Reversal of collateral ventilation using endoscopic polymer foam in COPD patients undergoing endoscopic lung volume reduction with endobronchial valves: A controlled parallel group trial.

EPF successfully reverses CV in severe COPD patients with a left oblique fissure that is 80%-95% complete. Following EBV, outcomes are similar to patients with complete fissures undergoing ELVR with EBV alone. EPF therapy to reverse CV potentially increases the number of COPD patients suitable for ELVR with minimal adverse reactions.