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Podcast Transcript: Innovating Pain Management: The Role of Spinal Cord Stimulators in Outpatient Care

with Dr. Douglas Beall

In this episode, guest host Dr. Dana Dunleavy and guest Dr. Douglas Beall delve into the transformative potential of neuromodulation in the treatment of chronic pain, particularly for painful diabetic neuropathy (PDN). Dr. Beall is an interventional musculoskeletal radiologist practicing at Oklahoma Spine in Edmond, Oklahoma. You can read the full transcript below and listen to this episode here on BackTable.com.

(1) Independent Practice & Neuromodulation

(2) Paresthesia & the Evolution of Neuromodulation Techniques

(3) Addressing Painful Diabetic Neuropathy with High Frequency Stimulation

(4) Treating Diabetic Neuropathy with Neuromodulation

(5) The Role of Interventional Radiology in Diabetic Neuropathy Treatment

(6) The Future of Pain Management

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Innovating Pain Management: The Role of Spinal Cord Stimulators in Outpatient Care with Dr. Douglas Beall on the BackTable MSK Podcast)

Ep 40 Innovating Pain Management: The Role of Spinal Cord Stimulators in Outpatient Care with Dr. Douglas Beall

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[Dr. Dana Dunleavy]
Welcome to the BackTable Podcast. This is Dana Dunleavy from Buffalo, New York. Douglas Beall, tremendous honor. Thank you for burning a weekend with me. You really need no introduction for many reasons, but maybe we could, while the topic is so hot right now about IR and DR surviving together, talk a little bit about your life. People talk about you with such reverence. Maybe I could just say that you got fired from your job and that's why you're the man you are today.

[Dr. Douglas Beall]
The honor is mine, Dr. Dana Dunleavy. It's an interesting path and I think most of the time to realize where we are, you have to realize where you don't want to be. I came out of the military, started to practice. My office was actually in the Department of Orthopedics and I'd come back after a fellowship in MSK radiology from Mayo Clinic and really started off in interventional and I was taken by the military and didn't really have a chance to finish that fellowship. I was placed in the Department of Orthopedics and worked that as an amalgam, working a lot with those guys. Then when I went to the University of Oklahoma, I did an interventional call, which is every third night at a level 1 trauma center, and had a chance to work with orthopedics and work as an IR, without even having finished a fellowship in it.

Then when the chairman changed, what I had set up at the time, I had developed what I called “clinical practice programs” and these were an amalgam. These were problem-solving, pain-solving, and issue-solving programs where people would come in and at the time they were doing almost no vertebral augmentation. I set that up and immediately went from zero to hundreds of cases a year, a lot of which were fed by level 1 trauma centers, a lot of which are just garden variety, osteoporotic vertebral fractures, as you know. Then, they would come back and they'd have back pain that was unrelated to extension with twisting.

Okay, that's a different pain. Let's do some facet injections. They'd come back with radiculopathy and I'd do epidural injections and do an amalgam and very quickly expanded to doing pretty much everything. I saw people with complex regional pain syndrome and then got into neuromodulation and grew it really way beyond the bounds of just simple augmentation. We've always had these skill sets and always played around. I remember it in residency and I did it in Baltimore at the Johns, same as you, Dr. Dunleavy. We would do injections and we would do anything, interventional spine in its formative years. I brought those techniques to bear.

Then, when the chairman changed, a new one came in and shut down my clinical practice programs. That really was, at that point in time, the primary thing that I wanted to do. That was my identity professionally. This was what I was publishing on and I just didn't see a reason for it. I didn't see a reason to stay if I wasn't going to be allowed to do this. I did something that I probably would not do today. I don't know if I would have the fortitude to do it today. I just put the resignation letter on the desk of the new chairman, and said, "I know I should give you two weeks, but you shouldn't have shut down my clinical practice programs. I quit effective immediately."

I went to a solo private practice at an affiliate hospital just in the north part of the city. I didn't know how to code, I didn't know how to bill, I didn't know what I was going to do. I barely even had a place to land, had no staff, had nothing. Within about a couple of months, I thought, "I can do this." Within about six months, I said, "I definitely can do this." Within a year, you couldn't pry it from my cold, dead hands. Developing all of this as problem-solving, you'd see various and sundry patients you get referred to primarily by your clinical practitioner partners and then friends and family. Where I am today is just, it's over 50% word of mouth. I'm not part of a vertically integrated network. I was solo for 18 years before I got partners this past year. It's just been a native way to grow. I think some of the things I really like doing now are seemingly not popular for some groups. For example, intrathecal pain pumps. I don't think they have a great reputation. They're fantastic. That's the secret. They're fantastic. It's just been passed down.

Vertebral augmentation is not done by interventional pain very much, but that's the single best thing we do in terms of patient satisfaction and outcomes. It's like the old adage, don't fill cement into the posterior third of the vertebral body. That's an old adage. It's been said many times and it's wrong now, just like it was wrong the first time people said it. Not only that, it's things are passed down. Don't do pumps. You're married to the patient. What does that mean? That's ridiculous. People are afraid of things like spinal cord stimulation and neuromodulation because people perceive it as complicated. The difference between complicated and complex: complex is like a jet engine. It's like disassembling a Ferrari. Complicated: my wife is complicated. There's a big difference between complex and complicated. Just because something's complex doesn't mean you can't figure it out, attach a generalized algorithm to it, and be successful. That's the way that we've navigated the world of what is termed MSK intervention. A lot of people call it interventional spine, interventional pain. It goes by a number of different words, but, essentially this is minimally invasive spine surgery and this is radiologic surgery or some other name that we need to develop to adequately describe it. What this is, this is a minimally invasive problem-solving way to propagate people's lives, improve their function, increase their quality of life, decrease their pain, and improve their ability to participate in life all the way until the time that they get older.

