Methods and devices for passive residual lung volume reduction and functional lung volume expansion

Abstract

The volume of a hyperinflated lung compartment is reduced by sealing a distal end of the catheter in an airway feeding the lung compartment. Air passes out of the lung compartment through a passage in the catheter while the patient exhales. A one-way flow element associated with the catheter prevents air from re-entering the lung compartment as the patient inhales. Over time, the pressure of regions surrounding the lung compartment cause it to collapse as the volume of air diminishes. Residual volume reduction effectively results in functional lung volume expansion. Optionally, the lung compartment may be sealed in order to permanently prevent air from re-entering the lung compartment.

1 . A method for reducing the residual volume of a hyperinflated lung compartment, said method comprising:
 sealing a distal end of a catheter in an airway feeding the lung compartment;   allowing air to be expelled from the lung compartment through a passage in the catheter while the patient is exhaling; and   blocking air from entering the lung compartment through the catheter passage while the patient is inhaling.   
   
   
       2 . A method as in  claim 1 , wherein the hyperinflated lung compartment is substantially free of collateral flow from adjacent lung compartments prior to sealing the catheter distal end. 
   
   
       3 . A method as in  claim 1 , wherein the hyperinflated lung compartment has collateral flow channels with one or more adjacent lung compartments prior to sealing the catheter distal end. 
   
   
       4 . A method as in  claim 3 , wherein the collateral flow channels at least partially collapse as the volume of the hyperinflated lung compartment is reduced. 
   
   
       5 . A method as in  claim 2 , further comprising introducing an oxygen-rich gas into the lung compartment after the volume is reduced to induce or promote absorption atelectasis. 
   
   
       6 . A method as in  claim 1 , wherein reducing the residual volume of a hyperinflated lung compartment causes functional lung volume expansion of the remaining lung compartments. 
   
   
       7 . A catheter for isolating and deflating a hyperinflated lung compartment, said catheter comprising:
 a catheter body having a distal end, a proximal end, and at least one lumen extending from the distal end to the proximal end, wherein at least a distal portion of the catheter body is adapted to be advanced through the airways of the lung;   an expandable occluding member disposed near a distal end of the catheter body, wherein said occluding member is adapted to be expanded in an airway which feeds the hyperinflated lung compartment such that access to the compartment is provided only through the lumen when the occluding member is expanded; and   a one-way flow element adapted to be disposed within or in-line with the lumen so that flow in a distal-to-proximal direction is allowed and flow in a proximal-to-distal direction is inhibited or prevented.   
   
   
       8 . A catheter as in  claim 7 , wherein the catheter body has a length in the range from 20 cm to 200 cm and a diameter near the distal end in the range from 0.1 mm to 10 mm. 
   
   
       9 . A catheter as in  claim 7 , wherein the expandable occluding member is an inflatable balloon, cuff, or braided balloon. 
   
   
       10 . A catheter as in  claim 7 , wherein the expandable occluding member has a width in the range from 1 mm to 30 mm when fully expanded. 
   
   
       11 . A catheter as in  claim 7 , wherein the one-way flow element is disposed in the lumen. 
   
   
       12 . A catheter as in  claim 11 , wherein the one-way flow element is disposed in the lumen near the distal end of the catheter body. 
   
   
       13 . A catheter as in  claim 7 , further comprising a hub disposed on a proximal end of the catheter body. 
   
   
       14 . A catheter as in  claim 13 , wherein the one-way flow element is disposed in the hub. 
   
   
       15 . A catheter as in  claim 14 , wherein the hub is removable and can be attached in-line with the lumen.