Cannulae having reduced flow resistance

• US 7,445,592 B2
• Filed: 06/10/2004
• Issued: 11/04/2008
• Est. Priority Date: 06/10/2004
• Status: Active Grant

• Current Assignee: TC1 LLC (Abbott Laboratories)
• Original Assignee: ORQIS Medical Corporation
• Inventors: Pecor, Robert
• Primary Examiner(s): MANUEL, GEORGE C
• Application Number:
  US10/866,535
• Publication Number:
  US 20050277803A1
• Time in Patent Office: 1,608 Days
• Field of Search: 600/16, 600/485, 604/6.14, 604/507
• US Class Current: 600/16
• CPC Class Codes: A61M 2202/0225 Carbon oxides, e.g. Carbon dioxide
• CPC Class Codes: A61M 2202/0413 Blood
• CPC Class Codes: A61M 2205/3523 using telemetric means
• CPC Class Codes: A61M 2205/3561 local, e.g. within room or hospital
• CPC Class Codes: A61M 5/14276 specially adapted for implantation

Abstract

A percutaneous cannula is provided for the exchange of blood within a patient'"'"'s vasculature. The cannula includes a main cannula portion and a tip portion. The main cannula portion comprises a proximal portion, a distal portion, a first lumen, and a second lumen extending through the proximal portion. The tip portion extends from the main cannula portion to a distal end of the cannula. The tip portion comprises a discharge opening and a redirecting member. The redirecting member is configured to direct blood flow being discharged through the discharge opening proximally along the cannula. At least one of the first and second lumens is configured to reduce the effect of flow resistance therein.

Claims

1. A percutaneous cannula for the exchange of blood within a patient'"'"'s vasculature, the cannula comprising:

a main cannula portion comprising a proximal portion, a distal portion, a first lumen, and a second lumen extending through the proximal portion, the first lumen having a first perimeter at a location within the proximal portion and a second perimeter at a location within the distal portion, the second perimeter being greater than the first perimeter; and

a tip portion extending from the main cannula portion to a distal end of the cannula, the tip portion comprising;

a discharge opening configured to discharge blood externally to the cannula; and

a redirecting member configured to direct blood flow being discharged through the discharge opening along the cannula toward the proximal portion of the main cannula portion.

2. The cannula of claim 1, wherein the first lumen is longer than the second lumen.

3. The cannula of claim 1, wherein the tip portion is connected to the first lumen.

4. The cannula of claim 3, wherein the first lumen is longer than the second lumen.

5. The cannula of claim 3, wherein the tip portion further comprises a surface extending across the first lumen, the surface configured to direct blood through the discharge opening.

6. The cannula of claim 5, wherein the surface is curved.

7. The cannula of claim 6, wherein the surface is spherical or parabolic.

8. A system comprising:

the cannula of claim 1; and

a pump configured to fluidly communicate with the first lumen and to fluidly communicate with the second lumen.

9. The system of claim 8, wherein the pump is configured to pump blood through the patient at subcardiac rates.

10. A method of treating a patient, comprising:

providing a percutaneous cannula comprising

a main cannula portion comprising a proximal portion, a distal portion, a first lumen, and a second lumen extending through the proximal portion, the main cannula portion comprising an inlet for one of the first and second lumens, and at least one of the first and second lumens is configured to reduce the effect of flow resistance therein; and

a tip portion extending from the main cannula portion to a distal end of the cannula, the tip portion comprising;

a discharge opening fluidly coupled to the inlet through one of the first and second lumens and located distally of the inlet; and

a redirecting member configured to direct blood flow being discharged through the discharge opening along the cannula toward the proximal portion of the main cannula portion; and

inserting the cannula into the vasculature of the patient such that the redirecting member is located in the vasculature.

11. The method of claim 10, wherein the first lumen is longer than the second lumen.

12. The method of claim 10, wherein the tip portion is connected to the first lumen.

13. The method of claim 12, wherein the first lumen is longer than the second lumen.

14. The method of claim 10, further comprising coupling a pump with the cannula such that positive pressure is applied to the first lumen.

15. The method of claim 10, further comprising

drawing blood into the second lumen;

directing blood into the first lumen toward the discharge opening.

16. The method of claim 10, wherein the first lumen has a first cross-sectional area at a location within the proximal portion and a second cross-sectional area at a location within the distal portion, the second cross-sectional area being greater than the first cross-sectional area.

17. The method of claim 10, further comprising drawing blood from the vasculature into the inlet and discharging blood through the discharge opening at a location distal of the inlet.

18. A percutaneous cannula for the exchange of blood within a patient'"'"'s vasculature, the cannula comprising:

a main cannula portion comprising a proximal portion, a distal portion, a first lumen, and a second lumen extending through the proximal portion, the main cannula portion comprising an inlet for one of the first and second lumens; and

a tip portion extending from the main cannula portion to a distal end of the cannula, the tip portion comprising;

a discharge opening fluidly coupled to the inlet through one of the first and second lumens and located distally of the inlet; and

a redirecting member configured to direct blood flow being discharged through the discharge opening along the cannula toward the proximal portion of the main cannula portion;

wherein at least one of the first and second lumens is configured to reduce the effect of flow resistance therein.

19. The cannula of claim 18, wherein the effect of flow resistance is reduced by configuring the first lumen with a first cross-sectional area at a location within the proximal portion and a second cross-sectional area at a location within the distal portion, the second cross-sectional area being greater than the first cross-sectional area.

20. The cannula of claim 18, wherein the effect of flow resistance is reduced by configuring the first lumen to induce a rotational component in the flow of blood therein.

21. The cannula of claim 20, further comprising a ridge extending into the lumen.

22. The cannula of claim 21, wherein the ridge is a spiral ridge extending about the lumen.

23. The cannula of claim 18, wherein the redirecting member comprises an expandable member configured to expand under the pressure of the blood flow directed through the discharge opening such that at least a portion of the expandable member is spaced from the discharge opening by a greater amount than prior to such expansion, the expandable member presenting a concave redirecting surface to blood flowing through the discharge opening when expanded.

24. The cannula of claim 23, wherein the expandable member has a proximal end with a perimeter, the expandable member having a contracted configuration in which the perimeter has a first length and an expanded configuration in which the perimeter has a second length, the second length being greater than the first length.

25. The cannula of claim 18, wherein the redirecting member is collapsible to cover the discharge opening during insertion.

26. The cannula of claim 18, wherein the redirecting member is collapsible to partially cover the discharge opening during insertion.

27. The cannula of claim 18, wherein the redirecting member is actuatable to a pre-defined shape.

28. The cannula of claim 18, wherein the tip portion comprises a plurality of discharge openings.

29. The cannula of claim 28, wherein the tip portion further comprises a plurality of redirecting members configured to direct blood flow being discharged through the discharge openings proximally along the cannula.

30. The cannula of claim 29, wherein at least one of the redirecting members comprises an expandable member having a distal end and a proximal end adjacent to a proximal end of a corresponding discharge opening, at least two sides of the expandable member being connected to the tip portion.

31. The cannula of claim 28, wherein the discharge openings are uniformly spaced radially around the tip portion.