Low velocity aortic cannula

• US 5,643,226 A
• Filed: 10/06/1994
• Issued: 07/01/1997
• Est. Priority Date: 02/24/1993
• Status: Expired due to Term

• Current Assignee: Cleveland Clinic Foundation, Michigan Critical Care Consultants, Inc.
• Original Assignee: 3M Company, Cleveland Clinic Foundation
• Inventors: Cornhill, J. Frederick, Huldin, Nelson L., O'Neill, William G., Cosgrove, Delos M., Boykin, Christopher M.
• Primary Examiner(s): Hafer, Robert A.
• Assistant Examiner(s): SMITH, CHALIN A
• Application Number:
  US08/319,374
• Time in Patent Office: 999 Days
• Field of Search: 604/30, 604/31, 604/39, 604/44, 604/46, 604/53, 604/264, 604/272-275, 604/280, 604/93, 600/15-17
• US Class Current: 604/264
• CPC Class Codes: A61M 1/3659 Cannulae pertaining to extracorporeal circulation
• CPC Class Codes: A61M 2025/0073 Tip designed for influencing the flow or the flow velocity of the fluid, e.g. inserts for twisted or vortex flow general flow characteristics A61M2206/10
• CPC Class Codes: A61M 2210/127 Aorta
• CPC Class Codes: A61M 25/007 Side holes, e.g. their profiles or arrangements; Provisions to keep side holes unblocked
• CPC Class Codes: A61M 25/06 Body-piercing guide needles or the like

Abstract

An improved aortic cannula having a sidewall with a proximal end, a distal end, and a lumen therebetween for conducting blood, the distal end being adapted for insertion into the aorta during heart surgery to provide blood to the aorta. The cannula has a cap substantially blocking axial flow through the distal end of the lumen. There are a plurality of outlet openings in the sidewall of the cannula adjacent the distal end. The distal end of the lumen is flush with or preferably distally beyond the distal ends of the outlet openings. The aortic cannula may have a bend therein, as is known in the art, in which case the outlet openings on the outside side of the bend are smaller than the outlet openings on the inside side of the bend, to reduce disparity in the flow that would otherwise be caused by the bend, substantially equalizing flow through the openings. According to the method of this invention, an opening is made in the aorta of the patient; the distal end of the cannula is inserted into the opening in the aorta; and blood flow through the cannula is initiated to provide blood to the aorta without jetting.

Claims

1. An improved aortic cannula having a sidewall with a proximal end, a distal end, and a lumen therebetween for conducting blood, the distal end being adapted for insertion into the aorta during heart surgery to provide blood to the aorta the improvement comprising:

a cap substantially blocking axial flow through the distal end of the lumen;

a plurality of arch-shaped outlet openings in the sidewall of the cannula adjacent the distal end, each of the outlet openings having an arcuate proximal end, and a straight distal end, the distal end having a beveled configuration sloping generally outwardly in the distal axial direction; and

the distal end of the lumen being located flush with or distally beyond the distal ends of the outlet openings.

2. The improved aortic cannula according to claim 1 wherein the cannula has a bend therein proximal to the outlet openings.

3. The improved aortic cannula according to claim 1 wherein the portion of the sidewall of the lumen immediately proximal to the outlet openings slopes outwardly in the distal axial direction.

4. The improved aortic cannula according to claim 1 wherein the distal end of the lumen extends distally beyond the distal ends of the outlet openings.

5. The improved aortic cannula according to claim 4 further comprising a raised land projecting proximally from the distal end of the lumen.

6. The improved aortic cannula according to claim 4 wherein the surface of the land is shaped like the surface of a segment of a sphere.

7. The improved aortic cannula according to claim 5 wherein the land extends proximally about 0.030 inches (0.762 mm) from the distal end of the lumen.

8. An improved aortic cannula having a sidewall with a proximal end, a distal end, and a lumen therebetween for conducting blood, the distal end being adapted for insertion into the aorta during heart surgery to provide blood to the aorta, the improvement comprising:

a cap substantially blocking axial flow through the distal end of the lumen;

a plurality of outlet openings in the sidewall of the cannula adjacent the distal end; and

the distal end of the lumen being located between about 0.005 inches (0.127 mm) and about 0.200 inches (5.08 mm) distally beyond the distal ends of the outlet openings.

