215. Seeing Mesh on Imaging

This week, the topic of discussion was: 

-Mesh
-Imaging 
-CT Scan 
-Ultrasound
-Xray
-MRI
-Adhesions
-Meshoma
-Mesh Weight 
-3D Anatomic Mesh
-Biologic Mesh 

Welcome to HerniaTalk LIVE, a Q&A hosted by Dr. Shirin Towfigh, hernia and laparoscopic surgery specialist who practices at the Beverly Hills Hernia Center. This is the only Q&A of its kind, aimed at educating and empowering patients about all things related to hernias and hernia-related complications. For a personal consultation with Dr. Towfigh, call +1-310-358-5020 or email info@beverlyhillsherniacenter.com.

Guest: Dr Ryan Juza, University of Wisconsin Department of Surgery

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Transcript

Dr. Towfigh (00:01:17):
Hi, welcome back to Hernia Talk Live. It's been a while. We had a little hiatus there. For all of you who are joining us live via Zoom or Facebook Live, welcome. My name is Dr. Sharin Towfigh. I'm your hernia surgery specialist and you're on either by Zoom or by Facebook at Beverly Hills Hernia Center as well as at Dr.Towfigh. As you know, you can follow me on Twitter or X at HerniaDoc or on my Instagram page. And today we have an amazing guest, Dr. Ryan Juza. He is a very talented minimally invasive surgeon, so he does laparoscopic and robotic surgery and his specialty is within abdominal wall reconstruction, which is kind of the grand scope of hernia surgery. You can follow him on X aryanjusa. So please welcome Dr. Juza. Hi.

Dr. Juza (00:02:15):
Hi, how are you?

Dr. Towfigh (00:02:16):
Good and thank you so much for accepting this. We are episode 215.

Dr. Juza (00:02:23):
That's great. That's wonderful. Yeah, I'm happy to. I'm glad to be on and discuss the things that we do every day and what keeps our lives interesting.

Dr. Towfigh (00:02:34):
We have some people watching already, but as I was explaining, these episodes are most significant afterwards when it's on our YouTube page. And so I hope that you share them with your own team of residents and so on. I learn a lot every time I have a guest like you on, so I have questions, but also as questions come through, I'm going to ask them from our audience and I would love it for you to answer them.

Dr. Juza (00:03:04):
That's great. Yeah.

Dr. Towfigh (00:03:05):
Okay. Well, I heard an amazing talk by Dr. Juza on imaging of mesh and those of you who follow me know I love radiology. There's a handful of us that really enjoy radiology. A former guest of us, Dr. Eric Pally is another one. So we like to read our own images and we often encourage our residents and fellows to do the same. And the reason for that is why Dr. Juza?

Dr. Juza (00:03:34):
The main reason is you want to have the most understanding of your operative field, what you're going to be working on before you get into it. When I talk with patients, I usually describe it in more layman's terms as it's like the blueprints for a builder. If I'm going to come in and do a building remodel or build a house, I want to know what the blueprints look like before I get in there so I can appropriately plan for and take advantage of all the scenarios or the potentials when I'm in there. And that's where imaging comes into play for hernias.

Dr. Towfigh (00:04:18):
That's a pretty good analogy. You don't want the contractor to just say, oh yeah, someone else told me about this house and they told me just to add a room and they never actually looked at the layout themselves before surgery. That's true. That's a really good point. I like that analogy.

Dr. Juza (00:04:36):
Start tearing down walls and getting into plumbing and get into places you don't want to be. Yeah, exactly.

Dr. Towfigh (00:04:44):
Excuse me. When we talk about imaging, we talk about ultrasound, CAT scan, MRI. Those are the top three. We don't really use much x-ray anymore. I don't know. Every so often there's indication for it, but do you agree x-ray's not really that helpful except in certain circumstances?

Dr. Juza (00:05:02):
Yeah, I don't use x-ray for any hernia imaging. I will point it out in some cases with residents, particularly the scout film, and maybe we'll talk about this later on. Sometimes you can pick up past hernia fiducials, so big metal tacks, you can pick those up on x-rays and things like that, but that's about the only time where you can see a soft tissue process on an x-ray. Typically, you need a soft tie image modality, like you said, with ultrasound, CAT scan or MRI.

Dr. Towfigh (00:05:40):
Yeah, the x-rays show the bones really well. Any foreign materials that are metallic, it can show gas. So you interpret that as how the GI function is, but it won't show you muscle. So it doesn't show you obviously a muscle of the abdominal wall unless you have a humongous hernia, you can see it's a distorted x-ray. Yeah, it doesn't help as much I would say. Agreed. Agreed. Correct. CAT scan is really the most common imaging used among hernia surgeons. It gives you a lot of information. You describe how you use a CAT scan just initially?

Dr. Juza (00:06:19):
Yeah. So yes, you're right. CT is probably the most commonly used, although all have their merits. So an ultrasound is good because it's quick. It can be done at the bedside. It doesn't require really specialized equipment beyond a typical ultrasound. And the big benefit of it is, well two, it's cheap and it can be dynamic. So you can have a patient valsalvaing or increasing their intraabdominal pressures. So you can get a dynamic image of the hernia and the defect of what's particularly sliding through it. CT, again, more commonly used. It's improved significantly since its outset a couple of decades ago and really provides the most complete imaging of the abdominal wall anatomy layers. It's got good tissue differentiation between muscle, adipose tissue, connective tissue.

