Tracheal growth and healing.

Studies of tracheal growth in the rat, puppy, and human being indicate that there is a linear relationship between body weight and tracheal cross-sectional area. Each tracheal cartilage grows continuously, and there appear to be no growth centers. Each cartilage enlarges by proliferation of chondrocytes on the convex surface and resorption of cartilage on the concave surface. Vertical incisions in the trachea heal by fibrous union without interruption of growth. These studies indicate that there is no optimal age for surgical repair of subglottic stenosis, since growth is constant and is not interrupted by vertical incisions in the tracheal rings.