System and method for preventing an air embolism in a surgical procedure

• US 6,106,497 A
• Filed: 01/29/1998
• Issued: 08/22/2000
• Est. Priority Date: 01/31/1997
• Status: Expired due to Fees

• Current Assignee: Medical Instrument Development Laboratories, Inc.
• Original Assignee: Medical Instrument Development Laboratories, Inc.
• Inventors: Wang, Carl C. T.
• Primary Examiner(s): Smith, Jeffrey A.
• Application Number:
  US09/015,168
• Time in Patent Office: 936 Days
• Field of Search: 604/26, 604/23, 604/122
• US Class Current: 604/122
• CPC Class Codes: A61M 1/92 with liquid supply means
• CPC Class Codes: A61M 13/003 Blowing gases other than for carrying powders, e.g. for inflating, dilating or rinsing
• CPC Class Codes: A61M 2205/3355 Controlling downstream pump pressure

Abstract

A system and method is provided for preventing the development of an air embolism in an animal during and after a cardiovascular surgical procedure. Also provided is a device that can accurately control the pressure and/or flow of gas into the heart cavity and related blood vessels.

Claims

1. A system for preventing an air embolism in the brain of an animal in a cardiovascular surgical procedure, comprising:

a) a source of a gas;

b) a mechanism for controlling pressure and flow of the gas therethrough, having an inlet end and an outlet end, the inlet end being connected to the gas source; and

c) a tube for conveying the gas therethrough having a first end and a second end, and a member for preventing blood from flowing from the heart into the gas conveying tube;

the first end adapted for placement in the heart of the animal and having a plurality of apertures for passage of the gas therethrough into the heart;

wherein the pressure/flow controlling mechanism is disposed between the gas source and the gas conveying tube; and

the gas source, the pressure/flow controlling mechanism and the gas conveying tube are in fluid flowing communication for conveying the gas therethrough;

and the pressure/flow controlling mechanism is operable to provide a flow of the gas through the system such that when the first end of the gas conveying tube is placed into the heart, the pressure and flow of the gas from the pressure/flow controlling mechanism through the gas conveying tube into the heart is effective to inhibit air from entering the heart, great vessel, or both, or to remove air from the heart, the great vessel, or both.

2. The system according to claim 1, further comprising:

a tube for removing fluid from the heart, having a first end, a second end, and a central channel, wherein the second end of the fluid removal tube is connectable to a mechanism operable to draw the fluid out of the heart and through the central channel of the fluid removal tube.

3. The system according to claim 2, wherein the fluid removal mechanism is a heart-lung machine comprising a pump mechanism.

4. The system according to claim 2, wherein the gas conveying tube and the fluid conducting tube are separate lumens of a multiple lumen tube.

5. The system according to claim 4, wherein the gas conveying tube and the fluid conducting tube are parallely arranged.

6. The system according to claim 1, wherein the gas is carbon dioxide.

7. The system according to claim 1, further comprising:

a mechanism for aspirating air having an inlet end; and

a tube for conveying air therethrough having a first end and a second end, the first end of the air conveying tube being connected to the inlet end of the air aspirating mechanism and the second end being insertable into the body of the animal.

8. The system according to claim 1, wherein the pressure/flow controlling mechanism is operable to provide a low flow pressure of the gas of about 5-20 mmHg into the heart to effectively prevent air entering into the heart and maintain the heart filled with the gas, and a high pressure of about 30-100 mmHg to effectively purge air from the heart.

9. The system according to claim 1, wherein the gas conveying tube is defined by a first lumen of a double lumen tube, and a second lumen of the double lumen tube defines an air exchange tube for removing gas from the heart having a first end with an opening and a second end adapted for connection to an aspiration source;

the gas conveying tube having a length greater than the air exchange tube such that when the double lumen tube is inserted through an incision of the left heart or aorta and the first end of the gas conveying tube is positioned in the lower portion of the left heart, the first end of the air exchange tube is positioned in the heart in proximity to the incision.

