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The effect of fetal tracheal occlusion on lung tissue mechanics and tissue composition
Author(s) -
Jani Jacques C.,
Flemmer Andreas W.,
Bergmann Florian,
Gallot Denis,
Roubliova Xenia,
Muensterer Oliver J.,
Hajek Kerstin,
Deprest Jan A.
Publication year - 2009
Publication title -
pediatric pulmonology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.866
H-Index - 106
eISSN - 1099-0496
pISSN - 8755-6863
DOI - 10.1002/ppul.20915
Subject(s) - elastin , medicine , congenital diaphragmatic hernia , lung , fetus , in utero , airway resistance , pulmonary compliance , respiratory physiology , anatomy , pathology , pregnancy , biology , genetics
Fetal tracheal occlusion (TO) is currently used to treat severe cases of congenital diaphragmatic hernia (DH). Clinical and experimental studies suggest an improved postnatal outcome, but lung tissue mechanics after TO have not been studied. We determined the effect of TO on mechanical impedance and lung tissue components in a rabbit model for DH. At 23 days of gestation (term = 31 days) either a sham thoracotomy or a diaphragmatic defect was induced. DH fetuses were randomly assigned to undergo 5 days later TO. Fetuses were delivered by term cesarean section to determine lung to body weight ratio (LBWR), dynamic lung mechanics and lung impedance. Airway resistance (R aw ), elastance (H L ), tissue damping (G L ) and hysteresivity (G L /H L ) were calculated from impedance data. Collagen I and III and elastin were quantified histologically. LBWR was significantly increased by TO compared to DH ( P < 0.001) and resistance and compliance of the respiratory system (R rs , C rs ) were improved as well. TO resulted in a significant decrease of R aw comparable to observations in sham‐fetuses, without effect on lung tissue mechanics H L , G L and hysteresivity. This coincides with a significant decrease of collagen I, III and elastin in comparison to DH fetuses. In this first report on lung tissue mechanics in a rabbit model of DH, TO had a substantial effect on tissue morphology yet this was not mirrored in lung mechanics. We conclude that the effect of TO on lung mechanics without in utero reversal of occlusion, is dominated by airway remodeling. Pediatr Pulmonol. 2009; 44:112–121. © 2009 Wiley‐Liss, Inc.