So, I'm gonna talk about the prenatal side of things a little bit. Uh, I like to keep it fairly simple. Um, it's appropriate to start with the prenatal side of things because it's had a tremendous impact on the understanding and management of, uh, these lesions. So, it's really a big part of the entire picture of lung lesions. And what we're talking about really are CPAs, as they're called now, uh, congenital pulmonary. Airway malformations, uh, uh, bronchopulmonary sequestrations, both interlobar and extra lobar, hybrid lesions, bronchogenic cysts, bronchial stenosis and atresias, and there's a whole sequence of, uh, bronchial atresia abnormalities. And these can be confused prenatally with a number of things commonly. One is CDH, although with current, um, uh, modalities of prenatal diagnosis and good expertise, that's usually fairly easily, uh, separable. Are differentiable. Um, and the other one that I see frequently are lung agenesis, and, uh, that can be mistaken because of the compensatory growth of the contralateral lung as a large, uh, microcystic secam. Uh, particularly right CDHs are misdiagnosed frequently as secams and vice versa because of the similar echogenicity of the liver and the right chest. So, those are some of the common, uh, misdiagnoses prenatally. Basically it's fairly simple to think about the prenatal manifestations of these lesions. It's based on mass effect and whether or not they induce physiologic derangement, which is heart failure or eye drops. So when these lesions get large, whatever they may be, you have a number of alternatives for treatment. One is obviously termination in some circumstances. Others include steroids, and steroids are an interesting story in that. In the past probably 4 or 5 years, maybe 7 or 8 years actually, uh, we've begun to give steroids for microcystic C pams when they exceed a certain size, when hydrops is threatened, and in reality, that's worked very well and it's reduced the need for surgical fetal intervention to almost zero in most fetal centers that do that operation, so. We've been very impressed with steroids and the treatment of microcystic CPAPs. Um, if steroids don't work, then if you have an immature fetus, then we'll talk about the potential for fetal interventions, um, either shunts or surgery, and after 28 weeks, the appropriate role of the exit procedure in the treatment of these lesions. So what do we know about CPAMs, uh, prenatally? Well, we've studied the natural history of CPAs fairly extensively, and, uh, they basically behave in a fairly predictable way, uh, as a group, but not on an individual basis. So, Doctor Chromoholm years ago, uh, characterized the CCAM volume ratio, uh, which is basically the volume of an ellipse, uh, as the three dimensional volume of the. Uh, CPAM over the head circumference to standardize for gestational age, and both retrospectively and prospectively, this has proven to be probably the most valuable prognostic indicator for CPAMs, and you can see the growth curve there. Basically, you can anticipate growth of CPAMs up until about 25 to 28 weeks when they tend to plateau, and then they'll actually regress in size, very, very often. Um, but they don't necessarily disappear, and we can talk about that as a controversial area, um. And if the CVR is less than 1.6 with a solid lesion at presentation, then there's less than a 3% chance of that lesion progressing to high drops, and that's a very important and valuable measurement for counseling patients and determining the frequency of serial follow-up on, on prenatal CCAs. The CVR of greater than 1.6 has a very high likelihood of developing eye drops and as high as 75%, and so those lesions weren't very close observation and the families can be counseled accordingly. Uh, we also use that as a threshold for giving steroids, uh, prophylactically to prevent eye drops. And so lesions that have a CVR of greater than 1.6 in our center. Will be, uh, treated with steroids, uh, prophylactically to try to avoid heart failure. So just a few um. Uh, examples of fetal lesions that, uh, we've treated over the years. This is a fetus at 21 weeks that prevented, uh, presented with a CVR of 2, without eye drops, received steroids, and this is probably the only case in the last 5 years of a microcystic CPM that didn't respond to steroids, uh, in our center. And in fact, uh, the fetus progressed. At 23 weeks, there was obvious eye drops present. Uh, skin and scalp edema, ascites, and you can see this, uh, huge mass that at that point had a CVR of 3.3. So, in that circumstance, um, You really only have one option, and this is uh. A video here of a fetal surgical procedure. This should be video number one, Steve. And this video just sort of shows, uh, the steps that we do with all fetal surgeries. Basically, you expose the uterus. You get complete uterine relaxation with a deep inhalational anesthetic, uh, before you touch the uterus, really. And then you map the placenta with ultrasound, uh, marking the surface of the uterus with, uh, electrocautery, uh, to be sure that you steer very clear of the placenta. There's polyhydramnios present, you usually, uh, drain that so that you can get an accurate idea, Of where the placental edge is. And then we place traction sutures through the myometrium and membranes uh to allow us to enter the uterus bloodlessly. You