Darrell Cass, MD, Director of Fetal Surgery at Cleveland Clinic talks about EXIT-to-resection surgery that can save the lives of newborns.
Has a partial C-section ever been done before? And could you walk us through Maverick’s procedure please?
CASS: We do these partial C sections. I guess that’s the term. But it’s better to be known as an exit procedure, ex-utero intrapartum treatment. And it’s a generalized strategy to deliver a baby where you can predict they’re going to have some kind of cardiorespiratory compromise where you can do things before you separate them from the placenta that can help stabilize them in that transition. So, we use this exit procedure strategy for a number of different types of conditions. The original one was for a fetus that has an airway obstruction. So, we can predict the baby’s not going to be able to breathe properly. So, we knew that the right approach was to keep the baby attached to the placenta, getting oxygen, getting rid of the carbon dioxide and then doing things to secure that airway. Well, we’ve also extended this to fetuses with high-risk lung malformations. And these are very, very rare. But these are malformations that stay big at the time of the baby’s birth. And most of the time, these malformations may grow very rapidly and cause fetal distress in the middle of the pregnancy and sometimes even unfortunately can even kill the baby unless you do some type of fetal treatment. But usually if they can get through that period, usually they shrink. And they’re not so problematic by the time the baby’s born. But very, very rarely, these lesions stay really big. They’re crowding the heart. They’re crowding the normal lung. And we came up with this concept of doing an exit to resection where we keep the baby attached to the placenta, keeping them on bypass, if you will, keeping oxygen flow, getting rid of the carbon dioxide and then doing something to help stabilize that baby in their transition to the newborn process. And in this case, we open up the chest and we remove the mass. And we may even complete the resection of the mass before cutting the umbilical cord. And the concept of that procedure actually was originally developed at Children’s Hospital of Philadelphia. But we were an early adopter of that, in fact, maybe the second adopter. We had some interesting patients that clearly that proved to be the right approach. So you asked the question of, you know, has this partial birth been done before? And the answer is absolutely. But the indication of exit to resection for a very large congenital lung malformation, that’s pretty rare. And I don’t know how many centers have adopted that approach currently. That is a procedure that we helped pioneer. And I do, I’ve done that now in 19 times, that same approach.
What were the major hurdles you had to face in this treatment?
CASS: That’s a tough question. Exit procedures, really, one of the toughest aspects is the anesthesia. You really have to have an experienced anesthesia team. And in this case, we had a great team with Dr. Hatta and Dr. Hoyt from obstetrics and pediatric anesthesia helping to provide great care to Mrs. Diemer. So, the reason it’s difficult is because in order to preserve placental blood flow, the uterus has to stay relaxed, whereas normally a C-section is done with the mom awake with the uterus actively contracting. And the goal of the anesthesia is just to make it so she doesn’t feel anything, no pain. But they keep the uterus contracting. Well, in that setting, when the uterus is squeezing, the placenta isn’t getting as much blood flow. So, one of the key principles of an exit procedure is deep general anesthesia. So, the mom’s deeply asleep. The uterus is very relaxed. And it’s getting natural blood flow that’s giving the baby the oxygen and getting rid of the carbon dioxide that’s needed. So, anesthesia is a critical aspect of this. In this particular case, things were a little bit more challenging because there was very severe polyhydramnios which is a buildup of amniotic fluid. And that can happen with a baby that has a very large lung malformation because the mass is occupying the chest. The chest is a closed space. This big mass is inside there. And it’s squishing everything else in the chest. And one of the things in there besides the heart, which is critical, is the esophagus that the baby is trying to swallow with. And that’s how the baby, the fetus, regulates the amniotic fluid volume they pee, which creates amniotic fluid. And then they actually swallow it and absorb it into their body. And that circulation helps regulate the amount of amniotic fluid. But if the esophagus is squished, then the fluid will build up. And in this case, the polyhydramnios was very severe. The AFI, the amniotic fluid index was about 55. And poor Mrs. Diemer, who’s not a huge woman, she’s rather petite, had this humongous uterus. And that provides technical challenges because to do the exit procedure, we have to open the uterus and the fluid will all spill out. And in this case, there’s a ton of fluid. And it spills out rapidly. That can promote the placenta from separating and can cause it to have dysfunction where it’s not working very well if it decompresses too quickly. And so that added an extra degree of drama in this particular case.
