okay. But it was non-significant for nodular. This is a univariate. And the same results were obtained for the multivariate analysis. It was statistically significant for moderately and highly diffuse nodular. But when we perform a threshold analysis we saw that for nodular there is actually a benefit only in sections from 10% to 10%.

Speaker 6: [00:27:58] And this is kind of logical because, you know, in the nodular, there is not much flair, as we showed you in the, in in the MRI before. So there is not much benefit in extending section beyond the 20% of, of the contrast enhancement in the nodular group, in the moderately diffuse, we found benefits from all the way up to 50%. As you can see here. And in the highly diffuse. We only saw benefits beyond 30% all the way up to 90 and 90 plus percent. So this is very important because now we can, based on this study, at least in these results, we we see that there is a very important benefit in the, in the super marginal resection of, of these patients. And of course based on their radiological characteristics before the surgery, the surgeons can decide how much the patients can need a need, a resection, an extent of resection based on this. And for example, in these highly diffuse tumors, we found that this is the maximum SMR correlated with a beneficial overall survival. You can see that the patients that had a resection above 90% with the ones had a better overall survival than the ones that had less than 90%. And this patient population had a greater survival of, let's say, if I remember correctly, almost nine months greater than the patients that had a resection with less than 90% for the moderately diffuse, the highest SMR percentage was 50. And this patient presented with a benefit of of, of an additional seven months. And in the nodular patients, the highest maximum significant.

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