Unilateral Extrapulmonary Airway Bypass in Advanced Emphysema

Background. Gas trapping in emphysema results in resting and dynamic hyperinflation. We tested the hypothesis that a direct connection between the lung parenchyma and the atmosphere could increase expiratory flow and thereby potentially improve dyspnea through the relief of gas trapping. Methods. Ex vivo we studied 7 emphysematous lungs and 3 fibrotic lungs (as controls) and measured expiratory flow before and after airway bypass insertion during a forced maneuver in an artificial thorax. Pilot studies were conducted in vivo in 6 patients with advanced emphysema using a size 9 endotracheal tube as a bypass surgically placed through the chest wall into the upper lobe. Results. In the ex vivo emphysematous lungs the volume expelled during a forced expiratory maneuver increased from 169 to 235 mL (p <0.05). In the in vivo group 4 patients retained the bypass tube for 3 months or more; total lung capacity was reduced, and the forced expiratory volume in 1 second increased by 23% (mean percent predicted at baseline versus 3 months, 24.4% versus 29.5%). Conclusions. An extrapulmonary airway bypass increases expiratory flow in emphysema. This may be a useful approach in hyperinflated patients with homogeneous emphysema. (Ann Thorac Surg 2010;89:899-906) (C) 2010 by The Society of Thoracic Surgeon