New and Emerging Minimally Invasive Techniques for Lung Volume Reduction: Procedure
Twenty-five endobronchial valves were inserted over a guide-wire placed bronchoscopically under general IV anesthesia with pressure-limited ventilation. Valves were inserted unilaterally in all segmental bronchi leading to the upper lobe most affected by emphysema in each patient. Median procedure time was 1 h (range 0.5 to 2.5 h). All patients were extubated immediately following the procedure.
Four of eight patients showed radiographic signs of volume reduction. These four patients showed the greatest improvement in pulmonary function test results. However, improvements in FEV1 and Dlco capacity were seen in some patients without collapse, suggesting improved V/Q ratios following valve insertion. For the entire group, significant improvements in median FEV1 (0.79 to 1.06 L; p = 0.025) and median Dlco (3.05 to 3.92 mL/min/mm Hg; p = 0.017) were seen at 4 weeks. There were no significant changes in RV, shuttle distance, or qual-ity-of-life scores. Ipsilateral pneumothoraces developed in two patients at 2 days and 4 weeks after the procedure, respectively. Three patients had exacerbations of COPD (two patients at 7 days and one patient at 30 days). A randomized controlled study of the Emphasys Endobronchial Valve in the United States recently obtained US Food and Drug Administration approval.
Another endobronchial valve for lung volume reduction has been developed, the Spiration Intra-Bronchial Valve (Spiration; Redmond, WA). The Spiration Intra-Bronchial Valve is an umbrellashaped device consisting of a polyurethane membrane on a nitinol frame (Fig 4). The valve is placed in the bronchus via a delivery catheter inserted directly through the working channel of a fiberoptic bronchoscope (Fig 5). The valves are produced in various sizes. in detail
Figure 4. Spiration Intra-Bronchial Valve consisting of an umbrella-shaped polyurethane membrane on a nitinol frame.
Figure 5. Spiration Intra-Bronchial Valve and delivery system shown folded (top) allowing passage through the working channel of a bronchoscope and deployed (bottom).