Image Guided Surgery Video Series, Episode 2 - Lung Nodule Localization & Resection Part 1

So we're back with episode two of our image guided surgery podcast. This is Rod Gerardo. And I'm M. Tombash. We're research fellows at Cincinnati Children's Hospital Medical Center. And we're joined by Denise Lou. I am Denise Lou. I'm one of the uh interventional radiology residents at University of Toledo. Our last episode, we gave you an introduction to the hybrid ORs and their advantage, uh how to build one. It was a fun episode. So if you haven't seen it yet, go check it out now. So, this episode, we're going to do something different. What are we going to do, M? In this episode, we're going to go through the lung mass localization and we're joined by expert who uses hybrid ORs on a daily basis. We have images for you posted below the media player in the app to see what we're talking about. So let's jump right in. This is a case of a patient with hepatoblastoma with suspected pulmonary metastasis. Uh she has a pulmonary met and it has clearly increased in size on surveillance chest CT scans. So my first question is before we had an hybrid OR, what would you have done and what would have been the approach to this patient for management of this kind of nodules? You know, if they're right on the periphery, you can often see them and don't need localization at all, but this is a little bit deeper, so it makes sense to localize it. And we would have done it downstairs um in the CT scanner and then brought the child up upstairs to an operating room. It would just require movement of the patient. That was Dr. Rashni Dasgupta. She is a pediatric surgeon at Cincinnati Children's and she does primarily oncology and a lot of long tumoral localizations. Pre-hybrid OR, there's a lot of movement involved going from one place to the other. But once you get there, what would the localization have looked like? Typically would we've we localized these as uh with the Copan's uh breast localization needle and wire, plus minus methane blue blood patch. This is Dr. John Ricadio. He's a pediatric interventional radiologist and he's the director of the pediatric interface for radiology research and innovation. More recently, uh Dr. Johnson has started localizing some of these with microembolization coils. So coils that typically we would use for vascular embolization. We're advancing those to that same uh Copan's needle, kind of having a combination of the micro coil and also the Copan's wire coming out. Just in case the wire were to become inadvertently pulled out, um during the thoracoscopic resection. That's not a trivial uh technical procedure. Dr. Neil Johnson. He is an Australian pediatric interventional radiologist. He uses the hybrid OR almost exclusively for lung localizations. He does something a little different using micro coils that are usually used for embolization. This may seem like a trivial change, but it's actually very technically challenging. The IR really need to practice beforehand to get a good feel or handle on controlling the coil because it's very important that it be deployed in the right place. Because we've had them they they're sort of a little bit smaller than the guide needle for the cone pin. So you have to be very careful and practice outside the patient beforehand and know what you're going and you have to have the holder for the coils really firmly established in the hub. Otherwise the coil delivers in the hub of the cope needle. So it's it's pretty technical and you have to practice and be very sure of what you're doing before you try it on the patient. Yeah, prior to the hybrid OR, the patient would be um usually intubated upstairs in the OR. Since we're operating on the lungs, the intubation is also a little more complex. Um and Roshti, I know that that you often do the the double barrel intubation. Is that correct? Yeah, they always have a double lumen uh ET tube or a bronchal blocker depending on the size of the patient. Right, exactly. So they typically would do that up in the OR area and then transfer the patient uh on a stretcher down to CT uh a couple floors, get them off the stretcher, get them onto the CT uh gantry, uh the CT table. Do the CT scan and the CT localization there, then get them off the CT table with the wire in place, uh kind of protecting that from hoping that that won't get dislodged and then transferring them back up to the OR and then positioning them in the thoracoscopic position for the surgeons to do the the thoracoscopy. Now, as you can imagine, this workflow before the hybrid OR is a little bit all over the place. So it's easy for some issues to arise. So there there are a number of opportunities for for the wire to get dislodged and um, you know, all that's done in the hybrid OR and and when possible, we try to actually position the patient in the thoracoscopic position to begin with. So there's a single prep and a single draping. Um that doesn't always work depending on the the location of the nodule, but uh when that does, you can do uh everything uh more efficiently and uh with less chance of that wire becoming dislodged. And with hybrid ORs, we save all this time not transferring the patient back and forth from imaging to OR. Uh let's look into some examples. Here we see some interop uh C arm, comb bean CT images. Um Denise, because I'm a simple blood and guts resident, what what do they mean by comb bean CT image? So a complete CT is a type of uh topography, like a CT where the C arm kind of rotates around uh the patient uh completely 360 degree uh while capturing multiple images from different angles. So it's basically like a CT but just done with a C arm. Cool. Simply put, radiographs, fluoroscopy, and CTs are all imaging modalities that utilize x-ray beams to create