9. The improved aortic cannula according to claim 8 wherein the distal end of the lumen is located about 0.090 inches (2.29 mm) distally beyond the distal ends of the outlet openings.

10. An improved aortic cannula having a sidewall with a proximal end, a distal end, and a lumen therebetween for conducting blood, the distal end being adapted for insertion into the aorta during heart surgery to provide blood to the aorta, the improvement comprising:

a cap substantially blocking axial flow through the distal end of the lumen;

a plurality of outlet openings in the sidewall of the cannula adjacent the distal end, the distal end of the lumen being located distally beyond the distal ends of the outlet openings; and

a raised land projecting proximally from the distal end of the lumen, such that the proximal end of the land is distal to the distal ends of the outlet openings.

11. The improved aortic cannula according to claim 10 wherein the proximal ends of the outlet openings have an arcuate shape.

12. An improved aortic cannula having a sidewall with a proximal end, a distal end, and a lumen therebetween for conducting blood, the distal end being adapted for insertion into the aorta during heart surgery to provide blood to the aorta, the improvement comprising:

a cap substantially blocking axial flow through the distal end of the lumen;

a plurality of outlet openings in the sidewall of the cannula adjacent the distal end, the distal ends of the outlet openings having a beveled configuration, sloping generally outwardly in the distal axial direction, the distal end of the lumen being located distally beyond the distal ends of the outlet openings; and

a raised land projecting proximally from the distal end of the lumen, such that the proximal end of the land is distal to the distal ends of the outlet openings.

13. An improved aortic cannula having a sidewall with a proximal end, a distal end, and a lumen therebetween for conducting blood, the distal end being adapted for insertion into the aorta during heart surgery to provide blood to the aorta, the improvement comprising:

a cap substantially blocking axial flow through the distal end of the lumen;

a plurality of outlet openings in the sidewall of the cannula adjacent the distal end;

the distal end of the lumen being located flush with, or distally beyond the distal ends of the outlet openings;

the cannula having a bend therein proximal to the outlet openings, and at least some of the outlet openings on the outside side of the bend being smaller than at least some of the openings on the inside side of the bend to reduce the disparity in flow between openings on the inside and outside sides of the bend that would otherwise be caused by the bend.

14. An improved aortic cannula having a sidewall with a proximal end, a distal end, and a lumen therebetween for conducting blood, the distal end being adapted for insertion into the aorta during heart surgery to provide blood to the aorta, the improvement comprising:

a cap substantially blocking axial flow through the distal end of the lumen;

a plurality of outlet openings in the sidewall of the cannula adjacent the distal end;

the distal end of the lumen being located flush with, or distally beyond the distal ends of the outlet openings; and

the cannula having a bend therein proximal to the outlet openings, wherein at least some of the outlet openings on the outside side of the bend are smaller than at least some of the openings on the inside side of the bend to substantially equalize flow through the openings.

15. A method of providing blood to the aorta of a patient, the method comprising the steps of:

making an opening in the aorta of the patient;

providing a cannula having sidewall with a proximal end, a distal end, and a lumen therebetween for conducting blood, the distal end being adapted for insertion into the aorta during heart surgery to provide blood to the aorta;

a cap substantially blocking axial flow through the distal end of the lumen; and

a plurality of arch-shaped outlet openings in the sidewall of the cannula adjacent the distal end;

each of the outlet openings having an arcuate proximal end and a beveled configuration sloping generally outwardly in the distal direction;

the distal end of the lumen being located flush with or distally beyond the distal ends of the outlet openings;

inserting the distal end of the cannula into the opening in the aorta; and

initiating blood flow through the cannula to provide blood to the aorta.

16. The method according to claim 15 wherein the portion of the sidewall of the lumen immediately distal to the outlet openings slopes outwardly in the distal axial direction.

17. The method according to claim 15 wherein the distal end of the lumen extends distally beyond the distal ends of the outlet openings.

18. The method according to claim 17 wherein the distal end of the lumen is located between about 0.005 inches (0.127 mm) and about 0.200 inches (5.08 mm) distally beyond the distal ends of the outlet openings.

19. The method according to claim 17 wherein the distal end of the lumen is located about 0.090 inches (2.29 mm) distally beyond the distal ends of the outlet openings.

20. The method according to claim 17 wherein the cannula has a bend therein proximal to the outlet openings.

21. The method according to claim 17 wherein the aortic cannula further comprises a raised land projecting proximally from the distal end of the lumen.

