Physiologic Characteristics of Malignant Unilateral Main-Stem Bronchial Obstruction: Diagnosis and Nd-YAG Laser Treatment

Publisher Website
Google Scholar
Abstract
To evaluate the effects of severe, unilateral main-stem malignant bronchial obstruction on airway of dynamics, we obtained maximal expiratory flow-volume (MEFV) curves in 11 patients 59.+-. 18 yr of age (mean .+-. 1 SD), three with and eight without underlying emphysema, before and after laser therapy (10 patients) or lung resection (one patient). Mean main-stem bronchial diameters before and after treatment were 1.1 .+-. 1.3 and 9.0 .+-. 0.8 mm, respectively (p < 0.05). In the three patients with underlying emphysema, MEFV curves showed a diffuse intrathoracic obstructive pattern before and after treatment; in the other eight patients, MEFV curves demostrated an apparently restrictive pattern, with associated airflow obstruction in four, reversible after laser treatment in three of these four. After treatment, all patients exhibited an increase in FVC with a roughly parallel shift of the MEFV curve and little change in the slope of the descending limb of the MEFV curve: FVC improved from 54 .+-. 16 to 86 .+-. 13% predicted in patients without emphysema and from 54 .+-. 16 to 77 .+-. 8% predicted in patients with emphysema, whereas the slope of the descending limb of the MEFV curve between 45 and 55% of FVC changed minimally from 2.0 .+-. 0.6 to 1.8 .+-. 0.5 s-1 in patietns without emphyema and from 0.8 .+-. 0.3 to 0.8 .+-. 0.1 s-1 in patients with emphysema. These results suggest that in the absence of underlying emphysema, severe unilateral mainstem bronchial obstruction usually results in an apparently restrictive ventilatory pattern on MEFV curves and less often in a mixed obstructive and restrictive pattern that improves after relief of the main-stem bronchial obstruction. In the presence of underlying emphysema, the main-stem bronchial obstruction may be physiologically masked.