Biological lung volume reduction: a new bronchoscopic therapy for advanced emphysema

BACKGROUND: Biological lung volume reduction (BLVR) using biological reagents to remodel and shrink damaged regions of lung has previously been accomplished in sheep with experimental pulmonary emphysema. This report summarizes the initial clinical experience including a 3-month follow-up using this technique in humans. METHODS: An open-label phase 1 trial designed to evaluate the safety of BLVR in patients with advanced heterogeneous emphysema enrolled six patients. Of these, three patients received unilateral treatment at two pulmonary subsegments (group 1) and three patients received unilateral treatment at four pulmonary subsegments (group 2). The incidence of adverse events and changes in pulmonary function test results, symptoms, and exercise capacity were evaluated. RESULTS: The mean (+/- SD) age of the six men enrolled in the study was 66 +/- 5.7 years (age range, 57 to 73 years). BLVR was well tolerated in both treatment groups and was not associated with any serious complications. All patients were discharged from the hospital on posttreatment day 1. Although the primary purpose of the study was to examine safety, improvements were observed in mean vital capacity (+7.2 +/- 9.5%; range, -2% to + 19%), mean residual volume (RV) [-7.8 +/- 8.5%; range, + 1% to -22%], mean RV/total lung capacity ratio (-6.6 +/- 4.7%; range, -1% to -15%), mean 6-min walk distance (+14.5 +/- 18.5%; range, 0 to + 51%), and in mean dyspnea score. On average, group 2 patients experienced greater benefit from BLVR than group 1 patients, suggesting a dose-response pattern. CONCLUSIONS: Preliminary results indicate that BLVR can be safe and may produce benefits in appropriately selected patients with advanced heterogeneous emphysema.