Systems and methods for reducing pressure at an outflow of a duct
Various systems and methods are provided for reducing pressure at an outflow of a duct such as the thoracic duct or the lymphatic duct. A catheter system can include a catheter shaft configured to be at least partially implantable within a patient's vein, a flexible membrane attached to the catheter shaft, the flexible membrane being a collapsible, tube-like member having a lumen extending therethrough, and a single selectively deployable restriction member formed over a portion of the flexible membrane at substantially a midpoint between a proximal end of the flexible membrane and a distal end of the flexible membrane, the restriction member being configured to control a size of the lumen so as to direct a controlled volume of fluid from an upstream side of the restriction member to a downstream side the restriction member.
1. A method of reducing pressure at an outflow of a duct, the method comprising:
positioning a device comprising a catheter in a blood vessel near an output of a duct, the catheter comprising a distal portion having an inlet and an outlet, the device comprising a selectively deployable restrictor a portion of which defines a tapered lumen;
deploying the restrictor; and
pumping blood through the tapered lumen into an impeller assembly of the device to thereby lower pressure near the output of the duct;
wherein the restrictor is mounted around the impeller assembly.
2. The method of claim 1 , wherein the restrictor occludes the blood vessel but for the lumen therethrough.
3. The method of claim 1 , wherein the vessel is an internal jugular vein, a subclavian vein, or an innominate vein.
4. The method of claim 1 , wherein the device comprises a second restrictor attached to a distal end of said device and the method further comprises positioning the second restrictor inside the blood vessel.
5. The method of claim 4 , wherein the restrictor and the second restrictor are positioned separately inside the blood vessel.
6. The method of claim 5 , wherein the method further comprises deploying the second restrictor.
7. The method of claim 6 , wherein the method comprises deploying the restrictor and second restrictor simultaneously.
8. The method of claim 6 , wherein the method comprises deploying the restrictor and second restrictor separately.
9. The method of claim 6 , wherein deploying the restrictor and second restrictor produces two occlusions within blood vessel.
10. The method of claim 9 , wherein the two occlusions define a low pressure zone between the first and second restrictors within a portion of the blood vessel.
11. The method of claim 1 , wherein the distal portion of the catheter comprises the impeller assembly with an impeller disposed therein.
12. The method of claim 11 , wherein the impeller assembly comprises the inlet and the outlet.
13. The method of claim 12 , wherein the device further comprises an elongate driveshaft extending proximally from the impeller, and wherein blood flows out of the impeller assembly via the outlet along the side of the impeller assembly.
14. The method of claim 1 , wherein at least a portion of the impeller is distal to the restrictor.
15. The method of claim 1 , further comprising activating the impeller inside the blood vessel thereby directing fluid by the tapered surface of the restrictor into the inlet, through the assembly and out the outlet.
16. The method of claim 1 , wherein the catheter comprises a diameter of between 9 and 15 Fr.
17. The method of claim 1 , wherein the restrictor comprises an inflatable balloon and the method further comprises inflating the balloon when the device is positioned in the blood vessel.
18. The method of claim 1 , wherein, when the restrictor is deployed, a second portion of the restrictor is not tapered.