10. The system according to claim 1, wherein the gas conveying tube is integrated with a balloon endoaortic catheter.

11. A system for preventing an air embolism in the brain of an animal in a cardiovascular surgical procedure, comprising:

a) a source of a gas;

b) a mechanism for controlling pressure and flow of the gas therethrough, having an inlet end and an outlet end, the inlet end being connected to the gas source;

c) a tube for conveying the gas therethrough having a first end and a second end, the first end adapted for placement in the heart of the animal and having a plurality of apertures for passage of the gas therethrough into the heart; and

d) a filter for removing microorganisms disposed between the pressure/flow controlling mechanism and the gas conveying tube, having an inlet end connected to the outlet end of the pressure/flow controlling mechanism for receiving the gas into the filter, and an outlet end connected to the second end of the gas conveying tube for passing the filtered gas thereinto,

wherein the pressure/flow controlling mechanism is disposed between the gas source and the gas conveying tube; and

the gas source, the pressure/flow controlling mechanism and the gas conveying tube are in fluid flowing communication for conveying the gas therethrough;

and the pressure/flow controlling mechanism is operable to provide a flow of the gas through the system such that when the first end of the gas conveying tube is placed into the heart, the pressure and flow of the gas from the pressure/flow controlling mechanism through the gas conveying tube into the heart is effective to inhibit air from entering the heart great vessel or both or to remove air from the heart, the great vessel, or both.

12. The system according to claim 11, wherein the gas conveying tube comprises a member for preventing blood from flowing from the heart into the gas conveying tube.

13. A system for preventing an air embolism in an animal in an cardiovascular surgical procedure, comprising:

a source of carbon dioxide in fluid communication with a tube insertable into the heart for conveying the carbon dioxide thereto, having disposed thereinbetween a mechanism for controlling pressure and flow of carbon dioxide therethrough;

the carbon dioxide conveying tube having a first end and a second end, and a member for preventing blood from flowing from the heart into the carbon dioxide conveying tube;

the first end adapted for placement in the heart of the animal and having a plurality of apertures for passage of carbon dioxide therethrough; and

the second end adapted for connection to the pressure and flow controlling mechanism;

wherein the pressure/flow controlling mechanism is operable to conduct the carbon dioxide into the heart through the carbon dioxide conveying tube at a pressure effective to eliminate air bubbles from the heart during the surgical procedure, after completion of the surgical procedure, or both.

14. An assembly for use in a cardiovascular surgical procedure for preventing an air embolism in the brain of an animal, comprising, in combination:

a) a mechanism for controlling pressure and flow of gas therethrough, having an inlet end and an outlet end;

the inlet end adapted for connection to a source of the gas;

b) a filter for removing microorganisms, having an inlet end and an outlet end;

the inlet end adapted for connection to the outlet end of the gas pressure/flow controlling mechanism; and

c) a tube for conveying gas therethrough having a first end and a second end;

the first end adapted for placement in the cardiovascular system of the animal and having a plurality of apertures for passage of the gas therethrough; and

the second end adapted for connection to the outlet end of the filter;

wherein the connections between the pressure/flow controlling mechanism, the filter, and the gas conveying tube provide a fluid communication for conveying the gas therethrough.

15. The assembly according to claim 14, further comprising a component selected from the group consisting of

a tube for removing fluid from the cardiovascular system having a first end and a second end;

the first end adapted for placement in the cardiovascular system of the animal, and the second end adapted for connection to a mechanism operable to draw the fluid out of the cardiovascular system and through the fluid removal tube; and

a tube having a first end and a second end;

the first end connectable to the second end of the gas conveying tube, and the second end adapted for connection to the outlet end of the filter.

16. The assembly according to claim 14, further comprising:

a check-valve adapted for insertion into the gas conveying tube, and operable to prevent blood from flowing from the heart into the tube.

