Abstract
Introduction: Endoscopic thermal vapor ablation (InterVapor™) has been demonstrated to induce lung volume reduction through the local delivery of heated water vapor to targeted lung segments. We examined patient subgroups based on emphysema heterogeneity for differential responses.
Methods: Subgroup analysis from a single-arm trial of InterVapor (single upper lobe treatment at 10 cal/g of tissue) in patients with upper lobe predominant emphysema. Inclusion criteria: FEV1 15%-45% predicted, RV>150%, TLC>100%, 6 minute walk distance (6MWD)>140 m, DLCO>20%. Primary efficacy endpoints: FEV1 ≥12% or SGRQ ≥-4 units at 6 months. Secondary efficacy: lung volumes (body plethysmography, HRCT), mMRC dyspnea, and 6MWD. Endpoints were analyzed for associations (Pearson correlation) and categorized based on tertiles of heterogeneity index (HI) (lower to upper lobe tissue to air ratio from HRCT).
Results: 44 patients received InterVapor. Demographics: 50% men, age 63 years, FEV1 0.86 L (31% predicted), SGRQ 59 units, 6MWD 300 m. Results at 6 and 12 months (mean change from baseline):
Conclusion: Efficacy from InterVapor for the treatment of heterogeneous emphysema appears to increase with increasing HI (i.e. upper lobe predominance). HI should be considered when projecting the magnitude of benefit after InterVapor.
- © 2012 ERS