POSTTRANSPLANTATION PHYSIOLOGICAL FEATURES OF THE LUNG AND OBLITERATIVE BRONCHIOLITIS

Obliterative bronchiolitis remains the major obstacle to long-term sur vival after lung transplantation. Herein we provide a brief review of the key literature as well as our own experience with this condition. Obliterative bronchiolitis has occurred in up to two-thirds of all lun g transplant recipients. The characteristic physiologic changes includ e declines in (1) forced expiratory volume in 1 second, (2) forced vit al capacity, and (3) diffusing capacity of the lungs for carbon monoxi de. Lung biopsy in patients with obliterative bronchiolitis reveals oc clusion of bronchioles in a patchy but extensive distribution. Mucous plugging and bronchiectasis may also be seen. Furthermore, intimal thi ckening of pulmonary vessels together with mild arteriosclerotic chang es of the muscular and elastic pulmonary arterioles may be observed. T o date, the main risk factor for the development of obliterative bronc hiolitis is recurrent, severe, and persistent acute lung rejection. Th e recommended management is prevention because the established fibroti c condition may necessitate retransplantation.