Evaluation of fetal pulmonary vasculature by power Doppler imaging in congenital diaphragmatic hernia.

OBJECTIVE: To evaluate the feasibility of prenatal power Doppler imaging of pulmonary arteries in congenital diaphragmatic hernia and to study its potential to predict outcome.

METHODS: A prospective observational study was conducted. Forty-two cases of congenital diaphragmatic hernia (32 left and 10 right) without associated anomalies were analyzed. Qualitative evaluation of pulmonary vasculature was based on power Doppler imaging performed at 26 to 38 weeks. The pulmonary arteries were studied in the lung contralateral to the hernia. Pulmonary Doppler angiography was considered satisfactory when 3 levels of bifurcation defining 3 distinct segments of the pulmonary arteries were imaged and was otherwise considered poor. We also recorded the gestational age at diagnosis, side of the hernia, abdominal circumference below the third percentile, amniotic fluid volume, lung/thoracic area ratio, left/right ventricle ratio, and, in left-sided hernias, stomach position, and we carried out a multivariate analysis to determine the contribution of each factor to predict neonatal mortality.

RESULTS: More than 3 divisions of the fetal pulmonary arteries were imaged in 20 cases; 1 or 2 divisions or none were imaged in 22. Neonatal mortality was significantly greater when fewer than 3 divisions of the pulmonary arteries were imaged (18 [82%] of 22) than when 3 divisions could be identified on power Doppler imaging (5 [25%] of 20; P = .0005). However, the lung/thoracic area ratio was the only factor that remained significantly associated with mortality in the multivariate analysis.

CONCLUSIONS: An altered pulmonary power Doppler image is associated with neonatal mortality, but estimation of the lung area remains the best predictor of neonatal outcome.