• 1. Einleitung
  • 2. Chirurgischer Ansatz
  • 3. Einschnitt
  • 4. Exposure of External Oblique
  • 5. Mobilization of External Oblique
  • 6. Inguinal Dissection and Identification and Preservation of Nerves
  • 7. Skeletonize Cord Structure and Look for the Indirect Hernia Sac / Peritoneum
  • 8. Skeletonize Hernia Sac and Examine Internal Inguinal Ring and Peritoneum
  • 9. Division of Cremaster Muscle Fibers with Genital Branch of Genitofemoral Nerve
  • 10. Divide Floor of Inguinal Canal
  • 11. Four-Layer Shouldice Repair
  • 12. Schließung
  • 13. Bemerkungen nach dem Op
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Shouldice Repair for Left Direct Inguinal Hernia

Divyansh Agarwal, MD1; Lauren Ott, PA-C2,3,4; Michael Reinhorn, MD, FACS2,3,4
1Massachusetts General Hospital
2Mass General Brigham - Newton-Wellesley Hospital
3Boston Hernia and Pilonidal Center
4Tufts University School of Medicine



Hi, I'm Dr. Michael Reinhorn, everyone calls me Micki. I'm a private practice surgeon working at Boston Hernia and Pilonidal Center. We're a private practice of two surgeons and two PAs. We are an academic affiliate and work within the Mass General Brigham Newton-Wellesley Hospital. We have mass general residents, MCPHS, PA students, and Tufts medical students. I'm going to be talking about the Shouldice repair, it's a no mesh inguinal hernia repair that I traveled to Canada to observe. I watched six of these repairs at Toronto, they all did them exactly the same way. And it's a highly reproducible repair when taught and done appropriately. The key steps of the repair, really about very similar to a Lichtenstein repair, where you get into the lower groin. But the external oblique is mobilized a lot more. There's a meticulous dissection of the cord, the nerve anatomy. Once that's performed, the transversalis fascia is opened looking for femoral hernias. And then a four-layer repair is performed with a monofilament material, either proline or stainless steel, if available in some institutions. The closure of the Shouldice we do with dissolvable sutures very much in the same way that most inguinal hernias are closed with external oblique and Scarpa's with a Vicryl sutures and either Monocryl or Vicryl for the skin.


So you got pubic tubercle, ASIS. So at the Shouldice Hospital, they make an incision that is the entire length here. What I have done, just because I do a lot of inguinal hernias, is I start at the tubercle, but I won't go quite as high because I don't feel like you need to as lateral. And then I try to make the line a little bit more in terms of the lines of the skin rather than this incision, just doesn't look cosmetically as good.

I'll take the mix. I'll use 20 cc of the mix to start. We can shut that. Oh perfect. So I use a combo of 0.25% Marcaine and lidocaine for most of this. I'll do it all ahead of time. When I was at Shouldice, they used a really, really high volume of the solution in the area and they do it with a lot less sedation on most patients, but he's sedated. He's pretty comfortably numb, I think. Some patients talk a little bit through, but I prefer them that they're not involved in a case. I find it distracting if the patient talks to me. So we'll give a lot upfront. This repair hurts a lot more than a posterior approach, which we usually do open unless they're obese and then they get a lap. And then I'll take the straight lidocaine. So for ilioinguinal nerve block, because it's blind, I'll go about one fingerbreadth lateral to the - or medial to the anterior superior iliac spine, come off the bone and inject here. I use 1% lidocaine because if you get this in the wrong plane, it will diffuse down and you can get a femoral nerve block. And if you're using lidocaine, it'll only last as long as the case, and then they can walk out here. If you use bupivacaine, we would get a femoral nerve block, and then the leg goes weak.


So, this part of the dissection is pretty standard. Slight differences from when I watched at Shouldice is they did everything without cautery. Cautery has an expense to it. 25, 30 bucks in Canada. So they only use cautery when they need it. And - they tied off all the vessels. I think the couple minutes less in OR time and efficiency is probably worth that $20, and so we'll do that.


Now - Once we get a little deeper, it's nicer to have the headlight to see in there, and I'll usually buzz anything crossing. If there's a small crossing vein, we'll buzz it. So here's our Scarpa's. I just cut right through it with cautery. You see a small little opening in Scarpa's. And then I'll bluntly get down to external. So if we come through Scarpa's, that lands us right on external oblique. All right, we'll take the wider retractors now. Now... Thank you. Big first, big difference. Those are a little big. I'll take the local mix.

