SELF-EXPANDING CANNULA

• US 20160158489A1
• Filed: 07/17/2014
• Published: 06/09/2016
• Est. Priority Date: 07/18/2013
• Status: Active Grant

• Current Assignee: University of Maryland Baltimore County (University of Maryland)
• Original Assignee: University of Maryland Baltimore County (University of Maryland)
• Inventors: Wu, Zhongjun, Griffith, Bartley P., Ding, Jun
• Granted Patent: US 10,912,920 B2
• Time in Patent Office: Days
• CPC Class Codes: A61M 1/3659 Cannulae pertaining to extracorporeal circulation
• CPC Class Codes: A61M 2025/0024 Expandable catheters or sheaths
• CPC Class Codes: A61M 2025/0031 characterized by lumina for withdrawing or delivering, i.e. used for extracorporeal circuit treatment
• CPC Class Codes: A61M 2025/0035 characterized by a variable lumen cross-section by means of a resilient flexible septum or outer wall
• CPC Class Codes: A61M 2025/0039 characterized by lumina being arranged coaxially
• CPC Class Codes: A61M 2025/0059 having means for preventing the catheter, sheath or lumens from collapsing due to outer forces, e.g. compressing forces, or caused by twisting or kinking
• CPC Class Codes: A61M 2205/0266 Shape memory materials
• CPC Class Codes: A61M 25/003 characterized by features relating to least one lumen located at the distal part of the catheter, e.g. filters, plugs or valves catheter tips A61M25/0067
• CPC Class Codes: A61M 25/005 with embedded materials for reinforcement, e.g. wires, coils, braids
• CPC Class Codes: A61M 25/04 in the body, e.g. expansible A61M25/10, A61M16/0488 take precedence

Abstract

Disclosed is a self-expanding cannula, systems using such cannulae, and methods of their use. The cannulae may comprise single lumen cannula (SLC) configurations and double lumen cannula (DLC) configurations, and include at least a first cannula and a self-expanding wire frame attached to the first cannula. Self-expanding wire frame is automatically expandable from a compressed state (providing a reduced cannula diameter as it is moved through a patients body to the site at which it is to be deployed) to an expanded state (which increases the diameter of the cannula to the diameter intended for its normal use). The expanded wire frame provides radial support to prevent a drainage canal (whether a patients blood vessel or a portion of the system inserted into the patients blood vessel) from collapsing as fluid is drained from the patient.

Claims

1. A system for fluid handling of a patient'"'"'s blood, comprising:

a first cannula having a distal first cannula end and a proximal first cannula end opposite said distal first cannula end; and

a self-expanding wire frame having a distal wire frame end and a proximal wire frame end opposite said distal wire frame end, said proximal wire frame end being attached to said distal first cannula end, said wire frame being automatically expandable to a maximum diameter when positioned to collect blood from a patient'"'"'s body.

2. The system of claim 1, wherein said self-expanding wire frame is automatically expandable to said maximum diameter in response to warming from a patient'"'"'s body temperature.

3. The system of claim 2, said wire frame being compressible to a reduced diameter when exposed to a temperature less than a human'"'"'s normal body temperature, said reduced diameter being sufficiently small to allow passage of said wire frame through a portion of the patient'"'"'s circulatory system.

4. The system of claim 1, said maximum diameter being selected so as to provide radial support to a vessel in which said wire frame is positioned against collapse during suctioning of blood through said wire frame and said first cannula.

5. The system of claim 1, wherein said distal first cannula end tapers toward a reduced diameter at a distal face of said distal first cannula end.

6. The system of claim 1, wherein said wire frame is configured as a wire helix.

7. The system of claim 6, wherein said wire helix follows a zig-zag pattern.

8. The system of claim 7, further comprising linkages between longitudinally adjacent segments of said zig-zag pattern.

9. The system of claim 1, further comprising a port extending into a sidewall of said first cannula.

10. The system of claim 9, further comprising a second cannula having an outer diameter sized to allow said second cannula to be positioned in and to move within said port, said first cannula and said wire frame.

11. The system of claim 10, wherein said second cannula has a distal second cannula end that is radio-opaque.

12. The system of claim 10, said second cannula further comprising a second wire frame embedded within a distal second cannula end.

13. The system of claim 12, wherein said second wire frame is automatically expandable from a reduced second wire frame diameter to an enlarged second wire frame diameter in response to warming from a patient'"'"'s body temperature.

14. The system of claim 10, further comprising a sheath having a distal sheath having an internal diameter selected to allow said first cannula, said wire frame, and said second cannula to be positioned within said sheath.

15. The system of claim 14, wherein said self-expanding wire frame is sufficiently flexible so as to radially compress to a reduced diameter when said first cannula, said wire frame, and said second cannula are positioned within said sheath and to automatically expand to said maximum diameter upon removal of said sheath.

16. The system of claim 14, said sheath having a line of weakening extending along a longitudinal length of said sheath and configured to allow said sheath to be removed from said first cannula, said wire frame, and said second cannula after placement of said first cannula, said wire frame, said second cannula within a blood vessel of a patient.

