Histological features of complete tracheal rings in congenital tracheal stenosis

Purpose Congenital tracheal stenosis is a disease in which complete tracheal cartilage rings (CTCR) cause airway narrowing. Although tracheal cartilage malformation has been suggested as a cause of CTCR, no histological studies have been performed. Here, we report a comparison of the tissues from CTCR and normal tracheal cartilage. Methods Thirty-one infants who underwent slide tracheoplasty at our institution from May 2016 to August 2019 were included. Tissues from ten autopsy cases without tracheal lesions were used as controls. The survey items were tracheal cartilage cell density, cartilage thickness, and chondrocyte findings. Results The median cartilage cell density from cases was 23/125 × 125 µm 2 and from controls was 23.5/125 × 125 µm 2 ( p = 0.90). The median cartilage thickness from cases was 689 µm and from controls was 840 µm ( p = 0.11). Comparing the ventral and dorsal sides of the CTCR tissues, the cell density was significantly different (median ventral 23/125 × 125 µm 2 ; median dorsal 19.5/125 × 125 µm 2 ; p = 0.034). There were no significant findings in the chondrocytes of the CTCR tissues. Conclusion CTCR tissues did not differ in cartilage density and thickness from normal tracheal cartilage.