PURPOSE:Surgical lung volume reduction(LVR) has been shown to improve symptoms and lung function in patients with severe heterogeneous emphysema. To avoid the inherent morbidity and mortality of surgical LVR, bronchoscopic placement of airway prostheses (=BLVR) has been recently described, although efficacy has been limited by collateral ventilation. The current study reports the feasibility and safety of a novel BLVR technique, independent of this limitation.
METHODS:Following medical optimization and rehabilitation, a 6 month pilot series of 11 patients with severe heterogenous emphysema received bronchoscopic application of thermal energy to an upper lobe target area. Based on extensive prior animal work, Bronchoscopic Thermal Vapor Ablation (BTVA, Uptake Medical Corp. Seattle) induces a controlled injury response to airway and parenchyma with gradual resultant LVR. BTVA utilizes a Vapor Generator and metal balloon vapor catheter, with target dosing at 3–7.5 cal/g according to a prior CT based tissue-air algorithm. The primary endpoint was safety and secondary endpoint preliminary efficacy measures.
RESULTS:9 women/2 men, mean age 61 years, 0.77±0.17 L (32% predicted) FEV1, 2.2±0.5 L (67% predicted) VC, 4.1±0.9 L (219% predicted) RV, 7.8±2.3 (34% predicted) TLCO, underwent 9 right and 2 left upper lobe unilateral treatments (=3 applications/lobe) in 22±5 minutes. All had immediate mild Xray opacification in the target area. All were discharged 24–48 hours post procedure. Serious adverse events (n=2) were probable bacterial pneumonia and exacerbation of COPD. Minor adverse events not requiring hospitalization included minor hemoptysis (n=6) and inflammatory pneumonitis (n=2). All are currently well, with less dyspnoea at 3–16 weeks post-procedure. 7 patients have completed D30 followup with a mean 9±8% FEV1, 9.9±12% VC and 13.1±23% TLCO increase and 7.4±9% decrease in RV.
CONCLUSION:Early data on BTVA therapy confirms feasibility, an acceptable safety profile and the potential for efficacy. Full 6 month followup data will be available for presentation in all subjects to confirm these findings, and define potential future variations to the clinical dosing algorithm.
CLINICAL IMPLICATIONS:BTVA holds the promise of a safe, simple and effective BLVR procedure.
DISCLOSURE:Gregory Snell, Consultant fee, speaker bureau, advisory committee, etc. GS has received a consultant fee for contracted work with Uptake Medical Corp, the study sponsor; Other The study was supported by Uptake Medical Corp, the manufacturer of BTVA products.; Product/procedure/technique that is considered research and is NOT yet approved for any purpose. The BTVA technique for emphysema is considered research and not yet approved for any purpose