What is congenital pulmonary airway malformation and what is the survivorship for infants without the surgery?
CASS: Well, the nomenclature for these lung lesions has been evolving and changing. And I would say it’s really not perfect. But the name we use very commonly these days is C-PAM, congenital pulmonary airway malformation. I don’t think it’s a perfect term, but it’s a term commonly used. We use other terms. C-CAM is congenital lung malformation. I kind of think that’s a better term because it’s a little bit more generic. And these are simple malformations of the lung. They’re not cancerous. It’s not a neoplasm, some kind of abnormal growth. It’s a malformed amount of tissue. If you look at it under the microscope, it looks like lung. It’s just disorganized and malformed. Oftentimes the airspaces are over extended. They’re dilated or simplified. They can often have abnormal blood vessels, blood supply going to these lesions. But it doesn’t work properly. Even though it might look like lung, it doesn’t work properly. It’s getting abnormal blood flow. The airspaces don’t work and function very well. These are kind of random events that happen. They occur in somewhere between 1 in 10000 and maybe 1 in 25000 live births. Maybe 1 in 12, 12,000 is about the number. There is no cause that we know of. Actually, in the past we did some laboratory research trying to look at different proteins that might be molecular causes for these conditions. And that’s been studied. And we think we know some things that regulate the lung development that might play a role. But we don’t really know the genetic causes of these. In general, they’re just bad luck. They don’t tend to run in families. So, if you have one child with a C-PAM, the odds of you having another is very, very, very, very low. It’s not high. So, it’s a simple, bad luck event. Now, most C-PAMs have a very benign course. These days with the common use of prenatal ultrasound, it’s common that they’re diagnosed before birth. You know, thirty years ago, they commonly weren’t diagnosed before birth. They were only picked up if they caused problems in the newborn. They’re commonly seen. Most of the time, they do not cause any symptoms to the fetus. They don’t cause any symptoms to the newborn baby. And we would then have time to electively decide, do they need any treatment or not? And it’s much less common that they cause problems. So, these are more rare. But sometimes these lesions grow very rapidly before birth. The fetus is trying to grow, and the mass can try to grow. And the mass is inside of the closed chest. And in some instances, it starts to cause fetal compromise, such as with Maverick. The mass gets really large. It squishes the heart. It impairs the venous and lymphatic blood return into the right side of the heart. That can cause fetal hydrops, build up of fluid in the chest and the abdomen and the baby’s skin. And if you start to get hydrops, that’s a bad sign. And then it can also lead to heart failure. And if that fetus starts to show signs of heart failure, we know that that’s a predictor of fetal death. Now, Maverick had fetal hydrops, but he never developed heart failure. So, he was followed very, very closely. But he kind of was able to limp through. He really had a lung mass that was exactly on the border. I think if it were one centimeter bigger, it’s possible he might not have made it before birth. And he might have required fetal in utero surgery like earlier in his development. But it was right on the border. And so he was able to make it all the way close to the normal time for delivery.
How was Maverick diagnosed and how did you come up with your surgical plan?