(00:07:29):
And so for me, just about everybody that I see is getting a non-contrast CT of the abdomen and pelvis. I don't see the benefit in contrast except in specific situations. That's probably too far down the rabbit hole for this discussion, but non-contrast. And from the abdomen, which is going to be above the xiphoid process all the way down to the pelvis will get you below the pubis. That's going to give you all of your soft tissue anatomy of the abdominal wall. And I most commonly read that on axial imaging only. That gives me the transverse cuts through the abdomen. You can see the circumferential abdominal wall muscles, the continuity or discontinuity of them as the case with hernias. And it really gives you the most complete picture of the abdominal wall musculature.

Dr. Towfigh (00:08:29):
Going back to ultrasound, do you do your own ultrasound?

Dr. Juza (00:08:32):
I don't do my own ultrasound. Yeah, that's hard. Didn't train in it. Yeah. It'd be very rudimentary if I tried.

Dr. Towfigh (00:08:40):
I have an ultrasound machine in the office, so I do use it for, let's say, diastasis or something that really doesn't need a lot of technology to diagnose and look at. I use it for injections.

Dr. Juza (00:08:53):
Yeah, I think that's a good idea for diastasis. As most folks come with a CT, we pick it up there. But for that specific feature or diagnosis, yeah, I like that idea.

Dr. Towfigh (00:09:06):
Yeah. So what I hear a lot is for some reason or another, some doctors don't believe you can see mesh on imaging. And as you'll discuss, that's totally not true. It may be difficult in some situations or maybe they can see the mesh, but there are certain meshes that you can't miss on imaging and there are other meshes where if you look high enough, you can tell. So maybe you can explain why or why not you can see mesh on certain imaging and not others and why that's important to understand.

Dr. Juza (00:09:44):
Yeah. Right. And that's one of the key questions we try to answer when we get CT imaging, because a lot of folks, at least that I see, are already coming with a recurrence. And if they've had a prior repair in this day and age, most repairs are being done with mesh. So it is very important. That's going back to the contractor analogy, that's going back into a house that's already been remodeled. Things have been reworked. Now I really want to know where everything is because I'm not just doing a first time redo. So I'll look at CT imaging for that in almost all cases. The only time I will use ultrasound for imaging or recurrence or looking for mesh is particularly for a groin. If I'm looking for mesh plug sliding through a recurrent defect or trying to determine if that's in a direct or an indirect space sometimes ultrasound can pick that up.

(00:10:49):
But by and large, it's CT imaging. And what we're looking for are a couple of, there's a lot of different ways to look for it on there, but a lot of it comes back to the type of mesh that's been placed and where it's been placed. So mesh that is placed... Well, let me take a step back. The different types of mesh, the easiest one to see would be a laminar sheet of mesh. These would be our cortex or PTFE, EPTFE meshes, expanding polytetrafluoride.

(00:11:35):
I'm missing on it right now, but EPTFE.

(00:11:38):
Yeah. And these are laminar meshes. They're typically very easy to see on CT imaging because they create a pretty straight continuous white line on the image. So it's relatively easy to pick them up. They appear thick because they're a heavier weight material. They don't get tissue incorporation or in growth, and so they stay as a continuous plane. They don't mix with the surrounding tissues very well. And they can also long-term calcify, and that's another indicator on there. You'll see when I say white, sometimes it can be bright white calcified structures there in the abdominal wall.

(00:12:26):
But that would, if I want to see some mesh in the bowel or in the abdominal wall, that's going to be the easiest one to find in there. And so I'll pick that up pretty readily. As you go to a lot more of the porous meshes, then we look at the mesh weight and mesh weight being how much mesh material is in a given space. So a heavier weight mesh obviously has more fibers to it. It's a denser mesh versus a lightweight or ultra lightweight mesh, which has more porosity, less mesh material. And the reason those differ, why you can see a heavier weight more than a lightweight mesh is one, as I mentioned before, that tissue incorporation. So a heavier weight mesh is going to have less tissue incorporation. It's going to stand out as its own layer in the abdominal wall. It's easy to differentiate from the appearance of muscle.

(00:13:32):
It does blend in kind of like connective tissue in terms of appearances, but it maintains a non-anatomic shape to it. And by that I mean you'll typically see non-anatomic wrinkles or undulations in the mesh or curls, particularly at the ends of it, where you look at it and you go, the normal body doesn't take that shape and you can see it in those layers. And again, also because you won't get tissue incorporation. The hardest ones to see are going to be the lightweight or ultra lightweight meshes. These are more greater porosity, less material. And what happens in those situations, you get a great deal of tissue incorporation, tissue in growth into the porosity in the mesh, and it just kind of melds and blends into the surrounding tissue. So it is harder to find those types of meshes. If I'm trying to figure that out -

Dr. Towfigh (00:14:36):
Just to clarify, there's a question they're asking online. You're mostly currently talking about CAT scan or CT scan, which we usually use, especially for the abdominal wall, ventral hernias and so on. Yes? Correct.

Dr. Juza (00:14:52):
Yep. This is specifically on CAT scan. Yeah. Yeah.

Dr. Towfigh (00:14:56):
And before you move on, another question from the audience, what is the difference between poor size and mesh weight?

Dr. Juza (00:15:03):
They go hand in hand. So the more porosity or they're inverse, the more porous a mesh is, typically the lighter weight it is because there's more open space to mesh material. Whereas a heavier weight mesh is going to have more mesh material and less pore size. So they are sort of inverses. Got it. And so beyond that, then we look at other aspects of the mesh, things such as a mesh coating. So there are meshes that we place in the abdominal cavity. They have an anti-adhesive coating on them. And now that coating will break down, go away over time, but a lot of times you can see that on imaging as a continuous layer indicating the space that the mesh is in.