images. Radiographs are a shot in time. Uh fluoroscopy gives us these real-time 2D images. And lastly, the latest fluoroscopic machines have the ability to do comb bean CT, which performs a 360 degree scan of a designated 3D volume of the patient. Basically giving you a slab of the cross-sectional images. The localization on the CT are simple. You draw a line between the skin surface and the target on CT images. And the beauty of the cross-sectional CT images is that you can account for the Z axis, giving you a 3D rendition or or that 3D space. And uh the key issue for this whole thing is briefing of anesthesia. The the the problems we've had have been based um on anesthesia staff not understanding what we're doing. Uh one of the most important aspect of these chest procedures is respiration motion. So anesthesia plays a crucial role in controlling the respiration and giving us apnea at the precise moment for targeting lung lesion. Secondly, positioning. Um as you can see there, we we needed so that we try and do it the same position as for the thoracoscopy without having to redrape etc. Then we localize the lesion, we basically go to a workstation and put that green line on. Um we put a an entry point. Um we we click on the lesion with a mouse, we click on the skin and the system draws the line. One of the advantages of this is we can adjust it. It goes directly through the middle of the intercostal space, which surgeons prefer going above the rib so that we avoid the arteries and the nerves that are below the rib. And uh so we get get that line, we go back into the room and the system arranges the C arm automatically, the computer arranges the C arm in exactly the right position. I actually put the needle into the plura to check its position and uh stabilize that with some some blue towels. And then once we've got it done, it's very important to do it quickly. You don't want to put the needle in and do a scan and then wait and fiddle around. And when some of our colleagues used to do that, they get pneumothorax other complications. I think Neil you bring up a really important point about the breath holding. And um basically uh it's really important to talk to the anesthesiologist and explain to them that we need the the same respiratory excursion on whenever we're doing the comb beam CT imaging and that has to correspond to when we actually are advancing a needle. So you can imagine they do the comb beam CT with full inspiration um and the location of that nodule is going to be different in 3D than if they did in a full expiration when you're trying to advance the needle. So these planned paths are planned from the respiratory excursion from that first CT. So unless you have the same respiratory excursion when you advance the needle, you're going to be off target. To ensure the same respiratory effort, we ask our anesthia colleagues to fully paralyze the patient and then disconnect the tubes from the ventilator. This way the patient can just exhale naturally and and stop at a very natural stopping point. Place and that seems to be the most reproducible rather than having CPAP of 20 or 25 or something like that. And secondly, we think um that reduces, having no positive pressure, reduces the chance of a pneumothorax. Totally agree, that's the same way that I do it as well. So even if you do get a complication and the most common one is having a pneumothorax, it's not a disaster. We just put a French five French sheath or a UE catheter and connect it to low wall suction which will take care of the pneumothorax. When you're doing this with a living breathing patient, then timing it up with respiration is difficult sometimes and takes a little bit of coordination with anesthesiology. It's kind of like um us doing a lung biopsy, right? If we do a lung biopsy, chasing after that lung nodule, especially that's why we say it has to be at least a centimeter. So most of our patients are not general anesthesia, they're outpatient. They can come in and just breathe on their own. We just tell them, hey, can you hold your breath at the same level each time. But that's not possible because you give them moderate sedation and then their breathing changes this. Ah, yeah. And then depending on if it's peripheral, if the lesion's peripheral, you get high risk of uh pneumothorax. If the lesion is more central, you get higher risk of uh pulmonary hemorrhage. And what about the resolution? Can you see nodules like you can in the traditional CT, Dr. Johnson? The answer is yes. Now, most of these images are done, if we've got a big module like this one or relatively big, then we turn the dose down and we just use enough dose of x-rays to get the job done, but we it also has a lung um optimization module that Nicole knows all about. And so we have been able to see every small lesion that we have seen on the traditional CT downstairs diagnostically beforehand, we've been able to see upstairs in the hybrid. So the the contrast resolution and spatial resolution is just as good. In fact, I think it's slightly better than traditional CT. And one more question. Let's say if you have multiple lesions, are you able to localize all of those? Yes, we can do multiple lesions at the same time. We, I think Dr. Johnson has done up to three. Uh sometimes when you do multiple, there's increased chance of pneumothorax, but then again just put a small uh catheter in there and suck it out, it's no problem. Usually depends on what the goal is of the procedure. Uh and and where the lesions are located. If they're all kind of within the same lobe, then I think for a thoracic surgeon's standpoint, they can just take it all out. Kind of like breast surgery, right? Multicentric versus multifocal. If they are all different lobes and you are worried that they're of different