CASS: So Mrs. Diemer was getting her regular obstetric care and the first thing doctors noticed was her size seemed to be too large for her gestational age. And so, they started doing some tests, ultrasounds. Then they noticed the baby’s heart was not where it was supposed to be. And that prompted a fetal MRI that helped them to diagnose that there was a lung malformation. Her original care team was pretty concerned. It was very large. And they were really worried about the well-being of Maverick and felt that there was a real high chance of him not being able to make it. And then a number of things happened. And one of the team decided that maybe she should come to see us. They knew that I had a good amount of experience with this exact type of problem. And just the family decided to come to us for another opinion just to see if, you know, what we thought. But that wasn’t until pretty late. I think she first came to see us about 33 and 1/2 weeks. So, it was pretty far along. So, a lot of the care had already happened. I did review that care. And I saw, wow, this is a really big lesion. And yes, he had hydrops, but it looked like the heart was still working OK. And when Mrs. Diemer came to see us, we saw that she had very marked polyhydramnios, that AFI was 54. There was an incredibly large lung malformation in the right lung. We measured that malformation. I believe it was about seven centimeters or so at the time in size, which is quite big. Anything over five is considered quite large for a small fetus. There was clearly hydrops. The heart seemed to be working OK. So, I really felt that the safest way to approach this delivery was going to be an exit procedure at that time. The fact is, before birth, the fetus’s lungs aren’t really doing anything. We have two sides to our heart. One side pumps blood to the body. The other side is supposed to pump blood to the lungs. Before birth, that blood gets shunted to the body through special channels that the fetus has that close up at the time of birth. So those lungs, they’re growing, they’re developing. They’re preparing to have to work. But before birth, and the baby is breathing, they’re practicing breathing during that development process. But before birth, the baby is not dependent upon the lungs to get oxygen or to get rid of carbon dioxide. They’re dependent upon the placenta. After birth, those lungs have to fill up with air. And there’s this big mass in there. It’s squishing the heart. The heart’s deviated. The normal lung that remains is going to have to fill with air and function. But there’s this mass that’s not going to move that’s squishing that normal lung. And I’ve seen this many times. I would have predicted the fetus was going to have immediate respiratory failure. We were going to have to escalate the care, turn up the ventilator pressures. That can actually compress the heart further. And you get into this vicious cycle where the circulation is impaired. The breathing is impaired. Some investigators have then put those babies on ECMO. ECMO is absolutely a treatment that’s possible. That’s a bypass machine where we have to surgically put cannulas into the baby’s neck and then circulate their blood out of the body through a machine and the machine does the job of the oxygen and getting rid of the carbon dioxide. And then it goes back into the baby. But that ECMO is high risk. We use it when we have to. But to use it, you have to thin the baby’s blood. That can lead to stroke. About 10 percent of babies that have ECMO will suffer a stroke as a complication of that treatment. So, if we have to use it, we do. But we try to avoid it if we don’t need it. And in my opinion and my experience, taking advantage of the placenta, you know, works the same as that ECMO. But I think it’s safer. Now, you do have to have an excellent team that has excellent maternal fetal medicine, excellent anesthesia, a good cardiologist that can monitor the baby, and a skilled and experienced team to do this because there are complications that can happen, just like with ECMO. But when I met with the family, I was feeling that that was going to be the right approach— or well, we discussed what the options were. And I discussed the pros and the cons of each. I discussed what my concerns would be. And I recommended exit to resection in this case. But our job is to try to provide these families with as much information as possible to educate them and to tell them what the options are. We can then recommend a certain line of treatment. But we try to partner with them to come up with the best care for them. And for any one family, they might choose different options depending upon what they think is, you know, in their head what the best balance of the risks and the benefits are. Kind of a long winded.
What were the risks with this surgery and how confident were you that Maverick would survive?