(1) Independent Practice & Neuromodulation

[Dr. Dana Dunleavy]
I love it. Part of the reason I bring it up is there's so much interest in what you alluded to, which is, can I do it? Right? I think everyone knows no matter what you'd find a way, but some people want to figure out how difficult it is going to be and whether it's Doug Beall's practice or some of my colleagues locally that have built the largest and most successful and highest quality practices. There's something about their prior groups that they felt they were being held back and they could do better by patients by doing it independently. That's why they moved in that direction.

I think that what you provided is tremendous support across the country for anyone that wants to do what you've done. They're not going through that really difficult first year that you did. The billing and the coding is there, all the aspects of finances are now available. There's a lot of mentoring.

The local neurosurgery group, which is world-renowned for endovascular neurosurgery, the chairman was actually let go twice because he was such a pioneer in that world. Now again, they're the leaders. It's very interesting. We recently talked to the founders of TRAVELIER, which is a group of physicians doing interventional radiology to cover underserved hospitals. Again, I think without guidance from you and others, it would be very challenging for them to pull that off.

[Dr. Douglas Beall]
The aspect about being a pioneer, you can always tell a pioneer because he's the guy with all the arrows in his back. There's a lot of truth to that. Doing things out of the box is welcomed by some people, not really welcomed by others. Being at the cutting edge, sometimes there's a sharp hard edge to ride and it works in your favor and sometimes not, but the real advantage I think that all interventional radiologists have regardless of their focus, whether they're MSK, IR-focused or IO or IR vascular, the real secret we have is that we're just great at guiding things under minimally invasive situations, under fluoroscopy, and under CT. We have three-dimensional knowledge, we're able to guide things under cross-sectional imaging very well, and that's not the case for all the specialties. We passed the Bear Bryant Test. When we used to go through the goop and yank somebody out of the rack in the middle of the night, they'd land in the ready position, and we'd pass that test. We'd land in the ready position, ready to guide stuff under fluoro.

Our formative years, we had a bottle in one hand guiding a needle through soft tissue under fluoro or CT with the other. That's where we came from, that's the heritage. That gives you the ability to do this on your own. You go out and if you practice clinical excellence, if you're just better at your job than any other specialty, there will always be a place for you regardless of what you do, where you are, just be better at clinical outcomes. Put the patient first, put your outcomes as a primary goal, measure what you do.

One of the secret things that I've done over the years that's really helped me is that I've been around pegging a square hole for my entire career, and I've had numerous people say, and it's just only abated in the last few years, but, "Oh, you shouldn't be doing that. Why are you doing this? That's not within your specialty, you shouldn't be doing that." One of the things that I've done to deal with that, to mitigate the impact of those statements, is I've measured everything that we've done.

I've run our 58th clinical trial. I've got four registries going on simultaneously now, and what this does is it's a huge advantage because you can say, "If you think I shouldn't be doing this, let me tell you that my average pain score goes from a 9 to a 1.4 after a kyphoplasty. That on the average, our sacroplasty produces a 6.4-point reduction that's better than anything that's been measured in the past five years. Our pain pump people get off their opioids reproducibly.” This collection of data, not only forestalls additional critical comments, but it also allows you to figure out where you are. It gives you your dashboard to figure out how you're doing and how much you're helping people. Also, it's valuable in terms of collecting and publishing level 1 evidence, you really can contribute to the science a lot, and it makes you attractive to industry.

What industry does is, I remember, I'll give you a little bit of inside baseball. We're doing a clinical trial, and one of the sponsors of the clinical trial sent me an errant e-mail, and I got this spreadsheet showing that the Cleveland Clinic was getting reimbursed twice as much per patient as I was. I was pretty mad about that and let it go and just didn't do much about it. I thought about, why in the world are they getting paid twice as much? I talked with my research coordinator, and she said, probably, they just have a lot more steps to go through, and they're probably just a lot more expensive with the bureaucracy. I think that that's probably true, and I talked to the sponsor a little bit about what they were reimbursing. They made the comment that the research coordinator at the sponsoring medical device company said, "Yes, we wish you had a lot more sites like yours because you enroll lots of patients that are appropriate patients for the therapy, and you're a lot cheaper, and things go, in general, a lot faster."

I understood that this is how we do it. We're small, we're nimble, we enroll appropriate patients, we have very little bureaucracy, one signature does it all, and that's why sites like ours are so attractive to industry, pharma, and medical devices. Even the NIH people who review these things because we're doing multiple research projects, we're enrolling lots of patients, and we're getting really great results, and it's not costing a fortune to do it.

[Dr. Dana Dunleavy]
Yes, it's so important, even yesterday, there was a discussion online between vascular surgery and interventional radiology about the lack of evidence of some of the things that we do. If you look at the work you've done, tremendous evidence behind it, and sometimes we talk about, the significance of reducing a VAS score by two, and many other things we're talking about, reducing by seven or eight, really incredible. I think with that, maybe we could move right into how you got involved with neuromodulation and how it impacts your practice in your region.

[Dr. Douglas Beall]
I'd seen neuromodulation at Hopkins from some of the guys that were there that I'm friends with now, stats and others, I remember seeing that. Then I got into the practice, and I had somebody with complex regional pain syndrome, formerly known as RSD, reflex sympathetic dystrophy, and it was a real problem. I thought these are home run cases for neuromodulation, and this was the early 2000s.

I reached out to my Medtronic rep, who was presently accounted for during the neuromodulation and pump business, I said, "I want to put a stimulator in this guy." He said, "Okay." Then I said, "When can we do it? Let's get him on the schedule." He said, "Let me get back to you." It was literally like a month later, and I said, "Todd, what's up with this? Why can't we get this done?" He goes, "We can't train you on it." I said, “Okay, I didn't know that I needed training to do this, just putting leads in the epidural space." He said, "Oh, okay, we can do it tomorrow." That was a Tuesday, we did it on a Wednesday, it was a two-lead trial, and after we finished, he said, "Boy, that was easy." I said, "Yes, this wasn't a big deal."

