Cannulae having reduced flow resistance

• US 20050277803A1
• Filed: 06/10/2004
• Published: 12/15/2005
• Est. Priority Date: 06/10/2004
• Status: Active Grant

• Current Assignee: TC1 LLC (Abbott Laboratories)
• Original Assignee: ORQIS Medical Corporation
• Inventors: Pecor, Robert
• Granted Patent: US 7,445,592 B2
• Time in Patent Office: Days
• 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 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; and

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

a discharge opening; and

a redirecting member configured to direct blood flow being discharged through the discharge opening proximally along the cannula.

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. 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.

6. The system of claim 5, wherein the pump is configured to pump blood through the patient at subcardiac rates.

7. 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 first lumen having 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; and

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

a discharge opening; and

a redirecting member configured to direct blood flow being discharged through the discharge opening proximally along the cannula.

using the cannula to treat the patient.

8. The method of claim 7, wherein the first lumen is longer than the second lumen.

9. The method of claim 7, wherein the tip portion is connected to the first lumen.

10. The cannula of claim 9, wherein the first lumen is longer than the second lumen.

11. The method of claim 7, further comprising coupling a pump with the cannula such that positive pressure is applied to the first lumen.

12. The method of claim 7, further comprising drawing blood into the second lumen;

directing blood into the first lumen toward the discharge opening.

13. 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; and

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

a discharge opening; and

a redirecting member configured to direct blood flow being discharged through the discharge opening proximally along the cannula;

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

14. The cannula of claim 13, 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.

15. The cannula of claim 13, wherein the effect of flow resistance is reduced by configuring the first lumen to induce a rotational component in the flow of blood therein.

16. The cannula of claim 15, further comprising a ridge extending into the lumen.

17. The cannula of claim 16, wherein the ridge is a spiral ridge extending about the lumen.