Episode 18: A New Non Invasive Treatment for Lower Back Pain - HIFU

Traditionally, the Radio Frequency Ablation (RFA) procedure for chronic back pain requires approximately six injections with 2-4 inch needles followed by the insertion of heated probes to burn the nerves that supply joints of the spine called facet joints. What if you could do all that without the need for injections or heated probes? An innovative Medtech company, Fusmobile took on that challenge and produced a device called Neurolyzer XR. 

Join me for an in-depth interview with Dr. Michael Gofeld who is the first doctor in Ontario to use Neurolyzer XR.

Will Neurolyzer XR replace traditional RFA? Should you try it, now that it is available in Ontario?

Find out.

Learn more about HIFU and watch an animated explanation at: https://unikamed.com/non-invasive-hifu-treatment-for-low-back-pain/ 

If you have any questions for Dr Karmy, feel free to email us at karmychronicpain@gmail.com.

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Chapters

• 1:10 Introducing Dr Gofeld
• 3:20 High-Intensity Focused Ultrasound (HIFU) - Coherence vs Incoherence
• 12:40 How HIFU Works in Treating Back Pain
• 17:34 Pulsed Radiofrequency
• 20:11 Diagnostic Blocks vs the Clinical Picture
• 23:51 Radiofrequency Ablation Procedural Pain and Responders
• 26:55 Side Effects and Contraindications
• 29:42 Next Generation of Ultrasound Guided HIFU - Neurolyser XR
• 32:22 Effectiveness and Literature
• 37:21 Understanding the Size of Lesion
• 40:41 Future of Approach
• 44:00 Dr Karmys Final Thoughts on HIFU

Transcript

0:00

I I truly believe that we can avoid diagnostic blocks and use a pulsed high intensity ultrasound mode to block these nerves. To so to create this block of the nerve function temporarily instead of needles using the same energy. And it's not my dream because, the preliminary studies were done and when I was in the University of Washington Act, interestingly enough, that's exactly what we did with professor Pierre Morat in Biophysics lab. We tested high intensity focused ultrasound as a, as a nerve modulation device on animals. So I know it should work. The devil's in the details, so we need to figure out the frequencies, the energy when it works, when it doesn't work, but that's the next step to avoid even nerve blocks with the needles. Hello, this is Dr. Karmy for Chronic Pain Chronicles, and today we have a guest with us, Dr. Gofeld. Hi, Dr. Gofeld. Hi, Dr. Karmy. Uh, Dr. Gofeld I guess career has some general parallels with my own. We both, I think, started in former Soviet Union. We both ended up in Canada. Both of us ended up treating patients with chronic pain, albeit using different approaches. Just in a way of introduction, certainly when I remember chronic pain over 20 years ago when I started in the field, it wasn't really, uh, well known most physicians didn't even know the field existed how did you end up getting into pain management? It's a good question. First of all, thank you for inviting me. I ended up in the pain management really by mistake. Um, well, not really a mistake. I was a resident, of anesthesiology and I had to do three months of chronic pain rotation. And I did my pain residency in Israel in the University of Tel Aviv. So I was sent to a pain clinic and I had very vague idea what pain clinic is about. And I couldn't help but feel that everyone gets the same approach. So everyone get, get. Get in with a back pain will get epidural blind and and some people with headache will get some occipital nerve block and, I had just started asking questions and that time my supervisor said, just don't ask questions, do whatever what you asked to do. And three months I did not get passed out of pain clinic. I was just actually, I was pretty much fed up because my the other resident I can't remember if she was sick or whatever. So I still stay another three months and I started reading and I said it's actually a fairly interesting field because I came across of JJ Bonica pain management and I decided it's very fascinating and basically at that moment I decided to jump in and continue my career in the pain rather than anesthesia. Wow. So the rest is in the history, right? So I guess fast forward to today and I wanted to talk a little bit about what you are doing now, and what you are doing now is treating back pain with ultrasound. And again, now, I'm not talking the kind of ultrasound that physiotherapists use. This is actually interventional procedure done in pain clinic. So can you tell me a little bit about that? Sure. First of all, my interest in ultrasound actually started from spine ultrasound. I think I was, at that time, I was in Sunnybrook and I was fascinated by work that was done by European colleagues on spine. And, you know, we in Canada, even now we're limited in access to operating rooms and fluoroscopy. And back in 2007, it was even worse. So, I