(00:16:02):
And that too, when you're placing a coated mesh like that, you're placing it underneath the abdominal wall. And for that reason, because it's not interposed between the layers, the muscle and connective tissue layers or muscle and fat tissue layers of the abdominal wall, it's easier to pick up because it stands out from the surrounding layers. So the next thing I would point out is just that mesh that's placed within the abdominal layers sandwiched in between there is harder to find compared with meshes that are either placed on top of the abdominal wall muscles or underneath the abdominal wall muscles. Those are much easier to pick out because they tend to maintain their own shape a little bit more. They're not constrained within those layers.

Dr. Towfigh (00:16:51):
You mentioned the waviness of meshes. How much waviness do you think is within normal as opposed to something that's balled up?

Dr. Juza (00:17:01):
Yeah, that's balled up. And so we all love to get our mesh to lay as flat as possible to conform to the abdominal wall shape as much as possible, but even the lightest meshes placed in between the layers will have some ripples or undulations in the layers that help them stand out a bit. We can see folds of mesh on CT scan. That's also not necessarily a terrible thing. It does happen sometimes. What you don't want to see is the sheath itself all wrinkled up into a small space, whether that means it's protruding out through a fascial defect, a recurrent hernia, or in the case of the mesh plugs that were more commonly used historically where you've got what's considered a meshoma, a big mesh granuloma where the body is kind of walled off around it. And that's basically just a big wrinkled piece of mesh placed into the abdominal cavity to be a space occupying lesion to prevent recurrence.

Dr. Towfigh (00:18:14):
Yeah. And then what do you look for? Let's say a patient comes to you, they've already had a hernia repair, maybe at least one with at least one piece of mesh in them. That complicates a neck surgery. So when you're planning for these operations and you're looking at the imaging, what specifically are you looking at to get information from that imaging?

Dr. Juza (00:18:35):
Yeah, so if I know they've got old mesh in there, previously placed mesh, I'll go back through the operative note for some keys on where they placed it and what type they placed it. The next thing I'm looking for would be things like curled edges. So a piece of mesh is usually an oval or a circle, but in general it has an edge around it and a lot of times you'll see those edge either fold down or fold up. And those exposed edges, particularly even if it's a coated mesh, the edges themselves are not coated because you want tissue incorporation. So if I'm looking at a CT scan and I know that they had a coated mesh placed intraabdominally, but I see that those edges are curled down, I'm going to anticipate there being some denser adhesions around there because that opens up the uncoated side of the mesh to direct contact with the bowel, and that's where you tend to see more adhesions.

(00:19:42):
Most of the time the underside of the mesh where there's coating, you'll still get adhesions to those, but they're typically flimsy, easy to take down type of adhesions. So that's a big one.

(00:19:57):
Again, I'm looking at where it was placed. I'm also looking, even if it was placed in between the layers, are there tissue planes or particularly fat planes between the mesh, I'm sorry, where the mesh is placed and the underlying bowel? Sometimes if there was an inflammatory reaction when the mesh was placed, you can get pretty dense adhesions to the underside of the abdominal wall where that mesh was and know and just understand. I go into it understanding that that's going to be a particularly challenging area of dissection and I'll plan my procedure accordingly.

Dr. Towfigh (00:20:36):
Yeah, you want to see where the mesh is in relationship to critical organs. So in the groin, like the bladder, the vessels in the abdominal ball, if there's a specific bowel loop that looks abnormally tethered to that area, then you may want to be careful for that. Is there any good imaging that will help you determine adhesions to the mesh?

Dr. Juza (00:21:01):
Direct adhesions to the mesh from the bowel? Yeah. Even a non-con CT of the abdomen will give you some of that. So I can pull up some pictures here if that would be helpful.

Dr. Towfigh (00:21:19):
Yeah. And before you do that, let me have you answer another audience question. Is the crease or fold of the mesh an actual meshhoma and equally capable of causing pain for the patient? How can you tell the difference on imaging between a non-painful crease or fold and a meshhoma or balling up?

Dr. Juza (00:21:40):
Yeah, that can be hard because as I said, a lot of folks can have some wrinkles or folds in the mesh and those don't always and most often do not cause discomfort. When I'm looking at fold, I'm looking at what structures it's adjacent to or near that could be causing problems. So to go back to your groin example, if I see a mesh plug in the groin, or if I see a preformed convex mesh that's placed in the groin most typically, and I see that it's folded and it's folded in the area where the nerves are known to typically run, or I see that I have a image where a heavyweight piece of mesh was cut to fit around the cord structures and that patient came in complaining of groin pain. So you can conceptualize if they've got pain, you've got a foreign body in that area that in some cases reasonable to assume or presume that the mesh could be causing discomfort through pain or through those rough edges or the edges of the mesh being adjacent to it.

(00:23:10):
A lot of that comes down to the patient as well though. So I'll typically see that in thin males or females when they don't have a lot of extra adipose tissue to cushion that foreign body from adjacent structures. And so we'll see it in those situations.

Dr. Towfigh (00:23:30):
Yeah, I think that's really important is the patient's body as well. I feel like exactly what you said, the thinner they are, the less tolerant they are of any folds or balling up in the mesh. The larger they are, the more you can have a lot of folded mesh sometimes in there and they're like, "Oh, I'm totally okay." Okay, as long as you're okay.

Dr. Juza (00:23:50):
That's notable. Yep. And if it's doing its thing, so yep.

