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Updated: May 14, 2026
Transuterine Fetal Tracheal Occlusion Model in Mice
Published on: February 5, 2021
Evaluation of histological changes after tracheal occlusion at different gestational ages in a fetal rat model
Rodrigo Melo Gallindo1, Frances Lilian Lanhellas Gonçalves, Carolina Teixeira de Resende Barreto
1University of São Paulo, School of Medicine of Ribeirão Preto, Division of Pediatric Surgery, Department of Surgery and Anatomy, Ribeirão Preto/SP, Brazil.
Objectives:
To evaluate the histological changes of tracheal cartilage and epithelium caused by tracheal occlusion at different gestational ages in a fetal rat model.
Methods:
Rat fetuses were divided into two groups: a) External control, composed of non-operated rats, and b) Interventional group, composed of rats operated upon on gestational day 18.5 (term = 22 days), divided into triads: 1) Tracheal occlusion, 2) Internal control and 3) Sham (manipulated but not operated). Morphological data for body weight, total lung weight and total lung weight/body weight ratio were collected and measured on gestational days 19.5, 20.5 and 21.5. Tracheal samples were histologically processed, and epithelial, chondral and total tracheal thicknesses were measured on each gestational day.
Results:
The tracheal occlusion group exhibited an increase in total lung weight/body weight ratio (p<0.001). Histologically, this group had a thicker epithelial thickness (p<0.05) and thinner chondral (p<0.05) and total tracheal thicknesses (p<0.001). These differences were more prominent on gestational days 20.5 and 21.5.
Conclusion:
Tracheal occlusion changed tracheal morphology, increased epithelial thickness and considerably decreased total tracheal thickness. These changes in the tracheal wall could explain the development of tracheomegaly, recently reported in some human fetuses subjected to tracheal occlusion.
