Hyperoncotic enhancement of pulmonary growth after fetal tracheal occlusion: a comparison between dextran and albumin

Albumin as an adjunct to tracheal occlusion in fetal rats with congenital diaphragmatic hernia: a placebo-controlled study

OBJECTIVE

We sought to investigate effects of intratracheal albumin injection prior to tracheal occlusion (TO) on lung proliferation in fetal rats with nitrofen-induced congenital diaphragmatic hernia.

STUDY DESIGN

On embryonic day 19, nitrofen-exposed fetuses underwent TO, TO and 50 microL of either intratracheal albumin 20% or saline, or remained untouched. Main outcome at embryonic day 21.5 was expression of the proliferation marker Ki-67. Secondary outcomes were lung-to-bodyweight ratio (LBWR), tropoelastin expression, density and spatial distribution of elastin, pulmonary/alveolar morphometry, and fetal survival.

RESULTS

TO increased Ki-67 messenger RNA and LBWR. Albumin further increased LBWR and density of Ki-67-positive cells but also fetal mortality. TO with or without adjuncts induced elastin deposits at the tips of arising secondary crests, increased air space size, and decreased septal thickness.

CONCLUSION

TO had effects on lung proliferation and advanced the morphologic appearance. Addition of albumin increased density of proliferating cells and LBWR, yet at the expense of additional fetal loss.

Temporary Fetoscopic Tracheal Balloon Occlusion Enhanced by Hyperoncotic Lung Distension: Is There a Role in the Treatment of Fetal Pulmonary Hypoplasia from Early Preterm Premature Rupture of Membranes?

OBJECTIVES

To assess the effect of fetoscopic tracheal occlusion (FETO) enhanced by hyperoncotic distension on pulmonary hypoplasia from preterm premature rupture of membranes prior to 22 weeks of gestation (ePPROM).

METHODS AND RESULTS

In a fetus with ePPROM since 19+5 weeks of gestation, MRI at 28+2 weeks provided a lung volume of 10 ml. FETO enhanced by hyperoncotic distension was performed at 28+3 weeks. After 4-5 days, balloon dislodgement was observed. The lung volume increased to 18 ml. The baby was born at 32+4 weeks and survived to discharge.

CONCLUSIONS

FETO enhanced by hyperoncotic distension may result in impressive lung distension in fetuses with pulmonary hypoplasia from ePPROM. Further research into the life saving potential of this strategy for this common and tragic gestational event is desired.

Hyperoncotic enhancement of fetal pulmonary growth after tracheal occlusion: an alveolar and capillary morphometric analysis

BACKGROUND/PURPOSE

Previous work has shown that intrapulmonary delivery of oncotic agents enhance overall lung growth after late gestational fetal tracheal occlusion (TO). This study was a post hoc analysis aimed at determining whether actual alveolar and capillary hyperplasias are maximized in this setting.

METHODS

Twenty-one near term fetal lambs were evenly divided into 4 groups: group I comprised sham-operated controls; group II had TO alone; and groups III and IV underwent TO and intratracheal infusion of equal amounts of either saline or 25% albumin, respectively. Approximately 2 weeks thereafter, their lungs were examined by detailed alveolar and capillary morphometry before birth. Statistical analysis included analysis of variance and the Bonferroni correction for multiple comparisons (P < .05).

RESULTS

Total alveolar and capillary numbers, as well as total alveolar surface area, were significantly higher in group IV and lower in group I compared with all other groups, with no differences between groups II and III. Alveolar capillary load was normal in all groups.

CONCLUSIONS

Intrapulmonary delivery of concentrated albumin safely enhances short-term alveolar and capillary hyperplasia in a late gestational model of fetal TO. This therapeutic concept may allow for TO to be effective and predictable when performed late in gestation.