It wasn't until much later, I found out that there was a controversy. Medtronic didn't want to train a radiologist to do neuromodulation, spinal cord stimulation. It's similar to what we face with kyphoplasty, they didn't want to train radiologists to do kyphoplasty, they thought it was only a surgeon. I'm hitting for the cycle here, Dana, they didn't train me to do pumps either, because they didn't want to alienate their primarily anesthesia-based colleagues, and hey, I get it, that's okay. As you know, some of our colleagues are still embittered by the kyphoplasty problem. They're still roiling over that, and that was in the late '90s. I think they need to get past that, it's stuck, like the woman with the hairstyle from the '80s, they need to get past that.

We did the neuromodulation, the trial, and this, as you know, neuromodulation works really well for a couple of things. It is just a home run for CRPS. For neuropathic pain, it just is the champ, it does the job, really, you can have 80% remitter rate on this now, and for painful diabetic neuropathy, we've got a 90% response rate, that's just crazy. Then, the remitter rate for that is right around two-thirds, about 65% are just gone, have the painful diabetic neuropathy gone for high-frequency neuromodulation.

I put this in and started doing it, and that was back in the day where we would be able to get leg pain. We'd be able to, for radiculopathy, we'd be able to treat complex regional pain syndrome, we would not reliably be able to treat back pain. Then we've gone through lots of iterations, occasionally I would try to use it for painful diabetic neuropathy or PDN. About one in four, one in five, I would hit it over the fence, and patients would do great, and it's the cruelest type of thing because they would do great. Then, the other next three or four just were duds. All of this was done with tonic stim. The tonic stim, for our listeners who are not familiar with it, goes all the way back; first one of these was done by a guy named Norman Shealy. He's a neurosurgeon in Minnesota, and he hypothesized that he could stimulate the A-beta fibers, which is non-nociceptive. Then that would interrupt the nociceptive signal from the A-delta and the C-fibers, and the first one was put on the spinal cord, which was pretty heroic, especially in the '60s, it was in '67, and then it was for intractable cancer pain. Then later on, they had external systems, and then the IPG wasn't developed until, I think it was '81 when Medtronic came out with their implantable pulse generator.

Then, the systems we have now are really the systems that I had, and this was a tonic system, these are low-frequency stim. It causes paresthesia, which is numbness, tingling, thumping, people describe it as a different sensation, and also different frequencies will produce different sensations, but the sensation blocks the pain. So you have a paresthesia in the place where you hurt, you block the pain, it's the Gate Theory from Melzack and Wall, and then the patient typically does pretty well.

Then it's a real struggle at that point in time, from when we started putting it in, to use it for things like back pain, and use it for things like painful diabetic neuropathy. It didn't really do very well until just recently, and with the advent of certain different waveforms, frequencies, and techniques, have we really been able to hit it over the fence for back pain and painful diabetic neuropathy.

(2) Paresthesia & the Evolution of Neuromodulation Techniques

[Dr. Dana Dunleavy]
Can you explain a little bit what is paresthesia, and why do we care?

[Dr. Douglas Beall]
Yes, so paresthesia is done with a low-frequency stim. Low-frequency stim is less than 1,000 Hz or so, and then you go from 1,000 to 3,000. It's higher frequency. Some companies call it high-density programming. Then the high-frequency proprietary is 10,000 Hz. 10,000 Hz is sub-perception. Once you get above 1,000 Hz, you start not being able to feel it, but it becomes neuro-inhibitory. Paresthesia-based is sending exactly, it's stimulating the A-beta fibers and blocking the pain, and it provides a sensation.

It does really well because the dorsal columns and the spinal cord, that's where the nerve tracts to the legs live. You're able to get leg and hip pain pretty well. It has to do with the position on the spinal cord. Once you get up to about T8 disc, T9, that's the reason it will stimulate the low back the best. The low back fibers are farther lateral, so it doesn't get those quite as well. You have paresthesia-based, which is low-frequency.

Then you have non-paresthesia, which is high-frequency, all the way from high-density all the way up to HFX or HF10. These are proprietary waveform 10,000 Hz stimulation. What this does is it really stimulates the dorsal horn and it's neuro-inhibitory and turns down the pain transmission. Because it's not selective in terms of anatomy, so whenever I did the trial for our patient, my first one was CRPS, he had right foot pain and right leg pain, and skin changes below the knee and typical CRPS syndrome. I placed it and made sure the paresthesias covered that right leg. I put two leads in there to make sure it just covered both sides. You can stimulate one lead or the other. I put two leads for redundancy, but he got great relief in that right leg. As long as the paresthesias were there, that was good and you'd have to anatomically match.

Put them on the table. I do these with sedation, nothing special. I troll the lead from about T8, which is back, to about T11, which is legs, and a little bit below T11 will get below the knee. Everybody's a little bit different. Lumbosacral transitional anatomy is present in about 15% of the population, so you have to be sure and count and make sure you have the right level. You troll until you cover the painful area with that paresthesia, with the numbness, tingling, electrical feeling. Then, that is your goal for tonic stim, for low-frequency stimulation.

For high-frequency stimulation, you put the leads at the 9-10 inner space, overlap them by two electrodes, leave it and go home. If you turn that on, people have done this, it's anatomic placement rather than a sensation placement. If you turn it on, you feel it somewhere in the front of one leg or around the knee. It's not really done for the purpose of paresthesia stimulation. It's done just for its neuro-inhibitory function to turn down the pain transmission.

I've found a combination of these two techniques to be really advantageous. We've gone from just tonic stimulation, low-frequency stimulation. We've gone to stimulation with differing waveforms. We have DTM, differential targeted multiplex. We have pulse stimulation patterns. We have multi-phase stimulation patterns. We've got high-frequency stimulation. We've got feedback loop systems. Now, some of the more modern low-frequency stimulation have a feedback loop to call the LCAPs, low compound action potential. It adjusts the stimulation at the same rate that it is the frequency. It's like a built-in real stat, keeps you in the therapeutic range.