(00:23:55):
And I think a lot of surgeons will make those choices too according to that. So go back to visualization of mesh on CT, heavy versus lightweight. In young, thin females, if I've got to repair a groin hernia, I'm going to tend to use a lighter weight mesh for better tissue incorporation and a less dense structure in a sensitive area versus a heavier set or more adipose tissue patient with a big groin hernia. I'll probably use a heavier weight mesh for additional support. So we do make choices regarding our types of repair based on patient characteristics as well.

Dr. Towfigh (00:24:38):
Yeah. Yeah, very too much. You want to show some pictures?

Dr. Juza (00:24:42):
Yeah. So we were just asking about, so let me click down here. I'm going to move this. This is

Dr. Towfigh (00:24:46):
Very exciting because we usually don't do this on herniatack lab. You may be setting a precedent. I don't want my guests to feel obliged they haven't do any work because I'm already taking up a full hour of your time. You could be with your family, but I do appreciate this extra effort.

Dr. Juza (00:25:03):
Yeah, no, it's my pleasure. This is just from a paper that we had written. And so to go back to what do we look at for around the bowel for characteristics, I'm going to blow this up here a little bit. Nice. The image on the left would give me concerns for a re-operation. So what we see here and the arrows are in there, but we see the abdominal wall musculature. They've got an obvious defect between the left rectus and the right rectus medial borders. But what you've got is a piece of heavyweight mesh that is in here. Was it very flat

Dr. Towfigh (00:25:38):
Actually? This is a very flat mesh.

Dr. Juza (00:25:41):
Yes.

Dr. Towfigh (00:25:42):
You can say some positive stuff about it. In fact, did the radiologist say there's mesh in here? It's hard to say that there's actual mesh unless you knew there was going to be mesh there.

Dr. Juza (00:25:52):
If you didn't know either through the operative report or typically radiologists, I haven't had many call mesh on CT imaging, but knowing that it's in there and where it's placed, and we can see the solid line that runs through here. And I think part of the reason this gets so straight is it was placed and then it herniated. And so that any wrinkles left in that mesh probably got stretched out as it stretched with the recurrence. But what you don't see is a lot of space in between the bowel and where the mesh is. There's no fat plane here. There's a little bit of a fat plane between the bowel wall and the center of the mesh here. But then again, over here on this other side, there's almost nothing. And if we look over to the other side, a different piece of mesh, this one was a bioabsorbable mesh actually.

(00:26:43):
So you can see a solid white line. The bioabsorbable meshes are a bit thicker and heavier weight or microporous, at least phasics is what I use most frequently. And so you can see a good line in between there. But what you also see is that there's a good thick fat plane in between here. So if I've got to go back in and re-operate on this patient, even though they don't have any evidence of recurrence, if I were to have to go back in, I know that I'm going to have pretty decent fat layers between the bowel and the abdominal wall/hernia repair that taking those apart are going to be much, much easier. I'm not going to be spending as much time chipping the intestines off of the underlying bowel.

Dr. Towfigh (00:27:37):
That's a great picture. So just for those of you who've never seen a CAT scan before, this is a cross-sectional view. So it's like slicing you like a piece of bread. And the back part of the image, the bottom part is your back and the top part is your belly part. And then the skin is that a really light gray line. I don't know if you can see my thing, but maybe your pointer.

Dr. Juza (00:28:06):
I can't se yours, but yep, this would be the skin dermis. Yep.

Dr. Towfigh (00:28:11):
And then the dark is fat. So you have fat underneath the skin and you also have fat around your intestines on the inside. So you want to see mesh with a little bit of fat between it and major organs. Correct. Because that implies that the mesh is not stuck to the organ. It's more stuck to fat than an organ. The problem with CAT scan is everything else is just gray. There's very little difference in the different grays. So the muscle is gray, the bowels are gray, the mesh is gray. And gray on gray doesn't show you a lot of definition. So it's helpful when there's the darker gray, which is the fat, to differentiate between different structures. But as you can see here, you can barely even see the mesh unless you know your anatomy really well or really careful to look at it because it's the same color as the overlying muscle and the bowel.

(00:29:19):
So on the left screen, the bowel's really stuck up into the mesh in many areas.

Dr. Juza (00:29:28):
Yep. And I think if I recall back to this case, this was one of my cases thinking back to it. I'm pretty sure this was a failed open retrorectus repair. And what I imagine was there was some posterior layer breakdown, probably in a delayed fashion, leaving the mesh exposed to the bowel with the retraction of that posterior layer. This side, probably not as much, but it definitely pulled away. So this

Dr. Towfigh (00:29:58):
Mesh was purposely placed a Away from the intestines.

Dr. Juza (00:30:02):
Correct.

Dr. Towfigh (00:30:02):
Layer that was preventing it from touching intestines tore maybe. No, so that actually leads to one of our questions, which is can adhesions occur in the abdominal cavity between the mesh and the intraabdominal contents, even though the mesh is placed extra abdominally or intraabdominally? Maybe talk about those two situations because before, I would say the past decade we've been more pushing the idea that maybe it's not a good idea to put mesh against the intestines, even if there is a barrier that's part of the mesh to help reduce the risk of interaction between bowel and mesh. It feels like the further away we put it from actual bowel, we think that's a better repair. But back in the day, especially with that other mesh that you were mentioned, the EPTFE, the only way we knew how to put it was put intraabdominally because we weren't as sophisticated with our laparoscopic techniques.

(00:31:11):
So do you want to talk about that? And then talk about also the question here is about pre-peritoneal mesh placement versus retrorectus and if you place the mesh between the peritoneum and the muscle or fascia, will that also potentially affect the intraabdominal contents or not?

Dr. Juza (00:31:29):
Yeah, for sure. By the way,

Dr. Towfigh (00:31:31):
Ryan, I didn't make up any of these questions. These are all audience questions.