Do you want smaller ones? I mean, I think these are the... It's fine, these are good. Felt bigger than what we've used. So again, lots of local, every step. This repair just hurts because you're suturing native tissues. You know, I think a lot of the reason mesh came about is because people thought it hurts less and lower recurrence rate. I don't think the recurrence rate has actually materialized to be that big a difference, but it certainly hurts a lot less when you use mesh. Metz.


All right, first key difference compared to a Lichtenstein. You take the external oblique and you mobilize the heck out of it, because we're going to use a lot of it for the repair. And so, we're going to mobilize a lot of this external oblique, and you can see, I'm going to sweep a little bit bluntly, get this retractor down. And, his external's a little weakened here. So, there are times where we don't have good external and we end up having to bail and doing a mesh repair. But that's why it's so important to mobilize a lot of the external oblique. And so you can see, compared to what you normally would've done, we've freed up probably about 3 cm, at least 2 cm of external oblique that we'll be able to use in the repair that we wouldn't otherwise I am on the iliac vessels here or femoral vessels, at this point. I need to go a little bit more medially with this dissection. You can see, there's a lot more external. We were pretty lateral. So I think this part is certainly a little bit more extensive than what you've done with a Lichtenstein, but you use all of this for the repair.


So now that we've done that, we're going to go about 5 cm away from the bottom - 15 blade - and I've already anesthetized this. And we'll start doing an inguinal dissection, similar to what you've seen before. And I carry this all the way down to that external ring. You immediately start seeing the nerves here, which is nice. One of the things I loved about Shouldice is they identified the nerves. I watched six inguinal hernias, and they almost, every time identified three nerves. So, iliohypogastric nerve is always medial, always runs from internal oblique fibers, along the rectus sheath, and then if you follow it long enough, we'll be able to watch it perforate the external oblique. So you see it coming up through the external oblique there? Mm hmm. We might be able to leave it in situ, we might need to mobilize it a little bit more. You can see there's a hernia here already. I'm going to open that external a little bit more. Metz. So - I think most people say, "Try to leave the nerves in situ, if you can." The reality is you can't always do that. So I do a lot of blunt dissection to define the anatomy. Snap. We'll just hold this external oblique leaflet up, and I'll sweep the cord a little bit more. And then we can get this retractor right back in. Get this retractor underneath it, perfect. So, as I look at the iliohypogastric, we're going to be putting stitches here in the internal oblique. So this iliohypogastric is going to get stitched if we don't move it. And so, I will mobilize it - Metz. So I don't grab it. I grab the loose tissues around it. And, we will do a neurectomy if we need to. I think I'm going to have to mobilize this nerve a little bit more off the internal oblique musculature. So, I continue to learn anatomy as I do this. I feel like I always learn hernia anatomy, but we now have beautiful rectus, internal oblique, and I think it's really important to name the actual tissues as they are. So people call this the conjoint tendon, but this is really rectus and this is really internal oblique. They're not joined together in any way. All right? So now ilioinguinal nerve, which is the nerve we more typically see. It typically comes from the internal obliques - I thought I saw it earlier - and will run along the cord. Is that it, Lauren? It looks, yeah, I thought I saw it down there too. Here, you grab here, and I'll take that one. I thought I saw ilioinguinal. Not clear. Am I holding it? It may be here with some of the cremaster fibers. He does not have really strong cremaster muscle here. You see how it's very attenuated?


So, I am going to divide the cremaster muscles, leaving some medially, but some laterally. The lateral fibers we're going to use as part of our repair to create a new internal ring. So, I'll take that. So I'm going to sweep these cremaster fibers laterally. And if I misspeak, you guys can ask a question, did I mean laterally or medially. But I'm going to sweep these fibers laterally, and we're going to be right on our cord. So, this looks to me like a hernia. The question is what kind of hernia it is? As I sweep tissues out, I'm only seeing fat. So let's get our cord out. I think it's just a big direct hernia, probably, is what we have. So if that's the case, then we should be able to easily encircle the cord with a Penrose. But, we've got cream master muscle fibers here. If we look here, look down below, here's our cord. So I'm going to take our cremaster muscles, and let's get a Kelly. And then a penrose that you just asked for. All right, so here's our cord. Here's our vas deferens, here are our vessels. So he's got a nice, really, really small thin cord. If you hold that.


