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Choosing a Surgical Navigation System that Fits Your ENT Practice
Megan Saltsgaver • Updated Jul 22, 2024 • 52 hits
Surgical navigation systems play a critical role in the safety and efficacy of contemporary ENT surgery. As navigation systems are increasingly integrated into operating rooms and office settings, it is important to consider several factors when choosing one that fits your practice. To help, rhinologist Dr. Raj Sindwani outlines the technical features of modern navigation systems that he feels are most critical for the ENT surgeon, with emphasis on advanced navigation in functional endoscopic sinus surgery (FESS).
This article features excerpts from the BackTable ENT Podcast. We’ve provided the highlight reel in this article, and you can listen to the full podcast below.
The BackTable ENT Brief
• Navigation provides real-time feedback during surgery and has safety mechanisms such as small vibrations or light flashes to direct surgeons away from important structures.
• Ease of use is one of the biggest factors to consider when trying to choose a navigation system for your ENT practice.
• Navigation registration is one of the most important steps to ensure that patients' anatomical landmarks are accurately displayed throughout the procedure.
• There are errors and inconveniences that can occur with the use of navigation. Surgeon adaptability is important when troubleshooting navigation systems.
• A surgeon’s clinical judgment should always take precedence over the navigation system. Navigation is a tool to help enhance safety, but it can have limitations.
Table of Contents
(1) Surgical Navigation Systems Improve Safety & Efficacy
(2) Setting up Surgical Navigation in the OR
(3) What to Look for When Choosing a Surgical Navigation System
(4) Troubleshooting Surgical Navigation Systems
Surgical Navigation Systems Improve Safety & Efficacy
Navigation technology significantly enhances the safety and efficiency of functional endoscopic sinus surgery (FESS). By providing real-time anatomical guidance, it helps surgeons navigate complex sinus anatomy and avoid critical structures. Although the use of a navigation system incurs additional costs, most surgeons agree that it increases their efficiency and confidence by continuously providing feedback throughout the procedure. Safety mechanisms, such as vibrations or light flashes, signal when the surgeon is too close to a critical structure. This technology also reassures patients and their families that every measure is being taken to minimize the risks associated with sinus surgery.
[Dr. Gopi Shah]:
Tell me, do you feel like the navigation systems have made a difference in operative time or cost with certain cases?
[Dr. Raj Sindwani]:
Yes, it's a good question because we're always, especially in this climate, trying to justify the capital and then ongoing disposable expense related to navigation, or really any technology we use in the OR. I would tell you, it's hard. It's a hard study to do because of the many variables that come into play. Appreciating that there is an upfront capital cost and then ongoing disposals. I think it's still very worth it. As you know there is a billing code, a CPT code that you can use for extradural navigation, 61782, and then 61781 is the intradural navigation. You do get some reimbursement for using the navigation. The idea is it should offset some of the costs over time that you're using.
Different studies have looked at this exact idea of, "Does it make us safer? Does it make us faster, and so on?" It's hard. I think it's like that parachute study. Now it's in everyone's OR. We use it routinely. It's hard to pause and randomize people to using navigation or without when the major complication rate for sinus surgery is so low to begin with. I think if you ask 100 people using it. I think they would say, "Yes, it makes me a more confident surgeon because I'm continuously corroborating what I think, where I am and what I'm doing." It makes us more efficient. I think it makes us more effective. I do think it makes us safer as well.
[Dr. Gopi Shah]:
Yes. I usually feel safer. Honestly, when I talk to families, all my patients are pediatric. When I'm talking to families about sinus surgery, and you're explaining what you're doing through the nose, when I can at least say, "Listen, it's a camera, but I also can calibrate my instruments to the CAT scan." You go through the risks of sinus surgery and yes, they're thankfully not high. That being said, it's nice to say that I have calibrated instruments and a CAT scan that I'm using at the time of surgery, real time. I think that it's helpful. I do feel safer when I do have my navigation ready to go.
