Lung function in lambs with diaphragmatic hernia after reversible fetal tracheal occlusion.
OBJECTIVE
Short-duration resuscitation (< or =4 hours) of lambs with diaphragmatic hernia treated in utero with tracheal occlusion have shown improved lung function compared with untreated diaphragmatic hernia. This may be a transient phenomenon in the treated diaphragmatic hernia lambs because of surfactant deficiency. Our objective was to analyze the effect of fetal tracheal occlusion with or without release of the occlusion 1 week before delivery on pulmonary function during a longer period of resuscitation (8 hours) in the diaphragmatic hernia lamb model.


METHODS
Four groups were compared: diaphragmatic hernia (n = 5), diaphragmatic hernia and tracheal occlusion until delivery (n = 5), diaphragmatic hernia and tracheal occlusion with release of the occlusion 1 week before delivery (n = 5), and normal controls (n = 4).


RESULTS
Despite persistently decreased surfactant levels, diaphragmatic hernia lambs treated with tracheal occlusion had normal-sized lungs with marked improvement in lung function and gas exchange over 8 hours when compared with untreated lambs with diaphragmatic hernia. Release of the tracheal occlusion 1 week before delivery added no benefit.


CONCLUSIONS
It appears that surfactant-independent mechanisms such as pulmonary growth and structural changes are of foremost importance in relating to improved compliance, oxygenation, and ventilation of diaphragmatic hernia lambs treated with tracheal occlusion.
Division of Pediatric Surgery of The Montreal Children's Hospital, McGill University Health Center, Montreal, Quebec, Canada.
Ioana
I
Bratu
Helene
H
Flageole
Jean-Martin
JM
Laberge
Lajos
L
Kovacs
Daniel
D
Faucher
Bruno
B
Piedboeuf
D000818:Animals; D000831:Animals, Newborn; D005315:Fetal Diseases / Q000503:physiopathology / Q000628:therapy*; D006548:Hernia, Diaphragmatic / Q000503:physiopathology*; D065630:Hernias, Diaphragmatic, Congenital; D008168:Lung / Q000254:growth & development / Q000473:pathology / Q000503:physiopathology*; D008170:Lung Compliance; D009929:Organ Size; D011659:Pulmonary Gas Exchange; D011663:Pulmonary Surfactants / Q000378:metabolism; D012129:Respiratory Function Tests; D012756:Sheep; D014135:Tracheal Stenosis / Q000150:complications / Q000196:embryology* / Q000628:therapy*
D011663:Pulmonary Surfactants