Open Fetal Surgery & EXIT Procedure with Dr. Jose Peiro

Today our guest is Dr. Jose Peiro, a pediatric surgeon at Cincinnati Children's, which has the nation's highest volume fetoscopic center. Dr. Peiro also specializes in neonatal and fetal malformations, and he's the endoscopic fetal surgery director in Cincinnati Children's Fetal Care Center. My first question is, why do we even think about fetal surgery, and why do we offer it to our patients? The answer is very easy. It's just because we have prenatal diagnosis. So in other words, we can detect things in utero very early in gestation. And fortunately, we have very good tools for prenatal diagnosis. The most important is the prenatal ultrasounds, the conventional ultrasounds at mid gestation around 20 weeks, will be the best. So most of the obstetricians and MFMs can catch most of the malformation at that point. So the rate of the detection of this malformation is very high in the developed countries. Obviously, with ultrasound, we have the 3D and the 4D modalities that basically we can see the surface, in this case, we can detect if it's an a cleft lip, plate, or things like that. And we can also see the movement, which helps us analyze how these babies move their legs, knees, and the flex and extension rates of the ankles, which is important for conditions like spina bifida. With Doppler, we can analyze the hemodynamic status of the baby taking the flows in the umbilical artery, in the ductus venosus, and also in the middle cerebral artery. We can have a good assessment how the baby is doing. Finally, we have a fetal MRI. MRI can contribute a lot to define the diagnosis after the ultrasound. Mostly defining on the brain, chest, and abdomen, providing a good help for define the condition and counseling of the parents. So we know that we will detect many of these malformations, and we know that some of them will be lethal or will have postnatal severe disabilities. So that's the goal of fetal intervention. Just try to rescue or improve these conditions. So what happens after the detection? For instance, in gastroschisis, I have good experience, just moving a little bit earlier, so we can reduce the injury on the bowel, so we have less serositis and better recovery in these babies. Let's talk a little bit about what kind of surgeries they do at Fetal Care Center here at Cincinnati Children's. Open fetal surgery is the most similar to neonatal surgery. So we have the patient in our hands. We can operate in a fetus the same as we operate in a premi. The only problem is we need to open the uterus. Fetal surgeons use dissolvable staples to limit the bleeding and maintain stability. But an opening in the uterus produces a scar, and that also can activate the dynamics because the uterus is very irritable. And sometimes, even though we give a lot of tocolysis to the mom, pre-term delivery happens a few days after the surgery if even if the surgery was a success. For that reason, all the fetal surgeons were trying to go away from fetal surgery, trying to look for minimally invasive surgery. So in what conditions a fetal surgeon might offer fetal surgery? Open fetal surgery still is used for large solid masses in the chest, for sacrococcygeal teratomas, and also for spina bifida. Let's start with fetal lung lesions. For example, CPAM. It's very easy to identify because we can see a multicystic component in the lungs of these fetuses by the ultrasound. Obviously, we need to be very careful about the microcystic, the solid CPAMs because the growth is very fast, and sometimes you can see how the mass can grow and make a shifting of the mediastinum compression on the other lung and also the heart. So the next consequence of this rapid growth will be hydrops. We can see acites in the abdomen, pleural effusion in the lungs, the scalp edema, so it's going to be a complete anasarca. So hydrops fetalis is very close to be complete fetal demise. That is the usual outcome of these babies if we don't do nothing. So how we can anticipate the babies are having risk for hydrops and demise and not. We use the CVR. CVR is calculated by the volume of the CPAM with times height times length times 0.523 and divided by the head circumference. The cut off is 1.6. Everything that measures less than 1.6 is very, very low risk of develop hydrops. And the contrary, more than 1.6, we have high risk of hydrops and complications. And for this condition, the first line of therapy is steroids. Maternal intramuscular betamethasone, like the one we use for lung maturation in a premi. Steroids can be injected to mom in one, two, or even three rounds weekly, so we can decrease the risk by decreasing the CVR. It's a good rescue in more than a half of these babies. So the other half or 40% probably don't respond very well. The only possibility before 30 weeks is just to put a shunt if it's a cystic component, but if it's solid, the only way is to do open fetal surgery and resect, do a lobectomy. The other condition, sacrococcygeal teratoma, is pretty similar to this. We can detect in the ultrasound and also in the