Selective organ hypothermia method and apparatus

• US 6,558,412 B2
• Filed: 04/12/2001
• Issued: 05/06/2003
• Est. Priority Date: 01/23/1998
• Status: Expired due to Term

• Current Assignee: Zoll Circulation Incorporated (Asahi Kasei Corporation)
• Original Assignee: Innercool therapies Incorporated (Taxus Cardium Pharmaceuticals Group, Inc.)
• Inventors: Dobak, John D. III
• Primary Examiner(s): GIBSON, ROY DEAN
• Application Number:
  US09/834,054
• Publication Number:
  US 20010016764A1
• Time in Patent Office: 754 Days
• Field of Search: 607/96, 607/104, 607/105, 607/106, 607/107
• US Class Current: 607/105
• CPC Class Codes: A61F 2007/0056 for cooling
• CPC Class Codes: A61F 2007/126 for invasive application, e.g. for introducing into blood vessels
• CPC Class Codes: A61F 7/12 Devices for heating or cooling internal body cavities

Abstract

A method and apparatus for performing hypothermia of a selected organ without significant effect on surrounding organs or other tissues. A flexible catheter is inserted through the vascular system of a patient to place the distal tip of the catheter in an artery feeding the selected organ. A compressed refrigerant is pumped through the catheter to an expansion element near the distal tip of the catheter, where the refrigerant vaporizes and expands to cool a flexible heat transfer element in the distal tip of the catheter. The heat transfer element cools the blood flowing through the artery, to cool the selected organ, distal to the tip of the catheter.

Claims

1. A method for reducing damage to neural tissue located in a patient after said neural tissue has become ischemic or has been otherwise affected by a disease or trauma comprising:

A. selecting a portion of the body containing the tissue, which portion receives a flow of a body fluid;

B. providing a heat exchange catheter device which comprises;

i) an elongate, flexible catheter having a proximal end, a distal end, and an insertion portion for insertion into a patient'"'"'s body;

ii) at least one fluid lumen through which a refrigerant heat exchange fluid may be circulated; and

iii) a heat exchanger located adjacent the distal end, said heat exchanger being operative to exchange heat between body fluid which flows in heat exchange proximity to said heat exchanger and the refrigerant heat exchange fluid which is circulated through said catheter;

C. inserting the catheter into the patient and positioning the catheter such that the body fluid will pass in heat exchange proximity to the heat exchanger before reaching the selected body portion;

D. circulating the refrigerant heat exchange fluid through the fluid lumen of the catheter device, such that body fluid will pass in heat exchange proximity to the heat exchanger, the refrigerant heat exchange fluid being at a temperature other than the body fluid, whereby the temperature of the body fluid will be altered, and will subsequently flow to said neural tissue;

E. maintaining the catheter in said position for a sufficient time to alter the temperature of the neural tissue.

2. The method of claim 1, wherein the body fluid is blood.

3. The method of claim 2, wherein the catheter is inserted into an artery.

4. The method of claim 2, wherein the catheter is inserted into a vein.

5. The method of claim 1, wherein the body portion is the brain.

6. The method of claim 5, further comprising:

F. maintaining the selected portion of the body at a temperature different than that of the rest of the patient'"'"'s body.

7. The method of claim 2, wherein the neural tissue is located in the brain and the blood vessel is selected from the group consisting of:

right common carotid artery;

left common carotid artery;

right internal carotid artery; and

left internal carotid artery.

8. The method of claim 1, wherein the neural tissue is brain tissue which has become ischemic or has suffered insult due to stroke.

9. The method of claim 1, wherein the neural tissue is brain tissue which has suffered insult due to cardiac arrest.

10. A method for changing the temperature of a selected region of a body, said method comprising the steps of:

A. providing a heat exchange catheter device which comprises an elongate flexible catheter, said catheter having a portion which is inserted into a patient'"'"'s body, having a heat exchanger, said heat exchanger operative to exchange heat between body fluid which flows in heat exchange proximity to said heat exchanger;

B. inserting the catheter into a blood vessel of the patient'"'"'s body through which blood flows to the selected region of the patient'"'"'s body, and positioning the catheter such that blood flowing to the selected region will pass in heat exchange proximity to the heat exchanger before reaching said selected region, and

C. utilizing the heat exchanger of the catheter device to change the temperature of blood which passes in heat exchange proximity to the heat exchanger, such that said blood will subsequently change the temperature of said selected region of the patient'"'"'s body,

wherein the method is performed to reduce necrosis of neural tissue.

