A system for improving airflow out of a diseased portion of an emphysematous lung, the system comprising: a delivery device; an expandable object (600, 700, 900, 912, 1000) for: placement, using the delivery device, into a pathway of two or more connected airways in a emphysematous lung having a diseased portion located at a terminal portion of a bronchial tree (106, 200, 910) within the emphysematous lung, wherein (a) a distal end of the expandable object (600, 700, 900, 912, 1000) is for placement within a first airway at a distal end of the pathway of two or more connected airways, the first airway comprising a bronchiole of generation 14 or higher that is within the terminal portion of the bronchial tree (106, 200, 910) at which the diseased portion is located, and (b) a proximal end of the expandable object (600, 700, 900, 912, 1000) is configured to be positioned in a second airway at a proximal end of the pathway of two or more connected airways that is of a lower generation than the first airway; and expansion, when placed within the pathway of two or more connected airways, to a diameter that expands at least a portion of the pathway of two or more connected airways to a diameter that is greater than a diameter of the portion of the pathway of two or more connected airways before the portion of the pathway of two or more connected airways is expanded; and a stent (300, 904, 1002) for placement, using the delivery device, into the pathway of two or more connected airways in the emphysematous lung, wherein (a) a distal end of the stent (904, 1002) is for placement within the first airway and (b) a proximal end of the stent (904, 1002) is configured to be positioned in the second airway wherein the stent (300, 904, 1002) is an open-form stent (300, 352, 402, 452, 500, 550, 582) and comprises a continuously open helical surface; wherein the stent (300, 904, 1002) comprises a diameter of between 1mm to 10mm and a length of between 2 to 10 cm. a delivery device; an expandable object (600, 700, 900, 912, 1000) for: placement, using the delivery device, into a pathway of two or more connected airways in a emphysematous lung having a diseased portion located at a terminal portion of a bronchial tree (106, 200, 910) within the emphysematous lung, wherein (a) a distal end of the expandable object (600, 700, 900, 912, 1000) is for placement within a first airway at a distal end of the pathway of two or more connected airways, the first airway comprising a bronchiole of generation 14 or higher that is within the terminal portion of the bronchial tree (106, 200, 910) at which the diseased portion is located, and (b) a proximal end of the expandable object (600, 700, 900, 912, 1000) is configured to be positioned in a second airway at a proximal end of the pathway of two or more connected airways that is of a lower generation than the first airway; and expansion, when placed within the pathway of two or more connected airways, to a diameter that expands at least a portion of the pathway of two or more connected airways to a diameter that is greater than a diameter of the portion of the pathway of two or more connected airways before the portion of the pathway of two or more connected airways is expanded; and placement, using the delivery device, into a pathway of two or more connected airways in a emphysematous lung having a diseased portion located at a terminal portion of a bronchial tree (106, 200, 910) within the emphysematous lung, wherein (a) a distal end of the expandable object (600, 700, 900, 912, 1000) is for placement within a first airway at a distal end of the pathway of two or more connected airways, the first airway comprising a bronchiole of generation 14 or higher that is within the terminal portion of the bronchial tree (106, 200, 910) at which the diseased portion is located, and (b) a proximal end of the expandable object (600, 700, 900, 912, 1000) is configured to be positioned in a second airway at a proximal end of the pathway of two or more connected airways that is of a lower generation than the first airway; and expansion, when placed within the pathway of two or more connected airways, to a diameter that expands at least a portion of the pathway of two or more connected airways to a diameter that is greater than a diameter of the portion of the pathway of two or more connected airways before the portion of the pathway of two or more connected airways is expanded; and a stent (300, 904, 1002) for placement, using the delivery device, into the pathway of two or more connected airways in the emphysematous lung, wherein (a) a distal end of the stent (904, 1002) is for placement within the first airway and (b) a proximal end of the stent (904, 1002) is configured to be positioned in the second airway wherein the stent (300, 904, 1002) is an open-form stent (300, 352, 402, 452, 500, 550, 582) and comprises a continuously open helical surface; wherein the stent (300, 904, 1002) comprises a diameter of between 1mm to 10mm and a length of between 2 to 10 cm.