[Dr. Raj Sindwani]:
I totally agree. It's interesting you mentioned the patient dynamic, because I do mention it to patients as well. When I tell them to get the CT scan specifically to the protocol that I want. I mentioned, "This may be a pain to come back to the main campus or to go wherever in our enterprise to get it. The reason I'm doing it is because then we can upload it in the OR and like the GPS on your car, Mrs. Jones, it can help me stay safe, stay in the lane I want to stay in." Because GPS, if you think about it, or navigation is literally commonplace now. It's on every one of our phones, all of our cars. In fact, you might argue it's to the nth degree in our everyday world, yet we're still walking to it in the operating room.
[Dr. Gopi Shah]:
It sounds like with these new systems, with the safety augmentation, you got a little-- A vibrator knock or whatever, a light that flashes if I'm getting switching lanes or getting off track. Getting too close to important structures that I don't want to get close to as well.
[Dr. Raj Sindwani]:
Yes, absolutely. I think that idea of using some of the technologies that do come from the same idea of our navigation in our phones or our cars, like using augmented reality or virtual reality. Which is part of some of these systems, is just one more element of that, of staying oriented and knowing where you are. I think being able to use that, and I do make the point that you want to make sure that you're using all of your visualization tools together in an ecosystem to make you as safe and effective as you can be. I think navigation has really come a long way, in that regard.
For many years, it's been a stagnant field. Now, as we introduce some of these new AI-like technologies, I think it is taking things to the next level. It's active. It warns you. It tells you when your registration may be off a little bit, so that you should check and corroborate with landmarks. Especially when we use this target-anti-target software as well, I think it just is changing the game.
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Setting up Surgical Navigation in the OR
In practice, the use of navigation adds a few extra steps to the beginning of surgery. After a patient is prepped and draped, surgeons need to register the patient’s anatomical landmarks accurately. This step ensures precise localization of the patient's anatomy for the navigation system throughout the procedure. Most navigation systems provide a mapped outline of the face for registration. Additionally, some systems offer pre-calibrated tools and tools that are ‘plug-and-play,’ such as probes and suctions that are compatible with navigation.
Dr. Sindwani emphasizes the importance of using clinical judgment to verify the system's accuracy. He recommends touching a known anatomical landmark, such as the back wall of the maxillary sinus, to ensure the system is correctly registered before proceeding with the surgery. This practice helps confirm that the navigation system is providing reliable guidance.
[Dr. Gopi Shah]:
Okay, let's say, you have the patient, it's the day of surgery, you've gone to holding, you've already signed, "done the consent, signed the patient in." You have your preoperative markings and pathways drawn out. What do you do next? In terms of preparation, what's your OR setup like? What do you like having things, ready to go? I think with the Stryker system, you can have some of your tools already navigated and things like that. Tell me what you like to do.
[Dr. Raj Sindwani]:
Yes, sure. They do have some plug and play tools that are automatically pre-calibrated. The first step after you've prepped and draped the patient is you'll want to register, and you can even register prior to prepping and draping actually with that system and others as well. Once you've registered, remember, that's a very foundational step in your surgery. That's where you're telling the computer through a transformational matrix where the patient's face anatomy are. Doing that accurately and precisely is super important, because everything else builds off how accurate you are ,and how accurate the system is, rather.
It's a very easy registration process. The system will actually help you set things up. It'll have a pop-up to tell you how close the emitter needs to be to optimize your accuracy. You'll do your registration, and then once I've prepped and draped the patient, I usually have my go-to instruments that are tracked. One of those is a pre-calibrated plug and play probe. They have several. You can also use universal adapters to put it really onto anything you like to track, Gopi. You want to track your micrometer blade, you can track that, your favorite curette, whatever it is that you like. In my hands, I like a straight probe, a curved probe, straight and curved suctions, and then the shaver blade as well.
[Dr. Gopi Shah]:
In terms of when you do registration, sometimes just trying to get it under, I forget, I always feel like it should be between one and two millimeters or maybe under one. Even that little bit of difference is a big deal when we're talking about millimeters. How do you help make sure your accuracy is good? Also, so what do you do when it's constantly failing? You've tried to register it like three times and you've tried to, the resident, the fellow, you, everybody's trying to do the thing and it's the same. Talk to me about that.