11. The method of claim 10, wherein the method is performed to warm the selected region.

12. The method of claim 10, wherein the method is performed to cool the selected region to a temperature below normal body temperature.

13. The method of claim 10, wherein the blood vessel is a vein.

14. The method of claim 10, wherein the catheter device provided in Step A comprises:

i) an elongate, flexible catheter having a proximal end and a distal end;

ii) at least one fluid lumen through which a refrigerant heat exchange fluid may be circulated through the catheter; and

iii) said heat exchanger being located at the distal end of the catheter and being operative to exchange heat between blood which flows in heat exchange proximity to said heat exchanger and the refrigerant heat exchange fluid which is circulated through said catheter.

16. The method of claim 10, wherein the method is performed to cool the brain.

15. The method of 14, further comprising circulating the refrigerant heat exchange fluid through the fluid lumen of the catheter.

17. A heat exchange catheter comprising:

a longitudinal catheter shaft with a proximal end and a distal end;

a heat exchange region comprising a plurality of heat exchange elements, each of said heat exchange elements having a length and opposed ends and each of said heat exchange elements being disposed such that, when the heat exchange region of the catheter is positioned in a body lumen or body cavity that contains body fluid, the body fluid may surround at least a portion of each heat exchange element,

wherein at least some of the heat exchange elements have a refrigerant fluid flow path therethrough.

18. The method of claim 17, wherein the shaft has a fluid inflow lumen and a fluid outflow lumen and a circulation pathway therebetween for the circulation of a refrigerant heat exchange medium, at least some of the heat exchange elements being in the circulation pathway to enable circulation of the refrigerant fluid heat exchange medium through the heat exchange elements.

19. The method of claim 18, wherein each heat exchange element has an inflow orifice on one end and an outflow orifice on the opposed end, the inflow orifice and the outflow orifice being in communication with the circulation pathway.

20. The method of claim 19, wherein each heat exchange element extends in a non-linear path from its inflow orifice to its outflow orifice.

21. The method of claim 19, wherein the catheter includes an inlet manifold open to the inflow lumen and to the inflow orifice of each heat exchange element, and the catheter includes an outlet manifold open to the outflow lumen and to the outflow orifice of each heat exchange element.

22. The method of claim 21, wherein the heat exchange elements comprise elongate hollow tubes and wherein each tube communicates with a respective manifold.

23. The method of claim 22, wherein the heat exchange elements form a basket shape.

24. The method of claim 21, wherein the heat exchange elements are hollow, the shaft including a fluid circulation path, and the hollow interior of the heat exchange elements being in fluid communication with the fluid circulation path.

25. The method of claim 17, wherein the heat exchange region is located on the distal region of the shaft.

26. The method of claim 25, further including an insulating region on the shaft located proximally with respect to the heat exchange region.

27. The method of claim 17, wherein the heat exchange elements are evenly circumferentially distributed about the shaft.

28. The method of claim 17, wherein the heat exchange elements have walls permitting a high rate of conductive heat transfer therethrough.

29. A system for heat exchange with a body fluid, comprising:

a refrigerant heat exchange medium;

a heat exchange catheter having a shaft with a proximal end and a distal end, the distal end of the catheter shaft being percutaneously insertable into a body cavity, the shaft having a circulation pathway therein for the circulation of the refrigerant heat exchange medium therethrough; and

a plurality of heat exchange elements each having a length and opposed ends, each element being attached on at least one of its ends to the shaft and disposed so that when inserted in a fluid body cavity having body fluid therein, the body fluid may surround each heat exchange element along a portion of the length of the heat exchange element,

wherein the plurality of heat exchange elements are hollow tubes and the circulation pathway extends through the heat exchange elements, for the circulation of the refrigerant heat exchange medium through the plurality of heat exchange elements.

