title: Lung hypoplasia in newborn rabbits with a diaphragmatic hernia affects pulmonary ventilation but not perfusion.
abstract: BackgroundA congenital diaphragmatic hernia (DH) can result in severe lung hypoplasia that increases the risk of morbidity and mortality after birth; however, little is known about the cardiorespiratory transition at birth.MethodsUsing phase-contrast X-ray imaging and angiography, we examined the cardiorespiratory transition at birth in rabbit kittens with DHs. Surgery was performed on pregnant New Zealand white rabbits (n=18) at 25 days' gestation to induce a left-sided DH. Kittens were delivered at 30 days' gestation, intubated, and ventilated to achieve a tidal volume (Vt) of 8 ml/kg in control and 4 ml/kg in DH kittens while they were imaged.ResultsFunctional residual capacity (FRC) recruitment and Vtin the hypoplastic left lung were markedly reduced, resulting in a disproportionate distribution of FRC into the right lung. Following lung aeration, relative pulmonary blood flow (PBF) increased equally in both lungs, and the increase in pulmonary venous return was similar in both control and DH kittens.ConclusionThese findings indicate that nonuniform lung hypoplasia caused by DH alters the distribution of ventilation away from hypoplastic and into normally grown lung regions. During transition, the increase in PBF and pulmonary venous return, which is vital for maintaining cardiac output, is not affected by lung hypoplasia.
authors.affiliation: Division of Neonatology University Children's Hospital and Perinatal Center, Ludwig Maximilian University, Munich, Germany.
authors.forename: Andreas W
authors.initials: AW
authors.lastname: Flemmer
authors.affiliation: Newborn Research Centre, The Royal Women's Hospital, Melbourne, Australia.|Department of Obstetrics and Gynaecology, The University of Melbourne, Melbourne, Australia.
authors.forename: Marta
authors.initials: M
authors.lastname: Thio
authors.affiliation: Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Australia.|Department of Obstetrics and Gynaecology, Monash University, Melbourne, Australia.
authors.forename: Megan J
authors.initials: MJ
authors.lastname: Wallace
authors.affiliation: School of Physics and Astronomy, Monash University, Melbourne, Australia.
authors.forename: Katie
authors.initials: K
authors.lastname: Lee
authors.affiliation: School of Physics and Astronomy, Monash University, Melbourne, Australia.
authors.forename: Marcus J
authors.initials: MJ
authors.lastname: Kitchen
authors.affiliation: Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Australia.|Department of Obstetrics and Gynaecology, Monash University, Melbourne, Australia.
authors.forename: Lauren
authors.initials: L
authors.lastname: Kerr
authors.affiliation: Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Australia.
authors.forename: Charles C
authors.initials: CC
authors.lastname: Roehr
authors.affiliation: Department of Mechanical and Aerospace Engineering, Monash University, Melbourne, Australia.
authors.forename: Andreas
authors.initials: A
authors.lastname: Fouras
authors.affiliation: School of Physics and Astronomy, Monash University, Melbourne, Australia.
authors.forename: Richard
authors.initials: R
authors.lastname: Carnibella
authors.affiliation: Department of Obstetrics and Gynecology, University Hospital Brugmann, Université Libre de Bruxelles, Brussels, Belgium.
authors.forename: Jaccques C
authors.initials: JC
authors.lastname: Jani
authors.affiliation: Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Australia.|Department of Obstetrics and Gynaecology, Monash University, Melbourne, Australia.
authors.forename: Philip
authors.initials: P
authors.lastname: DeKoninck
authors.affiliation: Division of Neonatology, Department of Pediatrics, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: Arjan B
authors.initials: AB
authors.lastname: Te Pas
authors.affiliation: Monash Biomedical Imaging Facility, Department of Physiology, Monash University, Melbourne, Australia.|Australian Synchrotron, Melbourne, Australia.|National Cerebral and Cardiovascular Center, Suita, Japan.
authors.forename: James T
authors.initials: JT
authors.lastname: Pearson
authors.affiliation: Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Australia.|Department of Obstetrics and Gynaecology, Monash University, Melbourne, Australia.
authors.forename: Stuart B
authors.initials: SB
authors.lastname: Hooper
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D005260:Female; D065630:Hernias, Diaphragmatic, Congenital / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology*; D008168:Lung / Q000098:blood supply*; D011247:Pregnancy; D012123:Pulmonary Ventilation; D011817:Rabbits; D012039:Regional Blood Flow; D013990:Tidal Volume