Methods and devices for passive residual lung volume reduction and functional lung volume expansion
View Patent ↗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 by using an occluding member that is adapted to be expanded in an airway which feeds the hyperinflated lung compartment such that access to the compartment is provided only through a passage of the catheter when the occluding member is expanded;
allowing air to be expelled from the lung compartment through the passage in the catheter while the patient is exhaling;
blocking air from entering the lung compartment through the catheter passage while the patient is inhaling by using a one-way flow element adapted to be disposed within or in-line with the passage of the catheter so that flow in a distal-to-proximal direction is allowed and flow in a proximal-to-distal direction is inhibited or prevented; and
determining whether collateral ventilation is present in the lung compartment, wherein determining whether collateral ventilation is present comprises detecting, using a flow-measuring device, air flow or accumulation from the isolated lung compartment over time; calculating, using a computer, a value of collateral resistance; and diagnosing collateral ventilation between the target lung compartment and at least one adjacent lung compartment based on the value of collateral resistance calculated by the computer.
2. A method as in claim 1 , further comprising blocking collateral flow channels if it is determined that the hyperinflated lung compartment has collateral flow channels with one or more adjacent lung compartments.
3. A method as in claim 1 , further comprising introducing an oxygen-rich gas into the lung compartment after the volume is reduced to induce or promote absorption atelectasis.
4. A method as in claim 1 , further comprising advancing the catheter through a bronchoscope to position the catheter distal end in the airway before sealing.