came across a work of European colleagues from Austria, and I said, well, you know, it looks interesting. Like Manfred Greher published that time, or Eichenberger. And and that's how I came to the field, of ultrasound guidance. So fast forward, I actually did my PhD in spinal sonography. And I expanded to some research and development. And in about eight years ago, I I was asked to be a consultant of a small startup. The idea of the startup was in my mind, pretty crazy because they said, okay, we'll just take a high intensity focused ultrasound And at that time it was available only in the Big, machines like uh, MRI and, they hope to minimize it to a sort of clinical use and apply this energy for the same application that we we've been using for like this radiofrequency for spine pain. And so I joined them and that's basically was a journey of eight years. So in a nutshell, basically it's called a high intensity focused ultrasound, which is not new in the field, but the portability is new. So basically in anyone who is not familiar with the field, any energy, if you focus, being electric energy, optic energy, magnetic energy, will produce some tissue effects and focused ultrasound produce two effects. One it's a tissue shaking, it's called um, histotripsy. Which is now what we use for pain and heating like heat effect. The heat is very Energy dependent. So the high energy is the higher heat produced And and the lesion size is growing. Now from the terms of technological advantage and technological ingenuity of this process, of this device is not in the principle, but in the guidance, in trying and, and, and Successfully departing from a MRI because MRI is a great imaging and it requires two beams that converge in it, and it's basically called coherence ultrasound that will produce a grain shape lesion, which is being used for example, in the brain, uh, hypho in Sunnybrook and And Toronto Western for the treatment of Parkinson's disease and essential tremors. That's not what the machine is called now Neurolyser XR is using. It's using incoherent ultrasound. So incoherent ultrasound produces like an area of about five centimeter that is diffused imaging because multiple beams going from different directions and confusing each other, except in this area of this range, the oldest beams will meet a bone tissue. And because of bone absorption of ultrasound is very high, it will create a blast. The lesion will grow from the bone outside, like a mushroom, but actually the shape of the lesion in animal studies and the, in silico studies, it looks like a Hershey chocolate, like a drop so that's exactly how lesion looks like. And because of this is incoherent mode, anytime it's directed under the x ray to the bone with a specific location, such as the medial branch it will create a lesion. So this is the ingenuity of this device and that allowed to depart from MRI to very simple and convenient imaging such as fluoroscopy that most of us have been using forever. And the target is pretty much the same. So that's another point. You don't need to recreate sort of, uh, your mechanics in the brain to find the target. The technique is different, but the imaging technique, the imaging modality and the target is pretty much the same. So just to, clarify for the audience, again, there's multiple types of ultrasound. There's the therapeutic ultrasound that's used by physiotherapists. There is ultrasound that you started with, which is simply used to create images. And then there's high intensity focused ultrasound, which is actually used to destroy tissue or heat up the tissue. And then , it comes, you are telling me, in two flavors. One flavor that is used for brain surgery, so to speak, under MRI guidance. And then there's the non coherent flavor, which is the novelty, I assume which creates this Hershey Kisses shaped lesion that's the one that, uh, you're working on. Yeah. So what is the fundamental difference between these? I guess one is non-coherent, one is coherent. But how are they different from imaging ultrasound or ultrasound that physiotherapists use? Sure. So we need to remember that even ultrasound diagnostic ultrasound still delivers thermal energy and histotripsy energy. And there are tables that, that attach to any machine, digital tables or actual tables that is specifically used in neonatology because there, there are limitations how much ultrasound A technician can deliver to a baby without making some brain damage that, for example, brain imaging ultrasound. Even diagnostic ultrasound, still, there is a emission and receiving. Ultrasound goes both ways. We call it transducer, but basically It's not just transducers in the emission and in the emitter and the receiver at the same time. So the transducer emits ultrasound waves. It goes through multiple layers of different tissues because of different speed it creates different permeability