ideology, you can localize them, but usually we just pick the biggest one and go after that. All right, so we'll move on, we'll show you guys some images of the needle advancement under plain fluoroscopy. Well, that's essentially what you would, what you would see just under plain flucopy. Uh if, you know, if you didn't have the graphics to follow. So obviously a nodule that small under plain fluro, you just can't see. So you'd be, you'd be kind of pushing blindly, but having performed the CT beforehand and having this live fluoroscopy superimposed over that CT along with your planned graphic. Uh you have the planned graphics to to uh guide your needle over down to the to the lesion. You know, because it's so difficult to see and like Dr. Ricadios says, you're basically pushing blindly, you can end up with an intraoperative bleed. You have this intraoperative bleed to watch. They have a display monitor that shows this live x-ray, the image with the graphics, and then they also have their preop CT so they can kind of compare all the images while they're for like doing their procedure. And as far as I know, you also have intraoperative 3D rendering opportunity. I wonder if you use it every time. What we can do is to give the the nodule a uh segmentation coloring in the in this example, a little green dot. And then uh this is the post CT scan after having localized it. But if you put a little coloring on the nodule, you can do a 3D rendering. You can rotate this image around in 3D space and, you know, kind of understand the nodule is, you know, inferior to the needle tip by whatever, 5 millimeters. Actual imaging is super helpful, but I think it's also it's helpful to have that be there with you guys and have that discussion of all right, we're a little bit medial or a little bit there. And then, you know, often um the interventionalist will be in the room with us and we'll kind of confirm with, okay, this is anterior, this is posterior, this is where it should be and make sure that everybody's on the same page. Um I think the imaging is helpful, but it's also really helpful to have, you know, you guys there real time and just confirm everything with with you. The thing is I think that it's obvious that uh proficiently radiologists and surgeons think slightly differently in 3D space and um that's natural and expected and it's good to have trusted colleagues um in all all areas to discussing it together so it's very clear. So um we stay in the room, John and I basically stay in the room um while that uh positioning is um is done while the surgery is done. If possible, we've sometimes got to go and do something else, but we try to stay in the room or come back to the room fairly quickly. I think you can, uh like we can do a lot of things. Uh a lot of times the thing is what is most efficient and still can get the thing done, right? Uh 3D rendering takes time. So do you really need it to see it or can you just go on without it? Yeah, so maybe it's a case by case basis. It's definitely a tool in the armentarium. So, regarding draping, you know, because previously it would be like you go to CT, you get that procedure done, then they wheel you out in the hallway, you go to the OR and then you get your surgery done, so you got to be draped for that. I mean, do you drape the patient for radiology first and then redrape for surgery or what are you guys doing? So the goal is that do we prep and drape once. So, that way again, you're saving time. There's some rare occasion because of where the nodule is that they may need to be supine or something like that rather than lateral decubitus, but that's relatively rare. So we're usually trying to again, limit the amount of changing, limit the amount of movement. Um one that helps make sure that the wire stays in place and two which is saves time. I'd say one added benefit from a technologist perspective is when we set up the patient like Dr. was just referring to is, we have Dr. and we have like our interventional radiologist in the room, helping the staff position so that we ever have everyone's happy when they get in there. And and then maybe one other thing about the the localization um ideally what you're doing is you're as you're advancing through prial plura and then and puncturing into visceral plura, you're injecting a little bit of methylene blue uh blood patch as you go down towards your target. It's a little bit of a coordination to be doing that at the same time and still staying on target. But the other thing that I think happens is it can happen for very peripheral nodules. If you're, if you don't have a decisive puncture through with with your needle and acceleration through the visceral plura, if you can imagine as you're as you're pushing your needle and if you're injecting fluid, methylene blue blood patch, it can just push away the visceral plural surface of the lung. So you think you've gone deep enough, yet you haven't actually punctured through the visceral plura. So then when you deploy your wire, you know, your wire um won't be within the lung. It's it's something that I I I'm conscious of when advancing the needle to really be decisive when puncturing the visceral plura. The efficiency that interventional radiology brings to a complex thoracic case cannot be understated because then of course, like you said, then the end result is, you know, more efficient and hopefully get better outcomes for the child, right? Yeah. And see you on the next part where we'll talk about how to do resection on nodule we just localized with image guided surgery. Great point, M. You're not going to want to miss part two where we talk about how they actually resect this lesion. But until then, I'm Rod Gerardo. I'm M. Tombash. And I'm Denise Lou. And remember, knowledge should be free.