Michael Smith, MD: This is Transformational Pediatrics. I'm Dr. Mike, and with me today is Dr. Anmol Goyal from Children's Mercy. And today we're going to be discussing a fascinating world of virtual surgical platform in 3D modeling, and in the role, the pivotal role that it's playing in pediatric cardiology.

Dr. Goyal, welcome to the show.

Anmol Goyal, MD, MBBS: Thank you for having me, Dr. Smith.

Host: So let's just, you know, just so people understand this, what is 3D modeling and, how do we make a model?

Anmol Goyal, MD, MBBS: So 3D modeling basically is looking at any object in a 3D space, especially in the world of pediatric cardiology, we use, ultrasounds or what we call echocardiograms. They help us give a two dimensional picture of what's going on in a kid's heart, and we have to piece it image by image in our mind to make a 3D structure.

But having the ability to create a 3D model helps us better understand the visual spatial orientation of different structures in a kid's heart, and help us in better understanding how things are connected in the heart and what the diagnosis is and what we can do for our patients.

Host: And how is this being used in clinical practice now? You know, in like decision making, surgical planning, even cardiac mechanical devices, I would assume.

Anmol Goyal, MD, MBBS: So we've been using patient specific MRI and CT datas to make these models and we use it for basically enhanced visualization for diagnostic purposes. But to your point, in surgical planning, we've been using it in transplant patients who needs mechanical devices like ventricular assist device to figure out where they should go in the heart.

Is there going to be enough space in the chest wall cavity where we can put this safely? We've been also been using it for some VSD closures, which are holes in the bottom chamber of the heart to see which is the best approach? Is it through the right side of the heart? Is it through the pulmonary valve?

Can we do it through a catheter based option and avoid some surgeries? We've been also using it for some stent planning. And there are some newer technologies where we can like do different types of stents and valves to figure out which valve or which stent will be the best fit for the patient, depending on their anatomy in a 3D virtual reality space.

Host: So in the context of surgeries, mechanical devices, even stent placement, how has 3D modeling improved patient outcome?

Anmol Goyal, MD, MBBS: There are particular kind of heart conditions in which surgery was the only considered option. One of such condition is called a partial anomalous pulmonary venous return in which one of the veins from the lungs that is supposed to go to the left side of the heart with the oxygenated blood ends up coming on the right side and surgery is still considered the cornerstone for treatment.

But with 3D visualization and planning, now people have started doing transcatheter options and giving that an option to the families to avoid open heart surgeries has been monumental. Other things that this field has revolutionized, it's in the field of heart transplant. Most of our kids have really big hearts.

So the way the transplant happens is you can only fit a certain size of heart in the patients depending on how much space there is. But with 3D planning, we can figure out how big of a heart can still fit in, and we can make some adjustments based on that to determine and increase their acceptance of a new heart since they're so rare to come by.

Host: Right. Wow, that's, fantastic. What kind of challenges do you face when implementing 3D modeling in pediatric cardiology?

Anmol Goyal, MD, MBBS: I feel like the biggest challenges has been the ability to get those crisp spatial resolution images, and the time it takes for push processing. I think the field has come a long way in the last five to 10 years with the ability to like do surgeries in virtual space, the role of augmented reality, fusion imaging and mixed reality.

 So I think the biggest challenge has just been just keeping up with the technologies to see how much we can do in a virtual space before we actually are able to recreate it perfectly on a patient.

Host: Well, this kind of brings up another question then, what kind of training are doctors getting? Does the training with 3D modeling start as a resident, or is it something that's more at a fellow level? And what about practicing surgical cardiologists?

what kind of training do they go through?

Anmol Goyal, MD, MBBS: So I don't think there's any dedicated training, at least in our curriculum as of now for this. Most of the institutes across the world have the ability to do some form of 3D modeling. So it basically comes down to the interest of the person who's in it to gather those skills. I would say it does take a little bit of dedication and time, but it all comes down to the interest of the person who's pursuing it.

I would say it starts probably somewhere in fellowship and we do an extra year of imaging where we basically learn about the nuances of what goes into a cardiac MRI and a cardiac CT to understand how we can get a better picture because it all starts there. If you have a good picture, you can get a RISE 3D model.

If you have a bad picture, you won't be able to make a model. So.

Michael Smith, MD: But do you see 3D modeling? What's its use going to be like say 20 years from now? And if it does continue to be utilized more and more and more, do you see it then being taught even at the resident level eventually?

Anmol Goyal, MD, MBBS: Yeah, I mean, I would say especially for like surgical residents and cardiology fellows, there are actually modules in process, like people are actually making modules right now to help them better understand how different congenital heart diseases are in an anatomical vari, like how many variations are there in a congenital heart disease, to help them better understand how things are flowing.

So it's really good for like medical training purposes. You can actually use these 3D models and print them with different materials to actually mimic how the elastic property of a blood vessel would look like, and the surgical residents can actually practice operating on these 3D models to get a sense of how it would feel when they're actually doing the operation.

