Ovine model of congenital chest wall and spine deformity: From birth to 3 months follow-up

Jesse Shen; Nathalie Samson; Jérôme Lamontagne-Proulx; Denis Soulet; Yves Tremblay; Marc Bazin; Charlène Nadeau; Sarah Bouchard; Jean-Paul Praud; Stefan Parent

doi:10.1002/jsp2.1295

Ovine model of congenital chest wall and spine deformity: From birth to 3 months follow-up

JOR Spine. 2023 Oct 18;7(1):e1295. doi: 10.1002/jsp2.1295. eCollection 2024 Mar.

Authors

Jesse Shen^{1

2}, Nathalie Samson³, Jérôme Lamontagne-Proulx⁴, Denis Soulet^{4

5}, Yves Tremblay^{6

7

8}, Marc Bazin⁹, Charlène Nadeau³, Sarah Bouchard^{1

2}, Jean-Paul Praud³, Stefan Parent^{1

2}

Affiliations

¹ Centre de recherche du CHU Sainte-Justine Department of Surgery Montreal Quebec Canada.
² University of Montreal Department of Surgery Montreal Quebec Canada.
³ Neonatal Respiratory Research Unit, Departments of Pediatrics and Pharmacology-Physiology Université de Sherbrooke Sherbrooke Quebec Canada.
⁴ Axe Neuroscience Centre de recherche du CHU de Québec Quebec City Quebec Canada.
⁵ Faculté de pharmacie Université Laval Quebec City Quebec Canada.
⁶ Axe Reproduction, santé de la mère et de l'enfant Centre de recherche du CHU de Québec Quebec City Quebec Canada.
⁷ Centre de Recherche en Reproduction, Développement et Santé Intergénérationnelle (CRDSI) Quebec City Quebec Canada.
⁸ Département d'obstétrique/gynécologie et reproduction, Faculté de médecine Université Laval Quebec City Quebec Canada.
⁹ Centre de recherche du CHU de Québec Université Laval Quebec City Quebec Canada.

Abstract

Background: The evolution and treatment of lung alterations related to congenital spine and chest wall deformities (CWD) are poorly understood. Most animal models of CWD created postnatally were not evaluated for respiratory function. The goal of our study was to evaluate the effects of a CWD induced in utero on lung growth and function in an ovine model.

Methods: A CWD was induced in utero at 70-75 days of gestation in 14 ovine fetuses by resection of the 7th and 8th left ribs. Each non-operated twin fetus was taken as control. Respiratory mechanics was studied postnatally in the first week and at 1, 2, and 3 months. Post-mortem respiratory mechanics and lung histomorphometry were also assessed at 3 months.

Results: Eight out of 14 CWD lambs (57%) and 14 control lambs survived the postnatal period. One severe and five mild deformities were induced. At birth, inspiratory capacity (25 vs. 32 mL/kg in controls), and dynamic (1.4 vs. 1.8 mL/cmH₂O/kg), and static (2.0 vs. 2.5 mL/cmH₂O/kg) respiratory system compliances were decreased in CWD lambs. Apart from a slight decrease in inspiratory capacity at 1 month of life, no other differences were observed in respiratory mechanics measured in vivo thereafter. Postmortem measurements found a significant decrease in lung compliance-for each lung and for both lungs taken together-in CWD lambs. No differences in lung histology were detected at 3 months in CWD animals compared to controls.

Conclusions: Our study is the first to assess the effects of a prenatally induced CWD on lung development and function from birth to 3 months in an ovine model. Our results show no significant differences in lung histomorphometry at 3 months in CWD lambs compared to controls. Resolution at 1 month of the alterations in respiratory mechanics present at birth may be related to the challenge in inducing severe deformities.

Keywords: deformity; development; growth; in vivo model; pre‐clinical models.