Cannula pumps for temporary cardiac support and methods of their application and use

• US 5,776,190 A
• Filed: 10/19/1994
• Issued: 07/07/1998
• Est. Priority Date: 10/30/1992
• Status: Expired due to Term

• Current Assignee: M.D. Robert Jarvik
• Original Assignee: M.D. Robert Jarvik
• Inventors: Jarvik, Robert
• Primary Examiner(s): Weiss, John G.
• Assistant Examiner(s): SNOW, BRUCE EDWARD
• Application Number:
  US08/325,848
• Time in Patent Office: 1,357 Days
• Field of Search: 623/2, 623/3, 604/175, 604/43, 600/16-17, 417/254-256
• US Class Current: 600/16
• CPC Class Codes: A61M 2205/3334 Measuring or controlling the flow rate
• 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 60/165 implantable in, on, or around the heart
• CPC Class Codes: A61M 60/174 discharging the blood to the ventricle or arterial system via a cannula internal to the ventricle or arterial system
• CPC Class Codes: A61M 60/178 drawing blood from a ventricle and returning the blood to the arterial system via a cannula external to the ventricle, e.g. left or right ventricular assist devices
• CPC Class Codes: A61M 60/183 drawing blood from both ventricles, e.g. bi-ventricular assist devices [BiVAD]
• CPC Class Codes: A61M 60/221 the blood flow through the rotating member having both radial and axial components, e.g. mixed flow pumps
• 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 60/38 Blood oxygenation
• 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 60/515 Regulation using real-time patient data
• CPC Class Codes: A61M 60/523 using blood flow data, e.g. from blood flow transducers
• CPC Class Codes: A61M 60/531 using blood pressure data, e.g. from blood pressure sensors
• CPC Class Codes: A61M 60/538 Regulation using real-time blood pump operational parameter data, e.g. motor current
• CPC Class Codes: A61M 60/585 User interfaces
• CPC Class Codes: A61M 60/824 Hydrodynamic or fluid film bearings
• CPC Class Codes: A61M 60/825 Contact bearings, e.g. ball-and-cup or pivot bearings
• CPC Class Codes: A61M 60/827 Sealings between moving parts
• CPC Class Codes: A61M 60/829 having a purge fluid supply
• 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 60/878 : Electrical connections within the patient's body

Abstract

A cannula pump is provided which incorporates a miniature rotary pump into a cardiac cannula of essentially the same size as currently utilized with routine cardiopulmonary bypass. The pump may be inserted via a single small incision in the heart to obtain both inflow and outflow cannulation simultaneously, and provide sufficient flow to completely unload the ventricle during its use. Because application of the device is extraordinarily simplified, it is suitable for rapid emergency insertion in any setting where the chest can be safely opened, including emergency room and battlefield applications. A small electric motor, implanted within the heart, provides power to the impeller via a small shaft supported on blood immersed bearings. A disposable cannula pump utilized with a reusable motor provides an inexpensive device for routine surgical use.

Claims

1. A method for supporting all or part of the pumping function of a heart, comprising the steps of:

a) providing a cannula pump including a cannula housing having a pump section and a motor section, the pump section having a pumping mechanism, the motor section having an electric motor mounted therein for imparting movement to the pumping mechanism, the pump section and motor section having substantially equal outer diameters, the cannula housing further including at least one blood inflow opening disposed in the pump section to permit blood to enter the pump section and at least one blood outflow opening to permit blood to exit the cannula housing;

b) positioning the cannula pump within one of the left and right ventricles of a patient'"'"'s heart such that at least the electric motor is contained within the one ventricle and the outflow opening of the cannula housing is disposed within a respective artery associated with the one ventricle; and

c) activating the electric motor such that the pumping mechanism directs blood entering through the inflow opening of the cannula housing through the outflow opening of the cannula housing.

2. The method of claim 1, wherein the step of activating the electric motor includes rotating an impeller of the pump mechanism such that the impeller imparts mechanical energy to blood within the cannula housing to direct the blood through the outflow opening of the cannula housing.