and reflection back. And this reflection back changes piezoelectric crystals, creates electrical signals, and we see it in the imaging. Okay? So this is the Diagnostic ultrasound. Therapeutic ultrasound that physiotherapy used is also sort of incoherent ultrasonography because, I mean even if something is coming back there is no registration. It's more dense area and it creates a heating and some gentle vibratory effect on the tissue, right? But it does not lead to a tissue charring, a tissue lesion because energy is very limited. It's rarely go more than 100 joules energy and with a high intensity focused ultrasound that energy can go anywhere up to 10, 000 joules, which can create a hole in the bone like a laser. But but obviously we don't do it. So in pain applications, we are usually used a range between 1000 and 1500 joules that can create a good size lesion without, exponentially increasing. By the way, with with other machines, there's not just um, MR guided. There's also ultrasound guided systems that mostly used for oncology applications, prostate cancer, breast cancer, or uterine fibroids, and a host of other other conditions, but they're also very bulky and very and very costly machines. Again, just to clarify there's sort of two machines involved. One is obviously the MRI machine, which traditional high intensity, ultrasound will use that obviously very large and then there's the actual , ultrasound machine, which is generating the waves. So clearly advantage of this new approach is that first of all, you can just use an x ray machine, which is much more portable than a MRI machine. But then you, are you saying that they're actually ultrasound machine that's generating waves is also more portable than what's typically used for brain surgery? Yes. Yeah. So s so the cradle that we use is smaller and it's mobile and the cradle with a piece of electric or, circles that creates different waves. And this is a transducer, so it's connected to a portable machine sizes that radio frequency generator that anyone who's familiar with radio frequency generator, not so large. And there's a an electronic connection to a fluoroscopy machine because they need to realign two imaging modalities, optic modality and x ray modality, right? And so it's actually using some sort of, of augmented reality to overlay two images, which is, again, not nothing new about it because, many imaging and and procedural imaging is used this overlay. So we overlay CAT scan on x-ray or MRI on ultrasound. But here it's, it's overlay the optic positioning system on the patient's skin to a fluoroscopy machine to basically Find the right target, all right, and then the energy can be delivered. So I have actually a pretty simple and cool animation. If you like, I can try and run it and explain on animation sites how actually it works. Maybe one picture was a thousand words. So fundamentally, what you're doing is you're treating facet joints, primarily I assume of lumbosacral spine. I'm not sure if you've extended it to treating sacroiliac joints or the back as well. And so what is the experience like? I assume you're still going to have to start with diagnostic blocks to decide whether or not patient would qualify for the procedure. Yeah. The diagnostic work is the same as as for lumbar lumbar radio frequency ablation, neuropathy. The device from the beginning was designed to the first target as a lumbar spine. It's a labeled application to lumbar spine. So Health Canada application, Health Canada approval is for lumbar spine, but that being said I have used it for sacroiliac joint ablation because it's fairly simple and easy. There is a study going on in University of West Virginia and on the sacroiliac joint formally using the same device. So there's not much departure from from anything that we know. But from the research standpoint, we have now studies that was done first in 2021. There was I participated and colleagues was in McGill. So there was a pilot study and then we continued study our clinic was together with Toronto Western hospital, we did so called Canadian pivotal study for Health Canada approval and it was only patients for lumbar lumbar spine facet joints. And the study in FDA pivotal study on 80 or 90 patients is finished in the United States. And now it's in the article has been written up and FDA is submitted. So who knows when, how long it's still take. I don't think it will take more than six months. So coming back, our clinical experience and research experience mostly and primarily is a lumbar, uh, area and related to facet joints. So the workup is the same. So clinical diagnosis of patient who have primarily axial low back pain, mostly elderly patients, you know, and some clinical predictors and diagnostic medial branch block. Okay. The next step is I believe that, since we are, it's we're talking about developments and and cool stuff. I I truly