[Dr. Raj Sindwani]:
Right. The newer systems do help you with that because they make sure that the emitter, for example, a pop-up will come on. It'll help you optimize where all of those pieces need to be, so that you have the appropriate field volume for that registration process to take place. The other thing with the Stryker system is it actually will tell you where to go to collect those points so that the system is optimally registered. You're not just randomly, picking points on the face. It will actually highlight with a display that comes up on the monitor that it wants more points, near the right side of the eye. Or near the nasal bridge or whatever the case may be.
I think there's a technology lift there that actually has come a long way to make sure that we register accurately, since it is such a foundational principle. I think beyond that, what you want to do to make sure that you trust the accuracy of the system is not rely on any one number. Yes, there's going to be a green, yellow, or red that's going to let you proceed to the navigation phase of your procedure. As long as you get past that meaning green light, that it'll let you track, then I would tell you to forget what that number actually was because it's an average.
Actually, sometimes those numbers don't even mean millimeters of accuracy, even more complex than it needs to be, I think sometimes. You'll want to use your clinical judgment. I like to scroll down the nose after I register, look at the sagittal view to see how tight that registration looks to me by my eye. Once we start, I purposely will put something track against a known clinical landmark. That scenario we said, "Well, I'm not sure if the navigation's accurate or not." Try to get some sort of corroboration, touch the back wall of the maxillary sinus, the front face of sphenoid, the cellar face, for example, during pituitary surgery. Where there's a landmark that to be what it is, and then you can look at all three orthogonal views to see how accurate the system is before you make any big decisions.
[Dr. Gopi Shah]:
Got it. Your landmarks, a lot of them are in the sinus. Do you ever use landmarks like the lateral orbital rim or between the teeth, anything on the surface of the face?
[Dr. Raj Sindwani]:
Absolutely, you can. With surface registration, which is what many of the systems now use, you can pick those point landmarks, use the lateral orbital rim, the nasion, columella, things like that. Sometimes all of us have had this experience where on the surface it looks pretty good.
[Dr. Gopi Shah]:
You can put it in.
[Dr. Raj Sindwani]:
You go 10 centimeters deep and it's not so good. A few things you can do is make sure you register more laterally and posteriorly on the face. These are some of the things that we really are trying to work through because where you're registering is not where you're operating. You're operating much deeper than that and you want to make sure that the fidelity of that registration is still holding up as you get deeper and deeper into the head.
[Dr. Gopi Shah]:
Yes. Tell me a little bit, you'd mentioned you like the straight and curved sections navigated as well as your straight and curved pointers. I know some of the systems you can put the tracker on, as you had mentioned, the microdebrider or other instruments. Do you do that routinely? How does it help you? When do you use tracked instruments? Is it just for teaching purposes?
[Dr. Raj Sindwani]:
Yes, it's not just for teaching purposes, but that is certainly an example or a user case for it. I think the main reason to use it is to make you more efficient, more effective, safer as a surgeon. I think that just depends on what people like to track. Some people like to track curettes and that's the beauty of these systems that opt for this type of customizability. You can, like you said, track whatever you like. Those happen to be my favorites only because sometimes to find your way into the sphenoid, a probe is helpful. Otherwise, I like the suction because you're so often clearing your field.
This is a practical matter. That's where I tend to lean to. In fact, we can use the microdebrider as an example of how the education piece might be of importance from a navigation standpoint. The one way that navigation can help us when we're training fellows and residents is it's sometimes the final arbitrator. If I say that's anterior ethmod artery and they say, "Well, I think it's over here," then the jury's out. We bring in the navigation and, lo and behold, the staff is right. That's one way to reinforce that as an arbitrator of what the anatomy truly is, as long as it's accurate.
The second way that I think it helps me as an educator is, unlike many other surgeries, I would say that otolaryngologists or anyone else does, there's only ever one surgeon at a time in a very real way. If a resident is operating with a powered instrument, like a shaver, for example, imagine it will be by the time I say, no, not there, here, it's too late. By having the tip of that shaver blade accurately displayed on the monitor, it lets me relax a little bit, knowing where that tip of the instrument is in a field of blood, in a field of a lot of polyps and things like that. Those are the two examples I would cite as how it really has made us better educators as well.
