Diagnosis and Nd-YAG laser treatment of unsuspected malignant tracheal obstruction.

Thirteen adult patients underwent palliative Nd-YAG laser treatment for relief of severe dyspnea due to malignant endotracheal obstruction. Three of the 13 patients had underlying chronic airflow obstruction (CAO) due to diffuse obstructive pulmonary disease. Despite dyspnea, cough, wheezing, stridor and/or hemoptysis, the diagnosis was delayed because of a normal chest roentgenogram in eight patients and nondiagnostic pulmonary function studies (including maximal expiratory and inspiratory flow-volume loops) in all three patients with CAO and in four of ten patients without CAO. The location of the tumor was extrathoracic in two patients, including one with CAO; intrathoracic in seven patients, including two with CAO; and combined extra- and intrathoracic in four. Tracheal diameter increased from 3.5 +/- 1.0 mm before, and to 9.8 +/- 2.0 mm after single or multiple laser treatments. Increased patency of the trachea after laser surgery was associated with improvement in expiratory and/or inspiratory flow rates and with symptomatic relief in all patients which persisted for 14.1 +/- 8.7 months (range four to 48 months). These results indicate that severe symptomatic narrowing of the extra- and/or intrathoracic trachea to a diameter of 2 to 5 mm may not be detected by conventional chest radiography or even by sensitive physiologic tests, especially in patients with underlying CAO. The resultant delay in diagnosis defers possible relief of disabling symptoms with palliative therapy, including Nd-YAG laser photocoagulation.