Procedures
LVRS, to remove the most emphysematous part of the target lung, was carried out by a thoracic surgeon under general anaesthesia, primarily using either unilateral video-assisted thoracoscopic surgery or unilateral robot-assisted surgery. Where required, an open thoracotomy was performed at the discretion of the surgeon. As per usual clinical practice, participants initially went to the high dependency unit post-operatively and were transferred to ward-based care as soon as deemed medically stable, for further post-operative management, prior to discharge.BLVR, placing Zephyr endobronchial valves (PulmonX) to occlude the target lobe, was performed 