What to Look for When Choosing a Surgical Navigation System
Choosing the right navigation system involves considering several key factors: ease of use, accuracy, customization, and support from the manufacturer, among others. The ideal system offers a straightforward registration and setup process, customizable tracking options for various instruments, and real-time feedback to ensure accuracy. The ability to personalize profiles for individual surgeons may also be important. The availability of software upgrades and a supportive manufacturer staff are crucial for maintaining system efficiency and reliability. Practical considerations, such as the system's compatibility with other specialties in the facility, should also be taken into account when purchasing expensive equipment like a navigation system.
[Dr. Gopi Shah]:
Tell me about what are you looking for in a system? There's so many different systems out there. I'm not saying, Raj, tell us, what you think is the best system, but really, what are the qualities that you look for navigation, I guess. Sometimes you'll find yourself-- Most of us will enter a group of practice, a hospital setting, where there's already a navigation system there. If you've been there long enough, at some point, you're going to hit a crossroads where you either have to upgrade the system or change systems. Maybe that's the better question. How do you know when to upgrade or change, and what is important to have in a good navigation system?
[Dr. Raj Sindwani]:
Each of these systems may have a little bit of a different half-life and the companies will tell you after a certain point, they're no longer supporting it for X, Y, or Z reasons. That would be a hard stop where you'll want to have control and support for things, like next generation instruments or whatever the case may be. Other than those hard stops, the system stops working or you don't have the parts and the pieces that you need to make it work effectively. I think there's a couple of different things that you would look for. Even agnostic to company, I think everyone from a user standpoint would agree things like ease of use, accuracy and precision, customization, and then a few other things.
I even might mention the wow factor. First from an ease of use, you want the registration and setup to be easy. You want to be able to switch fluidly from using one instrument to the other. You want to make sure, of course, it's accurate and precise. Again, I like the newer systems that have pop-ups to say, "Yes, the emitter is too close or too far. You need to move it this way." Even if there's a degradation in accuracy, as annoying as it is sometimes to have that screen flash where it says, "The accuracy is different now," it's nice and it makes you feel like you have a copilot in that computer that's in the navigation system.
The third thing I mentioned was customizability or customization. I think that has to do with this idea of tracking whatever it is that Dr. Shah likes to track or Dr. Sindwani likes to track. These universal adapters really go a long way to making whatever you want to customize your own thing. If you don't like the straight pointer, great. There's a malleable pointer. There's a curve suction, et cetera. I think even just being able to personalize under profiles, your screen setup. Do you want a larger coronal view or a larger endoscopic view? You can even use a lot of these on just one monitor now because the fidelity of the monitors and the whole visualization system.
Again, getting back to that idea of ecosystem, which I like to look for, because I want all these key pieces of technology to play well together during my surgery might be another thing. Now, I did mention the wow factor and how forward facing is the technology I'm deciding to go with. Maybe even the company that I'm deciding to go with. That's just because there's a lot going on in the navigation space. Even though I'm saying it's a tool, it still is a very expensive tool that you're going to be using for a while. You know that there's going to be iterations.
I wanted to make sure something has software upgrades available, has the next best thing just around the corner, or at least the company's looking for that next best thing. You could even say that they're a good partner and are engaged in trying to help your residency, your courses, your patients in the broader sense do well.
[Dr. Gopi Shah]:
Yes, no, those are all great points. Have you ever been, in terms of navigation, I think of OMFS, I think of neurosurgery, I think of ENT in your hospital, are you guys all using the same navigation? Or do you find that some services like this system and other services like that? How do you think about that? Especially because you were the chief of surgical operations. I'm sure those things may have come up, whether it was for this or other instruments and technology.
[Dr. Raj Sindwani]:
No, all those, let's call them practical considerations are very real, because these are at the end of the day, expensive purchases. The more service lines or more specialties you can get to use any one piece of equipment, the better is going to be your argument for purchasing that piece of equipment. It's a little bit harder in ASCs because you have a smaller number of surgeons potentially operating there. You might have three or four ENTs and two or three orthos, and so on. We're lucky here at the Cleveland Clinic. We have so many otolaryngologists alone. We have now coming up on five rhinologists.
