Sonographic evidence of abnormal tracheal cartilage ring structure in cystic fibrosis.

Objectives/hypothesis: Tracheal cartilage ring structural abnormalities have been reported in cystic fibrosis (CF) mice and pigs. Whether similar findings are present in humans with CF is unknown. We hypothesized that tracheal cartilage ring shape and size would be different in people with CF.

Study Design: Tracheal cartilage ring size and shape were measured in adults with (n = 21) and without CF (n = 18).

Methods: Ultrasonography was used in human subjects to noninvasively assess tracheal cartilage ring structure in both the sagittal and the transverse planes. Tracheal cartilage ring thickness was also determined from histological sections obtained from newborn non-CF and CF pigs. These values were compared with human data.

Results: Human CF tracheas had a greater width and were less circular in shape compared to non-CF subjects. CF tracheal cartilage rings had a greater midline cross-sectional area and were thicker compared to non-CF rings. Maximal tracheal cartilage ring thickness was also greater in both newborn CF pigs and human adults with CF, compared to non-CF controls.

Conclusions: Our findings demonstrate that structural differences exist in tracheal cartilage rings in adults with CF. Comparison with newborn CF pig data suggests that some of these changes may be congenital in nature.

Level Of Evidence: 3b