17. The system of claim 14, further comprising an introducer having an outer diameter sized to allow said introducer to extend through said second cannula toward and through said distal second cannula end.

18. The system of claim 17, said introducer having a tapered, distal introducer end.

19. The system of claim 10, wherein a distal end of said second cannula is distally positionable a sufficient distance away from said distal wire frame end so as to prevent extracorporeal recirculation of fluid that has been drained from and returned to the patient by the system.

20. A system for fluid handling of a patient'"'"'s blood, comprising:

a first cannula having a distal first cannula end and a proximal first cannula end opposite said distal first cannula end; and

a self-expanding wire frame attached to said distal first cannula end, said wire frame being automatically expandable to a maximum diameter when positioned to collect blood from a patient'"'"'s body and in response to warming from a patient'"'"'s body temperature.

21. The system of claim 20, wherein said self-expanding wire frame is embedded within a sidewall of said distal first cannula end.

22. The system of claim 21, further comprising a second cannula having a distal second cannula end and a proximal second cannula end opposite said distal second cannula end, and a port extending into a sidewall of said second cannula, wherein said second cannula is sized to allow said first cannula to be positioned in and to move within said port and said second cannula.

23. The system of claim 22, wherein said distal first cannula end is distally positionable a sufficient distance from said distal second cannula end so as to prevent the extracorporeal recirculation of fluid that has been drained from and returned to the patient by the system.

24. A method for fluid handling of a patient'"'"'s blood, comprising the steps of:

providing a first cannula having a distal first cannula end and a proximal first cannula end opposite said distal first cannula end, and a self-expanding wire frame attached to said distal first cannula end, said wire frame having a first diameter and being automatically expandable to a maximum diameter when positioned to collect blood from a patient'"'"'s body;

positioning said first cannula and said wire frame inside of a blood vessel in a patient'"'"'s body at a position at which blood is to be withdrawn from the patient'"'"'s body, and so as to cause said wire frame to automatically expand to said maximum diameter, wherein said maximum diameter is sufficient to prevent collapse of the blood vessel during suctioning of blood from the blood vessel; and

suctioning blood from the blood vessel through said wire frame and said first cannula.

25. The method of claim 24, wherein automatic expansion of said wire frame proceeds in response to warming of said wire frame from the patient'"'"'s body temperature.

26. The method of claim 24, further comprising:

providing a second cannula having a distal second cannula end and a proximal second cannula end opposite said distal second cannula end, said second cannula having an outer diameter sized to allow said second cannula to be positioned in and to move within said first cannula and said wire frame; and

prior to said positioning step, inserting said second cannula through at least a portion of said first cannula, through said distal first cannula end, into said wire frame, and through a distal wire frame end so that said distal second cannula end is positioned away from said distal wire frame end and defines an extended second cannula portion from said distal wire frame end to said distal second cannula end.

27. The method of claim 26, wherein said extended second cannula portion has a length dimension that is sufficient to prevent extracorporeal recirculation of fluid that has been drained from and returned to the patient by said first and second cannulae.

28. The method of claim 26, further comprising infusing blood into the patient through said second cannula.

29. The method of claim 28, further comprising the step of:

after said suctioning blood step, oxygenating blood suctioned from the patient;

wherein said infusing step further comprises infusing the oxygenated blood back into the patient.

30. The method of claim 26, further comprising the steps of:

prior to said positioning step, inserting said distal first cannula end, said wire frame, and said extended second cannula portion into a sheath so that said wire frame is positioned between an interior of said sheath and at least a portion of said second cannula; and

inserting an introducer into and through said second cannula from said proximal cannula end to said distal cannula end.

31. The method of claim 30, wherein said introducer has a tapered, distal end.

32. The method of claim 30, further comprising the steps of:

following said positioning step, removing said introducer and said sheath from said first cannula, said wire frame and said second cannula.

33. The method of claim 24, further comprising the steps of:

prior to said positioning step, inserting said distal first cannula end and said wire frame into a sheath; and

inserting an introducer into and through said first cannula from said proximal first cannula end to said distal first cannula end.

34. The method of claim 33, wherein said introducer has a tapered, distal end.

35. The method of claim 33, further comprising the steps of:

following said positioning step, removing said introducer and said sheath from said first cannula and said wire frame.

36. The method of claim 24, further comprising:

providing a second cannula having a distal second cannula end and a proximal second cannula end opposite said distal second cannula end, said second cannula having an internal diameter sized to allow said first cannula to be positioned in and to move within said second cannula;

prior to said positioning step, inserting said first cannula through at least a portion of said second cannula and through said distal second cannula end so that said distal first cannula end is positioned away from said distal second cannula end and defines an extended first cannula portion from said distal first cannula end to said distal second cannula end.

37. The method of claim 36, wherein said extended first cannula portion has a length dimension that is sufficient to prevent extracorporeal recirculation of fluid that has been drained from and returned to the patient by said first and second cannulae.

38. The method of claim 36, further comprising infusing blood into the patient through said second cannula.

39. The method of claim 38, further comprising the step of:

after said suctioning blood step, oxygenating blood suctioned from the patient;

wherein said infusing step further comprises infusing the oxygenated blood back into the patient.