Let's take a look for an indirect component. So we'll take a look here, and there's a little bit of preperitoneal sac - or preperitoneal fat, not sac. We'll dissect this down until we see peritoneum. So when I do a hernia dissection, I always say we're going to skeletonize the "sac," not the "cord." Because you essentially are doing the same thing, but you're not damaging cord this way and making it avascular. This is a pretty wimpy indirect component, which is both good and bad. It would've been nice to demonstrate an indirect hernia, but we did that when we filmed the open preperitoneal repair and dissection, very similar to a pediatric hernia repair. If you feel through, there is actually - the internal ring is tight. I can't get a finger through it. All right? So that's a good sign. I did not see peritoneum. Maybe down there? Is that peritoneal edge? That's peritoneal edge down there, you see the little rolled over white? So this is peritoneum, peritoneal edge. That's deep in the retroperitoneum. We don't need to go there.


Now in order to deal with a direct inguinal hernia, all this cremaster muscle fiber has to go. Now, the interesting part is, here's his genital branch of his genitofemoral nerve. How many times have you seen that? A couple of times. Okay, and so the issue is, is if you don't pull this up or ligate it, you can easily stitch it. And so - Kelly. And it will perforate the floor. It'll come through the retroperitoneum and it'll perforate the floor, together often times with the cremaster vessels. Here's inferior epigastric vessels, I'm pulling them up, and there's a branch of cremaster vessels coming up through the floor. We're going to ligate this. We take it en masse, and so that the nerve will reinnervate into the internal oblique when we create a new internal ring.

And in his case, his internal ring is fine, but we're still going to tighten it up. And I'll give a local before a neurectomy.

Generally, if we ever do a neurectomy, we want to make sure that the muscle fibers get buried in - or the nerve gets buried in muscle fibers. And that way you're less likely to have a neuroma or any problems. So now we may have taken both ilioinguinal and genital branch within this. But this, at Shouldice, they call a scarf. It wraps around the cord to create a new internal ring. I'll double ligate this because it's vascular. I tell the patients that they're going to have an area of numbness anywhere from two fingers wide to a hand width wide that may last for a couple of years after surgery. I think it's really important to counsel the patients accordingly. What I learned after counseling patients for a lot, and you can see, he probably felt that a little bit. So I might give a little bit more local and my knot is not perfect here. I'll take a little bit more of the mix. And cut the needle, actually I'll use it for the other side. So what I learned over time as we did more of these is that patients don't really worry, do you have that mix? Yep.

They don't really complain about numbness. They know it's there.

Most patients who have any type of surgery have a numb area where they were cut. But a lot of patients will complain about, cut it long, cut it about an inch and a half long. Because we'll stitch that later. And then we'll stitch the other side just to reduce bleeding. Cut that off, needle. So a slight variation on this from what was described - do you have a DeBakey? Where this got stuck on something. Let's see. I think the key to perfect surgeries, know that as surgeons, we’re not perfect and that we make little technical mistakes at every case and to identify them and correct them. And then at the end, you'll have a perfect operation, but you're not perfect along the way. But one variation is at Shouldice, they will tie this and suture this to the external on the way out. And I have had a bunch of patients early on complain that their testicle is higher and doesn't move as much. And so I leave some of that lateral cremaster, okay.


So, let's open up the floor. So now that we've got a clean floor, here's our epigastric vessels, you can see the color, and you've got a big direct hernia here. So, just going to clear off all these tissues, loose areolar tissue, so that we've cleared off the hernia. Okay. All right. So we've got a complete blow out of the floor, right? Take some Metz. Now Lauren, will you hold the sac out of the way a little bit just so I can cut the floor better. So, what I think is a really important move here is that you open up transversalis fascia and there's the aponeurosis of the transversus abdominis in here as well, and this gets you, they only look like one layer here. And I open this as far medially as I can get. And that gets you into the retroperitoneum. You do that, and then we'll probably excise all this transversalis fascia because it'll just interfere with our ability to close this. You have a moist sponge?

I'm going to have you help me here. So we'll take a moist sponge to push this out of the way so I can cut some of that redundant transversalis fascia. A lot of people call it the hernia sac. If one of you guys hold that, this one here. So this is redun- This is stretched out transversalis fascia. If you do this laparoscopically, people call this the pseudosac. If you do it open, people call it a sac, but it's not really a sac, it's just attenuated. I'll take this now.

