Abnormal ductus venosus streaming toward the right heart may provide an anatomical and pathophysiological rationale for the prognostic differentiation between „liver-up“ and „liver-down“–left diaphragmatic hernias in human fetuses

Background Definition of the liver position in fetuses with left diaphragmatic hernia has become one of the two main determinants for counseling about disease severity and postnatal prognosis in this condition. This study sought to provide an anatomical and pathophysiological rationale for this differentiation by searching for an association of liver position and ductus venosus streaming patterns.

Patients & Methods We prospectively studied 22 fetuses with left diaphragmatic hernias between 19+6 and 38+6 weeks of gestation employing multimodal echocardiography. Eleven fetuses had an intrathoracic liver position (“liver-up), the other eleven fetuses an intraabdominal liver position (“liver-down“). Liver-position and ductus venosus streaming site were compared in the two groups of fetuses.

Results Ten of the eleven fetuses with left diaphragmatic hernia and liver-up exhibited abnormal streaming of ductus venosus blood flow toward the right side of the heart, whereas only three of the eleven fetuses with liver-down exhibited the same flow anomaly.

Conclusions Liver-up left diaphragmatic hernias seem more commonly associated with abnormal streaming of the ductus venosus toward the right side of the heart than liver-down hernias. Since the abnormal streaming pattern of the ductus venosus has been associated with pulmonary blood flow and vascular reactivity anomalies in this condition, the relationship may offer a first pathophysiological rationale for this differentiation. Further studies in a larger series are needed to provide more robust scientific evidence for this early observation.

diaphragmatic hernia - fetal selection - fetal therapy - fetus