Congenital Diaphragmatic Hernias (CDH): Improving Outcomes with Advanced Imaging & Nutrition

GlobalC MD along with Cincinnati Children's Hospital, sharing knowledge to improve child health around the globe. I'm Jill Knepprath with Stay Current MD, and today we will be reviewing congenital diaphragmatic hernias, or CDH and possible ways to improve outcomes for these patients with Doctor Paul Kingma of Cincinnati Children's. CDH is relatively rare in 1 in 3,000-ish births when you're at referral centers. You tend to see a few more. We tend to see 20 to 30 babies a year that have CDH. CDH anatomy is variable, and variability greatly impacts these patients' survival. The initial ultrasound that occurs at roughly 20 weeks of the pregnancy, where the CDH is often identified, potentially other anomalies are also identified at that point, which can greatly impact the outcome. So what do outcomes look like for these patients when we're talking about? Prognosis, we should be worrying about their quality of life, but the first thing is survival. Despite intensive efforts to improve the care of these infants, overall survival for infants born with CDH remains static at about 70% over the past two decades. Imaging findings such as fetal lung volumes, liver herniation, and lung to head ratio contribute to prognosis. In the very beginning and kind of the early phases, we might just observe. What makes them sick, what seems to make them better, what are the things that we can associate with those who do better or worse, and so forth. The Cincinnati Children's Team has been trying to figure out what is happening with these babies after they're delivered during the fetal period. We've done a lot of imaging of the babies, of the lungs, but we've actually done very little as far as what's happening to the lungs after they're born. Do the lungs grow? How do they grow, and how does that correlate with outcome? Cincinnati Children's has the unique resource of having an MRI in their NICU, which allows them to easily get postnatal imaging for CDH babies, both before and after their repair. So, image on the left. Is a CDH baby, an MRI scan prior to repair, and the image on the right is the same baby a month after repair. And I hope you can appreciate that clearly the CDH was repaired and the lungs look larger. Dr. Kingway describes a special technique called the ultra-short echoT MRI. It allows us to determine the lung volumes postnatally and also the lung density and the lung mass. Postnatally. So it gives us some meaningful information. They looked at a small cohort of 13 babies at Cincinnati Children's who got postnatal imaging and compared that to their fetal MRI. And what we found is that thankfully, yes, the lungs do grow. The total lung volume increases, the right lung volume increases, and the left lung volume increases. When they quantified this, it was the non-CDH or good lung that grew better than the left side lung. Was growing at about 2 mils per week slower than the right lung. Then they asked what factors are at play that allow the CDH or the left lung to catch up. When we looked at the relative growth of that left lung versus the right lung, the relative growth of the left lung increased in babies that had better weight gain. And this made it clear how important nutrition is for this population, maximizing calories, maximizing protein intake, and so forth. To maximize their growth, considering that that growth is associated with better growth of that more severely hypoplastic lung. They looked at lung density and mass in addition to lung volumes. We found the same thing that babies who gained weight better had more growth of their left lung. It didn't really impact the mass of the right lung. But it did improve the mass of the left. Although they saw changes in lung volume and mass, the team recognized that these measures don't fully encompass lung growth, so they also looked at lung vasculature as an indicator for growth. And we used another MRI sequence called 2D time of flight to detect all of the blood vessels in the lungs, or the blood vessels down to a size of 0.7 millimeters. And then we could quantitate the volume of the blood vessels and divide that by the volume of the lungs to get what we call the vascular density measurement. What does vascular density have to do with outcomes? We found that the CDH, pulmonary vascular density, correlated very strongly with outcomes in babies with CDH. Such that the lower your vascular density on the graph on the left, the longer time you spent on the ventilator. Same thing if you looked at the level of support they were discharged on. If they're discharged on room air, they had significantly higher vascular density than if they were discharged on oxygen or mechanical ventilation. So we've got a few things that we can look at postnatally to monitor the outcome of these infants and see if we can improve these things. In summary, CDH outcomes remain challenging. Defect severity and lung growth are key factors in survival. Better nutrition and weight gain are linked to improved lung growth for babies after delivery. Additionally, pulmonary vascular density is a powerful predictor of respiratory outcomes. Global Cat MD along with Cincinnati Children's Hospital, sharing knowledge to improve child health around the globe.