Sustained efficacy from 3 to 6 months following bronchoscopic thermal vapor ablation (BTVA) in the treatment of heterogeneous emphysema

Abstract

Background: A recent approach to bronchoscopic lung volume reduction (LVR), BTVA, involves the localized application of thermal energy through heated water vapor to targeted areas of emphysematous lung in order to induce LVR.

Objectives: Evaluate efficacy and safety of BTVA in the treatment of heterogeneous emphysema during a clinical trial.

Methods: Open-label, single-arm trial of BTVA in patients with upper lobe predominant emphysema (n=44). Entry criteria: FEV₁ 15% - 45% predicted, RV>150%, TLC>100%, 6MWD>140 m, DLCO>20%, previous pulmonary rehabilitation. Primary efficacy endpoint: FEV₁ and SGRQ at 6 months. Other endpoints included FVC, RV, FRC, TLC, mMRC dyspnea, 6MWD.

Results: No procedural complications (mean procedure time=30 min). Lung function changes from baseline (mean (SE)) are summarized in the following table:

At 6 months, FEV₁ improvement was ≥12% in 55%. SGRQ improved by 14 (2) units with 73% of patients improving ≥4units, 6MWD increased 47 (11), mMRC improved 0.9 (0.2) units, BODE score improved 1.4 (0.3) units (all p<0.05). A total of 29 serious adverse events occurred in 19 patients, with the majority being respiratory. One fatal event was reported 67 days post-BTVA.

Conclusion: Unilateral lobar BTVA treatment of heterogeneous emphysema results in clinically significant improvements in multiple efficacy endpoints that are sustained from 3 to 6 months.