Mounier-Kuhn syndrome: report of 8 cases of tracheobronchomegaly with associated complications.

Mounier-Kuhn syndrome is a rare congenital abnormality characterized by atrophy or absence of elastic fibers and thinning of smooth muscle layer in the trachea and main bronchi. These airways are thus flaccid and markedly dilated on inspiration and collapsed on expiration. First- to fourth-order bronchi are affected. There is an increase in dead space, tidal volume and diminished clearing of secretions. The usual presentation is recurrent respiratory tract infections with a broad spectrum of functional impairment ranging from minimal disease with preservation of lung function to severe disease in the form of bronchiectasis, emphysema and pulmonary fibrosis, ultimately culminating in respiratory failure and death. A congenital connective tissue weakness, in combination with inhalation of irritants like cigarette smoke and air pollution, are raised as possible factors in the development of this syndrome. Eight cases of tracheobronchomegaly with its associated complications are reported. Computed tomography scan of the chest was used for the diagnosis of tracheobronchomegaly. Treatment is mainly supportive with chest physiotherapy and antibiotics; however, there are a few reported cases where insertion of a tracheal stent resulted in some success.