3. The method of claim 2, wherein the step of providing a cannula pump includes providing a rotary pump selected from the group consisting of axial flow, mixed flow and centrifugal pumps.

4. The method of claim 2, wherein the step of activating the electric motor actuates a magnetically actuated rotatable rotor of the electric motor to cause rotation of the impeller.

5. The method of claim 4, wherein the step of actuating the electric motor rotates a rotatable drive shaft operatively connected to the rotor to thereby cause rotation of the impeller.

6. The method of claim 1, wherein the step of positioning the cannula pump includes positioning an impeller of the pumping mechanism within the one ventricle.

7. The method of claim 6, further comprising the step of making a small incision in the apex of one of the left and right ventricles and the step of positioning the cannula pump includes the step of inserting the cannula pump through the small incision.

8. The method of claim 1, further including the step of making an incision in the patient'"'"'s heart in the one ventricle to permit positioning of the cannula pump at least partially within the one ventricle, the step of making an incision in the patient'"'"'s heart being performed prior to the step of positioning the cannula pump.

9. The method of claim 8, wherein the step of making an incision includes the step of making a small incision in the apex of the heart.

10. The method of claim 8, wherein the step of positioning the cannula pump includes introducing a constricted portion of the cannula housing within the incision made in the heart to at least partially position the cannula pump within the one ventricle.

11. The method of claim 1, wherein the step of positioning the cannula pump includes positioning a constricted portion of the cannula housing within a respective artery associated with the one ventricle, the constricted portion defining the outflow opening.

12. The method of claim 1, wherein the step of activating the electric motor causes the pump to direct blood entering through at least one inflow opening formed in a side wall of the cannula housing.

13. The method of claim 12, wherein the step of providing a cannula pump includes providing the cannula housing with a plurality of openings in the side wall.

14. The method of claim 1, further comprising positioning a second cannula pump at least partially within the other of the ventricles of the patient'"'"'s heart.

15. The method of claim 14, further comprising the step of activating an electric motor of the second cannula pump to direct blood through an outflow opening of the pump, the electric motor being positioned in the ventricle.

16. A method for supporting all or part of the pumping function of a heart, comprising the steps of:

providing a cannula pump including a cannula housing having a pump section and a motor section, the pump section having a pumping mechanism, the motor section having an electric motor mounted therein for imparting movement to the pumping mechanism, the pump section and motor section having substantially equal outer diameters, the cannula housing further including at least one blood inflow opening disposed in the pump section to permit blood to enter the pump section and at least one blood outflow opening to permit blood to exit the cannula housing;

b) positioning the cannula pump within one of the left and right ventricles of a patient'"'"'s heart such that at least the electric motor is contained within the one ventricle and an impeller of the pump mechanism is at least partially within an artery associated with the one ventricle; and

c) activating the electric motor such that the pumping mechanism directs blood entering through the inflow opening of the cannula housing through the outflow opening of the cannula housing.

17. A method for supporting all or part of the pumping function of a patient'"'"'s heart, comprising the steps of:

a) providing a cannula pump including a cannula housing having at least one blood inflow opening in a side wall of the cannula housing and an outflow opening, a pump mechanism disposed within the cannula housing and having an impeller mounted for rotational movement, an electric motor disposed within the cannula housing and having a magnetically actuated rotor, and a rotatable drive shaft operatively connected to the rotor and operatively connected to the impeller such that rotational movement of the rotor causes corresponding rotational movement of the impeller;

b) making an incision in the heart adjacent one of the left and right ventricles;

c) inserting the cannula pump within the incision such that the impeller and the electric motor are contained within the one ventricle and the outflow opening is disposed within an artery associated with the one ventricle; and

d) activating the electric motor such that the impeller imparts mechanical energy to the blood entering the inflow opening to direct the blood through the outflow opening.

18. The method of claim 17, wherein the step of making an incision includes the step of making a small incision in the apex of the heart.

19. The method of claim 17, wherein the step of inserting the cannula pump includes initially inserting a constricted portion of the cannula housing within the incision in the heart to at least partially position the cannula pump within the one ventricle.