Devices and methods for treating edema
The disclosure relates to devices and methods for the treatment of edema that uses an impeller with a balloon that may be mounted on the impeller housing. The invention provides devices and methods for treatment of edema that use an indwelling catheter with an impeller to lower pressure at an outlet of a lymphatic duct and a balloon on the impeller to guide and to restrict blood flow. The balloon restricts return flow from the jugular and guides that flow into the impeller cage. By funneling the flow into the impeller cage, a rate of flow down the vessel may be increased, resulting in a lateral pressure decrease effecting the lymphatic outlet. Because the lymphatic outlet is subject to a pressure decrease, fluids in the lymphatic system drain to the outlet and into the circulatory system.
1 . A device comprising:
a catheter comprising a proximal portion and a distal portion;
a cap secured to the distal portion;
one or more struts extending distally from the cap; and
an impeller housing attached to distal ends of the one or more struts, the impeller housing comprising an impeller assembly with an impeller operably disposed within the impeller assembly and one or more outlets positioned at a distal portion of the impeller housing, wherein the impeller housing, the cap, and the one or more struts define an inlet region comprising a proximal end and a distal end, the inlet region positioned at a proximal portion of the impeller housing and configured to direct flow into the impeller housing,
wherein the cap comprises a tapered guide surface extending distally from the distal end of the catheter into the inlet region, wherein the inlet region has a tapered surface and tapers towards the impeller such that fluid flow in the inlet region and into the impeller housing is aligned with the guide surface to thereby provide a continuously converging fluid flow pattern between the two tapered surfaces from the inlet proximal region to the inlet distal region configured to direct fluid flow into the impeller housing without recirculation.
2 . The device of claim 1 , further comprising an expandable member aligned over an exterior surface of the impeller housing, wherein an exterior surface of the expandable member is coupled to the exterior surface of the impeller housing, and wherein, when the expandable member is in an expanded state, the expandable member directs fluid flow to the inlet region of the impeller housing, wherein, when in the expanded state, a proximal face of the expandable member is substantially aligned with a distal portion of the inlet region.
3 . The device of claim 2 , wherein the expandable member comprises a fluidically sealed inflation space that is radially expandable relative to the impeller housing.
4 . The device of claim 3 , wherein the impeller assembly comprises an inflation tube connecting the inflation space to a lumen of the catheter, wherein the inflation tube extends, exterior of the proximal strut, between the catheter and the inflation space.
5 . The device of claim 4 , wherein the inflation space comprises an inflation port for expanding the expandable member.
6 . The device of claim 1 , wherein operation of the impeller within a blood vessel drives blood into the impeller assembly via the inlet region and out of the impeller assembly via the one or more outlets.
7 . A method for treating edema, the method comprising:
providing a device comprising:
a catheter comprising a proximal portion and a distal portion;
a cap secured to the distal portion;
one or more struts extending distally from the cap; and
an impeller housing attached to distal ends of the one or more struts, the impeller housing comprising an impeller assembly with an impeller operably disposed within the impeller assembly and one or more outlets positioned at a distal portion of the impeller housing, wherein the impeller housing, the cap, and the one or more struts define an inlet region comprising a proximal end and a distal end, the inlet region positioned at a proximal portion of the impeller housing and configured to direct flow into the impeller housing,
wherein the cap comprises a tapered guide surface extending distally from the distal end of the catheter into the inlet region, wherein the inlet region has a tapered surface and tapers towards the impeller such that fluid flow in the inlet region and into the impeller housing is aligned with the guide surface to thereby provide a continuously converging fluid flow pattern between the two tapered surfaces from the inlet proximal region to the inlet distal region configured to direct fluid flow into the impeller housing without recirculation; and
operating the impeller to thereby decrease pressure at a lymphatic duct.
8 . The method of claim 7 , wherein the device further comprises an expandable member aligned over an exterior surface of the impeller housing, wherein an exterior surface of the expandable member is coupled to the exterior surface of the impeller housing, wherein the method further comprises expanding the expandable member and wherein, when the expandable member is in an expanded state, a proximal face of the expandable member is substantially aligned with a distal portion of the inlet region and the expandable member directs fluid flow to the inlet region of the impeller housing.
9 . The method of claim 8 , wherein the expandable member comprises a fluidically sealed inflation space that is radially expandable relative to the impeller housing.
10 . The method of claim 9 , wherein the impeller assembly comprises an inflation tube connecting the inflation space to a lumen of the catheter, wherein the inflation tube extends, exterior of the proximal strut, between the catheter and the inflation space.
11 . The method of claim 10 , wherein the inflation space comprises an inflation port for expanding the expandable member.
12 . The method of claim 7 , wherein operation of the impeller within a blood vessel drives blood into the impeller assembly via the inlet region and out of the impeller assembly via the one or more outlets.