EP06.39: Prenatal contralateral pulmonary artery diameter is the best prediction of the hernia size in congenital diaphragmatic hernia

Thoracoscopic repair is one option in cases with congenital diaphragmatic hernia (CDH) in neonate, however it is difficult to estimate whether the thoracoscopic repair is successful because there are no ways to measure the defect size. Our object of this study was to evaluate the defect size of CDH neonates from the prenatal ultrasound parameters. The data was retrospectively collected between 2016 and 2023, in terms of the demographics, prenatal ultrasound and intraoperative status. The defect size was divided into two groups (more (M) or less (L) 50% of all diaphragms). Ultrasound parameters were evaluated as follows; contralateral pulmonary arterial diameter (mm), observed/expected lung area to head circumference ratio (o/e LHR), pulmonary arterial Doppler in contralateral PA (acceleration time to ejection time ratio=AT/ET), pulsatility index (PI). Twenty-eight cases of prenatally diagnosed CDH were born during the study period, two of which did not result in surgery and died, and two were right-sided CDH. There were 8 cases in which the defect size was > 50%, and all eventually needed open surgery. Contralateral PA size was significantly smaller in group M (p = 0.0002). o/e LHR was also significantly smaller in group M (p = 0.046). There was a trend of higher AT/ET ratio in group M (p = 0.080), but there was no trend in PA PI. Prenatal contralateral pulmonary artery size might be helpful to evaluate the defect size in neonatal left-sided CDH.