The one that I use the most for things like painful diabetic neuropathy is, without question, the high-frequency stimulation. That's been, in my experience, just, it's one of those things that you place it and you tell the patients that we're about 90 for 90. We have about 90% of patients that get 90% pain relief. That's been based on my own experience, but the new data comes out. It came out, it's a 24-month data that said we have a 90% response rate. To that, I say, yes, I agree. This is one of the things in the medical literature that I actually believe because it correlates and it agrees with my own experience.

[Dr. Dana Dunleavy]
Just to simplify that for our audience that might not have as much spine experience, we're talking about the initial neuromodulation that you were doing before 2015, which was paresthesia-inducing and after that, high-frequency, which is paresthesia-free. Also the difference is that, as you said, you're not mapping if you're doing high-frequency, you're just putting it out of location. Anything you want to add to that?

[Dr. Douglas Beall]
Yes. One of the things that the IR physicians have in their armamentarium, they do a lot of treating peripheral arterial disease. They treat people that are diabetics, treat people that are smokers. They see a lot of leg pain. They get a lot of referrals from podiatry. This is exactly the same patient population that will have painful diabetic neuropathy. There's about nearly six million people in the U.S. with PDN. I used to not like that disease process because you'd try a little gabapentin and it would be ineffective mostly. You'd have about a 50% hit rate on that. The patients typically had problems with the gabapentin side effects and a lot of them didn't like it. Then you try tonic stim and that was very effective for about one in four patients, but marginally effective otherwise. The average pain reduction is 50% at best.

Then, the high-frequency stimulation is fantastic. It's, as I said, 90 for 90. I'm out of the typical IR practice. I haven't done angiography in a decade or more, probably 15 years, and we're just so busy treating the, what you would call, interventional musculoskeletal patients. We have more people that we need to see than we can possibly see. We tried to expand. This is one of the areas of solid overlap, but there's huge overlap between the people, the IRs that do peripheral arterial disease and see these patients that have pain. You open up the vessels. The other common area is spinal stenosis. You make sure they don't have claudication or neurogenic claudication. After that, you confirm that they're good to go in both of those regards. Then you have a patient left with PDN that you don't know what to do with. This is something that spinal cord stimulation, neuromodulation, is tailor-made for the outpatient environment. Almost all of this is done best in the office for trials and then an ASC environment for trial or permanent implantation.

(3) Addressing Painful Diabetic Neuropathy with High Frequency Stimulation

[Dr. Dana Dunleavy]
I think many people may not realize how enormous the PDN problem is. When you and I have talked, either with our interventional radiology colleagues that do a lot of vascular work, either venous or arterial, or our discussions with vascular surgeons, we would say that some of our documented numbers, so we talk about 28 million patients in the US with diabetes, 14 million with neuropathy, and about 6 million that probably are appropriate for treatment with neuromodulation based on failed pharmaceutical attempts.

Almost every discussion I have with vascular surgeons who have no reason to feel inclined to do this procedure, say that those numbers are a big underestimate and that the most disappointing aspect of their practice is the fact that they revascularize a patient with critical limb ischemia and the patient's disappointed in them because they still have peripheral neuropathy or diabetic neuropathy.

Number one, I think you've very clearly elucidated just how successful neuromodulation is for PDN. In fact, more successful than failed back surgery or non-surgical back. What about some of the incredible findings of this two-year data about innervation? Can you talk about some of the studies on that?

[Dr. Douglas Beall]
You bet. I'm going to go back half a click in scope and scale this a little bit based on what you just said there, Dana, if that's all right. Typically, we would take people with back or leg pain and we would have about a 50% response rate, and a 50% response rate specifically means for half of the patients, we were able to cut their pain in half. We were able to reduce their pain by 50% in 50% of the patients. That was the typical response rate for tonic stim. Then we've bumped up some of the high-frequency stimulation. We bumped the 50% up to 80%. We're able to cut the pain in half in 80% of the patients.

That was the new level. That was the new area that we were getting to. We would have about half of the patients that were profound responders, which means cutting the pain by 80% or more. If you cut the pain by 80% or more, basically, it's the other term we apply there as a remitter. Because if you have a 1 or 2 out of 10 pain, having reduced your pain by 80%, but that's just pain with life, right? There's effectively no pain at all. If you're complaining about a 1 out of 10, then we can't be friends anymore. That's just the way things go.

We've taken that, we've raised the bar up and about that, we've got 80% for non-surgical low back. We have 80% and almost 60% profound respondents. Those are pretty good. Those are 60% remitter and non-surgical low back, and these are patients that either can't have surgery due to comorbidities or don't want to have surgery based on their own preference. Then, we've taken it to 90% response rate for PDN and most recent data that was released, the tier data. Then, the profound respondents are 65%. I mean, two-thirds of people are remitters, and that's just a tremendous number. This is why we gravitate toward epidural injection for acute radiculopathy. We gravitate for vertebral augmentation, for fractures and we gravitate for high frequency stimulation for PDA because these things just work. They work for sure, patients come back and they're not just like, “Ah, no, I feel a little bit better." They're like, "Oh my God. Thank you, thank you, thank you."

The other thing that's really interesting that I wasn't expecting at all. In fact, I'm not sure I believed the data when it first came out. We tend to be a little bit skeptical, I think it's a healthy skepticism. The data came out to about two-thirds of the people, a little over 60% of the people, had improvement in their neurologic function and their testing, the motor testing, sensory testing, and the reflex testing. The testing was filament testing, and it was standard neurologic evaluation. I'm doing temperature testing, two-point discrimination, and filament testing for one of our research studies now. It's quite painful, takes a while but it's very accurate, and so is this. We found that about two-thirds of the patients had demonstrable improvement in their neurologic function and sensory function. Which is also of course, neurologic, but this is profound. It happens in two-thirds of the patients.

