S. Koehler1, K. Boyd4, E. Gross1, E. Peterson3, A. J. Wagner1 1Children’s Hospital Of Wisconsin,Pediatric Surgery,Milwaukee, WI, USA 3Medical College Of Wisconsin,Maternal Fetal Medicine,Milwaukee, WI, USA 4Children’s Hospital Of Wisconsin,Pediatric Radiology,Milwaukee, WI, USA
Introduction: The overall survival for neonates with congenital diaphragmatic hernia (CDH) is 65-70%. Predicting which patients will survive allows pediatric surgeons to accurately counsel families during pregnancy. Currently, several imaging modalities and various attributes of these images are used to help predict survival. The complexity of these parameters can range from whether the stomach is in the chest on ultrasound, to the volume of the lung found on fetal MRI, to the ratio of the diameters of the right and left pulmonary arteries to the diameter of the aorta (McGoon index) on fetal echocardiogram. The most useful modality would be user independent, easily reproducible and not labor intensive. The aim of this study is to identify a modality that would fit these criterions.
Methods: This is a case series performed as a quality improvement measure. Patients were identified whom underwent both prenatal ultrasound diagnosis and fetal MRI assessment of congenital diaphragmatic hernia at a single tertiary institution from August 2014 until August 2016. Patients were excluded if a lung-to-head ratio (LHR)was not calculated for the ultrasound or if a total lung volume was not calculated on the fetal MRI. Prenatal and postnatal data were collected on all patients.
Results: Nineteen patients were identified who underwent both prenatal ultrasound and MRI imaging of CDH. Diagnosis of the CDH was made by ultrasound from 13 weeks estimated gestational age (EGA) to 33.5 weeks EGA. These patients underwent a total of 43 prenatal ultrasounds and each had a fetal MRI. Thirty of the 43 recorded LHR correlated with the observed to expected fetal lung volume (O/E FLV). Eighteen patients survived to delivery, eight to surgery and seven to discharge. Two patients are still currently admitted. The deceased patients included a twin who underwent radiofrequency ablation, a patient who had a severe intraventricular hemorrhage on ECMO, one was born at an outside hospital and did not survive to transfer, 4 of the patient's parents chose palliative care, and 3 had severe disease (O/E FLV < 15%). Patients with only some or no stomach herniated into the thoracic cavity on fetal MRI had 100% survival to surgery and discharge with the exception of one patient who is still admitted
Conclusion: Accurate prognostication of CDH has proven difficult. While improvements have been made in the last several decades, an ideal modality is still lacking. Several studies have shown that the fetal stomach position on prenatal ultrasound is strongly associated with neonatal outcomes. For instance, in one study, all patients with intra-abdominal stomachs survived without need for ECMO. While prenatal ultrasound is nearly universally used, it is highly user dependent and associated with a steep learning curve. We propose that a quick, easy, and reproducible technique to predict positive outcomes in CDH is assessment of stomach position on MRI.