So it just makes it easier to do the rest of the operation. If we look down here, I'm going to get into the retroperitoneum. This white is Cooper's ligament. And we'll look and make sure that there's no femoral hernia. And there really is no femoral hernia here, I'll feel. You can feel that there's no divot in the canal, it's solid. We see Cooper's ligament. So there's no femoral hernia, so I think a key difference between Shouldice and Lichtenstein is that you do look for the third defect, which is femoral. And I think the literature says there's about a 3% incidence of femoral hernias. And now we'll lift up into retroperitoneum. We have a little bleeding right here by the rectus, but there's the lateral edge of the rectus, okay. So we'll use that as our .4 closure. I need to get this off a little bit better off the peritoneum, just buzz me. So when you do a laparoscopic or a posterior repair, you get seromas because that fluid will get trapped underneath transversalis fascia, the stretched out component, okay.


All right. So we'll take the prolene, 0. All right. So here we have rectus abdominis. Here we have the edge of transversalis fascia that we cut. And way over here, we have the inguinal ligament, external oblique, Poupart's ligament, shelving edge, it's all one structure, right? So we're going to do the first layer of the Shouldice. Can we have the bed down a tiny bit? Sure. Is we're going to get this rectus, lateral edge, good, good. A little too low. A bit too far? A tiny bit too far. We're going to get transversalis fascia. Yeah, that's great. Thank you. And then for the first bite, I'm going to anchor it to the inguinal ligament just so I have something sturdy that my knot is into. You have a DeBakey? Oh, I have it here. I just looped my locked knot. The first loop's trying to connect the rectus to...? So the first layer, yeah, well, not really, actually. This is the first stitch just to hold things together. The goal of the first layer is to close our floor so that we can get the sponge out and we can do a nice, meticulous repair. It is not a strength part of the closure. But you'll see how we're basically recreating the floor. Now transversalis fascia, theoretically, is the strength layer of the abdominal wall, but his has failed, right? So to just use transversalis fascia for the repair doesn't make a lot of sense. So if we go on the underbelly of the rectus, lateral edge, and then I go to transversalis fascia, I'm going to create a new floor. Not making it look very pretty here. Here, let me get this retractor. This is partly, yup. There. So again, here's the lateral edge, underside of the rectus. After this will be... Transversalis fascia. Not the strongest tissues in the world. One more probably before we have to take that sponge out. I can slide this back, thank you. And, probably still need something in there. If you hold that, I'll take a DeBakey back. Thank you. So again, underside of the rectus clearly visualized. Transversalis fascia, clearly visualized, right? You want to dissect and speak in clear anatomic terms with this repair, with any time you're doing an inguinal hernia, I think you get better outcomes. If you take your instrument out for a minute, we'll see what is left for. So we have our cremaster bundle, then we'll suture the internal oblique. I'm going to drop my needle down and reposition your retractor so that we can really see here.

I'm going to feel through, feel here, there's a one-finger defect. And when I take this stitch, now, this is sort of a transition stitch that we're going to grab internal oblique muscle. We're going to bring this cremaster bundle down, underneath it to create a new internal ring. And then so that it has some strength, we're going to grab the inguinal ligament or external oblique.

And then we're going to double check our work here and make sure that it's not too tight. So can an instrument pass through? Not easily. So I may have done it too tightly. So a finger definitely doesn't go through, but I also think my instrument's not going through, so we'll just kind of loosen this up and say, "Will this go through here?" And it does, okay. So the cord is not ischemic, it's not too tight. And that's a little bit, you have to, at least in my experience, you have to eyeball it. There's no way to actually measure it other than you put the stitch in, and based on experience, you feel like you did it right.

