Objective    To investigate the causes and bronchoscopic features of pulmonary atelectasis

and explore the relationships of the features with the causes and lesion sites for better bronchoscopic treatment.     Methods    The clinical data

including history

imaging data

bronchoscopic findings

pathological results

and the approaches and outcomes of bronchoscopic treatment

of 1 359 patients with pulmonary atelectasis admitted to our hospital from October 2001 and May 2007 was retrospectively analyzed.      Results    There were 1 294 of 1 359 patients (95.2%) diagnosed by flexible bronchoscopy combined with pathological examination. In all these cases

tumor accounted for 37.2%

while inflammation was 35.5% and tuberculosis took the left 19.9%. Bronchoscopic manifestations including cauliflower-like neoplasm due to tumor (74.6%). Not specific findings

such as mucosal hypertrophy

congestive and unsmooth were observed in bronchoscopy examination. Tracheal cavity scar strictures or closures were often seen in tuberculosis (80.6%)

and purulent secretions  were almost caused by inflammation (92.9%). Bronchoscopic manifestations were also related to lesion sites of different lobes. Bronchoscopic treatment included bronchoalveolar lavage

freezing and balloon dilatation.      Conclusion    Flexible bronchoscopy combined with pathological examination is a direct method to diagnose pulmonary atelectasis. Manifestations of pulmonary atelectasis are related to the causes and lesion sites. Bronchoscopic therapy can ease airway obstruction to some degree and thus relief pulmonary atelectasis

in order to improve respiratory function.