believe that we can avoid diagnostic blocks and use a pulsed high intensity ultrasound mode to block these nerves. To so to create this block of the nerve function temporarily instead of needles using the same energy. And it's not my dream because, the preliminary studies were done and when I was in the University of Washington Act, interestingly enough, that's exactly what we did with professor Pierre Morat in Biophysics lab. We tested high intensity focused ultrasound as a, as a nerve modulation device on animals. So I know it should work. The devil's in the details, so we need to figure out the frequencies, the energy when it works, when it doesn't work, but that's the next step to avoid even nerve blocks with the needles. I'm not, honestly, I know of pulsed radiofrequency, I heard of it as a therapeutic approach in and of itself, in its own right, especially sometimes for lumbar, but sometimes even for mixed nerves where you wouldn't want to destroy them but I actually don't have any personal experience with it. Does it actually numb the nerve what happened? We're talking about pulsed radiofrequency. Pulsed radiofrequency, yeah. So pulsed radiofrequency, the theory behind pulsed radiofrequency is is electromagnetic load with 500 megahertz for, with energy of up to 50 watts. To up to five minutes, deliver it on a nerve tissue and , to be honest, it has never been proved in in any clinical setting, but on on the cell culture and animal setting the theory behind it, that is preferentially preferentially influence of C fibers. And leaving other nerve fibers intact. And how it uh, it influences other C fibers, because they are unmyelinated. So it would, sorry, increase the threshold of the action potential by about 5 millivolts. And by increasing this threshold, basically meaning the pain propagation, the, the action potential is is ceased or decreased. That's theory behind pulsed radio frequency. Now no one in the clinical world ever proved that actually it, it happens. But, based on some studies and evidence and clinical experience, it looks like it works better than any nerve blocks with local anaesthetics. My personal experience with research on pulse radiofrequency is a study that we tried to do in Sunnybrook on patients with shoulder pain. And double blind and randomized, and it definitely proved that patients with who received red, blindly and randomly pulsed radiofrequency of suprascapular block, the pain relief was longer and better than the patients who received suprascapular. So that's a theory behind pulsed radiofrequency. I don't know if you have personal experience with it. What I'm really asking is you do pulsed radio frequency. I don't, I suppose you get to put some anesthetic in there as well when you do it. So it's hard to know does pulsed radio frequency on its own create numbness. It should not create numbness. No, it should not create, it should create only pain, reduction of pain. Okay. So fundamentally where this is going is that right now the procedure requires a single injection to make diagnosis. And then after that all the rest of the treatments will no longer require injection. And potentially in the future, one could bypass injections completely and just use this treatment to treat back pain, right? That's pretty much, but you know, again, it's all regulations, right? So in the United States, for example insurances will not cover radio frequency unless two comparative blocks are done, right? In Canada, there are no regulations. I know, and I personally do the same if the patients clinical picture is fairly congruent with axial facetogenic pain. I may not even do diagnostic block because they're, we can talk about problems and biases of diagnostic block for another two hours. But if put in a scientific way, Steve Coyne he was in, in Walters Rees Hospital, now in North Western. He published a series of articles, very clever articles, showing that bottom line, the difference between two very precise diagnostic blocks and and no diagnostic blocks, radiofrequency ablation, the difference is about 10%. So given the fact that radiofrequency is today, is very safe procedure. So why bother to do diagnostic block if the clinical picture is very straightforward? So you're saying that the clinical picture predicts things almost as well as diagnostic blocks? Yeah, absolutely. Bottom line, about 50 percent of people without diagnostic blocks, based on the clinical picture, will receive fairly reasonable results for radiofrequency. And if you apply all kind of bells and whistles, two diagnostic blocks, blind, so you can increase this probability. to 60%. So is it worth it to invest time and subject patient for another two fairly non comfortable procedures if you just can skip and do radiofrequency? The history behind the diagnostic block is actually going way, way back to the start of radiofrequency because when radiofrequency