So now we're going to get some internal oblique muscle. This is the first, there's a meatier bite, and then I'm going to get external oblique fascia. So this is sort of the first of the two money layers of the procedure. Here, we're at the junction between internal oblique and rectus. So I'll get a little bit of rectus sheath, a little bit of internal oblique, and external. The key is not to have the external fold over onto itself, because you can make a false edge. So this is where your assistant on the other side can tell you if you're doing this right or not. All right, so now we're just at rectus to external. We're no longer just on internal. Any questions? It's nice anatomy, right? The only nerve we didn't clearly see, and I think we either had out of harm's way or ligate it, was the ilioinguinal nerve, the nerve that you most typically see. I was trying to get this in one bite and probably should have just done it in two. Now, going medially, you want to make sure you overlap on the tubercle, so I'm going to grab rectus, I'm going to get external, and I'm going to bring this stitch over. I think one of the, I have not seen this, I have had one recurrence that I'm aware of in a gentleman where he had a BMI of 32, a couple years after I did his surgery and our cutoff is about 26, is he had gained some weight, and it was a medial recurrence that needed a laparoscopic repair to fix. But I think one of the rookie mistakes that I hear is that you don't go medially enough and you end up with medial recurrences with this. So I really, especially on a direct hernia here, I'm going to pay really close attention and make sure, here's our tubercle and we're overlapped on it. I'll even do one more. And then here's our iliohypogastric nerve. I'm close to it, but we're, we're going to avoid it. And then, because we've overshot our first stitch, I'll do one more here. So again, rectus sheath to external oblique, and we'll tie our knot. So, you would think that this is enough and a lot of surgeons will do what's called the two-layer Shouldice, which is just this. What analogy that I've heard at Shouldice, and this makes sense from the engineering perspective is each layer that you do here takes some of the tension off. So if you do four layers, each layer's going to have a quarter of the tension rather than two that'll have half. The other one is that when you have a back and forth suture, you're creating an architecture a little bit like a Chinese finger trap where there's a movement. And so if one side flexes, the other side can relax. And so we're going to do this again two more times. Here's our iliohypogastric nerve out of harm's way.

Would you ever try to intentionally ligate the iliohypogastric? So we wouldn't ligate it. If I was doing a neurectomy, I'll demonstrate, I would be grabbing, lifting it up. I would, you can see how it's coming in here between the fibers of the obliques? I would lift it up, give local, and then just cut it flush with the internal obliques as I'm pulling it up, so it retracts into the internal obliques and innervates the internal obliques, so any of the sensory component comes from the muscle rather than a possible neuroma. That's how I was taught to do neurectomies. It's not common that we leave the nerves completely alone, because invariably one will get in the way. And, you know, having a really good assistant that knows this procedure, for me, keeps me out of harm's way, because like I said, I'll make a mistake here and there, and having someone to double check my work is important. That's how you end up with a perfect result in the end. We're all human, so to expect ourselves to not make any mistakes is shortsighted. And Lauren and I have done about over 500 of these together. So again, internal oblique now we're about to hit rectus. You see how the iliohypogastric really wants to slide in there. I've stitched that before in a closure, and the patient woke up in recovery with horrible pain. And now it's rectus to external oblique. And again, rectus sheath to external obliques. These are really strong fascial layers here. All right, so another difference between Shouldice, they'll use a stainless steel suture. Here, they'll take a reel, cut it and thread it and then sterilize it at their back table. You know, the thinking is is the benefit of stainless steel is just not that much compared to a monofilament in terms of how the tissues slide. And so, I haven't gone to the lengths of cutting my own stainless steel wire and threading it. It's also harder to use and this is so readily available. You coming back? Yeah.

And then the last layer is a little bit of just extra coverage. So you grab that rectus and then you grab more external and kind of bring it over. It's not for strength, but it just reinforces the repair. Gives it more external oblique coverage. So my bites are a little further apart. I keep having to push that nerve out of the way. And probably one more. So this is external to rectus or rectus to external. That nerve again, really wants to be part of the action. So that was a four-layer Shouldice. So anyway, so we don't use stainless steel. I do send the patients home the same day instead of keeping them overnight. In order to do that, we put dissolvable sutures at the skin. We have, over the last two years, we're somewhere between 89 and 91% of our patients who have this repair only used Tylenol and Motrin. The key to that is just counseling. Tell them to expect pain for the first five days.


And then here's external, so we'll close this over the cord. We'll put the cord back in the way, in its place, get rid of the snap on the external. Let's get the cord back to where it belongs. So now we've got external oblique that we've mobilized, and here's our edge of external. We used a lot of our external, so we'll use this to, so this becomes our new external ring. Not a lot of space because we use so much of it for the repair, but that's why that mobilization is important. We'll take a 3-0 Vicryl on an SH. Please.

