OC31.01: Measurement of pulmonary vascular volume using virtual reality three‐dimensional ultrasound in fetuses with left‐sided congenital diaphragmatic hernia

To study the pulmonary vascular volume (PVV) using three-dimensional (3D) virtual reality (VR) ultrasound in fetuses with a left sided congenital diaphragmatic hernia (CDH) and healthy controls. 3D power Doppler volumes of the pulmonary vasculature were obtained from 20 weeks' gestation onwards in fetuses with left sided CDH and healthy controls. The observed-to-expected lung-to-head ratio (O/E LHR) was retrieved in fetuses with CDH. The PVV was measured using the 3D ultrasound volume of the vasculature of the right lung in 4DView. Subsequently the volume was analysed in the BARCO I-Space Virtual Reality (VR) system using V-Scope software. Associations were studied between PVVs and survival and presence of chronic lung disease (CLD) in surviving fetuses. 49 fetuses with left sided CDH were eligible for inclusion and 109 volumes were recorded throughout gestation. 64 volumes (58,7%) were of good quality. The survival rate was 39/49 (79.6%), of which 18/39 (46%) developed CLD. The median [interquartile range] of the first measured (between 20-24 weeks' gestation) observed-to-expected lung-to-head ratio (O/E LHR) was 42.4% [31.3-51.5], indicating a moderate/mild pulmonary hypoplasia group. The median [interquartile range] PVV in mm3 at 20 (n = 44), 26 (n = 39) and 30 (n = 25) weeks gestational age (GA) for fetuses who survived versus non-surviving fetuses was 69.9 [37.9-190.0] vs 3.2 [1.9-91.0] (p0.04), 180.7 [48.0-485.1] vs 100.5 [58.3-384.1] (p0.46) and 251.3 [73.0-580.2] vs 96.2 [2.7-452.9] (p0.31), respectively. The PVV was not statistically significantly different between fetuses with and without CLD. Seventy healthy controls were eligible. Analysis in these fetuses is still ongoing. The PVV measured before 24 weeks GA is significantly higher in surviving fetuses with left sided CDH compared to non-surviving fetuses in a group of fetuses with moderate/mild pulmonary hypoplasia.