Incorporating Endoscopic Spine Surgery into Your Practice

Podcast Transcript

Introduction: Neuro Pathways, a Cleveland Clinic podcast exploring the latest research discoveries and clinical advances in the fields of neurology, neurosurgery, neuro rehab, and psychiatry.

Glen Stevens, DO, PhD:

Minimally invasive spine surgery aided by endoscopes offers a surgical approach to patients that can speed recovery, minimize postoperative pain, and improve outcomes. In this episode of Neural Pathways, we're discussing the evolving field of endoscopic spine surgery and how to integrate this approach in today's practice. I'm your host Glen Stevens, neurologist/neurooncologist in Cleveland Clinic's Neurological Institute, and joining me for today's conversation is Dr. Mike Steinmetz. Dr. Steinmetz is a neurosurgery-trained spine surgeon, Chairman of the Department of Neurosurgery and Director of the Center for Spine Health in Cleveland Clinic's Neurological Institute. Mike, welcome to Neuro Pathways.

Mike Steinmetz, MD:

Thanks, Glen. Thanks for having me. So good to spend some time with you here today.

Glen Stevens, DO, PhD:

Mike, we've known each other for a long time, many, many years, but for the rest of the audience, tell us a little bit about your background, how you made your way to the Cleveland Clinic.

Mike Steinmetz, MD:

Sure. Yeah. I came in a serendipitous route. I started out in actually southwest Texas. Thought I would always live in Texas for my entire life. I trained there, thought I would live there, started my neurosurgical training in that area, but ultimately, came here with the one and only, Ed Benzel, back in the late 90s and finished my training here and fell in love with the place. It's a phenomenal institution with tons of resources, does phenomenal patient care, just has the right model and it just matched me.

I finished my training in neurosurgery in Cleveland Clinic here in Cleveland, and then went on to do a fellowship in complex spine surgery in Madison, Wisconsin, and had the opportunity to come back here to Cleveland into the Spine Institute. I just couldn't resist that opportunity, so came back on as a staff in 2005 and just continued through the ranks and, more luck than anything, was able to follow in the footsteps of my mentor, the one that brought me to Cleveland, Ed Benzel, and eventually became the Chairman of Neurosurgery and the Director for the Center for Spine Health following him in both positions that he held here.

Glen Stevens, DO, PhD:

Mike, it's always great working with you, so I'm very excited about this today. For our non-surgically-trained audience, we'll start a little bit broad. I always looked at spine surgery as brute surgery, and then of course you guys started going to minimally-invasive surgery, that sounded better to me. Now, they use this term ultra-minimally-invasive surgery, which I guess we define as endoscopic spine surgery. In terms of endoscopic spine surgery, tell us how it differs from the traditional type of spine surgery and what's the approach?

Mike Steinmetz, MD:

Great question, Glen, because there is differentiation and it's often used exactly together but completely different. When we think of minimally invasive surgery, typically it's just doing the same operation we would as a standard bigger approach, but through a much smaller incision. Really, what it's doing is it's minimizing the collateral damage to the spine to do the operation. Really, what's allowed us to do that has been technology. It's been significant technological advances in computer-rated navigation and robotics and microscopy. But that's really working through a smaller incision, working through maybe a tubular retractor where you're still using your own eyes or a microscope to look through there in traditional tools that I would normally use just at a smaller corridor. How that differs from true endoscopic surgery is that we are putting a very small incision, almost like a laparoscope in the knee or the shoulder, putting that scope into the spine, and all of the tools actually fit through the endoscope and you're working through those.

It's completely different. Everything is much smaller. There's almost minimal trauma to the spine to get there. It's not for every pathology that we have because you've got to imagine you have limited working space and distance to do this. But for the right pathologies, you can really, really minimize trauma to the muscles. You can sometimes do it without removing any bone and sometimes do it with almost no blood loss doing it. It's a pretty remarkable technology all done through the very, very small endoscope, which may have an outer diameter of eight millimeters or nine millimeters. Everything is done through the scope.

Glen Stevens, DO, PhD:

We'll get to the specific types of things that are best to treat. Do you do a single scope or can you have multiple scopes?