just started Remember, it was 12 gauge blunt needle called ray electrode like a harpoon So that would make sense because the morbidity was pretty high and the procedure time was very low with radiofrequency So now it's more historical, and I think historical concept if, again, if it's just for the protocol to do diagnostic blocks. So I use very, fairly simple way to to distinguish between, or to find out if a person has a high probability of facet pain. It's age more than 55. It's radiological confirmation of the facet or ro spondylosis. So pain aggravated by movement and subsided by recover, by recumbent or rest and preferentially, it'll be out one side pain which aggravated by twisting movements and extension. Kind of, you know, more or less predictable because some people with flexion also have fascinogenic pain. But if I just tell an age relief by rest, And and at the site of pain with no neurological fissure. That will be almost hundred percent, those people will be with at least some component of facet generated pain. So it sounds like you can do this treatment and completely avoid injections. Correct. But does that mean the procedure is painless? No, that's not. It's I don't know if to, to, curse you or thank you for asking this question, but that's a difference between it's a perfect example of difference between the research and the clinical practice, because when we did our research, and including, by the way, American research, which I was surprised just a few patients reported pain Student Participants During this procedure that they could not tolerate without any sedatives, just literally a few, a handful. Now when we are now almost 30 patients out in the clinical, right? It's not. Some patients really have zero pain during the procedure, but some patients have 10 out of 10 pain and you need to provide some sedation or last week I, I I hated to do that, but I I just had to do facet joint blocks to continue noninvasive ablation of the joints because a person could not tolerate it. It looks like the procedure itself is more painful than radiofrequency. Again, based on the fact that radiofrequency, even without sedation, that most of the time we do sedation. But even without sedation, we, once the cannula is placed, or on the way the placement of cannula, we, we provide local anesthesia and also freeze the, uh, the site of lesion. That's not in this case. I guess just a sideline, I could be totally off base, but, uh, can, are there any factors that could predict whether or not somebody would experience pain with this procedure or not? Maybe if they have a huge, big myofascial component or nerve sensitization, like fibromyalgia type patients? It's probably it's also very, uh, very interesting predictor patients who complain that the background pain more than nine. So nine, 10, those patients a have a higher pain during the procedure. You can say they already have nine or 10 pain. So how worse it could be. So yeah, apparently. And and also those patients most of them would fail. And it, we could see it in the, in the studies as well. So patients with a, who reported 9, 10 out of 10 pain, genuinely speaking, they are very poor responders. Other than that, yeah, you just, you already pretty much guessed right. So patient with fibromyalgia, patient with generalized anxiety, patients with diffused myofascial pain, sure, they will have any type of pain sensitivity or hypersensitivity or central type of centralization of pain, they will have much higher uh, sensitivity. Procedural pain, which is not surprising. Are there any side effects or contraindications to this procedure? So first of all, patient size. So very skinny patients with the, when the distance between skin and and the medial branch is less than three centimeters. Believe it or not we have those patients, all patients on conversely patient when the when the distance is more than 10 centimeter. So the beam will not reach the point of increase in temperature on these patients and the skinny patient can burn skin. Other, some contraindication that I've never seen in that yet, but it's like a hypertrophic scar because it'll be very difficult to place the gel and create the sealed environment if it's a hypertrophic scar. But, on the other hand, patients do not need to stop anticoagulants. There is no need. Patients with implanted defibrillator, that I excluded from radiofrequency ablation, by no means you can treat it. Uh, patient with with metal post surgery, as long as the metal is not in the way of the beam, that, patients can be treated. And all these issues that are difficult with radio frequency because as I said anticoagulants now it's more lenient, but still many doctors required to stop anticoagulants., Implanted card defibrillators is no go with radio frequency. Uh, and the metal is not really, per se is is contraindicated. But when the metal is present already, a