Ninety-eight emphysema patients were treated at 13 international sites during a 3-year series of single-arm, open-label studies with the IBV valve and a multi-lobar treatment approach. Fifty six percent of subjects had a clinically meaningful improvement in health-related quality of life, but standard pulmonary function and exercise studies were insensitive effectiveness measures. Quantitative CT analyses of regional lung changes showed lobar volume changes in over 85% of subjects. Lung volume reduction was an uncommon mechanism for a treatment response with bilateral upper lobe treatment. A redirection of inspired air, an interlobar shift to health-ier lung tissue, was the most common mechanism for a valve treatment response.