Renal pump

• US 10,039,874 B2
• Filed: 03/13/2014
• Issued: 08/07/2018
• Est. Priority Date: 03/13/2013
• Status: Active Grant

• Current Assignee: Magenta Medical Ltd.
• Original Assignee: Magenta Medical Ltd.
• Inventors: Schwammenthal, Ehud, Tuval, Yosi, Glozman, Daniel
• Primary Examiner(s): Holmes, Rex R
• Application Number:
  US14/774,081
• Publication Number:
  US 20160022890A1
• Time in Patent Office: 1,608 Days
• CPC Class Codes: A61B 5/02055 Simultaneously evaluating both cardiovascular condition and temperature
• CPC Class Codes: A61F 2/07 Stent-grafts
• CPC Class Codes: A61M 2207/00 Methods of manufacture, assembly or production
• CPC Class Codes: A61M 2210/1082 Kidney
• CPC Class Codes: A61M 2210/12 Blood circulatory system
• CPC Class Codes: A61M 60/13 by means of a catheter allowing explantation, e.g. catheter pumps temporarily introduced via the vascular system
• CPC Class Codes: A61M 60/135 inside a blood vessel, e.g. using grafting
• CPC Class Codes: A61M 60/148 in line with a blood vessel using resection or like techniques, e.g. permanent endovascular heart assist devices
• CPC Class Codes: A61M 60/237 the blood flow through the rotating member having mainly axial components, e.g. axial flow pumps
• CPC Class Codes: A61M 60/33 of kidneys
• CPC Class Codes: A61M 60/411 generated by an electromotor
• CPC Class Codes: A61M 60/414 transmitted by a rotating cable, e.g. for blood pumps mounted on a catheter
• CPC Class Codes: A61M 60/422 the force acting on the blood contacting member being electromagnetic, e.g. using canned motor pumps
• CPC Class Codes: A61M 60/523 using blood flow data, e.g. from blood flow transducers
• CPC Class Codes: A61M 60/808 specially adapted for deformable impellers, e.g. expandable impellers
• CPC Class Codes: A61M 60/81 Pump housings
• CPC Class Codes: A61M 60/825 Contact bearings, e.g. ball-and-cup or pivot bearings
• CPC Class Codes: A61M 60/833 Occluders for preventing backflow
• CPC Class Codes: A61M 60/861 Connections or anchorings for connecting or anchoring pumps or pumping devices to parts of the patient's body
• CPC Class Codes: A61M 60/896 having flexible or resilient parts, e.g. flap valves

Abstract

Apparatus and methods are described including identifying a subject as suffering from a condition selected from the group consisting of: cardiac dysfunction, congestive heart failure, reduced renal blood flow, increased renal vascular resistance, arterial hypertension, and kidney dysfunction. In response thereto, blood pressure within a renal vein (32) of the subject is reduced, by placing a blood pump (150) inside the subject'"'"'s renal vein and activating the impeller to pump blood from the renal vein into the subject'"'"'s vena cava (26). Other applications are also described.

Claims

1. A method comprising:

identifying a subject as suffering from a condition selected from the group consisting of;

cardiac dysfunction, congestive heart failure, reduced renal blood flow, increased renal vascular resistance, arterial hypertension, and kidney dysfunction; and

in response thereto, reducing blood pressure within a renal vein of the subject, by placing an impeller inside the subject'"'"'s renal vein and activating the impeller to pump blood from the renal vein into a vena cava of the subject.

2. The method according to claim 1, wherein activating the impeller to pump blood from the renal vein into the vena cava comprises enhancing a rate of blood flow from the renal vein into the vena cava, without causing a substantial change in a direction of the blood flow relative to a direction of blood flow from the renal vein into the vena cava in an absence of activating the pump.

3. The method according to claim 1, wherein activating the impeller to pump blood from the renal vein into the vena cava comprises activating the impeller to pump blood from the renal vein directly into a portion of the vena cava that is adjacent to the renal vein.

