Devices and methods for treating edema

Abstract

The disclosure relates to devices and methods for the treatment of edema, which devices use a restrictor for flow compensation. Devices and methods of the invention further use a flow-restrictor in the circulatory system, upstream of an intravascular pump, to balance pressure changes induced by the pump and to compensate for downstream flow. The device may be provided as an indwelling, intravascular catheter with a mechanical pump such as an impeller and a selectively deployable restrictor such as an inflatable balloon. Congestive heart failure or edema is treated by \ operating the pump in an innominate vein and using the restrictor for flow compensation, to restrict the upstream flow and thus amplify or maintain pressure reduction at the lymphatic outlet.

1 .- 19 . (canceled) 
     
     
         20 . A device for treating edema, the device comprising:
 a catheter dimensioned to be at least partially implanted within the vasculature;   a proximal flow restrictor;   a distal pump, the distal pump comprising an impeller assembly that comprises an impeller housing with an impeller therein and an inlet region; and   an expandable member mounted around at least a portion of a proximal end of an exterior surface of the impeller housing, and wherein, when the expandable member is in an expanded state, the expandable member directs fluid flow to an inlet region of the impeller assembly;   wherein the device is configured for insertion into a jugular of a patient and deploying the proximal flow restrictor in the jugular vein upstream of the pump at least partially within an innominate vein downstream of a lymphatic duct restricts flow from the jugular vein to the innominate vein and at least partially creates a pressure depression at the outlet of the lymphatic duct; and   operating the pump to direct fluid flow through the innominate vein through the inlet region of the impeller assembly increases flow through the innominate vein in order to amplify or maintain the pressure depression at the outlet of the lymphatic duct.   wherein the device comprises a sensor that senses pressure changes in a jugular vein of the patient that results from the increased flow; and   the device is configured to adjust the proximal restrictor to restrict flow from the jugular vein to the innominate vein based on the sensed pressure.   
     
     
         21 . The device of  claim 20 , wherein the proximal flow restrictor includes an inflatable balloon and the device restricts the flow by inflating the proximal flow restrictor. 
     
     
         22 . The device of  claim 21 , wherein the device continually senses pressure change with the sensor and periodically or continually adjusts inflation of the proximal flow restrictor according to the sensed pressure. 
     
     
         23 . The device of  claim 22 , wherein adjusting the flow balances pressure downstream of the pump. 
     
     
         24 . The device of  claim 23 , wherein a proximal portion of the catheter is connected to a motor housing having a motor therein operably coupled to the impeller assembly. 
     
     
         25 . The device of  claim 24 , wherein the catheter is coupled to a computer system operable to read the pressure or control the inflation. 
     
     
         26 . The device of  claim 25 , wherein the proximal flow restrictor comprises a toroidal shape, in which a proximal surface of the toroidal shape directs fluid into the pump. 
     
     
         27 . The device of  claim 26 , wherein an inner radius of the toroidal shape is substantially the same as a radius of the proximal end of the pump. 
     
     
         28 . The device of  claim 20 , wherein the impeller comprise one or more blades on a shaft, with a radius measured from an axis of the impeller to an outer edge of the blades decreasing from a distal to a proximal portion of the impeller. 
     
     
         29 . The device of  claim 28 , wherein the outer edge of each blade comprises a dogleg defining a step-down in radius located adjacent a transition between the distal portion and the proximal portion of the impeller housing. 
     
     
         30 . The device of  claim 20 , a distal portion of the impeller housing has outlets and the impeller shaft flares outwards near a distal end of the impeller such that when the impeller is rotated, the impeller pumps blood through the impeller housing and out of the one or more outlets. 
     
     
         31 . The device of  claim 20 , wherein the device comprises a motor housing connected to the proximal portion of the catheter with a motor disposed within the motor housing. 
     
     
         32 . The device of  claim 31 , wherein the device comprises a drive cable extending through the catheter from the motor to the impeller with an inflation lumen extending along the catheter to the proximal flow restrictor. 
     
     
         33 . The device of  claim 20 , wherein an exterior surface of the proximal flow restrictor is physically coupled to an exterior surface of the impeller housing. 
     
     
         34 . The device of  claim 33 , wherein he exterior surface of the proximal flow restrictor is physically coupled directly to the exterior surface of the impeller housing without any membrane, sheath, or device between the exterior surface of the proximal flow restrictor and the exterior surface of the impeller housing. 
     
     
         35 . The device of  claim 34 , wherein the impeller housing comprises a metal and a portion of the proximal restrictor is fixed to a surface of the metal by an adhesive. 
     
     
         36 . The device of  claim 35 , wherein a portion of the surface of the metal is impregnated with a polymer to promote bonding to the adhesive. 
     
     
         37 . The device of  claim 20 , wherein the device is a purge-free device.