Mike Steinmetz, MD:

Traditionally, it started off with a single endoscope, where you have one scope that's your camera. You're utilizing the same endoscope for your lighting for your camera, and all your tools go through the endoscope. That's a single scope and that's limiting because you have a very limited angle to work through and approach. Now, it's becoming a little bit more popular to use bi-portal endoscopy, which I think is what you're implying is what you would also do for say a gallbladder, where you have a camera scope and then your tools work through different portals. Now, with the spine, you can use a bi-portal, where you can put the scope in one view, and you're using that just for the lighting and the visibility. Then, you could put a second scope and say a different angle or trajectory, and through that one you're just putting your tools through, so it broadens your approach there. Both are available. Probably the single scope, the single portal is more common though than bi-portal endoscopy today, but there's many people doing bi-portal endoscopy in the present time.

Glen Stevens, DO, PhD:

Just for my reference, how long has the endoscopic spine surgery been going on in general? You said five years, 10 years, 15 years.

Mike Steinmetz, MD:

Well, I would say even more than 15 years, Glen. Now, I'm going to say this and may take some flack on this, but when endoscopic spine surgery first came out, it was largely viewed as more of a fringe operation, a little bit more of snake oil sales to some extent. There were limits with the scope. It was more two-dimensional imaging. There was limited ability to do anything through it and only just a few people using it. It really wasn't a mainstream procedure and I think what's changed maybe in the last 10 years or less, Glen, is the technology has dramatically changed in the endoscopes now with three-dimensional scopes, slightly larger scopes, better 4D TV screens and improved tools you can use to the endoscope. It's really caught on more of a mainstream audience and has become much more popular where if you went to a spine meeting, a national spine meeting, say maybe more than 10 years ago, you would never see anything on endoscopy. No courses, no lectures.

Now, almost every course has, cadaver courses, lectures, research being presented on, and now it's becoming a much more accepted mainstream procedure probably within the last 10 years. Been there for a long time, but only I think really become more mainstream. Maybe even within the last five years, it's become incredibly popular, but certainly less than 10.

Glen Stevens, DO, PhD:

If we segment the spine into cervical, thoracic, lumbar, sacral, can you do all levels or is this almost exclusively done in the lumbar area?

Mike Steinmetz, MD:

When you become, I think, a more skilled endoscopic spine surgeon, you could do it at all levels and it is done at thoracic, cervical and lumbar. I would tell you the most common location is lumbar purely because of safety. Putting the endoscope in and around the nerve or the fecal sac or where the nerves are, easy to move them out of the way to get the scope in either going through the frame or through the lamina. But not uncommon to do in the cervical spine per se, a posterior cervical foraminotomy, it's done very common. Even some of the more complex discectomies in the thoracic spine, people are using it as well. But I think mainstream, run-of-the-mill case, it's going to be almost exclusively lumbar or posterior cervical, but more advanced techniques. Those surgeons that are really gifted can really apply it almost anywhere.

Glen Stevens, DO, PhD:

Mm-hmm. A lot of the spine programs are a combination of ortho and neurosurgery. Is it the procedure done equally amongst the disciplines or more one than the other or none necessarily?

Mike Steinmetz, MD:

I would say it's probably done equally amongst the disciplines, in my opinion. I will tell you, just out of interest, because we train both neuro and ortho fellows, if I'm working with a neurofellow through the endoscope for one of their earlier cases, it's very challenging for them to work in it and get used to it. If I take an ortho-trained fellow who's done a bunch of knee scopes and shoulder scopes, they are so facile at using it. It's done with both specialties, but I would imagine that the ortho-trained spine surgeons pick it up much quicker because they're just used to working through scopes in joints, where in classic neurosurgery training, even the more neuro-based spine training, it's not as common.

Glen Stevens, DO, PhD:

Yeah, that's what I would think, because they're scope in joints all the time that they'd be quite comfortable with the technology.

Mike Steinmetz, MD:

Yeah, they're very facile. Yeah, they're very facile very quickly.

Glen Stevens, DO, PhD:

Yeah. Are most programs offering this around the country? What's the percentage that offer this within their training?

Mike Steinmetz, MD:

I would still say it's probably a minority, Glen, to be honest with you. It's probably less than 25% of programs, probably have a dedicated endoscopic spine program, but it's growing. It's growing because I think what we're seeing is those programs that are training fellows or residents that are comfortable with it are now getting jobs in other programs and developing programs, so it is advancing, I think, fairly quickly. But I would still say, it's probably, and this is just a guess, Glen, I would say though it's still probably less than 25% of true established spine programs are have a higher-end endoscopic MIS program within their walls.

Glen Stevens, DO, PhD:

Let's say I trained at a program that didn't offer this, but I'm out in practice, I've been out for a few years and I decide I want to move this technology to my practice. How do I go about doing the training? Do I go to a course? Do I come visit at the Cleveland Clinic, because I visit my friend, Mike Steinmetz? What do I do?