30. A method of exchanging heat with a body fluid of a patient, comprising:

providing a catheter having a circulatory fluid flow path therein and a heat exchange region including a plurality of heat exchange elements each having a length and opposed ends, each element being attached on at least one of its ends to the heat exchange region and disposed so that when inserted in a fluid body cavity having body fluid therein, the body fluid may surround each heat exchange element along a portion of the length of the heat exchange element;

inserting the catheter into a body cavity and into contact with the body fluid; and

flowing a liquid heat exchange medium through the circulatory flow path so that the medium exchanges heat with the body fluid through the heat exchange elements,

wherein the heat exchange elements are hollow tubes and the circulatory fluid flow path extends through the heat exchange elements, the method including flowing the refrigerant heat exchange fluid through the heat exchange elements.

31. A catheter adapted to exchange heat with blood flowing through a blood vessel, the catheter comprising:

a shaft having an axis extending between a proximal end and a distal end, the shaft having an input lumen and output lumen;

a heat exchange region disposed at the distal end of the shaft and including a plurality of hollow tubes each having an outer surface adapted to be operatively placed in heat exchange relationship with the blood flowing in the blood vessel; and

the hollow tubes being disposed in fluid communication with the input lumen and the output lumen to facilitate a flow of heat exchange fluid through the hollow tubes to change the temperature of blood in the blood vessel.

32. The catheter recited in claim 31, further comprising:

a manifold included in the heat exchange region and being in fluid communication with the input lumen of the shaft;

another manifold included in the heat exchange region and being in fluid communication with the output lumen of the shaft; and

the hollow tubes extending between the manifold and another manifold in the heat exchange region of the catheter.

33. A method for treating a patient, comprising the acts of:

advancing a heat exchange catheter device into the patient; and

circulating refrigerant through the catheter device while preventing infusion of the refrigerant directly into the patient'"'"'s bloodstream, the catheter device including a heat exchange region established by;

one or more hollow tubes, or one or more chamber-defining enclosures, and

further comprising the act of treating head trauma in the patient while the patient'"'"'s temperature is below normal body temperature.

34. A method for treating a patient, comprising the acts of:

advancing a heat exchange catheter device into the patient; and

circulating refrigerant through the catheter device while preventing infusion of the refrigerant directly into the patient'"'"'s bloodstream, the catheter device including a heat exchange region established by;

one or more hollow tubes, or one or more chamber-defining enclosures, and

further comprising the act of treating ischernia in the patient while the patient'"'"'s temperature is below normal body temperature.

35. A heat exchange catheter, comprising:

first and second fluid conduits each having a proximal and a distal end;

multiple hollow tubes of substantially equal length, the tubes having substantially adjacent proximal and distal ends;

a proximal fluid transfer housing forming a sealed fluid path between the fibers'"'"' proximal ends and the first conduit;

a distal fluid transfer housing forming a sealed fluid path between the fibers'"'"' distal ends and the second conduit.

36. The catheter of claim 35, wherein the tubes have predetermined shapes.

37. The catheter of claim 36, further comprising:

pre-shaping built into the tubes to urge them into the predetermined shapes.

38. The catheter of claim 36, further comprising:

shape memory built into the tubes to urge them into the predetermined shapes.

39. The catheter of claim 36, the predetermined shapes comprising spiral windings.

40. The catheter of claim 39, the spiral winding of each fiber having an amplitude and phase common to all fibers.

41. The catheter of claim 39, the predetermined shapes comprising outward bowing of the fibers.

42. A heat exchange catheter, comprising:

fluid supply and fluid return conduits each having a proximal and a distal end;

multiple substantially parallel hollow tubes each tube having a distal end, the tubes having substantially adjacent proximal ends, each tube including a continuous fluid path proceeding from a fluid supply opening at its proximal end to its distal end and then to a fluid return opening at the proximal end; and

a fluid transfer housing defining a sealed fluid path between the tubes'"'"' fluid supply openings and the fluid supply conduit, and also defining a sealed fluid path between the tubes'"'"' fluid return openings and the fluid return conduit.

