Non-thrombogenic devices for treating edema

A device for treating edema, the device comprising:

• a catheter dimensioned for insertion into a vein, the catheter comprising:
• a proximal portion;
• a distal portion;
• a cage attached to the distal portion of the catheter, the cage comprising:
• a proximal region comprising one or more inlet openings;
• a distal region comprising one or more outlet openings, said distal region being occlusive to axial blood flow;
• an inner lumen;
• and
• an exterior surface between the proximal region and the distal region and having an impeller rotatably disposed therein,
• wherein the impeller is configured to pump blood through the one or more inlet openings through the cage to the one or more outlet openings to thereby create a low pressure region in the vein proximal to the one or more inlet openings, wherein the impeller pumps blood from the low pressure region through the cage to a region of higher relative pressure while mitigating recirculation,
• wherein, when the impeller operates to pump blood, the inner lumen, the one or more inlet openings, and the one or more outlet openings define a fluid flow path configured to mitigate blood recirculation;
• and
• an expandable member attached to the exterior surface of the cage between the proximal region and the distal region, wherein the expandable member surrounds a portion of the impeller and blood pumped through the cage,
• wherein a portion of a surface of the expandable member comprises a non-thrombogenic surface comprising a hydrophilic material or hydrophilic coating configured to selectively bind water molecules to the exclusion of one or more blood plasma proteins thereby preventing blood clots.