Mike Steinmetz, MD:

Well, again, great question. This is the reality. This is what's happening as surgeons that have been in practice for a few years want to start to apply this technology. There is somewhat of a non-dedicated pathway for this, but I think the pathway that I would lay out is important in that there are courses that are being taught at our national meetings. There are courses that are being taught within industry itself, so those that make the endoscopes, for example, the cadaver-based courses. What I would tell someone who's really never done this but wants to try it is to first go to one of these courses, probably more than one. Maybe two or three of them where they're cadaver-based and didactic-based, where you're learning the technology, you're learning how to target the spine with the endoscope to get into the spine safely.

You're understanding the anatomy, how the scope works, and you're doing it on a cadaver or even a simulator, so you get comfortable with it. But even at that point, not applying it to your clinical practice, I would recommend at that point then going to observe a program coming to the Cleveland Clinic, going to another dedicated endoscopic spine program and observe those surgeons and the pathologies they treat, so you can see what they're doing, because you can watch it all on a TV screen, which is beautiful for an observer. It's not direct observation.

The endoscopist is actually looking at a TV screen that you would be looking at the same point, but you can see the anatomy, see the pathology, see what it looks like when there's still compression, see what it looks like after it's decompressed and understand that fully and only move into clinical practice when you've got enough technical didactic skills on a cadaver, a simulator, probably more than once, maybe more than twice, you've observed it in real life, real practice. Then perhaps try it in a very easy, straightforward procedure like a transferal discectomy it. It's a pretty straightforward procedure. You've been trained on it, you're comfortable, you've been signed off on it, you're privileged, you've observed somebody do it. I would probably strongly recommend that pathway before taking this on in clinical practice.

Glen Stevens, DO, PhD:

Yeah, that's helpful, Mike. Let's say someone's out there listening to this and they decide they'd like to come here for an observership, that's something that would be an option for them?

Mike Steinmetz, MD:

Yeah, absolutely. They could reach out to us directly and we could work with them, make sure that there are some didactics for them, some cadaver courses, maybe even some simulation, and then some observation after that, and only getting into the clinical use of these technologies when there's comfort, when the skills have been shown and they really can see what it's supposed to look like should someone begin trying to do this in their own practice.

Glen Stevens, DO, PhD:

Before we get into the specific things that we're treating, you mentioned at the start about robotics and pairing robotics with the endoscope. Tell me a little bit more about that.

Mike Steinmetz, MD:

Sure. Typically, endoscopy is done with the use of fluoroscopy, x-ray guidance with live fluoro to target the endoscope to perform the operation. There's limits there based on the bulkiness of the fluoro equipment, the radiation exposed. Then comes integrated navigation. You can integrate an endoscope with an existing neuron navigation system. Most of them that are out there could integrate with your endoscope. Some of the newer scopes have navigation built into them. They've partnered with companies that are out there. But the advantage of, I think, a robot is the robot one has navigation built in, so you can use that part of it, but it also has, with the robotic arm, you can target. The difference that we teach with endoscopy is that you have to target the spine percutaneously in a safe manner to park the endoscope inside the spinal canal. That's something we don't do in spine surgery.

In spine surgery, we make an incision in the back, we remove bone, we directly look at the nerve, we move the nerve out of the way, we put a tool in there. With the endoscope, you're actually just putting it through a natural hole in the spine, the foramen, it's got to be targeted perfectly. If you're doing that with two-dimensional fluoro, it can be hard. You can navigate it with a freehand computer-aided navigation just some error. But with the robotic arm, you have the combination of navigation, which is perfect. You can see it in three dimensions, but with the robotic arm, you can target it. Pre-planned, you can plan your trajectory safely into the spine and then actuate it through the robotic arm. That coupling is the future, I think, of endoscopy, both the robotic targeting, plus the integrated neuron navigation is what's going to make this safer and easier to use in all people's hands probably at some point going forward.

Glen Stevens, DO, PhD:

Now, Mike, what percentage of people are doing treatment without even using neuronavigation?

Mike Steinmetz, MD:

With endoscopy?

Glen Stevens, DO, PhD:

Yeah.

Mike Steinmetz, MD:

Probably the majority of people at this point.

Glen Stevens, DO, PhD:

Okay.

