Bronchial cartilage alterations in lung transplantation.

Changes in the hyaline cartilage of the proximal bronchial tree were investigated in a group of combined heart-lung and double-lung recipients with and without OB. Ossification, calcification and fibrovascular ingrowth into the normally avascular hyaline bronchial cartilage were observed in almost all patients and were independent of small or large airway inflammation. Alterations in the integrity of hyaline cartilage have been produced by others in animals by ligation of the blood supply. Finding similar changes in airway cartilage of all transplanted lungs argues that there is relatively poor perfusion to the proximal air-conducting passage. Such a mechanism may contribute to the development of OB, bronchiectasis and a predilection for infections following pulmonary transplantation.