22. The method according to claim 21 wherein the surface of the land is shaped like the surface of a segment of a sphere.

23. The method according to claim 21 wherein the land extends proximally about 0.030 inches (0.762 mm) from the distal end of the lumen.

24. A method of providing blood to the aorta of a patient, the method comprising the steps of:

making an opening in the aorta of the patient;

providing a cannula having a sidewall with a proximal end, a distal end, and a lumen therebetween for conducting blood, the distal end being adapted for insertion into the aorta during heart surgery to provide blood to the aorta;

a cap substantially blocking axial flow through the distal end of the lumen; and

a plurality of outlet openings in the sidewall of the cannula adjacent the distal end;

the distal end of the lumen being located flush with, or distally beyond the distal ends of the outlet openings; and

a raised land projecting proximally from the distal end of the lumen, such that the proximal end of the land is distal to the distal ends of the outlet openings;

inserting the distal end of the cannula into the opening in the aorta; and

initiating blood flow through the cannula to provide blood to the aorta.

25. The method according to claim 24 wherein the proximal ends of the outlet openings have an arcuate shape.

26. The method according to claim 24 wherein the distal ends of the outlet openings have a beveled configuration, sloping generally outwardly in the distal axial direction.

27. A method of providing blood to the aorta of a patient, the method comprising the steps of:

making an opening in the aorta of the patient;

providing a cannula having a sidewall with a proximal end, a distal end, and a lumen therebetween for conducting blood, the distal end being adapted for insertion into the aorta during heart surgery to provide blood to the aorta;

a cap substantially blocking axial flow through the distal end of the lumen; and

a plurality of outlet openings in the sidewall of the cannula adjacent the distal end;

the distal end of the lumen being located flush with or distally beyond the distal ends of the outlet openings;

the cannula having a bend therein proximal to the outlet openings at least some of the outlet openings on the outside side of the bend being smaller than at least some of the openings on the inside side of the bend to substantially equalize the flow through the openings;

inserting the distal end of the cannula into the opening in the aorta; and

initiating blood flow through the cannula to provide blood to the aorta.

28. The method according to claim 27 wherein the distal end of the lumen is distal of the distal ends of the openings in the sidewall.

29. A method of providing fluid to the aorta of a patient comprising the steps of making an opening in the aorta of the patient;

inserting the distal end of the aortic cannula through the opening into the aorta, the cannula having a lumen with a closed distal end, and a plurality of circumferentially-spaced openings in the sidewall of the cannula, providing fluid under pressure to the lumen the closed distal end of the lumen and the side openings cooperating to form a hollow sheet-like conical flow of fluid from the cannula into the aorta.

30. The method according to claim 29 wherein there is a raised land projecting proximally from the distal end of the lumen, the proximal surface of the land being distal of the distal ends of the openings in the sidewall.

31. A method of providing blood to the aorta of a patient, the method comprising the steps of:

making an opening in the aorta of the patient;

providing a cannula having a sidewall with a proximal end, a distal end, and a lumen therebetween for conducting blood, the distal end being adapted for insertion into the aorta during heart surgery to provide blood to the aorta;

a cap substantially blocking axial flow through the distal end of the lumen; and

a plurality of outlet openings in the sidewall of the cannula adjacent the distal end;

the distal end of the lumen being located flush with or distally beyond the distal ends of the outlet openings;

the cannula having a bend therein proximal to the outlet openings at least some of the outlet openings on the outside side of the bend being smaller than at least some of the openings on the inside side of the bend to reduce the disparity in flow between openings on the inside and outside sides of the bend that would otherwise be caused by the bend;

inserting the distal end of the cannula into the opening in the aorta; and

initiating blood flow through the cannula to provide blood to the aorta.

32. A method of providing fluid to the aorta of a patient comprising the steps of making an opening in the aorta of the patient;

inserting the distal end of the aortic cannula through the opening into the aorta, the cannula having a lumen with a closed distal end, and a plurality of openings in the sidewall of the cannula, the openings being evenly spaced around the circumference of cannula tip;

providing fluid under pressure to the lumen the closed distal end of the lumen and the side openings cooperating to form a hollow sheet-like conical flow of fluid from the cannula into the aorta, each of the openings generating a lobe forming the hollow sheet like conical flow.