Modeling Transuterine Fetal Tracheal Occlusion in Murine Model: A Surgical Procedure for Ligation of the Fetal Trachea Within a Pregnant Mouse

Place an anesthetized pregnant mouse of desired gestation age in the supine position. Sterilize the abdominal area. Perform laparotomy—a surgical incision through the abdominal wall. Dissect the abdominal muscles to expose the abdominal cavity.

Identify the uterine horns—long tubular structures that house multiple fetuses—allowing them to develop simultaneously. Gently exteriorize the uterine horns from the abdominal cavity, positioning them in a transverse orientation. Further, visualize the neck of the candidate mouse embryo.

Gently insert a surgical needle with the suture of appropriate thickness transversely through the uterine horn region, away from the placenta. Advance the needle further to the anterior part of the neck where the trachea is located. Direct the needle to exit the neck opposite the uterine horn. Carefully tighten the suture to occlude the trachea, ensuring uterine wall integrity. Return the uterine horns into the abdominal cavity.

Inject warm saline into the peritoneal cavity to facilitate pregnancy progression. Close the surgical incision and allow the mouse to recover. The established mouse fetal tracheal occlusion model can be used to study the impact of occluded trachea on lung development.