Dr. Juza (00:31:36):
That's great.

Dr. Towfigh (00:31:37):
So just the sophistication of this audience is amazing. Go ahead.

Dr. Juza (00:31:41):
Yeah, it's great. Yeah, absolutely. So the discussion of where to place the mesh, whether outside of the abdominal cavity or against the underside of there, underside of the abdominal wall, that's a discussion that's currently going on in the hernia world. Some still feel that mesh in the abdomen with coated mesh is okay. That's a loaded question there. So I'm going to not get too deep into that, but it is placed both within the layers of the abdominal wall and underneath the abdominal cavity. If you place your mesh within the layers of the abdominal wall, so excluded from the abdominal cavity, you still can get adhesions to the mesh or to the areas through small tears that may develop in the posterior or that layer in between the mesh and the bowel. Also, if the patient has any patients get inflammation in certain areas or seromas hematomas, and if you get a hematoma, which is a big bruise in those areas or even a small bruise in those areas, they can also induce an inflammatory reaction interposed between the mesh and the underlying layer, and that can transfer down to the mesh underneath, or at least that's what we suspect happens.

(00:33:11):
Having gone back into cases before where the mesh is placed in between the abdominal wall layers, you will still find cases where the bowel is adherent to areas where the mesh was placed.

(00:33:26):
We also use suture to close those layers when we do it, so you can get bowel adhesions to those areas where there are sutures placed. So even placing the bowel within the layers of the abdominal wall does not preclude the development of adhesions to the layers to the inner layers of the abdominal wall. As far as a retromuscular retrectus versus a preperitoneal placement of the mesh, both are excellent places to place mesh. We a lot of times call them the privileged planes of the abdominal wall because they are well-perfused, well-integrating anti-adhesive layers of the abdominal wall. So it's a great place - Good blood place.

Dr. Towfigh (00:34:20):
Yeah.

Dr. Juza (00:34:21):
Yeah. So it's a great place if you're going to put a foreign body, a synthetic foreign body in the abdominal wall, it's a great place to place it to encourage tissue in growth and manage any of the tie trauma. It's just a great healing surface. The decision between a retromuscular or a pre-peritoneal location-free mesh for me comes down to the size of the hernia. So a pre-peroneal placement of the mesh is great. There are some limitations to it. It's hard to develop the peritoneum more than five, six centimeters out from the middle, the linealba. Once you get out past the mid-body of the rectus out towards the semilar line or beyond, peritoneum is very, very thin there and it's harder to develop that tie plane to have a durable plane or space to tuck your mesh into. So that's the first thing. Also, when you do that, the further you go lateral on one side, you have to get that far lateral on the side you start on, and that really forces you to place your ports more and more lateral.

(00:35:42):
And so that can be very challenging as well. But the other downside to a pre-perineal approach is you are limited in ways in the size of the defects that you want to repair, not just because of the size of the flap that you can create, but because once you start getting larger and larger fascial defects, then you want to start thinking about adding a release of the connective tissue or a myofascial release to permit medialization, bringing the muscles to the midline or to better allow those muscles to come to the midline without significant tension. And you only get that release of tension with a retromuscular or a myofascial release. So if I'm looking at a larger hernia, and for me it's up to about three, four centimeters with a pre-perineal repair up above that, then it gets a little bit harder to do and you're starting to put your closure on some tension.

(00:36:47):
So above that, that's when we start looking at doing a retromuscular repair and placing our mesh in that retromuscular space.

Dr. Towfigh (00:36:55):
Okay. More questions for you. Let's unshare so I can see better.

Dr. Juza (00:37:00):
Yeah.

Dr. Towfigh (00:37:01):
Okay. This is a great question because I get this question asked a lot. What happens to the mesh when you lose weight?

Dr. Juza (00:37:10):
It's still there. It's still incorporated in those tissue layers. It may be on a little less stretch, particularly if you lose a lot of visceral adiposity, fat from inside of the belly, because your mesh is placed around the outside circumference of the abdominal cavity against the muscles. And so when you lose that intraabdominal fat, you decrease the intraabdominal circumference and so it would not be under as much stretch, but it still would sit laminar in between the layers of the abdominal wall muscles. It won't get so redundant that it starts to ball up because it's part of the muscles.

Dr. Towfigh (00:37:51):
Yeah, so it should not ball up, but you may just see more waviness maybe? I mean you would need a lot of abdominal wall weight loss to see more of a wavy.

Dr. Juza (00:38:01):
Yeah, I think you'd have to see pretty significant. And I think because we limit a lot of these operations, we optimize patients ahead of time. You'd be talking about a pretty substantial weight loss. So I haven't seen any patients with significant weight loss come back in with mesh, redundant mesh

Dr. Towfigh (00:38:21):
Weight loss. I agree. It's pretty interesting how your body just protects that area.

Dr. Juza (00:38:27):
I

Dr. Towfigh (00:38:27):
Would also say some people get tummy tuck, so by definition you're shifting the muscle, but you're not shifting the mesh. And even those patients do just fine. They don't get a mesh oma from a tummy tuck.

Dr. Juza (00:38:40):
Yep. Yeah. I guess if you had more folks with a lamina or a very dense heavyweight piece of mesh, that may be less accommodating, but I haven't seen that.

Dr. Towfigh (00:38:56):
How common is it for the peritoneum to tear to allow these adhesions that you were talking about to form?

Dr. Juza (00:39:03):
Small tears would be fairly common. Major disruptions in the peritoneum would be pretty uncommon. If it happens intraoperatively while we're operating, we repair them. So uncommon.