We have our own systems, plural, and we've actually been able to play with multiple different vendors as well in that regard, which lets us compare and contrast getting to our prior discussion. It's true, if you have a group that's going to be using them in a shared manner, you want to make sure that those systems do offer spine software, neuro software, and so on. It's interesting that you mentioned that. Currently, there's a lot of overlap between neuro and ENT, and rhinology specifically because of our skull-based procedures. When we're doing a case in my neurosurgeons room, we happen to have several systems, as I mentioned, we may use a different system, and then the ENT room might be a second system.
I think from a training standpoint, that's actually a fun environment to be in because in a very real way, you get to see pain points over here and solutions over here and vice versa. There may not be any one perfect system for all things considered.
Troubleshooting Surgical Navigation Systems
Though navigation systems are designed to enhance surgical technique, frustrating errors can occur during their use. Potential issues include patient head movement, bent instruments, an unavailable representative, unstable universal adapters, and staff unfamiliarity with the equipment. Frequent staff education and a supportive industry rep can help mitigate these problems and ensure smoother operations. Because different hospitals can have different navigation systems, provider adaptability is essential.
[Dr. Gopi Shah]:
Now I want to talk about troubleshooting, familiarity with systems, whether from the staff standpoint as well as the surgeon's standpoint. You may not always be operating at the same hospital or surgery center, so that you may not always be using the same system. Or you may be taking calls and something needs to go in on call and this hospital has a completely different system than what you're used to. Tell me a little bit about troubleshooting and systems that have helped with some of those problems.
[Dr. Raj Sindwani]:
No, and it's a really good point. Of all the things I mentioned for what you might consider ease of use, which is what you're getting to now, might trump a lot of different things. I would admit my lens is through an academician. I've got a fellow, a senior resident, a junior resident, three other people deep that are going to troubleshoot before I feel that friction. I'm very sensitive to the insular environment that I live and play in, so to speak. If I was on call, like you're saying, and you're going to a community hospital and there isn't that type of support. Obviously, from a company standpoint, I'm sure they would love to have a rep at every one of your cases, but that's going to be hard to assure.
I think ease of use would absolutely trump some of these other considerations because it does have to be plug and play, easy to set up, easy to troubleshoot. Not just for you, the surgeon, because now you're scrubbed, but also for your entire team. I think the companies that we partner with really go out of their way, to make sure that the scans are easily downloaded to the system, that it's one or two buttons to get the thing fired up. That it keeps Dr. Shah's profile for how she likes things set up, saved so they don't have to reinvent the wheel. They spend a lot of time in servicing for our scrub techs and our nurses, as well as in my world, for our trainees and the surgeon.
I think getting familiarity is the point. In the normal course of use is super important for those late nights, for those unexpectedly complex or twists and turns we all experience in our cases to go well. I think once you're in that scenario, though, things that can introduce errors or inaccuracies that you want to be on the lookout for. One, outside of just the software, the registration paradigms that vary system to system, will be things like movement of the patient tracker that's placed on the forehead. Movement of the patient's head that might be turned out of the volume box, for example, bent instruments.
We mentioned, we talked a lot about universal adapters. Those could slip if they're not on tight enough. Again, often it's the scrub tech that's tightening them down. These are all things that you should be on the lookout for. Again, the way you confirm that there may be an issue is checking against or corroborating with intranasal, ideally, clinical landmarks. Once that happens, again, with the Stryker system, this is going to prompt you saying, "Well, the accuracy may be off." It's actually a hard stop that you have to click past when it senses the system that something may be arrived for you to corroborate or then re-register.
At that point, you're going to just try to decide what it is you want to do. You've got a couple of options. Once you've checked those intranasal landmarks, if they're not accurate, you can say, "Oh, well, I'm not using this. I'm going to keep going," because you're almost done or you're confident with your landmarks. Option two could be to re-register. You'll look to the system to tell you that, and you'll get a sense of whether the registration or the patient's tracker slipped, for example, you'll want to re-register. If you think it's an instrument issue. You noticed that universal adapter has shifted, you'll want to recalibrate.
Registration is the patient's head and that interplay, the calibration is the actual instrument that you're using itself. I think those are the main things that you would want to look for. I think the key is just when your spider sense starts tingling, things aren't right, then I think it is worth pausing and deciding on which of those few things is going to be your next course of action.