frequency, energy, which is electric energy, is focused on a metal, right? So it will be basically a big grounding pad in implanted in the patient body. So the lesion size. will never reach the the size of ablation. So it actually expanded areas of applications. I may also think a patient with severe scoliosis, there will be not a good candidate for HIFU. Only because the it will be very difficult to adjust the cradle on the patient's skin. But those pretty much are contraindications. They're not really absolute contraindications, all of them relative contraindications. Two follow on questions. Okay. One is can one, since you have interest in spine, can one do HIFU with ultrasound guidance? And a somewhat related question, can one do high intensity focused ultrasound on pregnant patients? With this device on the pregnant patients, no, because it still requires fluoroscopy imaging. Images is a fluoroscopy guided high intensity focused ultrasound. People have some cognitive dissonance that, oh, it's ultrasound or fluoroscopy. It's a fluoroscopy guided high intensity focused ultrasound. Now, the the next generation is called, that's why it's called Neurolyser. Remember the Neuralizer in Men in Black? So that's the, that's where the idea came from, Neuralizer, but, in the movies it's with Z and and this machine I talk about with S, probably because of the not to go to patent infringement. It's called Neurolyser XR. XR stands for X ray. The next generation the company is working on is Ultras Neurolyser US. Which is exactly what you just said. It's ultrasound guided, high intensity focused ultrasound. And it's even it's more, it's a smaller system. Very clever because in contrary to, to, uh, fluoroscopy x ray, ultrasound also knows how to identify the depths. So in this case this augmented reality works pretty good because the sensor will focus the beam exactly on the, on, on the depths that is necessary, right? But I I think it will be great for For joints like denervation of joints that now is being used only with radiofrequency, maybe some other applications, maybe even oncology applications. I'll be very cautious about spying, certainly can be done, but the, because the transducer itself, the imaging transducer is pretty small. It may not fit, patients with a good size, but at that time, if it when it's available. And again, my prediction, it will be available within six months because the approval process will be fast. The moment the GLP good laboratory practice study is finished, which has been done now, it will be straightforward application for regulatory approval. But I don't think it will work ultimately for patients with increased body mass index on lumbar spine. Thoracic spine, I guess it will work. Cervical spine, it will be probably wonderful application. Peripheral joints. Maybe even soft tissue the future will show, you know how it goes. Usually some clever PhDs in in, in inventing a method and and more and doctors will try it for different applications. You know, I can see it in different ways but the ultrasound system is on the way. And okay. So we talked about Some of the contraindications. So let's talk a little bit about effectiveness. So how does it compare in terms of effectiveness to radiofrequency, standard radiofrequency ablation? I'm assuming you didn't do side by side studies. This is just your initial impressions. Um, so we did side by side imaging study. And it's kind of interesting story behind it. Because the application for FDA was under 510K de novo, which basically something that is known, but there's some element of unknown. So FDA asked the company to produce a comparative study on animals first. So the first study was done and published when on on the on pigs. One side was done with standard radiofrequency. The other side was done with HIFU and MRI and histology was done after. So HIFU was by far better than radiofrequency. Radiofrequency produced only 50 percent visible lesions. And HIFU in the lowest energy produced 71 percent of lesions and the high energy up to 96. And, but, FDA is pretty tricky, uh, organization. So they said, okay, fine, we're happy you did it. But can you show us any study on MRI after radio frequencies on humans? So we can corroborate. And and to my astonishment, I did not find any study. It was nothing. Zero. Later, one of American colleagues produced some study and, but it was not quite relevant. So what we did study our cell. We did study, we already had studied MRI after HIFU with a fairly significant, depends how you look at correlation, association with the pain relief size of the lesion and presence of the lesion on MRI. But we did the same with radio frequency. And when we did the radio frequency, the results, radio frequency on humans, basically, people who went to us to have radiofrequency and we offer them to do a MRI free MRI five days after and Ten patients sign up and we