Airway growth after cricotracheal resection in a rabbit model and clinicalapplication to the treatment of subglottic stenosis in children

Objective: To evaluate the effects of a partial resection of the anterior c ricoid arch on the growth of the laryngotracheal complex in an animal model and to study the lumen caliber and cross sectional surface area following resection as the animals are allowed to grow. Laryngeal, subglottic, and tr acheal measurements in the infant and pediatric larynges in autopsy specime ns are also investigated. Design: A controlled animal study was done compar ing the operated rabbit group to the nonoperated group. Twenty-nine infant rabbits were compared to a control group of ten rabbits. In addition, autop sy dissections were performed on infant and pediatric larynges to obtain me asurements of various laryngeal and cricoid relationships. Methods: Thirty- nine pasteurella-free New Zealand white female rabbits between the ages of 8 and 11 weeks were used in this study. In the experimental group, cricotra cheal resections were performed by removing the anterior cricoid cartilage and the first tracheal ring, A primary anastomosis was then performed. The animals were kept alive for 4 months and then humanely euthanized, The lary ngeal complex was then removed and histological sections of the cricotrache al region were mounted on glass slides and stained with H&E, Measurements w ere taken of the cricoid and upper tracheal lumen and cross-sectional area. Results: Twenty-seven of the study group survived until the time of sacrif ice. All of the control group survived during the study period. The two gro ups were comparable in regard to weight, lumen size, and cross-sectional ar ea. There were no statistical differences between the groups. Conclusions: The experimental data support the hypothesis that partial cricotracheal res ections can be performed safely and effectively in young rabbits. The poten tial clinical significance is described in light of the autopsy data.