It was so important because there's not any other medication, any other strategy, anything else that I've ever seen that does that. I think this is unique and what is the mechanism? It's the mechanism of action. I don't even want to hypothesize on that. There's a lot of things we could talk about that for an hour, but thank God we won't. We'll just skip to the fact that there's a study specifically focusing on the primary and secondary endpoints or the neurologic function of the patients. If you're able to actually reverse the disease process, and if there's one thing that you could certainly say about painful diabetic neuropathy and neuropathy in general, it's just not reversible.

I held that as a truth for many years, but it looks like it is reversible, at least in a certain portion of the patients. Driving up this morning, I had the radio on and I heard an advertisement for four different neuropathy clinics around the city where I live. It was a noninvasive treatment of neuropathy and I asked, “how about that?”

I'm reviewing a legal case now where one of the non-medical “specialists,” I use the specialist in air quotes, was treating the patient with neuropathy, with things like massage and light therapy and a vitamin or mineral cocktail and some of other things. I think that's all well and good, but it's not going to work. These things and the response rate even to the membrane stabilizers. We've got gabapentin, pregabalin, and you've got tricyclic amitriptyline. You have Cymbalta duloxetine. These things work just mediocre to poor. If you were to put them on a scale of 1 to 10, they work about a three or a four-level of good. Of course, there's no scale for that but I want to give the listeners this to see, to have all of the therapies that you could apply all of them and they still are mediocre to poor outside of high-frequency spinal cord stimulation. That's the only thing that I've found, the single thing, that exists that will improve and reverse the neuropathic changes, the neuropathy changes. It's by far the best thing in terms of symptomatic improvement.

I live in a city of about a little over a million people and much the same as you do, Dana. Why are there four clinics around? It's a small city, four neuropathy clinics, because it's common. You mentioned about six million people with painful diabetic neuropathy. I realize that comes from the CDC numbers, but I think that's a gross underestimate. It seems to be maybe half of those are split between our two cities because there seems to be, PDN just comes in, we should but we don't advertise for it. We just use the mantra if you hurt, come in and see us and we'll figure it out. We're a non-chronic opioid clinic and there are so many good things.

This is an example of one of those things that's non-medications, non-opioid, and for people that are responders, which 90% of people respond well to the trial. It's going to be life-changing for them. It's one of the two things I do that you can actually test before you do the implantation surgeries. The implantation is a surgery, it's a minimally-invasive light surgery, but as a surgeon, you don't want to give people anesthesia of any kind until you deem it necessary. You can do a test drive, a trial, and when somebody gets 90% relief for a chronic unremitting problem, you cannot lock your office door tight enough to keep them out. They will find their way back to you.

This is one of those things, I like it because I don't have to convince, I don't have to give advice. I say, "Here's what it is, here are the numbers where you should be, here is our personal experience with this therapy. Let's do a test drive." By the time they come back to have the leads pulled out, they're like, "Okay, when can I get this schedule? I'm not leaving until I know when I can get one of these put in.” This is, it's been, practice changing and it's for a very common problem.

(4) Treating Diabetic Neuropathy with Neuromodulation

[Dr. Dana Dunleavy]
Yes, I think that's such a rewarding aspect of it. The trial is so easy for us and for the patient and for the family and it really is unique in that you can do this very simple test drive as you said. You and I both try very hard to make sure that authorization is in place for the PERM because these patients finish their trial. Not only does it change their life, but as that trial finishes, they go back to the pain they were in before. They're pretty mad, they want that success that they had as soon as possible. To your point, it shouldn't be months down the road after the trial ideally.

Again, that's a really nice aspect. I want to get a little bit nerdy and go back to some of the things you mentioned in terms of the success of high-frequency neuromodulation. You've used terms like number needed to treat with vertebral augmentation, but we also have some data on that in terms of gabapentin number needed to treat is about eight, serotonin reuptake inhibitors number needed to treat is about six. With high-frequency neuromodulation, the number needed to treat is only one. What does that mean?

[Dr. Douglas Beall]
NNT, we love NNT because it gives people personal experience. How many people do you need to treat to have success? You can identify the treatment success as however, you want. For me to have a responder means I cut their pain 80% down, decrease. That to me means they're a responder. Gabapentin is around eight. I've seen a study recently that said that was a little bit more permissive on the gabapentin and said the number needed to treat for some margin of success, which it didn't say or I didn't see it, was three, but the number needed to treat for a complication or side effect was four. That's the thing about gabapentin, by the time you get up to the point where it's making a neurologic improvement and the neuropathy, it's also giving a side effect because of the way it functions. A lot of people don't like it because of the fog that leaves them in. It just gives them a strange feeling. It can make them sleepy, and it's the same thing with the serotonin and norepinephrine reuptake inhibitors: the dual oxetane. A lot of these things that patients just don't like and they just don't like it well enough to continue to do that.

The number needed to treat spinal cord stimulation is just a little over one. Basically, it's right at 1.3 to be specific. Almost every single person that comes through the door will have a treatment success as how it's defined. It's not everyone, if it were everyone it would be one. For every person that comes in, that means the number needed to treat for a treatment success, one-to-one that would be everybody. If it's one and two, the number needed for treatment success is two. This should give everyone an idea about how effective this is.

If almost everybody gets treatment success, it's a pretty darn good treatment. It puts it right up there with everything that we do. It puts it up there with vertebral augmentation and we have mortality numbers for that. The number needed, we've never measured the number needed to treat for vertebral augmentation, but it's going to be right at one, maybe slightly over. This is one of the few therapies I know that are just reliable to the point where it's almost money in the bank that you know that the person's going to get better.

[Dr. Dana Dunleavy]
To get nerdy once more, because you and I are known for this, what is intraepidermal nerve fiber density? And, in talking about that, I think that our nation has done a wonderful job of improving awareness of breast cancer diagnosis, screening treatment. Not as well with this, about treatment for diabetes, diabetic neuropathy. To start, as we talk about nerve fiber density, what has a higher mortality, breast cancer or a diabetic foot ulcer?