CASS: So, there’s always risks to an exit procedure. Well, there’s risk to any surgery, of course. There’s bleeding, infection. And those are risks to an exit procedure as well, either for Maverick or for Mrs. Diemer. But with the exit procedure, they are high risk type procedures. We have to have the mom very relaxed under general anesthesia. Her blood pressure may go down a little bit. The anesthesiologists are going to have to treat that. There’s a risk of placental abruption where the placenta separates from the uterus. Not only does it then not function well, it doesn’t provide the oxygen that we’re looking for. But it also can lead to maternal bleeding when that does separate. So, we have to be on the lookout for that. We have to open the uterus in a specialized way where there isn’t ongoing bleeding. When they do a normal C-section, they are working very quickly to get the baby out. And they typically just open the uterus quickly. There’s a little bit of bleeding. They deliver the baby, and then they attend to the mom’s bleeding. But they’re trying to get the baby out quick and then they refocus on the bleeding and the uterus. And that’s the typical strategy. But when we do an exit procedure, we do it just like open fetal surgery, where we open the uterus in a specialized way, where there’s no bleeding at all from the edges of the uterus that’s open. So that’s a risk. And then, you know, things can just go wrong, and Maverick’s heart could stop. He has a big mass in his chest. He’s hydropic. He’s sick. He’s been this way for a while. And, you know, there’s a risk that he could die. And also, there’s a risk that Mrs. Diemer could have complications— pulmonary embolism, blood clots, you know, infections, things like that. Fortunately, you know, we’ve looked at this. And the risk to the mother seemed to be very low in skilled teams that are used to doing this. The primary risk is bleeding, blood loss for the mother with an exit procedure. The statistics show that her risk of needing a blood transfusion is slightly higher than with the standard cesarean delivery, just slightly higher. But we’re aware of all of these things. So we counsel the family about the pros and the cons. We make a recommendation. And then we decide with them what the best approach is. So, yes, there were risks. How was I feeling about it? I guess I was confident. And the reason I was confident is because I had done this exact thing 18 times before. And in every instance, things went well. And in every instance those children left the hospital. And in every instance they’re going to kindergarten or first grade. And they’re developing and doing perfectly well and normal. You know, we’ve studied this because the option would be to also just deliver the baby and then do the best we can after birth. And that we presented as an option to the family. And we studied this back in about 2012 or so. And we compared a group where we had done these exit procedures on to a group that didn’t have an exit procedure. And that was for different reasons. Sometimes because we couldn’t do the exit procedure for different reasons, but largely it was because it was before we came up with that approach. And it was clear that the exit procedure babies. so in that report there, I think there were nine of the exit babies. All had done well. Their average hospital stay was about ten days or so. The ones that didn’t have the exit, their average hospital stay was something like 30 to 60 days. And unfortunately, two of them died from complications that I was talking about, about the management. So I think that provided a little bit of evidence that this is a good approach. But, you know, there are lots of options and lots of approaches. And every baby is a little bit different. And the care needs to be individualized for a particular fetus and mother and family based on what their makeup is and what their situation is.
What was the outcome of Maverick’s surgery and what were the other possibilities?
CASS: Maverick’s surgery was very tricky. You know, our team here at the Cleveland Clinic, this was our second exit procedure that we had done as the same team, the same group. The first one went beautifully. But because this is not our 100th or so, we did a lot of preparation, team meetings. We did some simulations and walk through just so everybody knew their roles and what the right approach was going to be. And our anesthesiologist did an amazing job because they took the initiative to set up a second operating area in the same room. And that may sound kind of common sense. But it’s actually not common because a room is generally outfitted for one set of technology, one ventilator machine that needs oxygen, carbon dioxide air piped into it. There needs to be electronics digital so that the machine can digitally report to the medical record system and all of that stuff. And they made sure we were in a room that was set up for two of those systems. And they had a separate bed available for the baby and one for the mom. And that was brilliant. And so, we prepared for it. This was a hard case. I was looking back at my records. I think this was the one with the largest amount of amniotic fluid, by far. In fact, many of our cases did not have polyhydramnios. And that does complicate the procedure because the uterus is very stretched. And the placenta is being