Bronchoscopic Lung Volume Reduction Coil Treatment for Severe Emphysema: A Systematic Review and Meta-Analysis of Individual Participant Data

Background: Lung volume reduction coil (LVR-coil) treatment provides a minimally invasive treatment option for severe emphysema patients which has been studied in multiple clinical trials. Objectives: The aim of the study was to assess the effect of LVR-coil treatment on pulmonary function, quality of life, and exercise capacity using individual participant data. Method: PubMed, Web of Science, and EMBASE were searched until May 17, 2021. Prospective single-arm and randomized controlled trials that evaluated the effect of LVR-coil treatment on forced expiratory volume in 1 s (FEV1), residual volume (RV), St. George Respiratory Questionnaire (SGRQ) total score, and/or 6-min walk distance (6MWD) and were registered in an official clinical trial database were eligible for inclusion. Individual patient data were requested, and a linear mixed effects model was used to calculate overall treatment effects. Results: Eight trials were included in the final analysis, representing 680 individual patients. LVR-coil treatment resulted in a significant improvement in FEV1 at 3-(0.09 L [95% confidence interval (95% CI): 0.06-0.12]) and 6-month follow-up (0.07 L [95% CI: 0.03-0.10]), a significant reduction in RV at 3-(-0.45L [95% CI:-0.62 to-0.28]), 6-(-0.33L [95% CI:-0.52 to-0.14]), and 12-month follow-up (-0.36L [95% CI:-0.64 to-0.08]), a significant reduction in SGRQ total score at 3-(-12.3 points [95% CI:-15.8 to-8.8]), 6-(-10.1 points [95% CI:-12.8 to-7.3]), and 12-month follow-up (-9.8 points [95% CI:-15.0 to-4.7]) and a significant increase in 6MWD at 3-month follow-up (38 m [95% CI: 18-58]). Conclusions: LVR-coil treatment in emphysema patients results in sustained improvements in pulmonary function and quality of life and shorter lived improvements in exercise capacity. Since the owner of this LVR-coil has decided to stop the production and newer generations LVR-coils are currently being developed, these results can act as a reference for future studies and clinical guidance.