[Dr. Douglas Beall]
Yes, exactly. What happens with the diabetic foot ulcer is they get an ulceration and then they have vascular problems, they get it infected, then they get an amputation and their mortality rate is right up there and exceeds many cancer mortality rates. This is, by the time somebody with a diabetic foot ulcer, that is the past time probably to throw everything at it. You want to get the person before they develop that ulcer and you want to make sure, as we stated previously, that the arterial supply is adequate, you want to make sure the activity is adequate, and in addition to, we always say PDN, with the P being painful, just the diabetic part of the numbness part of it is it can wreak havoc. If somebody's diabetic, they have no feeling, they walk over a straight pen, I've seen this, pencil, they stub their toe, they just have an ulceration from ill-fitting shoes. We've seen all of this and that is the tipping point. That's the beginning of the end for that lower extremity as it goes through and the ulceration can't heal, they can't continue to can't feel it, they will get, transmetatarsal amputation, or show parts, they'll get a long BKA, will shorten up to short BKA. This is just the beginning of the end for a lot of people like this and that's one of the things that the mortality for these patients is exceedingly high. I would like to really catch these people before that happens, and that's why neurologic study is so important.

We measure the fiber density, and that's an objective finding on transdermal biopsy. You can measure the motor sensory and the reflex improvements, and you can measure the two-point discrimination, the numbness, and these are things that are objectively improved. At least on the two-year data, we found that two-thirds of the patients had objective improvements in these categories, and I think sometimes we will focus on the pain out of the PDM, but the numbness is actually one of those things that can really lead to an ultimate disaster down the road.

[Dr. Dana Dunleavy]
How about A1C?

[Dr. Douglas Beall]
The hemoglobin A1C for the clinical trials was right at seven. That's a little high, it's not bad. To be in the trial, the sensor PDM, you had to have a BMI less than 45, which is very generous, and a hemoglobin A1C less than 10, which I think is incredibly generous. These people had long-term neuropathic problems. They had years, six, seven, eight years of neuropathic problems, and so to take people like this and then measure what happens to them is really classic. These are typical patients.

I think there's a misnomer that if you have your hemoglobin A1C right around six to seven, that's pretty good for a diabetic and you shouldn't really have problems and that your neuropathic symptoms will improve, but that is just absolutely false. That is not true. You can have well-controlled blood sugar as measured by hemoglobin A1C that's right around seven, and it will not remit. It will not improve, it will not be of any benefit for the neuropathic problems. It can benefit other things to keep your blood sugar under control. I'm not making the argument that blood sugar control is not important, it's critically important, but it won't improve your neuropathy.

What is seen in the sensor PDM trial is these people came in and they were pretty much typical and they were productive members of society keeping their hemoglobin A1C under descent control right around seven. They still had refractory symptoms until the point that they underwent spinal cord stimulation. This is compared against conventional medical management, and as we know, conventional medical management doesn't do hardly anything. Typically, it's mediocre to poor in terms of treating diabetic neuropathy.

I'm really excited to see what the objective findings will show us, a trial focusing on the neurologic assignments and symptoms and improvement, and having just gone through an investigator's meeting where the neurologic exam and the assessment and evaluation was gone into in-depth, and now as part of another trial, I'm going to have to do that. I realize that this is very accurate. This is going to provide good data, and it's a lot more involved than just saying on a scale from 0 to 100, can you mark where your pain is, or on a scale from 0 to 10, where are you today in terms of your pain. It's much more extensive than that. I think we're going to get great data. We should get good improvements, past performance to predict future results. I think two-thirds of those people will demonstrate good objective improvements, and it's going to be interesting to see that the focus may change on not only symptom modification remitting, but it will focus on disease process. It will actually cause improvement of peripheral neuropathy.

(5) The Role of Interventional Radiology in Diabetic Neuropathy Treatment

[Dr. Dana Dunleavy]
I think as we circle back towards the end and think about our colleagues as interventional radiologists, we would never want our patients to be in a wound clinic without also having their venous and arterial disease treated. Similarly, in this situation, we want the arterial and venous disease treated, and we're providing high-frequency neuromodulation, and all of the aspects you said from improved pain scores, improved A1Cs, improved nerve fiber density, what we're hoping is that we have a cost savings to the healthcare system and to our nation in terms of decreased wounds and decreased hospitalization.

In that discussion, what is your thought about why interventional radiologists have held back from offering this and improving access so that you don't have so many advertisements for unstudied pain clinics?

[Dr. Douglas Beall]
They just don't know about it, Dana. I think it's the same thing that whenever I first started, the medical device company didn't even want to let me use it because they thought they would upset the other customers. Of course, that's not true. It's the same thing as kyphoplasty and the surgeons and the radiologists, and it's the companies that realize that, "Hey, these radiologists are actually seeing patients like this," and the device manufacturer for the high-frequency stimulator realizes that.

I haven't been doing peripheral arterial disease in two decades probably, and it's not because I don't like it, I love it, but the point is that I see lots of these patients from a neuropathic standpoint. These are the same exact patients that are present in most of my IR colleagues that do what we think of as a conventional interventional radiology practice. I remember talking to one of my colleagues early on about this like, "Hey, you really should look into this. We're 90 for 90 on these things and patients do great. I bet you have some patients like this," and he goes, "Are you kidding me?" He said, "Most of what I see has this," and it was somebody that does a lot of peripheral arterial disease. That's when I first realized as I took a divergence from IR early on, this is a realignment, this a risk convergence because the patients we treat now have a huge overlap.

