Abstract
Specific gas volume (SVg), which converts CT lung density into the physiological index of volume of gas per gram of tissue, has been recently proposed as both global and regional index for planning and evaluation of lung volume reduction in emphysema. We aimed SVg to study treated (TL) and untreated (UTL) lobes at different lung volumes before and after EBV.
CT scans of 11 patients with severe emphysema from a subset of VENT (Endobronchial Valve for Emphysema Palliation Trial) were analyzed at baseline and at 6 months after EBV. Valves were placed in 9 upper and 2 lower lobes. Lobar volumes (V) and average SVg were calculated at total lung capacity (TLC) and residual volume (RV). Results are in Tables.
At baseline, significant differences between TL and UTL were present both at TLC and RV (p<0.01). SVg was significantly higher in TL compared to UTL only at RV (p<0.001). After successful EBV treatment,V significantly decreased both at TLC and RV (p<0.01) in TL.
Our results suggest that SVg assessed at RV should be considered as an additional parameter to identify target lobes for EBV.
Acknowledgement: The Endobronchial Valve for Emphysema Palliation Trial (VENT) study research group for access to the data. Members are listed in the Supplementary appendix of N Engl J Med 2010; 363:1233-44.
- Copyright ©ERS 2015