can see that, uh, we're continuing to monitor using ultrasound there to make sure that, um, We don't hit the fetus with our traction sutures. I usually have this video running at twice normal speed. So, so this may take a little longer, uh, to show you than I usually do. And I have to think of things to say since it's running at half the speed it normally does. Um, you can see that's why you operate so slow. Yeah. Well, this is usually where I joke how fast fetal surgeons are, but, um, I can't do that today. Um, No, we're very slow and deliberate. Uh, you can see the uterus bleeds a lot. It's not a very friendly, uh, organ for surgeons. So we put in these traction sutures and then we uh cauterize through the myometrium. I don't know, Steve, if there's any way to speed this up a little bit. So, what about placental position? Uh, how, when you're trying to access something like this, it's, uh. Well, it, you have to avoid the placenta. So, if you have an anterior placenta, you have to actually bring the uterus out and do a posterior uterine incision. And so that requires you to, uh, divide the rectus muscle and, uh, do a bigger abdominal incision. So, here, uh, we're really moving quick. And, uh, you can see the uterine stapler. It's, uh, an absorbable stapler. Controls the myometrium, compresses it, uh, for hemostasis and controls the membranes, which is a very important component of fetal surgery. We can then bring out the fetal part of interest and we treat this like we would a postnatal operation. Uh, IV access is extremely important. We've had to resuscitate, uh, fetuses, give transfusions, do a variety of things during fetal surgery, and, uh, that allows us to, To do so. So, the first thing we do is get IV access, put on a pulse oximeter so we can monitor the fetus. We do continuous, uh, echocardiographic monitoring of the fetal heart. We have a cardiologist scrubbed at the table. He gives us a continuous readout on, uh, cardiac function and filling. Um, and that's an invaluable, uh, component of this as well, because you do have things like cord compression or oligohydramnios that, uh, cause fetal bradycardias. Sometimes when we decompress tumors out of the chest, the fetus will become bradycardic. Um. And that's due to, to loss of preload on the heart. So, we usually preload the, the fetuses via the IV before we decompress the chest. Oh, and I think I missed it. What's the gestational age right now? Uh, 23 weeks in this fetus. And then, uh, the video stopped. But we also replaced the amniotic fluid. That video should have kept going. So, uh, to the video. Um, we usually replace the amniotic fluid with, uh, lactated ringer solution, uh, warm lactated ringers with a catheter in the amniotic space. Huh. I don't know why that is. So, in any case, we, we do the operation just like you would, uh, postnatally. It's basically a lobectomy. We, uh, tie off the hilar structures and use a, usually a stapler or ligature to divide the residual lung parenchyma. Then, obviously, you have to close the uterus in a way that prevents, uh, any amniotic fluid leakage and controls the membranes, and we do a three layer closure of the uterus, uh, after the procedure. So, that's basically open fetal surgery, which, again, is required very rarely for these lesions, and I don't want to give the impression that we do that on a frequent basis. Um-hum. So, this is, uh, the post-op follow up of that patient. Um, at 3.5 weeks, you can see he has good compensatory lung growth and actually was delivered at 35 weeks, uh, without ventilation required. And so, you can get tremendous compensatory lung growth between the time you resect and the time you deliver to these kids. And in general, um, when that occurs, they have a very good outcome. So, at CHOP in our overall experience, we have around a 60% survival. Um, that's been consistent over all the years we've done open fetal surgery. Um, and the kids that survive have good quality of life outcomes. Uh, we've had no, uh, major neurologic sequelae or other, uh, bad quality of life impacting, uh, Uh, things in our survivors. So, it's, it's a mixed experience, but a good one. Our, our losses are usually kids that have, uh, gone a little too far with their eye drops and can't, uh, tolerate the procedure or have early preterm labor, uh, cutting things short. So, macrocystic seca, uh, is the other variety that frequently causes eye drops. Uh, macrocystic seams are less predictable, and even, uh, patients with a CVR of less than 1.6 will occasionally, uh, uh, grow rapidly and induce eye drops. So, this is an extreme example of eye drops with a macrocystic seca. You can see the extreme skin and scalp edema, the marked ascites, and treated with a vesco, uh, or pleuro amniotic shunt. You see the shunt on the right side there, and, uh, it converted a CVR of 3.6 to 0.8, um, and obviously reversed the associated high drops, and that's, uh, the ideal scenario and occurs when there's really truly a macrocystic se cam. A lot of these sea cams, as I'll show in a minute, also have a large solid component, and the, the shunt can't entirely, um, decompress that, but still can reverse the hydros. So, the shunt experience has been about 70% survival. And the reason for losses are usually due to early delivery and associated prematurity, inadequate compensatory lung growth in that