PURPOSE: One-way valve bronchoscopic lung volume reduction (BLVR) has been evaluated to treat patients with emphysema. Valve treatments rely on full lobar occlusion, which may be compromised by the presence of interlobar collateral ventilation. We evaluated the presence of interlobar collateral ventilation using excised human lungs with complete and incomplete fissures.
METHODS: Excised human lungs from patients with known COPD from autopsy were used to evaluate interlobar collateral ventilation. Nearly complete and incomplete fissures were identified by visual inspection and palpation. Balloons were placed in each of the airways leading to all the lobes of the left and right lungs. The lungs were placed in a vacuum chamber and inflated by applying vacuum on the lung's exterior. Successful occlusion of the airways was demonstrated by the lung remaining deflated while under vacuum. The balloon occluding the upper lobe was then removed while keeping all of the other airways occluded with balloons. Collateral ventilation to adjacent lobes was then determined based upon the inflation of the adjacent lobes.
RESULTS: Six right and three left human lungs were evaluated. Eight had incomplete fissures and all but one exhibited significant interlobar collateral ventilation. Five lungs had fissures that were from 0 to 25% complete. In these cases the adjacent lobe inflated very fast upon removal of the upper lobe balloon. Two lungs had fissures that were nearly complete (76% to100%) and in these cases the adjacent lobe inflated at a slower rate. One lung with a partial fissure (26% to 50%) and one lung with a complete fissure demonstrated no evidence of collateral ventilation.
CONCLUSION: Interlobar collateral ventilation is present in the majority of patients with COPD with incomplete fissures and this compromises the ability of intrabronchial valves to achieve full lobar occlusion and atelectasis.
CLINICAL IMPLICATIONS: One-way valve BLVR procedural outcome greatly affected by collateral ventilation.
DISCLOSURE: David Ost, Employee P. Wu - employee.; Consultant fee, speaker bureau, advisory committee, etc. M. Ginsburg - consultant to PneumRx,R. Maxfield - consultant to PneumRx,D. Ost - consultant to PneumRx,R. McKenna - consultant to PneumRx; No Product/Research Disclosure Information