Um, I, I guess the, the one thing that I was surprised by is the number of cases that, uh, they've done an exit procedure with, uh, with a lobectomy at the time of exit procedure because we've. Not had a case where we thought that was necessary. Well, uh, everyone realizes you don't have much volume in Toronto, Jack, so I'm not sure that's legitimate, but, uh, you know, certainly, uh, you could argue that we have overused the exit with, uh, CAMs. There's no question that some of them definitely required it and benefited from it. You can also, uh, say that in some cases you can squeak kids through with some risk of mishap, uh, by not doing an exit procedure, um. As I said, I think we've gotten more selective as time has gone by, and we really reserve it for, you know, the average CVR on them has been over 2, which is those are big lesions, and we reserve it particularly for cases where there's evidence of compression. So you have diaphragmatic aversion, marked mediastinal shift, often ascites and other issues. Sometimes the kids are a little premature. So for a variety of reasons, you want a nice controlled. You know, resection without the need for any kind of emergent ventilation and potential for hypoxemia. So, um, you can argue that we overuse it. I, I think for the most part it's been, we do get very severe cases of CHP, and I think it's been justified. OK. When do you do the ECMO? Was that during the exit procedure or are those for patients, uh. No, Required ECMO during. We haven't used exit to ECMO. We always give them a test of, uh, conventional ventilation because it's very rare to need ECM in, uh, CCA patients. Um, very rare. JM. Jake, I was going to say you have to remember they're in the states and everything is bigger, including the sea cans. That's right. I can imagine what it's like in Texas. That's right. I think what Alan says is true when you look at the number of patients that required ECMO. I mean, I think they're getting referred complex cases from all over and all the simple cases are staying where they are. So their view, their percentage of exit and percentage of fetal surgery, I think is skewed. It does not represent the true natural history of these congenital lung lesions. Alan, we have a question from, uh, did, did you want to respond to, to Jean-Martin? No, I, I agree with him, OK. Um, we have a question from, uh, Ravindra Ramadwar. Uh, he says, what is the incidence of subsequent conception after fetal surgery? That's been studied about, uh, 4 times now and, and published, and, uh, basically, uh, there's no clear reduction in the ability to have subsequent pregnancy after fetal surgery. The difference is you're not allowed to labor after you have the incision that's performed with fetal surgery. So, it's equivalent to a classical cesarean section in the upper part of the uterus. And those patients should never, uh, labor with future pregnancies. But we've had very little in the way of any long term, uh, maternal morbidity aside from the requirement for cesarean delivery. And, uh, overall, we've had, uh, none of the really feared complications like uh placenta accreta uh at the hysterotomy site. Uh, those kinds of things that you might anticipate occurring haven't been uh observed thus far, fortunately. Any questions from you, Steve, at all, or John, John, do you mean well, I, my question was about the exit procedure. You know, at Akron Children's we're certainly nowhere near the level you are at CHOP, and we've never done an exit procedure. What would be your thoughts on, uh, a, a pediatric hospital that's busy? Starting up a, a program like the exit procedure, what, what, do you have any, any discussion. Well, I mean, the exit procedure, uh, is different. And it, it's not a cesarean section. It requires an anesthetic team that's very tuned into the issues required for uterine relaxation and the maternal issues. It requires, uh, uh, expertise with the hysterotomy and, uh, so, it's a whole team of people that do it. It's certainly something that I think, uh, uh, a, Qualified team can learn and be trained in, uh, come observe a few or whatever, um, uh, without having to have a fetal surgery program. So, I think it's something that's, uh, can be more widely disseminated than fetal surgery can. Uh, but it's a very valuable, uh, part of, you know, what we do as pediatric surgeons. We do a lot of cervical teratomas, uh, airway, uh, obstructive problems. So, we've done, uh, close to 100 exits now at CHOP in the past 10 years or so, and that's, um, you know, again, we have an unusual referral