One of the disadvantages of this therapy is that it's expensive. These leads and the IPG are expensive. It's technology and that's a disadvantage, but one of the advantages is that it's very well reimbursed. The IR, development of an IR to essentially a surgical subspecialty. That's what IR has become. The IR is no longer just solely a hospital provider like a fish swimming in the stream with his mouth open waiting for food to jump into it. Now, we have to go out and hunt, and we have to change our sites of service and we have to have offices because we are essentially a surgical subspecialty and we see patients. Your mom may not know what you do for a living, but she knows you help Betty Lou and that she can come back and see you. You have what looks like a regular doctor's office, but you have an OR in the back and that's your OBL, your office-based lab. You have the ability to do cases, yes in the hospital where you climbed out of the primordial soup, but you also have the ability to do it in the ambulatory surgery center, the ASC. This is reimbursed in the hospital and it's expensive technology in the hospital. It's reimbursed well, but I want to put some numbers to this so our listeners can scope and scale this.

For example, an office-based trial, a test drive, is reimbursed at about $3,500 in the office, and the lead price is a few hundred dollars. The ASC reimbursement for trial is right around $9,800 in the ambulatory surgery center. Permanent IPG placement and two leads, it reimburses between about $31,500 and $34,500 for a permanent implantation. Out of everything that we do in the ASC, this is the single best-reimbursed item, and it's the single thing that allows us really to keep the doors open and the lights on. This is something I think the listeners should know about. You're not having to do a lost leader here. This is not just simply charity work for people with PDN, a disenfranchised group. Yes, this is a disenfranchised group because we previously hadn't had anything to treat them with. Then, our colleagues are doing great work, they do great work for arteries, peripheral arterial disease work, angioplasty and stent placement. Their partners, colleagues are doing great venous work and they come out with vascularized limbs. They're not going to get ulcers, but boy, they sure run the risk of wearing an ulcer on their foot because their foot is numb, or if it's painful, it drives them crazy. It disrupts their sleep, it creates a chronic pain scenario. It seems like we should be able to combine these two things.

As I mentioned, the single best people to do this, neuromodulation spinal cord stimulation, are interventional radiologists and whatever I've taught courses for spinal cord stimulation, neuromodulation, I've taught hundreds of these. You can always tell when IR steps to the table, when there's multiple specialties involved, you just show them the epidural highway and bang, the lead is in place before you can blink your eyes. You can always tell the skillset and the visual-spatial skill of an IR. This is not only in somebody's wheelhouse, this is a huge patient population that you can, not only take care of their vascular problems but you can hit for the cycle, you can take care of all the vascular problems plus you can take care of the pain and these are almost identical patient population.

[Dr. Dana Dunleavy]
I think that's a great point too that there are resources out there for our colleagues that might not have had tremendous exposure to this during their fellowships which we know there's a lot of variability in fellowships. One of the misconceptions that I hear is that you're going to have this apposition or competitiveness from vascular surgery or neurosurgery.

In fact, there's nothing more beneficial in terms of the referral pattern that I've noticed by offering trials to these patients. Number one, it's very helpful to the vascular surgeon who is treating vascular disease but can't take care of the neuropathy, and as you said, these reimburse very well. If we are doing trials, the neurosurgeons all of a sudden are very interested because these do reimburse very well. We do the test drive for them. We can either do the PERM or we can offer the PERM to them and I think that that's important. For instance, as you said, ideally, all of our colleagues should have access to OBL and ASC, but for those that just have OBL currently, they can do the trial, and then offer the PERM to someone else. Do you want to talk about that?

[Dr. Douglas Beall]
Yes, absolutely, and that's one of the things. This is really an extension of the referral stream that we have. This is not competitive to those two groups, and in fact, if you want to be your neurosurgeon's best friend, all you have to do is tee a couple of these up. They have a successful trial and these are easy cases to put in. As I mentioned, the surgery is a surgery, yes, but it's two small incisions, it's under the skin, two epidural leads and this is an easy thing to do that is very sustainable. This keeps the lights on in your ASC, and so you will make a huge fan.

I prefer to do all these on my own. I like this patient population. The medical device company will provide a rep and your rep is your unpaid employee who will go out and adjust the patient, will talk to the patient, will get feedback, electronic analysis, and reprogramming. It's done really by an algorithmic method. There's thousands of patients in the algorithm that you've made adjustments and these patients do better or worse. For each adjustment, for each patient to do better or worse, it refines the algorithm for success to improve the patient's symptoms. You learn, this is almost an artificial intelligence way, from your past trials and successes to make you even more successful.

It gives the IR doctor a relationship with the medical device company that previously would ignore them. The reason why they're not thought of is because of that history, but that history, just like it changed with kyphoplasty, is changing with spinal cord stimulation, neuromodulation, especially for painful diabetic neuropathy. I think that IRs will find that they are welcomed with open arms because they have huge repositories of these people that can be helped greatly with the technology that's a no-brainer to apply.

[Dr. Dana Dunleavy]
Yes, absolutely. I think that the other misconception is that the pain colleagues will be worried, and again, the diabetic neuropathy patients tend to live within our specialty in vascular surgery. They're really not being seen currently in general, and so there's a lot of appreciation by the whole community that is performing pain treatments once we get involved.

[Dr. Douglas Beall]
There's no shortage of these patients, that's for sure. I think we've evolved, not only in terms of companies recognizing the impact of the interventional radiologists in this area, but we've also modified and become more of a multi-specialty big tent type of attitude. As you know, I've trained people from surgeons to anesthesiologists and family practice physicians and I'm a firm believer in the big tent philosophy that if you want to do something and you're good at it and you're dedicated and committed to it, you've got great visual-spatial skills, then I will help you. By doing this, we create lots of good associations.