Mike Steinmetz, MD:

I would say probably a minority. The problem about neuronavigation, it's a little bit cumbersome, it's a little bit time-consuming, and you can really, if you're a good endoscopist with fluoroscopy, you could do it really quick, very efficiently. Adding a step that takes a little bit longer is always a hard step or a hurdle for people to get over, so I would still say it's a little bit of a minority. But again, as all of these technologies advance, this is the future. That is the way we'll go. Probably next fully-integrated with navigation and after that, probably fully integrated with robotics as robotics become more and more common.

Glen Stevens, DO, PhD:

Do you integrate intraop MRI with these at all or it's not necessary?

Mike Steinmetz, MD:

Yeah, not necessary. Probably, if you did, it would be intraop CT scan, which is essentially what we do with our neuronavigation.

Glen Stevens, DO, PhD:

Once you put the devices in, do you get shifting of anything if you do use neuron navigation? Because I know cranially, you can shift.

Mike Steinmetz, MD:

Yeah, do not, does not happen here, yeah.

Glen Stevens, DO, PhD:

So not an issue there.

Mike Steinmetz, MD:

Not an issue, yep.

Glen Stevens, DO, PhD:

Why don't we move towards what's ideal? I suppose if I had an extruded disc fragment, that might be something, but tell me what's ideal for these.

Mike Steinmetz, MD:

I think it depends on your experience level. I think early on, believe it or not, it is ideal is a younger person with fairly normal anatomy, meaning not a lot of arthritic degenerative changes in the spine, just like you, that has more of a contained disc herniation, meaning it's not extruded, it's not beyond the annulus. The reason I say that is, traditionally, endoscopy is a transforaminal approach, an outside-in approach. You're putting the endoscope through the foramen underneath the exiting nerve route, below the exiting nerve route, underneath the traversing nerve route. The endoscope will push the traversing nerve route up and over the disc fragment such that with the view of the endoscope, you're seeing the disc, and then you can open it and take it out. To do that the safest, you want the biggest open frame, and so a young person, nice tall disc, the foramens open, not a lot of bone spurs that are going to prevent a good trajectory into the foramen, and the disc is contained in line with the disc for the endoscope.

For me, that would be the perfect first case for someone to tackle, contain disc herniation, young healthy person. Because if you could imagine it, as you become older like much older than you, the disc collapses, the foramen collapses, you have bigger bone spurs on it. It gets more and more difficult and risky to put the endoscope through the foramen, and so the risk of nerve damage is there. Early on, it's that younger person, and I think that's why this is not an approach early on that you can't just become an endoscopic spine surgeon because it's not the right operation for everybody. It's for a certain subset of patients.

But I think then, as you get more skilled, well then, you could be more advanced. As you get really good at it, then you could advance to the foramen, then with an endoscopic drill, you could drill open the frame into a greater extent, get the scope in, maybe move the scope at a different angle, get that contained fragment out as an example. But that's more of a 400-level case as opposed to the 101 level case, where you're now just getting comfortable working through the scope safely, you could see the anatomy, you know what it looks like before and afterwards, you feel good, patient does well, and then did that under your belt and then move on to bigger, more complex cases.

Glen Stevens, DO, PhD:

Can you do any instrumentation with the scope or no?

Mike Steinmetz, MD:

We do place cages with the scope. It's actually a very nice way to do an inner body fusion. For example, if I do a minimally-invasive, a classic minimally-invasive transforaminal, lumbar inter body fusion, so that's four screws, two rods, say an L45, and I put a cage in the disc space. I could do that through a very small incision, but I've got to drill away the complete facet joint, find the traversing L5 nerve route, physically retract it out of the way, open the disc, put the cage in. I'm putting tools in and out of the disc space across the nerve. You could see that it's hard, there's blood loss, traumatizing the area.

With the endoscope, I can actually put the endoscope transforaminally towards the disc, puncture the disc with a working cannula, take the scope out, and now I'm in the disc space and I'm just working through that working channel, the disc. I can do that quickly, efficiently, very little blood loss. It's a very nice way to do it. No, I can't put screws through it, but I can put a cage in it quickly, and we do that not infrequently in the lumbar spine.

Glen Stevens, DO, PhD:

Can you put an artificial disc in?

Mike Steinmetz, MD:

Not now. The difficulty with the endoscope or the working channel is it's so small. Even when we put cages into the lumbar spine, so to say, it's a smaller profile cage, the footprint is smaller, and so we worry about subsidence or fracturing through the endplate of the disc space with a cage. Right now, trying to put a disc replacement in its current dimensions would be challenging. but like all technological issues, they will get better or advance. I'm sure they'll be at some point where we can put some device that's small that'll expand larger and still be a motion-preserving device, but currently, no.

