Airway growth following cricotracheal resection in puppies.

A canine animal model was developed to study the effects of cricoid resection on cricoid cartilage growth and subglottic lumen size. Twenty-four healthy, postweanling mongrel puppies, aged 5 to 7 weeks, were randomly divided into two groups. The first group, consisting of 13 puppies, underwent cricotracheal resection with primary anastomosis. A second group, consisting of 11 puppies, served as controls and did not have surgery. Animals from both groups were killed at age 13 weeks. Most of the animals, however, were allowed to mature to adulthood and were killed between age 26 to 28 weeks. Comparative histologic examinations of the laryngotracheal complexes of operated-on and control dogs showed uninterrupted cartilage growth at the anastomosis site after cricotracheal resection. There was no significant difference in the mean area of the cricoid lumen between the two groups when luminal area was adjusted for body weight. The results demonstrate that cricotracheal resection in this animal model does not interrupt cricoid luminal area or cricoid cartilage growth, and provides rationale for further investigation of cricoid resection with primary anastomosis in humans. Cricotracheal resection in growing puppies appears to be an excellent model for further studies in the surgical treatment of acquired subglottic stenosis in infants and children.