Dr. Towfigh (00:39:22):
Yeah, a tiny...

Dr. Juza (00:39:28):
Oh, I just lost your volume there. Can you hear me okay? Oh yeah, I can't hear you.

Dr. Towfigh (00:39:52):
My hand hit the microphone.

Dr. Juza (00:39:53):
There we

Dr. Towfigh (00:39:54):
Go.

Dr. Juza (00:39:54):
Now I got you.

Dr. Towfigh (00:39:57):
Oopsie-doopsy. Can you hear me now?

Dr. Juza (00:40:01):
I got you now. Yep.

Dr. Towfigh (00:40:03):
Yeah, this microphone's too sensitive. Can all the science you're currently providing about the abdominal wall meshes also be applied to the inguinal hernia repair?

Dr. Juza (00:40:14):
So there are tissue-based repairs for the groin, but still more commonly we're doing those with mesh as well. They are by and large the same types of meshes for the groin that we use in the abdominal wall and image findings can be the same. More commonly in the groin because it's not as smooth or flat. We've got the curvature of the groin. Sometimes it's easier to pick up the appearance of the mesh around the curves of the pelvis than it is in the abdominal wall.

Dr. Towfigh (00:40:54):
Yeah. Okay. I have some more questions to ask you that were submitted ahead of time, so you may like some of these. Okay, this one's about radiation with imaging. How do you minimize their risk about radiation?

Dr. Juza (00:41:12):
Yeah, so first we'd say the two alternatives would be ultrasound or MRI. Ultrasound most commonly won't get enough outside of an inguinal hernia. Will probably be insufficient for most bigger hernias for diagnostic imaging if the surgeon requires that, but it doesn't have any radiation. An MRI doesn't have any radiation, but it's a more involved procedure. It can't be claustrophobic and they can be expensive so that would be another alternative. But I guess I would, to shorten the answer, say that the radiation from a CAT scan is much less than it used to be and is nominal in almost all cases. I forget the stats on how many CT scans you can get in a lifetime until you become at risk, but it's quite a few. So I wouldn't worry much about radiation from a quick CAT scan for imaging.

Dr. Towfigh (00:42:34):
Here's a question. Why don't they make mesh that can be easily seen on imaging or do they make mesh that is easily seen on imaging?

Dr. Juza (00:42:43):
I think most meshes are made with the intent of a durable repair and incorporation. I have seen some companies come out and make some prototypes of meshes with built-in fiducials or markers that can be more readily seen. I think we just haven't had the need hasn't been there. So the unmet need wasn't there and so the product hasn't been developed, but it would be fairly easy if you wanted to put some clips around the perimeter of the mesh and then implant it. We used to use more metal tacks with securing meshes and those are very easy to see on imaging. That's what we were talking about with x-ray at the beginning. I

Dr. Towfigh (00:43:30):
Would say if more of the general surgeons themselves who use the mesh read their own imaging, then there may be more an interest of industry to include imaging-friendly meshes. My concern is that a lot of surgeons don't read their own imaging and therefore miss and they rely on the radiologist. The radiologist, unless they have a really good working relationship with a hernia surgeon to understand what we do, what's important to us.That first image you showed, very likely a radiologist would've said no hernia. Whereas clinically that's a hernia. But technically it's not a hernia because there's no hole that anything is going through, but that's just an unstable repair. The one on the right was a perfect repair. Correct. Definitely two different outcomes, but a radiologist may call both of them no hernia recurrence.

Dr. Juza (00:44:32):
Yeah, no I agree. And back to your, a lot of surgeons won't read their own CTs. I agree, and that's something that was beaten into me and I continue to beat it into all my trainees about making sure you can read and interpret and what to look for on these. I think there is a greater amount of education that could or should be done with a hernia world. I think you and I probably do a lot more of this as opposed to a generalized general surgery practice. So because we do so much of it, we spend more time and therefore focus on it more. But I think it is important to look at and read your own CTs for that.

Dr. Towfigh (00:45:15):
Question, does Dr. Duza have images of meshoma he can share? What does a meshoma look like?

Dr. Juza (00:45:21):
Of a meshoma. Let me see if I've got a... I'm going to have to go into my stock for that one.

Dr. Towfigh (00:45:28):
While you're working, can I ask you another question?

Dr. Juza (00:45:31):
Yeah.

Dr. Towfigh (00:45:32):
What is meant by the term 3D anatomic mesh, and what are some of the advantage or disadvantages of that? And how do you personally decide to use these meshes in specific patients as opposed to a flat mesh?

Dr. Juza (00:45:46):
Yeah, so a 3D would be like the mesh that I mentioned earlier. It's a preformed contoured mesh meant to fit in a generalized or a specialized shape. So when we talk about inguinal hernias, we're talking about the pelvic bowl and the pelvis is shaped like a bowl, unlike the abdominal wall, which is shaped like a wall. It's much easier to fix a flat wall like the abdomen than to fix the pelvis that's got some curvature to it. So asking you shall receive, surgeons started saying, "I would like a mesh that better fit, better contoured to the shape of the pelvis." And so the mesh manufacturers started producing mesh that has a curvature in it so it fits along that pelvis better.

Dr. Towfigh (00:46:45):
Yeah, very true. I do like the anatomic mesh or the meshes that are a little curved in the pelvis. Abdominal wall, we don't really have, I don't know of any non-flat meshes for the abdominal wall. It's really the ones in the pelvis where you need the curvature that you can benefit from that. Yeah.

Dr. Juza (00:47:12):
There was a brief time they made those specialized parastomal meshes that had sort of a crown cone on them to feed around there, but I think those fell out of favor pretty quickly or didn't make a whole lot of a splash. Got it.

