Lung volume reduction surgery is a highly effective palliative treatment for patients with advanced emphysema. Bronchoscopic methods for lung volume reduction (LVR) are highly desirable for patients who are at risk for complications from major surgery.
The purpose of this study was to evaluate the ability of a novel intrabronchial valve (IBV) system developed by Spiration Inc., Redmond, WA, to safely produce LVR. The IBV is designed for easy bronchoscopic deployment, removal and replacement, allowing optimization of clinical efficacy and minimizing postobstructive complications. In this study, IBV devices were placed in the airways of healthy dogs, and the extent to which LVR was achieved was monitored over a 3-month period.
After baseline pulmonary function tests (PFTs) were performed in six healthy dogs (23±3 Kg), appropriately sized IBV devices were deployed bilaterally using flexible bronchoscopy. A total of 46 valves were deployed (8,7,7,8,8,8) mostly in upper lobes. One month later, IBV in 4 of the 6 animals were evaluated using bronchoscopic and radiographic techniques. Selected IBV were removed and replaced to optimize placement and fit. At three months, pulmonary function testing was repeated.
IBV devices were easily loaded, deployed and repositioned using minimally invasive bronchoscopic techniques without complications. Postprocedural cough at rest, lasting less than 48 hours was the only side effect. Three months later, all valves were observed in their original locations. The change from baseline PFT (TLC= total lung capacity; FRC = functional residual capacity; and CL= lung compliance) at 3 months is tabulated below. No clinical complications were observed.
PFT parameterAverage Change From Baseline% ChangeANOVATLC (liters)−0.290−13%p=0.0062FRC (liters)−0.158−8%p=0.0165CL (mls/cm H20)−49−24%p=0.057
IBV devices produced measurable lung volume reduction in these six animals. The valves were easily implanted, repositioned, removed and replaced using standard bronchoscopic techniques. No complications were observed.
Appropriately placed IBV can produce measurable lung volume changes that may improve breathing mechanics in patients with advanced emphysema. The IBV may address a current clinical need and further investigation for this novel technology is warranted.
S.N. Mink, Spiration Inc., Discussion of product research or unlabeled uses of product.