New and Emerging Minimally Invasive Techniques for Lung Volume Reduction: Conclusion
Spiration, Inc. (Redmond, WA) began a US Food and Drug Administration-approved clinical trial of vacuum-assisted lung reduction (VALR) in April 2002. The current elastomer sleeve under study is deployed with a button-activated introducer using gentle vacuum pressure to draw lung tissue into the sleeve (Fig 7). The sleeve applies radial compression via a band to the proximal lung tissue in the sleeve, sealing the compressed lung. Sutures are placed through the sleeve and the proximal compressed lung (Fig 8). The distal compressed lung and sleeve are removed, leaving a short cylinder of compressed lung on the surface. whitening gel
The VALR device was recently tested intraopera-tively on six patients immediately prior to lobectomy for lung cancer. In each case, 20 to 30% of the affected lobe was compressed with a single device applied to a portion of the lobe not involved with cancer. Compressed lung inside the distal portion of the sleeve was resected after lobectomy. Lobe reinflation following resection showed no air leaks or tissue trauma. Development of a thoracoscopic VALR system is underway (S. Springmeyer; personal communication; October 2003).
The value of LVRS in selected patients has been demonstrated in a large randomized controlled tri-al. Efforts are underway to achieve similar beneficial results with minimally invasive techniques. Further study is needed to determine the optimal minimally invasive method for lung volume reduction and to compare the results of minimally invasive techniques directly with surgical lung volume reduction. Bronchoscopic lung volume reduction may permit lung reduction in patients with previous thoracotomy or pleural adhesions who would currently be excluded from surgical lung volume reduction. Bronchoscopic valve insertion may be used to predict outcomes of lung volume reduction before contemplating surgery.
The preclinical and early clinical trials with minimally invasive lung reduction are promising. With further careful study, the risk/benefit profile of these procedures will be determined, allowing patients with emphysema and their physicians to choose among a number of viable options for lung volume reduction.
Figure 7. Spiration VALR elastomer sleeve using gentle vacuum pressure to draw lung tissue into the sleeve.
Figure 8. Remaining short cylinder of compressed lung and proximal portion of Spiration VALR elastomer sleeve following removal of distal compressed lung and sleeve.