volume, but I think, uh, most hospitals experience kids from time to time that would benefit from an exit. Most large children's hospitals. So, I think the key is, I mean, we perform exit procedures, but the key is that you have to have the maternal expertise. Um-hum. At your hospital. And so, I think to bring a, a mother into a freestanding children's hospital that doesn't have the maternal expertise is probably a bad idea because you have to, you have to protect, first and foremost, you have to protect the mother. And so. Yeah, that's absolutely right. So, I, I think in most places you would need a children's hospital in association with a maternal center. A few places have them together, um, but if you have the, you know, if you have all of the components to do an exit, there's no reason why you can't. Learn to do an exit procedure. How many places in the US or around the world perform exit procedures? Is it? I really, I don't know the answer to that because some people. Call it a glorified cesarean and exit procedure. Um, I don't know how many do it right. There are probably 4 or 5 in the US that OK. You know, clearly have the qualifications and, uh, the background to do, Good exit procedures. You know, uh, the limitation is, is having a freestanding children's hospital, uh, is, you know, without the maternal fetal delivery. Well, even if you have, if you have, you know, for many years a job before we, we developed an in-house fetal center, uh, we went over to University of Pennsylvania or we brought the mothers back and forth, uh, to do the fetal surgery, so. Uh, if you have a, an adjacent connected, uh, obstetric center, then, uh, it can be done. Yeah. But it's, it, I mean, it, you shouldn't underestimate, it's, I mean, Alan's so good at it that in their centers so good, but I mean, it's a, we did one a few weeks ago and it's a huge undertaking. I mean there is weeks and weeks of planning to go in. Discussions of the entire team. There's, you know, in our center, there's 15 to 20 people who are involved. It's a, you know, there's all sorts of things that go on. And so, I think it's not something to undertake. Yeah. Lightly, but it, it can be done very well and very safely. And I, I think if you do one a year, it's probably not enough to justify doing exit procedures. If you have the potential to do 3 to 5 a year or something, then it's probably something that is, uh, a reasonable thing to think about. Um, Alan, we have a question, uh, from Sweden. Uh, Doctor, uh, Naji says he wants to know your opinion about conservative management if the fetus or newborn is asymptomatic. Well, we're gonna, we're going to get to that, uh, in my next talk, which is on postnatal management. I'm sure there'll be a lot more discussion about that than, uh, just about any other topic. So, um, why don't we reserve that, that answer for the next, uh, presentation. Perfect. Alan, I have a question. Yeah, OK. Um, we see, uh, kids occasionally with, uh, either a, a sequestration or a hybrid lesion that has a large feeding vessel, and those kids will sometimes develop pre-hydrops or high drops. What's you're thinking about, uh, the approach to those? Is there any, uh, role for trying to ablate that vessel as part of? Well, I, I think you have to ask what the mechanism of the hydros is, uh, Jack. I've seen very few, if any, where I thought it was a high output failure form of hydrops. It's very rare. Most of those BPSs that cause high drops usually have associated pleural effusions, mediastinal shift, and high drops on that basis, or their mass effect is enough to result in high drops. So I think, you know, if you did have one, which again I haven't seen. That was a high output physiology, uh, based on their systemic feeding vessel and, and shunt, um, then it might make sense to, uh, I think, do a fetal operation to, uh, correct it. I think some people have advocated doing, uh, embolization or sclerotherapy procedures. And, uh, I guess if you don't have the capability to do fetal intervention, fetal surgery. You might consider that, but it really is something that, you know, injecting alcohol, for instance, into fetal vessels or even embolic substances into fetal vessels is something that I think has quite a bit of potential hazard. And hasn't really been adequately studied, you know, things like neurologic effects of using alcohol as a sclerosin in the fetus, I think, are, are very worrisome. And so, I personally, I'm not a big advocate of the lesser, less invasive approaches. Um, I don't think they're indicated very frequently to begin