OC224: Fetal positron emission tomography during acute hypoxia and after fetoscopic coagulation of major placental vessels

Abstract

Accurate prediction of the likelihood of survival shortly after fetoscopic endoluminal tracheal occlusion (FETO) for the treatment of severe congenital diaphragmatic hernia (CDH) might help some parents decide whether to continue or terminate a pregnancy. We evaluated differences in fractional moving blood volume (FMVB) of the lung in fetuses with CDH treated with FETO, and their association with outcome. Methods: FMVB was evaluated in 24 fetuses 7 days before and 10-14 days after FETO. The percentage change between measurements was used to calculate ROC curves and likelihood ratios for the prediction of survival after tracheal occlusion. All cases were followed up until the neonatal period. Results: Fifteen cases (15/24) survived after the neonatal period (62.5%). The percentage change in FMVB was significantly greater in survivors than non-survivors (52.4% (SD 43.5%) vs. 8.9% (SD 18.9%), P = 0.01). The area under the ROC curve for survival was 0.852 (95% CI, 0.696-1.008). A positive test was defined as a change in percentage of 23.5% or more. The test was positive in 12/15 survivors and 1/9 non-survivors (sensitivity 80%, specificity 88.8%, PPV 92.3%, NPV 72.7%, positive LR 4.44). Conclusions: Changes in the fetal lung blood perfusion measured with FMBV after FETO might be incorporated into composite scores to establish the likelihood of survival shortly after treatment in CDH fetuses treated with FETO.