did it. So again, it was also shocking that only 26 percent of these patients were found visible lesion on MRI, so we did we don't have clinical comparison but imaging comparison is by far better of HIFU. Did I get you, did I understand you correctly, only 26 percent of people with traditional radiofrequency ablation were found to have lesions, and what, 100 percent of patients with HIFU ended up with 100%. We found 50 percent had a lesion and up to 70 percent have edema, which is by the way, secondary effect of heating, right? Not the lesion, but edema. We could not take histologist study on on patients, right? Uh, but when the differences are a bit clinically difference, first of all, difference between radio frequency and hyphal. It's more painful, as I said, more painful during the procedure, but after the procedure, within 10 15 minutes, the procedural pain is gone, as well as low back pain. Radiofrequency patients, because of the needle, because of whatever is going on, they often have sort of protracted back pain. For a few days up to even a couple of weeks or sometimes longer, and it's probably because of muscle damage of the needling. HIFU patients obviously don't have needling, so responders are usually responding almost instantaneously. Now, for how long? I think it's actually fairly similar to radiofrequency. Probably somewhat better, just based on the study results. Thanks. But if you take statistical, statistically, it's within the same range of up to a year pain relief, reasonable pain relief up to 50 percent still pain relief. And but I, I just repeated HIFU on the patients who were in our first study, which is three years after. And some of them. Believe it or not, they said I still feel better. My pain is returned, but if I compare it with how it was before the study procedure is still better. So I will not. I will not do I will not make a frivolous comments because, oh, yeah, it's a wonderful and the pain will be gone forever, but it looks like it works for longer than radiofrequency. So again, the size of the lesion I always thought of as a little bit of a double edged sword. You make the lesion too big, you might catch some of the nerves that innervate paraspinal muscles, and I'm always worried could it spread and affect the root. You make it too small, you don't catch enough of the nerve, and then you don't have a very long effect. Any thoughts relating to How do we deal with this? Okay, so first of all, nerve root is not because it's actually protected by bone. So the bone of of the pedicle is protecting from the beam going to, to the nerve root, right? Radiofrequency cannula you can erroneously place right in the, in, right there, but here's, it hits the bone and it protects. Now, because as I said, it's incoherent. You can technically pass this beam, beams through spinal cord and nothing will happen because within this five centimeter incoherent we call it therapeutic envelope the temperature increase, it increases up to 42 to 43 degrees, which is not lesional temperature, and then it dissipates. So it goes like cones and it goes continue dissipating. So that's number one. Number two in all studies in clinical cases, it's now probably like around 200 cases worldwide There were no any nerve root damage whatsoever. Number three about the size I agree, and this extended discussion , if you create a radiofrequency or other lesion and you can catch, lateral branch, intermediate branch, and motor branches, the multifidus muscle, etc. When I said the target is the same, I I made it a little bit more oversimplified because the target is the same. for the ideal target because for lumbar medial branches is actually focused on the very low part of the pedicle where only sensory branches of, uh, facet joint remains. And radiofrequency there cannot be done because the mammal accessory ligament is sheltering medial branch. For HIFU, it's actually a bonus, this mammal accessory ligament, because it's concentrate in energy. It's actually creates a sparing effect. At least, our theory in models shows that it creates a share uh, sheltering sort of effect on, on, on other tweaks or branches. And ablates only articular bunches, right? It will be good to show it more experimentally, but I think it will be the next project with on a patient. So there's not much and the lesion size is a dose dependent. So with a thousand joules on a normal size patient, it will be about one centimeter shape. Same as a, cooled RF or timed RF. In ideal world, right? And on a more high kind of weight patients, it's 1, 500 joules. It's not because to increase the lesion, it's just to, to create the same lesion because you need to deliver more energy through depths of the tissue. Okay? So I don't think it will create any problems with muscles or any other structures. You talked about pulsed radiofrequency as a possible application, you talked about maybe broadening