Bronchiolitis Obliterans

Bronchiolitis obliterans (Image sourced from Bristol Biomed Image Archive with permission)
  • Severe irreversible injury of the bronchioles, can be a sequelae to chronic bronchiolitis or bronchitis
  • Bronchioles are ill equipped to remove airway inflammatory exudate and debris (see 'functional anatomy')
  • The fibrin-rich exudate is infiltrated by fibroblasts -> fibroblasts synthesise collagen in the exudate -> results in polyp formation inside the lumen -> permanent obstruction of the bronchiolar lumen.
  • Can occur within 7-10 days of the inception of the bronchial inflammation
  • Hypertrophy of mural smooth muscle of medium to small-sized pulmonary arteries
  • Results in pulmonary hypertension - cor pulmonale - potential cause for right-sided heart failure