A novel murine model for the examination of experimental subglottic stenosis.

OBJECTIVE

To develop a novel mouse model of acquired subglottic stenosis (SGS) using heterotopic transplanted laryngotracheal complexes (LTCs).

DESIGN

Pilot randomized controlled animal study.

SUBJECTS: Forty-eight C57BL/6 mice.

INTERVENTIONS: Twenty-four donor C57BL/6 mice underwent LTC harvesting. The LTCs were then implanted deep to a cutaneous dorsal flap in 24 allogenic recipients. Sixteen LTCs underwent direct subglottic injury before transplantation, while 8 control LTCs were transplanted without injury. Transplanted LTCs were harvested 1, 2, 3, and 4 weeks after surgery. Tissues were fixed and cut transversely in 6-microm sections from the larynx to the second tracheal ring. Movat pentachrome staining was performed for connective tissue and morphometric analysis. Digital images of the subglottis were captured at x 20 magnification. The thicknesses of the lamina propria and the epithelium were measured at 5 random and equally spaced locations within the subglottic lumen. Vascular endothelial growth factor 164 (VEGF 164) and transforming growth factor beta1 (TGF-beta1) immunohistochemistry was performed on representative sections.

RESULTS

Lamina propria thickness was significantly greater in transplanted LTCs 3 and 4 weeks after injury compared with controls (P = .03, P = .01, respectively). Combined results (groups harvested at 1-4 weeks) revealed a significant difference between all 8 control animals and all 16 experimental animals (P < .001). Epithelial thickness was also greater in the transplanted LTCs 2, 3, and 4 weeks after injury to the subglottis compared with controls (P = .04 for weeks 2 through 4). Movat pentachrome staining showed random distributions and high concentrations of connective tissue within the lamina propria of the subglottis. The VEGF 164 and TGF-beta1 staining patterns were consistent with previous in vivo models of SGS.

CONCLUSION

Heterotopic transplanted LTCs in mice can provide an inexpensive and flexible model for experimental investigation of acquired SGS.