to other targets, possibly using ultrasound guided rather than fluoroscopy guided procedures in the future any other thoughts on what the future holds for this approach? If you go in and and, send your audience to FAST Foundation website, there's a focused ultrasound foundation, you'll find I don't know, not maybe not hundreds, but multiple studies that are going on different applications, um, including what is, Kind of to, in our field there are few studies going in neurology and few studies that are going in in oncology for bone metastasis, soft tissue metastasis. And some other studies trying to figure out what is the neuromodulating potential of high intensity focused ultrasound. And and other studies show that e sonication with high intensity focused ultrasound after surgeries and then injecting a regenerative medicine there would increase the proliferation of fibroblast. So it's, there are point, plenty of study there. Brain imaging is probably will be exploding. Uh, Berg just finished, as you probably know, they just finished the study on the high intensity focused ultrasound to treat severe OCD with a very good results. But, I don't think in any time soon and PainKillings will own MR guided machines. So we'll stick with the portable, but I would say if I had an option to do, uh, to create a histotripsy, for example, in a small machine, which is currently unavailable, that will be a great for any sport injuries for calcific tendinopathy. You know, now we send patients for shockwave therapy of the calcific tendinopathy. Honestly, it doesn't really work well because A, it's a low energy and B, uh, physiotherapists don't focus it right. So, that will be great, but for now we have some technological problems. I can imagine that, if we can block nerves, block, just do a nerve block non-invasively. That will be great for regional anesthesia. So who will need to do inject medications, reimbursement is a separate issue, right? So if you, if you cannot bill for this, I don't know if doctor will do it but practically it can be pretty, pretty cool if you can do all nerve blocks without even, you know, injecting anything. You'll put us all out of business. I don't know, maybe we'll all be out of business. Or we'll we'll advocate to change codes. Because, you know, if we, if we did produce nerve block, who cares how did we do it, right? Thank you for talking to us about needle free interventional procedure to treat back pain. I found it very informative and we will post some additional information on our Instagram and our website, hopefully with a video on how this is done. Thank you Dr. Gofeld.. Thank you, Dr. Karmy, talking to me. So what are my final thoughts on high intensity focused ultrasound? Well, first of all, let me make it clear that this is not going to fix everyone with back pain. Uh, assuming it works as well as traditional radiofrequency ablation, it'll likely help about 15 one 5% of patients with chronic pain. Also, even this procedure does not involve injections it is not a pain-free procedure because you're still destroying tissue. Setting these qualifiers aside, I still feel it is a huge advance in interventional pain management. This is the first interventional pain procedure which can be performed without penetrating the skin with a needle. There are many patients who are terrified of needles who would refuse, uh, most types of intervention pain procedures, but who would be willing to undergo high intensity focused ultrasound. The company behind this device is called Fuse Mobile, and it is rolling out Neurolyser XR in stages. At this point their only clinic offering high intensity focused ultrasound treatments in Ontario is Unika Medical Center in Toronto where Dr. Gofeld works. Presumably, as the company gains more experience with outcomes of this procedure, they will allow additional, uh clinics in Ontario to offer this procedure. This is not unlike our stem cell study for osteoarthritis, which at this time is just limited to my clinic in Brampton. But we'll eventually be broadened to include other clinics as we gain more experience with the stem cell injections. Thank you. Thank you for listening to this episode of Chronic Pain Chronicles with Dr. Karmy. You'll find a link in the episode description to an explanation and animation by unika on non-invasive HIFU treatment for lower back pain. If you enjoyed today's discussion, be sure to follow or subscribe so you don't miss what's coming next. Until then, take care and remember, you're not alone on this journey. I'm Raveena Aujla Till next time. I. Disclaimer, when it comes to your health, always consult with your own physician or healthcare provider for personalized advice and guidance. The information provided in this podcast is for educational and informational purposes only, and should not be considered medical advice or a substitute for professional medical care.