Catheter pump

• US 9,358,329 B2
• Filed: 03/13/2013
• Issued: 06/07/2016
• Est. Priority Date: 07/03/2012
• Status: Active Grant

• Current Assignee: Thoratec LLC
• Original Assignee: Thoratec LLC
• Inventors: Fitzgerald, Keif M., Keenan, Richard L., Harrison, William J.
• Primary Examiner(s): So, Elizabeth K
• Application Number:
  US13/801,528
• Publication Number:
  US 20140012065A1
• Time in Patent Office: 1,182 Days
• US Class Current: 1/1
• 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 60/148 in line with a blood vessel using resection or like techniques, e.g. permanent endovascular heart assist devices
• 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 60/216 including a rotating member acting on the blood, e.g. impeller
• 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 60/411 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 60/508 Electronic control means, e.g. for feedback regulation
• 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 60/857 Implantable blood tubes
• CPC Class Codes: A61M 60/859 Connections therefor

Abstract

A catheter pump is provided that includes a rotatable impeller and an elongate cannula. The elongate cannula has a mesh that has a plurality of circumferential members disposed about the impeller. The elongate cannula has a plurality of axial connector extending between a proximal side of a distal circumferential member and a distal side of a proximal circumferential member. The circumferential members are radially self-expandable. The cannula is configured to minimize fracture within at least in the distal zone of the mesh as the elongated cannula moves into a sheathing device.

Claims

1. An apparatus for pumping blood, comprising:

a rotatable impeller;

an elongate cannula having a plurality of circumferential members disposed about the impeller, one or more of the circumferential members having an undulating configuration including a plurality of proximal and distal apices, each proximal apex connected to a distal apex by an elongate strut; and

an axial connector having a distal portion coupled with a proximal apex of a first circumferential member and a proximal portion coupled with a second circumferential member disposed proximal of the first circumferential member, the axial connector comprising a central portion extending between the distal portion of the axial connector and the proximal portion of the axial connector, the central portion comprising a curved segment having no inflection points at which the curvature of the curved segment changes between convex and concave, the central portion extending along a majority of the axial connector.

2. The apparatus of claim 1, further comprising:

a plurality of circumferential connectors disposed between alternating struts of adjacent circumferential members; and

a plurality of axial connectors comprising a distal end coupled with a proximal side of a proximal apex of the first circumferential member, a proximal end coupled with a distal face of a second circumferential member disposed adjacent to and proximal of the first circumferential member, and an arcuate section disposed therebetween, wherein the arcuate section comprises a single convex portion disposed between the proximal and distal ends.

3. The apparatus of claim 1, wherein the elongate cannula comprises an impeller zone disposed about the impeller and a distal zone disposed distal of the impeller zone, and wherein the axial connectors comprise a first plurality and further comprising:

a second plurality of axial connectors is disposed between a proximal side of a proximal apex and a distal side of an adjacent circumferential member in the distal zone of the cannula, the axial connectors of the second plurality being more flexible than the axial connectors of the first plurality.

4. The apparatus of claim 1, further comprising an enclosure disposed about the circumferential members to enclose a lumen along a length of the cannula between an inlet and an outlet.

5. The apparatus of claim 1, wherein the elongated cannula comprises a region of enhanced local stiffness around the proximal apices.

6. The apparatus of claim 5, wherein a circumferential connector is disposed between alternating adjacent elongate struts of a pair of adjacent circumferential members throughout a distal zone of the cannula.

7. The apparatus of claim 5, wherein each apex in a distal zone of the cannula is configured such that upon expansion a first lateral side adjacent to each apex moves away from an axial centerline of the apex by a greater amount than a second lateral side adjacent the apex, such that circumferentially spaced zones of high strut concentration are formed adjacent to proximal apices.

8. The apparatus of claim 7, wherein opposing sides of alternating elongate struts of at least two adjacent circumferential members in the distal zone are not connected by circumferential connectors.

9. The apparatus of claim 8, wherein the cannula comprises a first length disposed over the impeller having a first stiffness and a second length disposed distal to the impeller having a second stiffness less than the first stiffness.

10. The apparatus of claim 7, wherein a circumferential connector is provided between opposing sides of alternating adjacent elongate struts of at least two adjacent circumferential members in the distal zone.

11. The apparatus of claim 10, wherein each circumferential member in the distal zone is attached to another circumferential member by a circumferential connector.

12. The apparatus of claim 11, wherein at least about one-half of the struts in the distal zone are connected to other struts by circumferential connectors.