And then, we have been also been using it for patient communication and helping the families understand what their kids' heart look like and why we need to do the surgery and the risk and the benefits of doing these surgeries. So I think there's a lot to be done in this field. And from a futuristic standpoint, I would say machine learning has really taken over, the field of engineering and biomedical engineering.

So there's a lot of virtual simulations to mimic how it would work when the heart is beating because all of these models are more in a static plane. Although we can have an image where the heart is at its maximus and at its smallest, and we can mimic how it would look in a beating heart.

But, I think, when blood starts flowing, the heart rate is in the same, the blood pressure is in the same, how things are changing when hemodynamics are changing. That is something that we are trying to model now as we go forward in the future.

Host: Just so we all understand this a little bit better, can you kind of walk us through, let's say we need a 3D model of a kid's heart. Can you kind of walk us through how you eventually get to that model from like, first thing you do, second, third, like, and when it's finally finished.

Now we, just need a high level here, but I think it would be helpful for us to have a, a little understanding of what you're putting into this to get that model.

Anmol Goyal, MD, MBBS: Of course, Dr. Smith. So it all starts with the first image, so it would be a cardiac MRI, of the patient with an angiogram, or it can be a cardiac CT with contrast. And basically we use that image and we basically, extract those images and put it in a third party software called Elucis, which is an FDA approved software, from a company based in Canada.

Over there, there's a couple of different ways of creating a 3D model. You can do something called as a volume rendering model in which you have the ribcage, the lungs, all the muscles and the heart in the middle. Or you can just pick the heart and pick the structure of interest in the heart and model that calling threshold modeling.

And basically, you go structure by structure and connect things together and you get a complete model. Then in this virtual reality space, you can either export that file and put it in a printer if you want a physical model. And you can size it accordingly. You can make it as small as you want or as big as you want.

It just depends on the cost of the material, for that. But if you are in the virtual space, you can move any of the structures of the heart, however you want, put them back together. And you can even remove things. You can make holes, you can patch holes. So there's a lot we can do. And then depending on the question for which we are making the 3D model, we basically go from there and sit down with the surgeons to go over the potential pathways, where to make an incision, how to move things.

And what would be the best approach for this particular patient?

Host: When you finally have that 3D model, how accurate is it?

Anmol Goyal, MD, MBBS: So, like I said, it all comes down to the initial imaging. We have what we call a photon counting CT here at Children's Mercy, which basically helps us drop our resolution down to 0.3 millimeters now, from 0.6 to 0.7 millimeters from our prior scanners. When it comes to MRI, we are still up to 1.2 millimeter resolution.

So, when we do these models in our kids who are like three kilos, five kilos, and the vessels we are talking about moving or doing surgery on are like a couple of millimeters, having that 0.3 resolution is really, really good. So I'm fairly confident about the accuracy of our models that we are making here at Children's Mercy.

Host: So let's move into patient and family education. I think you touched on this a little bit, but I just want to ask it again. What role is 3D modeling helping in patients and families understand what the diagnosis is, what the procedure's going to be.

Anmol Goyal, MD, MBBS: There's so many variations in the kind of heart diseases that we see in our kids. It's really hard to say. There are many medical terms that get thrown out. Ventricular septal defect, double outlet right ventricle. And it's really hard for families to truly understand what it means. They do understand that something's going on with the heart, but to truly grasp what is happening, sometimes a visual picture helps. So having these 3D models for them, or at least the ones that I have gone over with the families, have really helped them understand like, okay, this is why my kid is blue, or this is why, we have to do surgery because there's this big hole in the heart.

And then we can show them how the surgeons do the surgery and what the risks are about, where certain things are and how careful the surgeons are and how quickly they have to do certain things and where they need to put things together to make sure all the blood is going in the right direction and things like that.

So, it has really helped them understand, at least from some of the feedback that I have gotten, and That's where we are using it right now, just for like better understanding of the anatomy and the risks that are associated with pursuing a particular procedure.

Host: It goes back to what a picture is worth a thousand words, right? Something like that.

To wrap all this up, when it comes to 3D modeling, what's the one thing you are most excited about for its future?

Anmol Goyal, MD, MBBS: I think the thing that most excites me is how quickly the field is going and how much we can do in the virtual space. I would still say it's a tool. It doesn't replace what we do directly, but it's a great tool that is slightly underutilized because it seems like we have the ability to move things and do things in virtual space and fix the nuances that might come up during the actual procedure to eventually improve patient outcomes.

Host: That is fantastic. This was great information, very, very fascinating, and I wish you good luck in your future endeavors with 3D modeling. Thanks for coming on the show today.

Anmol Goyal, MD, MBBS: Thank you, Dr. Smith for having me.

Host: For more information, you can visit children'smercy.org/departments-and-clinic/heartcenter or to make it easy, you can go to children'smercy.org and from the homepage, simply select departments, scroll down and select heart center. If you enjoyed this podcast, please share it on your social channels and check out the entire podcast library for topics of interest to you. This is Transformational Pediatrics. I'm Dr. Mike. Thanks for listening.