PURPOSE: The IBV(r) Valve (Spiration Inc. Redmond, WA) is a minimally invasive treatment that has diverse applications in acute and chronic conditions of the lung. The valve, comprised of a Nitinol frame and a polymer membrane, is designed to conform to dynamic changes in airway caliber. In contrast, metallic airway stents are designed to resist compression and are reported to have high clinical fracture rates (19.5%), migration rates (12.2%) and sequelae (Chan, BMC Pulmonary Medicine 2008, 8:7). This study examines the in-vivo durability of the IBV Valve.
METHODS: Clinical trials with the IBV Valve included chest radiographs (CXR) at regular intervals after valve placement. Fracture and migration data on valves was subsequently acquired by two methods. First, all radiology reports from interval visits were reviewed for comments. Then, 34 CXR from 27 of the 109 total patients were specifically reviewed by JC, JK, and BS for valve fractures from 2 institutions participating in the trials. In addition, valves removed from patients were evaluated by optical microscopy for fracture. Many of the valve evaluations were performed on the same valves at different times by different evaluators providing increased confidence in the data.
RESULTS: There were 2,831 total valve evaluations made on 689 valves as follows: 367 specific valve evaluations, 131 valves evaluated microscopically, and 2,333 valve evaluations from review of the CXR reports from clinical radiologists. No (0) fractures were observed in 2,831 separate evaluations. Additionally, no (0) valve migration was reported clinically or observed in the radiological data. The figure shows the distribution of valve evaluations over time up to 4 years after valve placement.
CONCLUSION: The results show with high confidence that the IBV Valve design is durable in patients with severe emphysema.
CLINICAL IMPLICATIONS: Metallic airway stent fractures and sequelae are frequent. While other studies have shown that the IBV Valve has low complication rates, this study further differentiates the IBV Valve design, with its ability to accommodate dynamic compression, from airway stents by its high in-vivo durability.
DISCLOSURE: Jeffrey Kanne, Shareholder Brandon Shuman, Steven Springmeyer and Xavier Gonzalez are all shareholders in Spiration.; Employee Brandon Shuman, Steven Springmeyer and Xavier Gonzalez are all employees of Spiration.; Product/procedure/technique that is considered research and is NOT yet approved for any purpose. While the IBV Valve is approved for air leaks in the lung, it is not yet approved for treatment of Emphysema in the United States. It is in the Pivotal phase of clinical trials for this indication.