And try not to injure any of the vessels, so external, and external, you can see how much of that external we've used. Despite all that extra mobilization, I barely have enough space to close, and I'm not going to retack that cremaster fibers because I left enough medially. So he'll have some cremaster reflex, and we don't want him to feel like that testicle is high riding. So cutting that cremaster muscle fiber seems like a drastic maneuver. Dr. Shouldice studied that in the '60s, and the recurrence rate went from 4% to 2% when he did that. And then he stopped doing it, and recurrence rate doubled again. And so I think that move helps to really create a nice tight internal ring. It helps you see the floor, the canal, so much better, like you saw transversalis fascia clearly with nothing on it. So, I think that move is really important. It does give numbness. I don't think you need to keep these patients overnight in the hospital or the facility, they all go home. We've sent 500 of them home the same day. But there's the cost of that is a dissolvable suture instead of skin clips. Let me just take a look down here for a second, it looked a tiny bit oozy. Just make sure. He has that other retractor. Yeah. Good.

And then Scarpa's we'll close with 3-0, and then Adson, and then Lauren will just close the skin with - are you using Monocryl? Yeah. With Monocryl. So, we tell them no absolute restrictions, but I tell them not to go work out at a gym for a month, not to lift heavy weights. The reality is, the sutures of the repair is what holds a repair together. And so, theoretically, they can do more, but if they do more, you get more swelling, more inflammation, higher risk of wound issues. I've seen a wound infection for a guy that went back to work in a hospital three days postop. So you know, it's still hernia surgery. Needle down on your Mayo, it's unprotected. Thank you. So, that's the restriction on activity. I'll move over and you want to finish? I'd love to, sure. In terms of postop, and then the skin is just a subcuticular closure. There's nothing terribly unique about what we're doing here. So, Tylenol and Motrin every six hours together around the clock for the first three to five days. We only send a prescription if they ask for it. I've done a Shouldice on his other side, he didn't use any. So, I don't do double Shouldices at the same time. It is too painful. I've done it a couple of times five years ago and I've learned the hard way, it's not always in the patient's best interest. They may think it's convenient, but they're pretty debilitated for the first two to four weeks. And then patient selection is really key. You want someone where you can see this anatomy every time. So we see this anatomy every time, I did not see the ilioinguinal nerve well, I think we got it out of the way with the cord, but, he's thin enough that we can see the obliques, we can see transversalis. Once their BMI is over 26, they have enough adipose tissue that the muscles are marbleized. Almost like they're just fat between the muscles, so you're not getting as good tissues when you're closing them up. So we try to avoid on operating on patients who are overweight, not just obese. They just get mesh. And then the patients have to have good healthy tissues. So if they're older and their tissues are super stretched out, that's not good collagen and elastin combination. Like he developed a direct inguinal hernia. Why a direct on this side, indirect on the other side? There's something about his elastin-collagen mix, right? His tissues were strong and I think this will be a solid repair, but not every patient's a good candidate for it. So, any questions? It's kind of cool, right? It's… It's fun. Anything else Lauren, that we do differently from Shouldice? Not really. So just the polypro suture, dissolvable suture so they go home. You know, I watched six of these at Shouldice and I've had one of their surgeons watch over my shoulder here at this hospital just to get feedback. I feel like feedback is really important when you're learning something new. I had done 3000 inguinal hernias before I started doing these, so my anatomy knowledge was better than average, but there's still so much more to learn.


So that was a nice example of a direct inguinal hernia. In some ways, it's better to show off a direct hernia because you have to do the indirect and femoral dissection anyway, and a direct really shows how the tissues get in the way, so this was a really good example of how to push the tissues that are herniating through the direct space out with a sponge and really get a nice retroperitoneal dissection done. The repair was exactly what I expected. The only difference was that typically, we easily see the ilioinguinal nerve sitting on top of the cord and get it out of the way. In this particular case, we did not easily see it. And so we grabbed it in a bundle with the cremaster muscles and potentially with the genital branch of the genitofemoral nerve. We did see a much larger genital branch of the genitofemoral nerve than we typically see. So the nerve anatomy is always variable on these cases and you have to know where to look for the three nerves. There are some variations where the iliohypogastric and ilioinguinal nerves are together, or there's maybe only one of the two, but we typically try to identify all three nerves so that we don't trap one by accident. So those big differences from the normal repair that we would do, and I would say, 97% of the time, the nerve anatomy is identical, the muscular anatomy is identical, and the tissues are pretty straightforward to dissect.