[Dr. Gopi Shah]:
Have you ever had to call your rep on the weekend or in the evening because everything you've done isn't working, and we haven't started the case. The patient's been on the table for about 30, 45 minutes because I don't know what your threshold is with time, but yours, and it's a hot fest in the setting of a large subperiosteal abscess. It's super swollen, and there's concern about vision, so where time is of the essence.
[Dr. Raj Sindwani]:
You want to have that nav in those settings. You want to have that extra buffer of safety and confidence as we've been discussing. Yes, you're pointing to the fact that you do want support in these cases. You don't want to partner with a company that just drops the nav off and says bye-bye and they're onto their next site or their next sale. You do need to partner with the local reps who should be available, amenable to helping you out. It's interesting, you mentioned that because I'm just thinking back years ago. I remember that happening, not super infrequently, but more recently, I think with the newer systems and so on.
I would say I think that happens a lot less where you actually have just pause, break, scrub, or have someone FaceTime me. Saying, "Oh, I don't know why."
[Dr. Gopi Shah]:
It is the worst.
[Dr. Raj Sindwani]:
This is the worst. You're stressed. There's a patient asleep and you're just there. It's coming at you from all dimensions. I have been there. I have done that and I've hated it as much as you.
[Dr. Gopi Shah]:
Me too.
[Dr. Raj Sindwani]:
I think making sure you're partnering with the right folks in this regard is going to be super important.
[Dr. Gopi Shah]:
The other thing is I feel like the training for the staff is something that has to happen every six months, and then eventually once a year, because there's so much staff turnover too. You might have that person that knows your system, or the three people that really know it, maybe they're all gone after two or three years. It's like starting from zero again, and then nobody wants to scrub that case because it's a new system. You're right. Having a partnership and a good relationship with your rep, the company I think is vital and you want them to want to come to your hospital.
You want that the nurse or charge, whoever the tech can get ahold of the rep as well. It's not just that you're the middle person, that communication, those lines are already open. The other thing I find helpful is literally a step-by-step of what to do from to plug in, navigating system, turn on power. I want everything like that. Dumb it down so that when I go, I'm just like, "Okay." Even taking the time to make little instruction things on every single system I found was helpful for us.
[Dr. Raj Sindwani]:
No, that's really good advice. I agree because of the current state of affairs and our healthcare industry, there is a lot of turnover or off service personnel who just pop in for a case here and there. There's always that all on call example that you cited where you know it's not going to be an otolaryngology nurse that's going to scrub with you. Those things do get people nervous. I think it's the best laid plan sometimes. I think that the stronger the team is that you can surround yourself with the better your outcomes are going to be in every regard.
[Dr. Gopi Shah]:
Raj, any final pearls or thoughts on navigation?
[Dr. Raj Sindwani]:
Yes, I guess just parting thoughts would be, navigation is at the end of the day, just a tool. It's a cool tool. It's amazing. It's empowering all the things that we've highlighted today in our discussion, but it is still just a tool that doesn't make a poor surgeon a great surgeon. You want to know that it has limitations and ultimately, you're the one responsible for the outcomes that you get. This can just enhance and help you along the way. I think that deserves being mentioned. I guess the second thing to end on a positive note, I would say is, I really feel like we're at an inflection point for the world of navigation on this space.
As I said, for literally two decades, it's been a stagnant area with not a lot of innovation. Again, if we contrast it with the way we use navigation in our everyday lives, clearly, there's so much potential here with the application of AR, VR, and all those things that now we're starting to really see come to fruition. It's been really exciting to see what some of the opportunities are here for expanding the boundaries of skull based orbital and rhinologic surgeries, and also what we can accomplish together for our patients.
Podcast Contributors
Dr. Raj Sindwani
Dr. Raj Sindwani is the vice chairman and section head of the Head and Neck Institute of Cleveland Clinic in Cleveland, Ohio.
Dr. Gopi Shah
Dr. Gopi Shah is a pediatric otolaryngologist and the co-host of BackTable ENT.
Cite This Podcast
BackTable, LLC (Producer). (2024, June 4). Ep. 174 – Advanced Navigation Systems for FESS: Enhancing Safety [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.