MRI very easily. It's important to analyze if it's component is more cystic or more solid. Solid are more dangerous because they more rapid grow and also the vascularization that we can analyze with the Doppler. The classification of Altmant that we use postnatally can also serve in the analysis of these MRIs. Just to delineate what type of teratoma is, and also we can decide if we need to do something or not. The other condition that they're working a lot at Cincinnati Children's is spina bifida and mylomeningocele. So open fetal surgery is the world standard, still we are offering, but you will see that it's other innovations on the road. It is required to operate on the first day of life just to avoid infections and protect the spinal cord as much as possible. The problem comes from early in the embryo, usually at four weeks of embryonic time. Normally, the spinal cord is protected by the different layers, but in spina bifida, it is non-protected. It's completely facing the outside and also open like a book. That's the first hit, the malformation itself, but the most important thing is the second hit. This neural tissue is not prepared to be in contact with the amniotic fluid. We know the amiotic fluid is rich in meconium, in enzymes that progressively will damage, will destroy this exposed spinal cord and their nerves. Also during the delivery, the spinal cord can almost be destroyed. So it is very important to say that this condition is very progressive in utero. So we are losing all the neurons that should help this baby to move the legs. So what happens when we do neonatal surgery for spina bifida? We need to assume the sequella of this malformation that basically in the lower part of the body, we have fecal incontinence, urinary incontinence, sexual dysfunction, orthopedic anomalies, and also motor impairments, even needing a wheelchair at some point depending on the level of the injury. But also in the head because the compression of the brain stem produce obstruction. You can see like a black in a bottle, brain retains that fluid and the build up produce hydrocephalus. At 24 weeks, half of the fetuses have already hydrocephalus, and for the others, 95% of the time, they will have hydrocephalus later in the pregnancy. Hydrocephalus is important because these babies will need a derivation, some kind of ventricular peritoneal shunting with all the problems that produce, and also that generates migration disorders, etopia second these babies. To summarize, we can say that the pathophysiology of spina bifida makes the spinal cord exposed the amniotic fluid, have secondary neural damage, and hydrocephalus. So how can we stop that? So we can avoid amniotic fluid touching the nerves and we can avoid this leak of CSF. That's the rationale of open fetal surgery and also whatever repair in in in spina bifida. That's why the moms trial started just to try to compare prenatal surgery with postnatal surgery using the same technique they use in neonates. Closing the dura, the layers and the skin, sometimes using patches of the skin. And then the results show that these babies have a significant benefit from having perineal surgery. Surgeons reduced at least a half of the need for shunting. They improved the mental scores and the motor outcomes. In most of the cases, they revert completely the high brain herniation. For dural plasty, we introduce a rolet patch through the canula, so with one stitch, we can maintain in position as a dural patch. After that, we try to close the skin primarily or sometimes we need to put a patch. What we can say is that Dr. Peiro and his team are creating less maternal morbidity and they're able to allow the moms to deliver their babies vaginally. Next one is the exit procedure, which is another kind of open fetal surgery happens at the time of delivery. And it's a very interesting strategy that we use when we detect something that can produce a neonatal asphyxia or difficulties for intubation. We have many indications and cases. Most likely neck masses that are compressing the trachea, but also others like conjunctal obstructions or severe micrognathia may have a benefit from this technique. We can achieve between 1 hour and 3 hours maintaining the oxygenation from mom through the placenta to the cord to the baby. So it's a controlled situation. We don't need to rush to secure the airway. Obviously, we need to paralyze and thetize the fetus. Maternal monitoring and stability is also important. And we use inhalational anesthetics for uterine relaxation. Cases like teratomas in the neck, sometimes even in exit, you can do a straightforward intubation. Sometimes you can use rigid instruments or laryngoscopy, and sometimes even with that is not possible. With the exit procedure, we have time to do a partial resection of the teratoma, identify the trachea and then intubate the baby. So then once the intubation is done, we don't need to be more on placental support, so we can clamp the cord and do the surgery in next door OR, so we can complete this teratoma resection. In summary, in summary, fetal surgery