stretched. So, we did the procedure and things were going well. The uterus was open, the fluid came out slowly. And Maverick was doing fine. He was being monitored. And we got his airway secured. We got some IVs in him to give him medications. And then it became clear the placenta wasn’t working as well as we were hoping. And so I worked very quickly to open his chest and get the mass out of the chest. And that was very fast. And I could tell that the uterus, the placenta was not behaving. And so then once the mass was out, I made the decision to go ahead and start to ventilate him, to breathe for him. And he did OK. And so, then we cut the cord and moved him three feet away to his own table. And then one team stayed with Mrs. Diemer. And then I went with Maverick. And with my great anesthesiologist, Dr. Hatta, we stabilized him. And then I completed the surgery to remove this mass. So, it got cut short. We worked quicker and cut short because of issues about the placenta. When we then studied this placenta, we saw that it was very scarred. I think that was because this hydrops had been going on for six, seven weeks, which means that the baby was waterlogged and congested. And the placenta can get that way, too. And I think it was giving out. It was wearing out, basically. And we had basically came to its lifespan. But I think because of the great team and the great preparations, we were able to audible in the middle and make some adjustments. And I think that’s where I think an experienced team comes along, that, you know, I think that having done 18 of these before, it’s just helpful. You know, as new places come along that can provide this type of technology, you know, there’s a learning curve. And the more experience you have, the better. And it’s when things go well, everything goes well. Everybody can do it. When things get difficult, then your experience, I think, really matters. And I think I’m so grateful to this amazing team here at the Cleveland Clinic that everybody was able to make adjustments and get Mrs. Diemer and Maverick through this very safely. Mrs. Diemer recovered beautifully. She’s tough. I think she was up walking around like the next day. I don’t know if she was supposed to, but she was. I think she was there at Maverick’s bedside, you know, right away. As soon as her doctors let her be clear, she was down with Maverick. And she seemed to recover very smoothly. You can ask her how her recovery was. But it seemed like it went smoothly. And then Maverick recovered perfectly well, very appropriately. So, the mass was out. This mess was nonfunctioning, malformed tissue that was crowding his heart and crowding the rest of his lungs. But it had been there a long time. So, his lungs, when he was born, were a little bit small. And he had very mild what’s called pulmonary hypertension, which is meaning that the blood pressure going to the lungs was higher. And that’s because there just wasn’t as much lung tissue as normal. And so, he was being treated for that pulmonary hypertension. He was on the ventilator for a little while and then he just made slow improvements and slow recovery, got off the ventilator, was on some oxygen for a little while and then got better, got off the oxygen, got off the pulmonary hypertension medications, started eating and then ate like a champ. We usually wait till their breathing is stable before letting him eat. But once he started eating, he was like a champ. He just was scarfing it down. And then when he was eating, OK, he was breathing, OK, didn’t need any oxygen, he was growing and gaining weight, then we were able to let him go home. And I can’t recall the exact specifics. He may have been in the hospital about five-ish weeks off the top of my head. But that, you know, it took some slow time for him to get to that point. But it was a steady improvement. He did not have any complications or setbacks. And I think since he’s gone home, he’s continued to do better. He’s never gotten oxygen. He’s not on any pulmonary treatment medications. He’s been growing and gaining weight. And there’s no sign of any complications that he’s had. And he’s doing awesome.
And then how was partial blood remaining in the attached umbilical cord beneficial?
CASS: So again, this general strategy of exit to resection, it’s a great name, I love that name “exit” because you’re exiting the baby from the womb, but you’re doing it in a controlled way to try to stabilize them, to optimize that transition point. And we’re taking advantage of the placenta, which is just a natural bypass machine that provides oxygen. It provides nutrients. It helps get rid of carbon dioxide. And so, this exit to resection strategy was perfect for Maverick, which was a very difficult situation. It was a high-risk lung malformation. It was very large. It was causing compression on the heart, compression on the normal lungs. It was pushing on his esophagus, leading to this big polyhydramnios. And an exit procedure was the perfect strategy. We thought that was the case before it was birth. That’s what we recommended. We were able to execute it. And Mrs. Diemer and Maverick seemed to recover very perfectly as a result. And I’m just so grateful. And it’s incredibly rewarding to see little Maverick.
Interview conducted by Ivanhoe Broadcast News.
END OF INTERVIEW
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