circumstance, or sometimes residual mass effect that, um, still requires invasive treatment, as I'll show you in a minute. One of the sequelae of shunt placement that wasn't recognized early on in our endeavor but has become. Uh better recognized now is that you can get really marked chest wall deformity if you place shunts for giant macrocystic secams early in gestation, and this is most prominent when you do shunts at 18 to 20 weeks. And I think it's really related to just collapse of the chest wall as opposed to the, the harpoon placement of the shunt. Um. And it, it can be quite dramatic, and I've actually followed a number of these kids now, and it becomes less pronounced over time, and thus far they haven't required, uh, chest reconstructive procedures, but it's certainly something to, uh, warn the parents about. So, this is another case of a macrocystic seca, a CVR 2.6 with eye drops. And you can see this lesion has much more of a solid component to it and less of a cystic component. Often, you have se cams that have multiple macrocysts. The rule is that they generally communicate, and so, the placement of a shunt can decompress those lesions dramatically. Um, in this case, we got partial decompression enough to reverse the eye drops, uh, but there was still persistent ascites and mass effect. Uh, ascites alone, we don't consider eye drops. Um, and, uh, ultimately, because of the ongoing extreme compression of the lungs, we went for an exit procedure and there's a video of an exit procedure if, uh, it'll run. Even another video too. ect om ies are, Your microphone has been turned on. We'll talk about that more. But basically, the exit procedure is designed to maintain utero placental blood flow during delivery and resection of the mass. Uh, we get complete uterine relaxation again, and maternal general anesthetic. We open the uterus in the same way we do for open fetal surgery. And basically, we bring out the part of the fetus that requires treatment. In this case, uh, the chest. You can see the size of this lung mass, uh, at the time of resection. And basically, we do a lobectomy on placental support. Uh, and that way we don't have to try to ventilate a baby with a, a, uh, softball sized mass in his chest. Um And then once the lesion is out, we can close the chest, uh, initiate ventilation, and divide the cord. And take the baby down to the nursery. OK. All right. So, the exit procedure's been, uh, a very important intervention for, uh, uh lung lesions in our, uh, hospital. And basically, it depends on, uh, what we anticipate will occur after the baby is born. Uh, if we anticipate that we won't be able to ventilate the baby because of the size of the mass in the chest and that, uh, an emergency decompressive procedure would be required to ventilate the infant, then you're much better off delivering by an exit procedure if you have the capability to do so and perform the lobectomy in a, in a controlled fashion without risk of hypoxemia, etc. And we can maintain infants with normal blood gasses for an hour and a half, uh, by, uh, a well performed exit procedure. So, we've done, uh, 16 cases of exit procedures that CHOP for lung lesions. 4 of those have required ECMO. ECMO is a very unusual requirement for, uh, lung lesions because of their late enlargement. So, you don't have the same effect on, uh, lung hypoplasia as CDH, for instance. And out of those 16, we've had 15, uh, survivors. So, it's been a very effective intervention. Just a few unusual and difficult cases here. Twins are always a challenge. And particularly because you have no ability to do fetal intervention with twins, it's generally considered a contraindication. And you can perform exit procedures, but they're much trickier when you have twin gestations. In this particular case, you can see in the image there that it really does look like a diaphragmatic hernia. It was referred as a diaphragmatic hernia in one of the twins. Um, and in fact, it was a CCA. We were able to delineate the, uh, diaphragm, uh, and also just, uh, observed that it wasn't bowel in the chest. Um, And this particular woman had an incompetent cervix. Uh, we were unable to perform an exit procedure in this case. We had to perform an emergency resection of a large type 3 C cam. Um, and that, uh, went reasonably well and turned out all right, although this is just an example of a kid that you couldn't ventilate because of the size of the mass and really would've, uh, been better treated by an exit procedure if it were possible. And there's another example of a kid that, uh, had a huge, uh, space occupying mass at the time or near term, 35 weeks. But you can see in here on the late MRI, which can be helpful in, uh, trying to decide whether you want to do an exit or not, that you really have a reasonable lung volume on the contralateral side. You can see that particularly on the, uh, transverse cross-sectional image there. Um, and so, in this case, uh, we elected to Uh, go ahead with a C-section and immediate resection, and I think this can be done in the majority of kids with large C cams at birth. Most of them don't need exit procedures. I reserve exit procedures for kids where you really see mass effect with diaphragmatic aversion, can't visualize the opposite lung, uh, easily, uh, dramatic mediastinal shift. Oops, I keep hitting the wrong button.
