Postnatal lung mechanics, lung composition, and surfactant synthesis after tracheal occlusion vs prenatal intrapulmonary instillation of perfluorocarbon in fetal rabbits Oliver J. Muensterer a, * , Andreas W. Flemmer b , Florian Bergmann a , Kerstin S. Hajek b , Hui Qi Lu c , Georg Simbruner d , Jan A. Deprest c , Holger Till a a Department of Pediatric Surgery, Dr. von Hauner Children’s Hospital, University of Munich, 80337 Munich, Germany b Department of Neonatology, Dr. von Hauner Children’s Hospital, University of Munich, 80337 Munich, Germany c Department of Obstetrics and Gynecology, Katholieke Universiteit Leuven, B-3000 Belgium d Department of Neonatology, University Children’s Clinic, Innsbruck, A-6020 Austria Abstract Background/Purpose: Fetal tracheal occlusion (TO) accelerates lung growth but decreases surfactant production. We have previously shown that instillation of perfluorooctylbromide (PFOB) into fetal rabbit lungs leads to lung growth similar to TO. This study compares neonatal lung mechanics and surfactant production after prenatal intrapulmonary PFOB instillation vs TO. Methods: In each of 18 pregnant rabbits on gestational day 27, sets of 4 fetuses underwent either (1) intrapulmonary instillation of 1 mL PFOB, (2) TO, (3) instillation of 1 mL 0.9% NaCl (saline), and (4) hysteroamniotomy without fetal manipulation (control). Fetuses were born by cesarean delivery after 48 hours. Fetuses of 12 rabbits were mechanically ventilated for 15 minutes to evaluate lung compliance and airway resistance. Pulmonary surfactant protein B (SP-B) was quantified by immunohistochemistry in fetuses of the remaining 6 rabbits. Results: Compliance was decreased in the TO group after cesarean delivery (0.33 F 0.13 mL/cm H 2 O) compared with PFOB (0.59 F 0.12 mL/cm H 2 O), saline (0.50 F 0.12 mL/cm H 2 O), and control (0.52 F 0.10 mL/cm H 2 O) fetuses. Mean fetal lung to body weight ratio was higher in TO and PFOB fetuses compared with saline and control. Higher water content and lower numbers of surfactant protein B– positive cells were found in the TO-treated fetuses. Conclusions: Both prenatal intrapulmonary instillation of PFOB and TO accelerate lung growth, but TO is associated with decreased postnatal lung compliance, possibly influenced by decreased surfactant production and increased fluid retention. Conversely, instillation of PFOB preserved lung compliance and surfactant synthesis. D 2005 Elsevier Inc. All rights reserved. 0022-3468/05/4001-0005$30.00/0 D 2005 Elsevier Inc. All rights reserved. doi:10.1016/j.jpedsurg.2004.09.008 Presented at the 35th Annual Meeting of the American Pediatric Surgical Association, Ponte Vedra, Florida, May 27-30, 2004. * Corresponding author. Tel.: +49 89 5160 2811; fax: +49 89 5160 4726. E-mail address: oliver.muensterer@ccc.uab.edu (O.J. Muensterer). Index words: Perfluorocarbon; Tracheal occlusion; Lung mechanics; Compliance; Resistance; Fetal rabbit Journal of Pediatric Surgery (2005) 40, 26–31 www.elsevier.com/locate/jpedsurg