I've learned more from other specialties and my wife says I haven't had a new idea since 1992, but I can steal ideas from other people and employ them for my practice. That's not really a serious comment, of course, but I have learned lots from physiatrists, anesthesiologists, neurosurgeons, orthopedic spine physicians. It's been tremendous, and once we do that and share the knowledge, I think we're a little bit past. We're to the point where we have great minimally invasive interventional techniques that have come light years ahead of whenever I first started in terms of efficacy. These are things that can be employed, and to treat a huge population, there's no shortage of chronic pain. This is one of the things that, low back pain, second in terms of doctor business next to the common cold. Single greatest cause of disability worldwide, no shortage of people with diabetic neuropathy. These are things that are growing around us everywhere in terms of prevalence, and so the better we get at it, the more patients we will be successful at treating and there's definitely no shortage of them around.

(6) The Future of Pain Management

[Dr. Dana Dunleavy]
Just to confirm what you've said, I've observed you teaching courses on neuromodulation and it's amazing. All the observers see the interventional radiologist walk into the room and they fear this procedure, and then realize how simple and efficacious it is. I want to encourage everyone that's interested to reach out for that.

Since we're so passionate and we've gone for a while, we can close out, but maybe we could do a follow-up on technique because I know people want to hear the really simple technique even for the PERM, which is like a metaphor, except it has five times the RVUs. As a teaser closing out, I recently met with some pain physicians, some neurosurgeons, functional neurosurgeons talking about cancer pain and just how little resources there are for non-pharmaceutical pain treatments and how NCCN guidelines keeps bringing these interventional pain procedures to the top of the pyramid. We were talking about invasive procedures like cingulotomy, myelotomy. Really, it's so important that this step is part of that algorithm. Anything that you want to tease as we come back in the future?

[Dr. Douglas Beall]
The cancer pain and the interventional oncologic treatments, minimally invasive, that's a whole category and it's a big and growing category. One of the biggest areas of growth in all of IR is interventional oncology or oncologic procedures, IO. There are people that we know that make their whole career out of being an IO physician. This is very gratifying as our techniques improve, as our technologies improve, we're going to find a huge area of new applications in oncology whether it be from targeted drug delivery, neuromodulation, minimally invasive screw and cement reinforcement, the neuroablative category that includes RF, cryo, microwave. There's many things like this and this is a whole area that really could use a discussion to bring everyone up to speed, up to date on the current offerings. There's no slowdown, there's a continual speed up on the technology that's coming down the pike.

As an example, I just met with a medical device company that's wanting to have cryo, RF, and microwave all in one offering. You can't really have them in one box, but the idea was to have them in two separate boxes that look like one box to be able to have an oncologic ablation machine. I think that's a tremendously great idea. There's lots of activity coming down the pike on this and it will be a good topic for discussion in the future.

[Dr. Dana Dunleavy]
Absolutely, and people sometimes talk about my practice as obscure pain because of simple things like genitofemoral, pudendal, intercostal blocks, neuromodulation. This is one of the simple things.

[Dr. Douglas Beall]
Yes. I don't think it's obscure. I just think you're able to do things that other people don't typically do, and when they look at your practice, yes, you do augmentation, epidural injections, facet blocks, but yes, you're also able to do the other stuff too. That's really what comes to the forefront because that's novel and other people are not really doing it.

I don't like to post things that are just garden variety. If I put things out on social media, I want it to be, "Hey, this is different," or maybe it's, "Look for this," or, "Here's a lesson to do or not to do on certain things." You tend to focus a little bit on the arcane and esoteric. You don't really post garden variety cases out there very much. That also influences the perception. I think if you're able to do the more complex and esoteric stuff, you're probably pretty darn good at the other common things as well.

[Dr. Dana Dunleavy]
We'll close it out, but besides all the courses that you offer, we have SIR, ASSR, OEIS, all conferences that you've been kind enough to offer training at. Anything you want to add as we close?

[Dr. Douglas Beall]
Yes. We have presentations at SIR, OEIS, ASSR. If one of the listeners is going to the OEIS and wants to participate in our discussions, just reach out to me. I'd sure like to have an active participant. One of the disadvantages about societies like the OEIS is I'm a little bit new to them because I tend not to, E is endovascular, so I tend not to do a lot of endovascular stuff. The upside is we can introduce technology we've spoken about today to a whole new segment of physicians, IR docs that might not know about this and might be slightly unfamiliar with it. We're having a whole segment on minimally invasive spine and pain. This is something I sure would like the listeners to, if they're interested in that, being one of the participants and one of the speakers, just reach out to me.

[Dr. Dana Dunleavy]
I think you were innovative in participating at OEIS last year, which was thought to be a little crazy at first given that it's the outpatient endovascular interventional society, but there's been tremendous interest in all of those physicians that are already at OBLs and ASCs doing vascular work to offer neuromodulation for PDN. I think this is exciting moving forward.

[Dr. Douglas Beall]
Yes, for sure. They've given us a whole block. Because of that interest, I gave a presentation last year and one of the attendees came up to me afterwards and said, "Wow, just wow, what was that?" Was just very interested in it. His point was that it's a little bit foreign and a little bit interesting and he wanted to really know more. I gave a talk called Fun Through Kanban's Triangle, and there's all kinds of strange things in there, but IRs can look at this and say, yes, that's in my wheelhouse. I think that's exactly what they'll say with this session, that it can and should be in their wheelhouse.

Podcast Contributors

Dr. Douglas Beall

Dr. Douglas Beall is the Chief of Radiology Services at Clinical Radiology of Oklahoma.

Dr. Dana Dunleavy

Dr. Dana Dunleavy is a musculoskeletal and vascular IR in Buffalo, New York.

Cite This Podcast

BackTable, LLC (Producer). (2024, January 29). Ep. 40 – Innovating Pain Management: The Role of Spinal Cord Stimulators in Outpatient Care [Audio podcast]. Retrieved from https://www.backtable.com

Disclaimer: The Materials available on BackTable.com are for informational and educational purposes only and are not a substitute for the professional judgment of a healthcare professional in diagnosing and treating patients. The opinions expressed by participants of the BackTable Podcast belong solely to the participants, and do not necessarily reflect the views of BackTable.