Dr. Towfigh (00:47:26):
Yeah, for sure.

Dr. Juza (00:47:30):
Rather than search through all my images and it's probably on my phone somewhere, I just went and pulled up a CT from Google. I'll share that if you like. Share this over here. Sure.

(00:47:49):
There we go. This is a meshoma. So we've got another axial CT scan here. And so here's the pelvic wings, the sacrum back here. And what we're seeing is the rectus muscles. These are the epigastrics right here. And this is a mesh plug that's been placed into an inguinal canal. And it looks like, as you mentioned earlier, everything's gray. It is gray. And so we would just look at the non-anatomic appearance of this. This wouldn't connect with any other structure in the abdominal cavity. So it's not the bowel. They did get contrast. They had the patient drink contrast. So we have the bowel lighting up with contrast. This doesn't light up, so it's not a luminal structure continuous with the bowel. And then again, going back to preoperative history, this patient we know, if they've had a plug like this, has had an open inguinal hernia repair at some point in their life and a mesh plug was placed into that canal.

(00:48:57):
And you can imagine, I mean, we talked about a lot of images where you had a flat sheet of mesh laying across against the abdominal wall muscles and that performs very well. Even if the little wrinkles in it, patients don't really notice. It's not like the mesh is poking or stabbing or causing a lot of issue. But this thing is the size of a ping pong ball placed in there. And so sometimes patients can feel that. Not always. Some patients do great. So if anybody's on here and has had a mesh plug placed, they know they've had a mesh plug, that doesn't mean that you're going to have a problem, but we do know they tend to cause more problems than a laminar, a flat sheet of mesh.

Dr. Towfigh (00:49:42):
Yeah. Well, some patients don't even know they have a plug in them. And they may tell you they had a hernia surgery and it would be incorrect to assume the type of mesh used. So when you do imaging like this, it's very helpful. This would be a disaster to go in if you weren't prepared for it because it has a lot of implications. It could be stuck to major vessels. Yo may have to convert to a different type of surgery. Getting imaging before a planned operation, especially with a redo, I think almost every redo deserves some type of imaging. This is like a ball. I've actually had, this is where it's very important to work with your radiologist as a surgeon is they call this a tumor. I've had

Dr. Juza (00:50:31):
Them call that, yep.

Dr. Towfigh (00:50:32):
Right? I've even had them biopsy it and

Dr. Juza (00:50:35):
They're like,

Dr. Towfigh (00:50:35):
"Oh yeah, there's a mesh in there."

Dr. Juza (00:50:38):
They were surprised. Yeah.

Dr. Towfigh (00:50:40):
So radiologists may or may not know all the different meshes that come out, but if you're working with a good radiologist or they care to learn from you, I highly recommend that there's always that communication because this could very well be... It could be a lot of things. Just that one picture can be a lot of things.

Dr. Juza (00:51:02):
Yeah. And I'll often do that too when time permits. If you get a CAT scan like this and then they don't call it, I try to follow up with them and point out that's what this is. This is what a mesh plug looks like on CT many years later. And that way they look for it in the future. Hopefully they recognize it.

Dr. Towfigh (00:51:29):
Yeah. A long, long time ago before you were in residency probably, we did this paper for the RSNA, the Radiologic Society of North America, where we documented all the different meshes and what they look like on imaging, what's normal and what's abnormal. And I mean, it was eye-opening for the radiologist because they don't know. So they may or may not know the different images of what a mesh looks like, and then they may or may not know what's normal versus abnormal. Is this normal? Probably is normal, but then there's some symptoms you can get from it. Or if this were a flat mesh that looks all balled up, then definitely that's abnormal. So yeah, it's very important that the surgeon themself actually looks at imaging because we get much more relevant information from it.

Dr. Juza (00:52:25):
Yeah, no, I agree. Yep.

Dr. Towfigh (00:52:28):
Question for you. Do medium weight meshes actually exist? And if so, how do you decide whether to use a lightweight, medium weight, or heavy weight mesh? And for direct hernias, when you decide between a medium or a heavy weight mesh, how do you figure in patient body type and size, hernia size and risk of pain versus occurrence in this critical decision?

Dr. Juza (00:52:57):
Yeah, that's a great question. So I guess we'll start with the patient factors, the main one being body habitus. A thinner patient and female would be more likely to place a lighter weight mesh in there. These days I use predominantly a midweight mesh because it's a good universal mesh. It can be placed down our eight millimeter ports and it is adequate for almost all cases. I'll use a heavier weight mesh if it's a larger defect or they've had multiple recurrences and I want more durable reinforcement of that inguinal canal or abdominal wall in the groin. But then also patient factors. So I had a patient who was a bodybuilder. I knew that they were going to be really using that repair and so I wanted to have pretty durable closure. I had another patient who had a large inguinoscrotal, so a hernia that's going down pretty large going down into the scrotum and I knew that their floor is going to be all blown out.

(00:54:13):
So I'll upsize or use a heavier weight mesh in those situations. Also,

Dr. Towfigh (00:54:21):
Do you want to dispel the myth of mesh weight versus chronic pain?

Dr. Juza (00:54:27):
Yeah, I mean they definitely don't go... It's not a one-to-one. A heavier weight mesh maybe felt more because it is a denser mesh. But if placed in the right location away from the nerves, a good dissection has been performed, that should contour and serve the patient very well. You don't want to make the error of say, I'm going to put a lightweight mesh in everybody. And then you run the risk of mesh fracture or mesh e-ventration, which is where the mesh just pushes back out through the defect.

