Pulmonary Artery Measurements as Postnatal Prognostic Tool in Right Congenital Diaphragmatic Hernia

Right-sided congenital diaphragmatic hernia (RCDH) is a rare and often fatal congenital anomaly, primarily attributed to lung hypoplasia, which is associated with small branch pulmonary artery (PA). This study investigated whether postnatal PA measurements obtained through echocardiography are associated with mortality or the extracorporeal membrane oxygenation (ECMO) requirement in neonates with RCDH.

A retrospective study was conducted on neonates with RCDH born between 2008 and 2022. Echocardiography was performed on the day of birth. The diameter of the main PA (MPA) was measured at the maximal dimension, and the diameters of the left PA (LPA) and right PA (RPA) were measured at the bifurcation. The primary outcome was mortality or ECMO requirement. Parameters, including the LPA:MPA ratio, RPA:MPA ratio, Nakata index, McGoon ratio, and ejection fraction (EF), were analyzed and compared with the observed-to-expected lung-to-head ratio (o/e LHR), initial blood gas, and defect size as predictive values.

Among 39 neonates with RCDH, 25 (64.1 %) survived without ECMO. The non-survivor or ECMO group exhibited lower o/e LHR, reduced EF, smaller LPA and RPA diameters, and larger MPA diameter than survivors. Lower LPA:MPA ratio, Nakata index, McGoon ratio, and higher initial PaCO₂ were associated with adverse outcomes. Notably, the LPA:MPA ratio showed the highest predictive capability (area under the curve, 0.983; p < 0.001).

The LPA:MPA ratio is a promising postnatal predictor of mortality or ECMO requirement in neonates with RCDH. Additionally, Nakata index, McGoon ratio, and initial PaCO₂ are significantly correlated with outcomes.

This is a level III.

Prognostic study.