VENTILATION-PERFUSION SCINTIGRAPHY AND LUNG-FUNCTION TESTING TO ASSESS METAL STENT EFFICACY

Stent implantation in malignant bronchial stenoses is a highly effecti ve method of providing symptomatic relief by restoring bronchial paten cy, Whether an improvement in ventilatory conditions is paralleled by an increase in blood Row and gas exchange has not yet been determined, Methods: Fourteen patients with malignant, high-grade obstruction of bronchi who had metal stent implantation were investigated, Before the intervention and again 8 days afterward, both quantitative technegas ventilation and Tc-99m-MAA perfusion Scans (V/Q scans) and lung functi on tests were performed, Results: Stent implantation was successful in all patients, with a significant reduction in the degree of bronchial stenosis (prestent: 93% +/- 1.5%; poststent: 16% +/- 3.5%), After ste nt implantation, ventilation scintigraphy revealed an improvement in t racer deposition by 65% (prestent: 37% +/- 8%; poststent: 61% +/- 6%; p < 0.05) within the affected lung. A complementary increase of 71% by perfusion scintigraphy was obtained (prestent: 27% +/- 4%; poststent: 46% +/- 5%; p < 0.01%). Based on scintigraphic criteria, stenting was successful in 93% (n = 13) of all patients, Lung function studies per formed after the intervention showed significant improvement in vital capacity (VC, p < 0.01), forced expiratory volume in 1 sec (FEV1, p < 0.05), peak expiratory flow (PEF, p < 0.05), arterial oxygen (PaO2, p < 0.05) and carbon dioxide (PaCO2, p < 0.05) tension, and oxygen satur ation (p < 0.05). Conclusion: Stenting of malignant high-grade bronchi al obstructions leads to an increase in bronchial patency and in activ ity distribution of both ventilation and perfusion scintigraphy of the affected lung, accompanied by significant improvement in lung functio n parameters.