with, and I think if you have one of those lesions, it would probably be better served by. If you're capable and open approach or referral to a center that does open surgery. Your, your video that stopped short, um, there's some questions about that. Uh, talk to us about how it is different doing a lobectomy in a fetus of 23 weeks. Is it, is it the same as, uh, what are some of the technical challenges, some of the differences and findings? Well, I think, um, the basic operations the same. What's different, different is the consistency of the tissues and the size. And the size, I don't think is a major limitation. As, as pediatric surgeons, we operate on neonates, premature infants. 28 weekers, etc. And so, the, the size difference isn't uh really the limitation. What the limitation is, is the delicacy of the tissues. And as you get down to 23 weeks, if you get down to 20 weeks like we currently do with myeloma. Meningocele, it actually begins to get very gelatinous and friable. And so, um, you really have to be very careful. And the mishaps we've had have usually been related to traction, to things like that where you tear tissues that, uh, you wouldn't normally tear with open surgery. We use, uh, most of the same instruments, although we use things like Q-tips and stuff like that that are a little more delicate for some of the fetal stuff. But, um, overall, it's not, uh, I don't think that much different than doing an operation on a premature infant until you get down to the, the point where the tissues are, are really becoming, uh, gelatinous and have poor integrity. OK, so just like a minor point. So, we spent all this time positioning the babies for our open surgery or thoracoscopic surgery. How do you position, Is it moving around? How do you stabilize the fetus? Well, the, the fetus is anesthetized. So, you have anesthesia from the mother. Yeah. And you have a, an anesthetic and paralytic shot that you give the fetus in addition, so the fetus isn't moving around. OK. You position the fetus before you open the uterus. So, you've got an amniotic fluid space and you convert the fetus to the position that you want to, Him to be in or her to be in. And so, if you're operating on the chest, you really want to get the arm on that side out of the hysterotomy to expose the chest adequately for a thoracotomy, right? And then you stabilize him with the arm and they're sort of like a quirk in the fluid with the hysterotomy, right? So, you're infusing amniotic fluid. The fetus will come up and almost seal the hysterotomy. Um, and it'll be buoyed by the, uh, amniotic infusion underneath it. So. That's so cool. It's fairly stable. It's not, uh, you know, the penis doesn't move around. It doesn't really. Cause you do put. While you're out. You don't put like, uh, something on either side of them to keep it. Nope. Wow, OK. It stays fairly stable. Once you control the arm for a thoracotomy, it's. Right. You pretty much have them. OK. You have them where you want them. But have you had to do any, uh, Doctor Flake, any pneumonectomies on, The fetuses and what are the, what are the long term issues with that? Yeah, we've, we've never, um, done a complete pneumonectomy successfully. We did have a case, I'll talk about a little, uh, later, uh, bronchial, uh, main stem bronchial atresia. That uh. We tried to do a pneumonectomy on and that, uh, infant didn't survive the fetal procedure. So, we have not had a successful pneumonectomy, um, thus far. But we've done bilobar, bilobectomies. We've done, uh, Resections where you leave a very small piece of, because a lot of these kids will have abnormal fissure formation, and so it's very hard to sometimes, uh, separate them in an anatomic fashion. And we've had a number of kids where we've left and, and the residual lung tissue has been compressed and is very small to begin with. So, we've had a number of kids where we've left a very small fragment of lung in one, pleural space and that grows dramatically. Um. It's amazing how, how much a small piece of lung tissue will grow as long as you preserve its, You know, airway and vasculature. Ramesh wants to know about, um, if a mother has had earlier C-sections, can you still do fetal surgery? Yeah, we, we still can. Uh, the uterus heals, uh, incisions fairly well. Most C-sections are done through the lower uterine segment. And so if that's the case, it's really not an issue for interference with our incision. Um, if they've had a classical cesarean section, which is fairly unusual, then we would simply make sure ours is somewhere else. Jack,