Dr. Towfigh (00:55:07):
Yeah,

Dr. Juza (00:55:07):
Which

Dr. Towfigh (00:55:07):
Can all cause pain that a heavier weight mesh would not have.

Dr. Juza (00:55:11):
Correct.

Dr. Towfigh (00:55:12):
Yeah.

Dr. Juza (00:55:13):
There's a lot of factors that go into it for sure.

Dr. Towfigh (00:55:16):
There's at least one study that shows that a higher rate of chronic pain after lightweight mesh. So that seems to be because of that less stable repair that big person, thin mesh or big hernias, thin mesh usually doesn't jive. You need to match the body with the size of

Dr. Juza (00:55:39):
The

Dr. Towfigh (00:55:39):
Hernia with the quality of the mesh. It's so interesting because if you're a tailor or a clothing designer, you would never make the mistake of a silk shirt being sewn with a really heavyweight thread or a leather jacket with a really super thin thread. And it's just so interesting that surgeons don't necessarily make that logic necessarily.

(00:56:15):
And there's all these studies on chronic pain and this and that. And it's like you had a big hernia and you put a super small mesh in, or you had a big guy and you put a small or thin piece of mesh in. So what'd you think is going to happen? I feel like we've kind of lost logic sometimes. We always do the same thing on every patient and there needs to be a litle bit more though got into it same way I guess someone who makes clothing makes that correlation between the outfit and the size of the body and the quality of the material being used.

Dr. Juza (00:56:54):
Yeah. And that's hard because each surgeon is unique, but also each patient more so each patient is unique and the factors that go into what's going to lead to chronic pain or recurrence or complications, it's multifactorial. There's so many confounding and I don't know, maybe AI will be able to eventually figure out the algorithm and be able to spit out in real time for you. Because we're talking about mesh weights, we're not talking about mesh sizes either because they come in a medium, a large and an extra large. And so this person gets an extra large heavyweight and this person gets a medium lightweight and any combination of those. So when you throw all those factors in it's tough and you're right, but I think a lot of people go with what's familiar and comfortable because once you have success with a product repeatedly, then you're less inclined to step away from it, but it's good to reassess.

Dr. Towfigh (00:58:04):
You mentioned phasics mesh and how it can look maybe thicker on imaging. Can you see absorbable or biologic mesh on imaging?

Dr. Juza (00:58:13):
You can, and it tends to behave a little bit more like a laminar, particularly the biologics in that it's a flat continuous sheath. The lines can be pretty visible on imaging. They both break down over time. Even the biologics will break down over time, and so they'll be less visible at that point. But to take phasics, which is intended to break down over about two years, usually you can still see the remaining scar tissue and the scar tissue shows up as I said earlier about an non-anatomic configuration of the tissue. Some of the rigidity or stiffness, waviness can be retained in those tissue structures. We might have to see in 20 years whether that's still true or not.

Dr. Towfigh (00:59:18):
What's your prediction?

Dr. Juza (00:59:21):
I think imaging and everything else will advance as much as that. And so I think we'll still be able to find some. They'll have some way of marking, identifying different instead of things all being gray, it'll be better refined to pick up different levels, how we do Hounsfield's units on different things to be able to on a smaller scale pick that up. So I think it'll continue to advance and show us better imaging.

Dr. Towfigh (00:59:53):
I think we'll probably be so advanced that we can just virtually travel through the tissue planes, you know? Ah, right here it's folded or this is where it's stuck to the abdominal wall. Right now we get slices, right?

Dr. Juza (01:00:09):
Right.

Dr. Towfigh (01:00:10):
We do have the ability to see it in 3D. It just takes longer time and probably costs. And so for most imaging, we don't get a three-dimensional reconstruction, but I'm sure it'll be so advanced that we can virtually travel through. I don't know.

Dr. Juza (01:00:26):
Yeah, that'll be commonplace.

Dr. Towfigh (01:00:28):
And they'll be like, "Really? You were doing it. You were going slide by slide by slide and in your mind recreating this? That is so backwards."

Dr. Juza (01:00:38):
Yeah, right. Well, 20 years ago that you were probably putting the individual slides up on the bot.

Dr. Towfigh (01:00:44):
I mean, that was your job as the intern. Find the imaging first and then line them all up, make sure it's well presented.

Dr. Juza (01:00:54):
And now you just scroll it on your phone.

Dr. Towfigh (01:00:56):
Yeah, this is true. All right. We had one more question, but we have run out of time. Can you believe it? Oh,

Dr. Juza (01:01:03):
Okay.

Dr. Towfigh (01:01:04):
Very, very good. Okay, I'm going to share a screen now because that went fast, didn't it?

Dr. Juza (01:01:10):
It did, yes.

Dr. Towfigh (01:01:11):
Yes. Always goes fast. I always learn a lot and I enjoy having my colleagues on. I get to see you in Denver soon for the American Hernia Society. Will you be there?

Dr. Juza (01:01:22):
Yep, we'll see you there. Yep.

Dr. Towfigh (01:01:24):
Fantastic. And we'll talk a little bit more about all of these things. Thanks to everyone for joining us. Don't forget, this episode and all prior episodes are all on YouTube or on, I think they're also as a podcast. Yeah, so you can listen to it as a podcast while you're driving around, try to learn more about hernias. Thank you to Dr. Juza. He is at the University of Wisconsin Department of Surgery. Very, very talented surgeons in that department and I'm very happy for you to be here as my guest. Don't forget to like, share, follow, do all that good stuff, and I'll see you again next week, hopefully. Thanks everyone.

Dr. Juza (01:02:07):
Thanks.