4. The method according to claim 1, wherein activating the impeller to pump blood from the renal vein into the vena cava comprises activating the impeller to pump blood from the renal vein into the vena cava, without removing blood from a venous system of the subject into a non-venous receptacle.

5. The method according to claim 1, wherein placing the impeller inside the renal vein comprises protecting the subject'"'"'s renal vein from being injured by the impeller, by placing the impeller into the renal vein, with a cage disposed around the impeller, the cage separating an inner wall of the renal vein from the impeller.

6. The method according to claim 5, wherein placing the impeller into the renal vein with the cage disposed around the impeller comprises placing the impeller into the renal vein, with the cage disposed around the impeller, the cage and the impeller being engaged to one another by an engagement mechanism, such that in response to the cage becoming radially compressed, the impeller becomes axially elongated such that the cage maintains a separation between the wall of the renal vein and the impeller.

7. The method according to claim 1, wherein:

placing the impeller inside the subject'"'"'s renal vein comprises;

placing inside the subject'"'"'s renal vein;

an impeller configured, in a radially-expanded configuration thereof, to pump blood through the renal vein by rotating; and

a radially-expandable cage disposed around the impeller;

radially expanding the cage and the impeller inside the renal vein, such that the impeller is separated from an inner wall of the renal vein by the cage,

the impeller being engaged with respect to the cage, such that, in response to the cage becoming radially compressed, the impeller is axially elongated, such that the impeller remains separated from the inner wall of the renal vein; and

activating the impeller to pump blood from the renal vein into the subject'"'"'s vena cava comprises operating a control unit to pump blood from the renal vein into the subject'"'"'s vena cava, by rotating the impeller.

8. The method according to claim 7, further comprising operating the control unit to:

measure pressure within the subject'"'"'s renal vein at a first location within the renal vein that is upstream of the impeller, and at a second location within the renal vein that is downstream of the impeller; and

control rotation of the impeller responsively to the pressure measured at the first and second locations.

9. The method according to claim 7, wherein operating the control unit to rotate the impeller comprises operating the control unit to rotate the impeller, while the cage is maintained in a rotationally fixed position.

10. The method according to claim 7, wherein the cage includes struts that are shaped to define cells, and wherein radially expanding the cage comprises separating the renal vein wall from the impeller even if the renal vein wall protrudes through a cell of the cage, by radially expanding the cage.

11. The method according to claim 7, wherein:

placing the impeller and the cage inside the renal vein comprises placing the impeller and the cage inside the renal vein, the impeller being coupled to the cage such that a longitudinal axis of the impeller is aligned with a longitudinal axis of the cage,

the cage includes a cage that defines a central portion thereof that has a generally cylindrical shape, an outer surface of the cage at the generally cylindrical portion of the cage being parallel to the longitudinal axis of the cage, and

radially expanding the cage inside the renal vein comprises radially expanding the cage inside the renal vein such that the outer surface of the cage at the generally cylindrical portion of the cage engages the inner wall of the renal vein, the cage thereby becoming oriented within the renal vein such that a longitudinal axis of the cage is parallel to a local longitudinal axis of the renal vein.

12. The method according to claim 7, wherein:

the renal vein has a given diameter in an absence of the cage;

radially expanding the cage comprises widening a portion of the renal vein such that a diameter of the portion of the renal vein is greater than the given diameter; and

radially expanding the impeller comprises radially expanding the impeller such that a span of the impeller is at least equal to the given diameter.

13. The method according to claim 7, further comprising operating the control unit to:

measure flow through the renal vein; and

control rotation of the impeller responsively to the measured flow.

14. The method according to 13, wherein operating the control unit to measure flow through the renal vein comprises operating the control unit to measure blood flow via a thermal flow sensor that is disposed within a housing, the housing being configured such that blood flow through the housing is substantially in a direction parallel to a local longitudinal axis of the renal vein.