43. The catheter of claim 42, the tubes having shaping built into the tubes.

44. The catheter of claim 43, the shaping comprising a temperature dependent shape memory.

45. A heat exchange catheter comprising:

a body communicating with a source of refrigerant via refrigerant supply and refrigerant return pathways, the body defining a distal end;

plural hollow tubes extending away from the distal end, each tube defining a respective distal portion and a refrigerant supply path for conveying refrigerant from the refrigerant supply pathway of the body to the distal portion, each tube also defining a respective refrigerant return path for conveying refrigerant from the respective distal portion to the refrigerant return pathway of the body.

46. The catheter of claim 45, where each tube is configured in a loop, a first segment of the loop establishing the refrigerant supply path of the tube and a second segment of the loop establishing the refrigerant return path of the tube.

47. A heat exchange catheter, comprising:

a first conveyance means for conveying a refrigerant along a first path;

a second conveyance means for conveying a refrigerant along a second path;

multiple substantially parallel, hollow tubes, the tubes having substantially adjacent proximal and distal ends;

a fluid transfer housing means for forming a sealed fluid path between the tubes'"'"' proximal ends and the first conveyance means;

a redirecting means for forming a sealed fluid path between the tubes'"'"' distal ends and the second conveyance means; and

actuating means for spreading the tubes under predetermined conditions.

48. A heat exchange catheter, comprising:

a first conveyance means for conveying fluid along a first path;

a second conveyance means for conveying fluid along a second path;

multiple substantially parallel hollow tubes each tube having a distal end, the tubes having substantially adjacent proximal ends, each tube including a continuous fluid path proceeding from a refrigerant supply opening at its proximal end to its distal end and then to a refrigerant return opening at the proximal end; and

a refrigerant transfer housing means for providing a sealed fluid path between the tubes'"'"' refrigerant supply openings and the first conveyance means and also defining a sealed refrigerant path between the tubes'"'"' refrigerant return openings and the second conveyance means.

49. A heat exchange catheter, comprising:

a first conveyance means for conveying refrigerant along a first path;

a second conveyance means for conveying refrigerant along a second path;

multiple hollow tubes each having refrigerant supply and return ends proximately located to form a loop of tube; and

a refrigerant transfer housing means for providing a sealed refrigerant path between the supply end of each tube and the first conveyance means, and also defining a sealed refrigerant path between the return end of each tube and the second conveyance means.

50. A tubing set for delivery of a refrigerant heat exchange fluid between a heat exchanger and an indwelling catheter, the tubing set comprising:

first tubing means for delivery of fluid between the heat exchanger and the indwelling catheter;

a second tubing means, attached to a distal end of the first tubing means, for delivery of fluid between the indwelling catheter and a fluid reservoir; and

third tubing means for delivery of fluid between the reservoir and the heat exchanger.

51. A catheter having an elongate configuration with a proximal end and a distal end, the catheter comprising:

an outer tube having an elongate configuration and a first lumen;

an inner tube disposed in the first lumen of the outer tube and having a second lumen extending between the proximal end and the distal end of the catheter;

portions of the inner tube defining a first fluid flow path extending along the second lumen between the proximal end and the distal end of the catheter;

portions of the outer tube and the inner tube defining a second flow path extending between the first tube and the second tube; and

a plurality of hollow tubes providing fluid communication between the first fluid flow path and the second fluid flow path.

52. The catheter recited in claim 51, wherein:

each of the hollow tubes has a proximal end and a distal end;

the distal end of each of the hollow tubes has a fixed relationship with the distal end of the inner tube; and

the proximal end of each of the hollow tubes has a fixed relationship with the distal end of the outer tube.

53. The catheter recited in claim 51, wherein the hollow tubes are adapted to receive a refrigerant heat exchange fluid from the first flow path and to release the refrigerant heat exchange fluid into the second flow path.

54. The catheter recited in claim 51, wherein the hollow tubes are adapted to receive a refrigerant heat exchange fluid from the second flow path and to release the refrigerant heat exchange fluid into the first flow path.