Glen Stevens, DO, PhD:

Can I find a sensory nerve root that someone's having pain with and do something with it, block it or anesthetize it or radio frequency or that type of thing with the scope or no?

Mike Steinmetz, MD:

Yes, but more for back pain. What people are using the endoscope for is a dorsal ramus radiofrequency of the facet joint. Classically, where you would do a medial branch block of say the L4, L5 facet, and if it worked, you would do a fluoroscopic guided needle placement to the inferior lateral age of the facet, use radiofrequency and in a blind fashion hoping you're destroying the nerve with radiofrequency. You can with the endoscope, place it in the lateral aspect, facet right near the transverse process. Actually, visualize the dorsal ramus, see the nerve branch and do a direct radiofrequency ablation of it. It's a much more direct way to do it and that is done.

Glen Stevens, DO, PhD:

Okay. Any biopsies with this?

Mike Steinmetz, MD:

People do disc-based biopsies, so it is used in some people's hands, although we don't do this here. For disc space infections, the benefit here is not only could you do a biopsy of the discs, just like our radiologist would do, they could put a needle in and take a piece out for pathology, but not only could I do that through the endoscope, I could also then irrigate and debris out the disc space. That's done not infrequently for discitis.

Glen Stevens, DO, PhD:

Okay. Is this an outpatient procedure, inpatient or bit of both or what?

Mike Steinmetz, MD:

It's essentially outpatient. You can do it under local anesthesia. Even the fusion, you can do local anesthesia and certainly the discectomies are done under local anesthesia. They're also done under general anesthesia as well. For example, here at the Cleveland Clinic, we do them under general anesthesia with neuromonitoring, but it's done very commonly under local anesthesia and even in an outpatient surgery center.

Glen Stevens, DO, PhD:

I know it's a crazy question, but anything with an anterior approach or is all this posterior?

Mike Steinmetz, MD:

This is all posterior. Now, there was a time when there was a laparoscopic approach anteriorly, just like you would do for laparoscopic abdominal surgery, but it really fell out of fashion. There were some complications with it and really no better outcome than just a mini open. It's all, for the most part, Glen, what we're talking about today is posterior.

Glen Stevens, DO, PhD:

Okay. Mike, just tell us the advantages of, in your opinion, the endoscopic versus other.

Mike Steinmetz, MD:

Minimal to no tissue trauma. Honestly, it's a nine-millimeter incision, almost no muscle damage, although there is a little bit, but almost none, could be almost no blood loss, like minimal to less than 10 ccs of blood loss. Very fast approach, can be done completely under local anesthesia if that's your choice. Sedation or local anesthesia. There's a real minimalization of epidural scarring, which could be a real problem with spine surgery. Even micro discectomies through a traditional interlaminar approach, you get epidural scarring here and you do it, say transforaminally. You're minimalizing it.

I would say, the last advantage, this is talking about a pure transforaminal approach. You get access to the lateral third of the foramen, which is a big deal. When we do anything in a traditional interlaminate approach in spine, you really cannot access the lateral one-third of the foramen, unless you do a fusion and take all the bone off with a decompression. The benefit with the endoscope is you can get into the entire foramen, including that lateral one-third. That is often where traditional transforaminal surgery fails because you can't get that far lateral from inside the canal. The endoscope, you can get there and do it pretty effectively and efficiently, so quick, efficient, minimal trauma, minimal blood loss, essentially no bone removal most of the time, outpatient surgery, get patients back right away and can be done awake, if that's your practice.

Glen Stevens, DO, PhD:

Future, where is it going?

Mike Steinmetz, MD:

Yeah. I think the future is just better technology. Even right now, the scopes are getting better. I think, honestly, what's driven this is the economics. When it was more of a fringe type procedure, companies were not dumping R&D into endoscopic technology for the spine. As it's become more common and more accepted, and now that we can do fusions through it, the economics have approved, so the companies are now putting R&D dollars into different scopes. Bigger scopes, better tools that you can work through safer, more effective integrating with navigation and robotics. I think technological advances with imaging and tools that can be used to the endoscope, perhaps even cages that can be used to the endoscope, and then integration with robotics and navigation. I think that's the future. It'll be done easier and safer in more people's hands.

Glen Stevens, DO, PhD:

Well Mike, I've really enjoyed today's discussion. I've learned a lot and I'm sure our audience has as well. Really looking forward to the continued development in this field, and like to thank you for joining us on Neuro Pathways today.

Mike Steinmetz, MD:

Thank you, Glen. This has been great, and I appreciate the time and the effort you put into it.

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