- Localised irreversible dilatation of bronchi often with thickening of the bronchial wall.
- Congenital – structural (bronchial atresia); abnormal mucociliary transport (Kartagener’s); abnormal secretions (cystic fibrosis) or secondary to impaired immune system.
- Post childhood infections.
- Distal to bronchial obstruction (mucus plug, foreign body, neoplasm).
- ‘Traction bronchiectasis’ secondary to pulmonary fibrosis.
- _ Types of bronchiectasis
- Cylindrical or tubular (least severe type).
- Saccular or cystic (most severe type).
- Most common presentation is in children.
- Increasing breathlessness.
- Chronic cough with excess sputum secretion.
- Recurrent chest infections with acute clinical exacerbations.
- Posterobasal segments of lower lobes most commonly affected.
- Bilateral in 50%.
- CXR – dilated, thick-walled bronchi giving cystic and tram-lining appearance particularly in the lower lobes. There may be volume loss and overt ‘honeycombing’.
- There may be associated areas of infective consolidation and pleuroparenchymal distortion.
- HRCT – lack of bronchial wall tapering is the most consistent feature. ‘Signet ring’ sign demonstrating a dilated bronchus adjacent to a smaller normal-calibre artery. The dilated bronchus extends out towards the pleura (<1 cm). Mucus plugging present.
- Bronchiectasis may be difficult to appreciate on plain films and even sometimes on CT.
- The main differential on plain films and CT lies with the honeycombing seen in advanced pulmonary fibrosis.
- On CT, bullous emphysema can mimic cystic bronchiectasis. However, expiratory films confirm air trapping in emphysema and a degree of airway collapse in bronchiectasis.
- Regular postural physiotherapy with mucus drainage.
- Early use of antibiotics, sometimes with long-term prophylactic regimes.
- Bronchodilators may help in acute infective attacks associated with bronchospasm.