13. The apparatus of claim 1, further comprising a sheath configured to be positioned over the elongate cannula to move the cannula from an expanded configuration to a collapsed configuration.

14. The apparatus of claim 1, further comprising a biocompatible polymeric film disposed about the circumferential members to enclose a lumen along a length of the cannula between an inlet and an outlet.

15. The apparatus of claim 1, further comprising a film support member having a first end connected to an elongate strut of a first circumferential member and a second end connected to an elongate strut of a second circumferential member, the film support having a length greater than the distance between the first and second circumferential members in the unexpanded state of the cannula, the film support member segmenting an area defined between the adjacent circumferential members to reduce the unsupported area of a film disposed over the cannula.

16. The apparatus of claim 1, further comprising a sheathing device, wherein the elongate cannula has a mesh that comprises the plurality of circumferential members, the circumferential members being radially self-expandable,

wherein the cannula is configured to minimize fracture at least within the distal zone of the mesh as the elongated cannula moves into the sheathing device.

17. The apparatus of claim 16, wherein the struts are located laterally of a plane intersecting the apices and a central longitudinal axis of the cannula and being intersected by a plane intersecting an adjacent apex and the central longitudinal axis of the cannula.

18. The apparatus of claim 16, the elongate cannula having an impeller zone over the impeller and a distal zone disposed distally of the impeller zone, the distal zone having enhanced concentration of struts per unit area about the axial member when the cannula is expanded.

19. The apparatus of claim 18, wherein the mesh pattern of the impeller zone and the mesh pattern of the distal zone are different.

20. The apparatus of claim 19, wherein when expanded, the cannula comprises a plurality of spaced apart helical zones with enhanced concentration of struts per unit area formed.

21. The apparatus of claims 16, wherein a plurality of axial connectors are provided between adjacent circumferential members, the axial connectors having an apex connection, a strut connection, and a plurality of inflections disposed therebetween.

22. The apparatus of claim 16, further comprising a plurality of circumferential connectors extending between alternating adjacent elongate struts of a pair of adjacent circumferential member.

23. The apparatus of claim 22, the elongate cannula having an impeller zone over the impeller and a distal zone disposed distally of the impeller zone, wherein the plurality of circumferential connectors comprise a first plurality disposed in the impeller zone and a second plurality disposed in the distal zone of the cannula, the first plurality of circumferential connectors providing greater stiffness than the second plurality of circumferential connectors.

24. The apparatus of claim 23, wherein circumferential connectors of the first plurality have a length along the struts that is greater than the separation between adjacent circumferential members.

25. The apparatus of claim 24, wherein each circumferential member is connected to at least one other circumferential connector by the axial member disposed therebetween.

26. The apparatus of claim 23, wherein circumferential connectors of the first plurality have a length that is at least about two times the separation between adjacent circumferential members connected by circumferential connectors of the first plurality.

27. The apparatus of claim 23, wherein circumferential connectors of the first plurality and the struts joined thereby provide greater concentration of material per unit area than the circumferential connectors of the second plurality and the struts joined thereby.

28. The apparatus of claim 27, further comprising an enclosure comprising polyurethane disposed about the mesh structure to enclose a lumen along a length of the cannula between an inlet and an outlet.

29. The apparatus of claim 1, wherein the axial connector has a length that is less than the distance between the proximal apex to which the distal end of the axial connector is connected and a proximal apex of the second circumferential member that is axially aligned with the proximal apex to which the distal end of the axial connector is connected.

30. The apparatus of claim 1, wherein the distal portion of the axial connector comprises a distal end of the axial connector and the proximal portion of the axial connector comprises a proximal end of the axial connector.

31. An apparatus for pumping blood, comprising:

a rotatable impeller;

an elongate cannula having a plurality of circumferential members disposed about the impeller, one or more of the circumferential members having an undulating configuration including a plurality of proximal and distal apices, each proximal apex connected to a distal apex by an elongate strut; and

an axial connector having a distal portion coupled with a proximal apex of a first circumferential member and a proximal portion coupled with a second circumferential member disposed proximal of the first circumferential member, the axial connector comprising a central portion extending between the distal portion of the axial connector and the proximal portion of the axial connector, the central portion consisting of a single convex curved segment, the central portion extending along a majority of the axial connector.

32. The apparatus of claim 31, further comprising a sheathing device configured to cause the elongate cannula to collapse from an expanded configuration to a collapsed configuration.

33. The apparatus of claim 31, wherein the distal portion of the axial connector comprises a distal end of the axial connector and the proximal portion of the axial connector comprises a proximal end of the axial connector.