55. A method for operating a heat exchange catheter within a blood vessel, the method comprising:

inserting into a blood vessel a heat exchange catheter with an inner tube disposed within an outer tube to define a first flow path interiorly of the inner tube and a second flow path between the inner tube and the outer tube, and a plurality of hollow tubes disposed in fluid communication between the first flow path and the second flow path; and

creating a flow of a refrigerant heat exchange fluid by introducing the refrigerant heat exchange fluid into one of the first flow path and second flow path.

56. A heat exchange catheter, including:

an elongate shaft extending along an axis between a proximal end and a distal end;

first portions of the shaft defining an inlet lumen extending between the proximal end and the distal end of the shaft;

second portions of the shaft defining an outlet lumen;

a manifold in fluid communication with the inlet lumen at the distal end of the shaft;

another manifold in fluid communication with the outlet lumen of the shaft;

a plurality of hollow tubes disposed to extend between the manifold and another manifold in fluid communication with the inlet lumen; and

the catheter being adapted to receive a refrigerant heat exchange fluid at the proximal end of the inlet lumen, and to direct the refrigerant heat exchange fluid through the hollow tubes to exchange heat through the hollow tubes.

57. The heat exchange catheter recited in claim 56, wherein the manifold is disposed distally of another manifold.

58. The heat exchange catheter recited in claim 56, wherein the outlet lumen is disposed outwardly of the inlet lumen.

59. The heat exchange catheter recited in claim 56, wherein the heat exchange fluid is Freon.

60. A catheter adapted to exchange heat with blood flowing through a blood vessel, the catheter comprising:

a shaft having an axis extending between a proximal end and a distal end, the shaft having an input lumen and an output lumen;

a plurality of hollow tubes defining a heat exchange region of the shaft and collectively defining an outer surface of the heat exchange region;

the input lumen of the shaft coupled to the hollow tubes of the heat exchange region at a first location, the output lumen of the shaft being coupled to the hollow tubes of the heat exchange region at a second location such that a heat exchange fluid introduced into the input lumen will enter the hollow tubes of the heat exchange region at the first location and will exit the hollow tubes of the heat exchange region at the second location through the output lumen.

61. The catheter recited in claim 60, further comprising:

a clot inhibiting coating covering the hollow tubes.

62. A method for exchanging heat with a body fluid in a body conduit, comprising the steps of:

introducing into the body conduit a catheter having an inlet lumen and an outlet lumen;

providing the catheter with a first cavity in heat transfer relationship with blood in blood vessel;

introducing a refrigerant heat exchange fluid into the inlet lumen and into the first cavity;

exchanging heat between the refrigerant heat exchange fluid and the blood in the blood vessel;

removing the heat exchange fluid from the first cavity through the outlet lumen; and

during the providing step, providing the catheter with a plurality of hollow heat exchange tubes each extending in fluid communication with the inlet lumen and the outlet lumen, the heat exchange tubes collectively defining the first cavity in heat transfer relationship with the blood in the blood vessel.

63. The method recited in claim 62, wherein the second introducing step includes the step of introducing the refrigerant heat exchange fluid into the hollow tubes.

64. A heat exchange catheter having a elongate configuration and extending between a proximal end and a distal end, the catheter being adapted for cooling the blood of a patient, comprising:

a heat exchange region of the catheter;

a plurality of tubes included in the heat exchange region, with each of the tubes having a hollow configuration and being adapted to receive a refrigerant heat exchange fluid; and

a coating disposed on the outer surface of the tubes to inhibit the formation of blood clots on the cooled tubes.

65. The heat exchange catheter recited in claim 64, further comprising a chemical included in the coating and having characteristics for inhibiting the formation of the blood clots.

66. The heat exchange catheter recited in claim 65, wherein the chemical includes heparin.

67. The method recited in claim 64, wherein the creating step includes the step of:

providing a refrigerant heat exchange fluid in the form of a liquid.

68. The method recited in claim 64, wherein the creating step includes the step of:

providing a refrigerant heat exchange fluid in the form of a gas.

69. The method recited in claim 64, wherein the creating step includes the step of:

cooling the refrigerant heat exchange fluid prior to introducing the fluid into the catheter.

70. The heat exchange catheter recited in claim 64, wherein the heat exchange fluid is a cooling fluid.

71. A catheter, comprising:

an elongate heat transfer extension housing at least one supply lumen and at least one return lumen running longitudinally along the extension, the extension also including a distal fluid exchange reservoir providing a fluid redirecting path between the supply and return lumens; and

shape memory structure causing the heat transfer extension to assume a coiled shape under predetermined shape-active temperatures and a non-coiled shape under predetermined shape-relaxed temperatures different from the shape-active temperatures.

72. The catheter of claim 71, further comprising:

a supply line and a return line; and

a fluid transfer housing forming a sealed fluid path between the supply lumen and the supply line, and also forming a sealed fluid path between the return lumen and the return line.

73. The catheter of claim 71, the lumens comprising a central lumen surrounded by multiple peripheral lumens.

74. The catheter of claim 71, the shape memory structure comprising:

temperature dependent shape memory built into the heat transfer extension urging the extension into the coiled shape whenever the extension experiences the shape-active temperatures.

75. The catheter of claim 74, the temperature dependent shape memory only being built into a distal region of the heat transfer extension such that, under the shape-active temperatures, the distal region of the extension assumes a coiled distal region while leaving a substantially straight proximal region of the extension.

76. A catheter, comprising:

an elongate heat transfer extension housing at least one supply lumen and at least one return lumen running longitudinally along the extension, the extension also including a means for distally directing fluid between the supply lumens and the return lumens; and

shape memory means for causing the heat transfer extension to assume a coiled shape under predetermined shape-active temperatures and a non-coiled shape under predetermined shape-relaxed temperatures different from the shape-active temperatures.

77. The catheter of claim 76, further comprising:

a supply line and a return line; and

a fluid transfer means for directing fluid between the supply lumen and the supply line, and directing fluid between the return lumens and the return line means.

78. A catheter, comprising an elongate heat transfer extension housing at least one supply lumen and at least one return lumen running longitudinally along the extension, the extension also including a distal refrigerant fluid exchange reservoir providing a fluid redirecting path between the supply and return lumens, where at least a portion of the heat transfer extension has a coiled shape with multiple coil turns.

79. A method of operating a heat exchange catheter that includes an elongate heat transfer extension housing at least one supply lumen and at least one return lumen running longitudinally along the extension, the extension also including a distal refrigerant fluid exchange reservoir providing a fluid redirecting path between the supply and return lumens, shape memory structure causing the heat transfer extension to assume a coiled shape under predetermined shape-active temperatures and a non-coiled shape under predetermined shape-relaxed temperatures different from the shape-active temperatures;

the method comprising operations of;

inserting the catheter into a patient'"'"'s body;

responsive to heat of the patient'"'"'s body, the shape memory structure causing the heat transfer extension to assume the coiled shape; and

circulating a refrigerant heat exchange fluid through the catheter.

80. The method of claim 79, the lumens comprising a central lumen surrounded by multiple peripheral lumens, the operation of circulating a refrigerant heat exchange fluid through the catheter comprising:

circulating fluid outward through the peripheral lumens to the distal tip and then in a reverse direction through the central lumen.

81. A method for treating cardiac arrest in a patient using hypothermia, comprising the acts of:

resuscitating the patient; and

inducing hypothermia in the patient, wherein hypothermia is induced by circulating heat exchange fluid through a catheter positioned in the patient'"'"'s central venous system.

82. A method for changing the temperature of a selected region of a body, said method comprising the steps of:

A) providing a heat exchange catheter device which comprises an elongate flexible catheter, said catheter having a portion which is inserted into a patient'"'"'s body, having a heat exchanger, said heat exchanger operative to exchange heat between body fluid which flows in heat exchange proximity to said heat exchanger;

B) inserting the catheter into a blood vessel of the patient'"'"'s body through which blood flows to the selected region of the patient'"'"'s body, and positioning the catheter such that blood flowing to the selected region will pass in heat exchange proximity to the heat exchanger before reaching said selected region; and

C) utilizing the heat exchanger of the catheter device to change the temperature of blood which passes in heat exchange proximity to the heat exchanger, such that said blood will subsequently change the temperature of said selected region of the patient'"'"'s body, wherein the method is performed to cool the heart.