17. The assembly according to claim 14, further comprising, at least one of:

a mechanism operable to draw fluid thereinto, having an inlet end adapted for connection to the second end of the fluid removal tube;

a mechanism for imaging gas bubbles in the body of the animal; and

a source of gas having an outlet end adapted for connection to the inlet end of the gas pressure/flow controlling mechanism.

18. The assembly according to claim 14, wherein the gas conveying tube is integrated with a balloon endoaortic catheter.

19. A method of preventing an air embolism in the brain of an animal in a cardiovascular surgical procedure, comprising:

a) providing a system comprising;

i) a source of gas;

ii) a mechanism for controlling pressure and flow of the gas therethrough, having an inlet end and an outlet end, the inlet end being connected to the gas source;

iii) a tube for conveying the gas therethrough into the cardiovascular system, having a first end and a second end, and a member for preventing blood from flowing from the heart into the carbon dioxide conveying tube;

the first end adapted for placement in the cardiovascular system of the animal and having a plurality of apertures for passage of the gas therethrough; and

the second end adapted for connection to the pressure and flow controlling mechanism; and

iv) a tube for removing fluid from the cardiovascular system, having a first end, a second end, and a central channel therethrough;

the second end connected to a mechanism operable to draw fluid through the central channel;

wherein the gas source, the pressure/flow controlling mechanism and the gas conveying tube are in fluid communication for conveying the gas therethrough, with the pressure/flow controlling mechanism disposed between the gas source and the gas conveying tube;

b) placing the first ends of the gas conveying tube and the fluid removing tube into the cardiovascular system;

c) administering the gas into the cardiovascular system at a pressure and flow effective to purge air from the cardiovascular system; and

removing fluid from the cardiovascular system via the fluid removing tube;

d) reducing the flow of the gas into the cardiovascular system; and

e) removing the gas conveying tube and the fluid removing tube from the cardiovascular system.

20. The method according to claim 19, wherein the cardiovascular system is the heart, and the gas conveying tube and the fluid removing tube are placed into the left ventricle of the heart.

21. The method according to claim 20, wherein step b) further comprises:

inserting a tube into an opening in the aorta, and aspirating the purged air and gas through the tube.

22. The method according to claim 21, wherein step b) is performed prior to the surgical procedure, and the method further comprises prior to step d):

allowing the left ventricle to fill with blood while administering the gas to purge the air therefrom through the opening in the aorta; and

closing the surgical wound.

23. The method according to claim 21, wherein step b) is performed prior to the surgical procedure, and the method further comprises prior to step d):

closing the surgical wound; and

administering the gas to purge the air from the left ventricle through the opening in the aorta; and

removing fluid from the left ventricle via the fluid removing tube.

24. The method according to claim 19, wherein the cardiovascular system is a great vessel selected from the group consisting of the aorta, a heart artery, a carotid artery, an axillary artery, and a pulmonary vein.

25. The method according to claim 19, wherein step c) comprises administering the gas at a pressure of about 30-100 mmHg.

26. The method according to claim 19, wherein step d) comprises administering the gas at a pressure of about 5-20 mmHg.

27. The method according to claim 19, wherein step c) further comprises:

conveying the fluid removed from the cardiovascular system to a device for treating the blood to remove dissolved gas, add oxygen, or both; and

transmitting the treated blood into the animal.

28. The method according to claim 19, further comprising:

monitoring the amount of gas bubbles in the blood of the animal.

29. The method according to claim 28, wherein step b) is performed after the completion of the surgical procedure, and the method further comprises prior to step c):

the step of closing the surgical wound.

30. A system for preventing an air embolism in the brain of an animal in a cardiovascular surgical procedure, comprising:

a source of carbon dioxide;

a mechanism for controlling pressure and flow of the carbon dioxide therethrough, having an inlet end and an outlet end, the inlet end being connected to the carbon dioxide source; and

a multiple lumen tube having first and second channels defining a fluid removal tube and a carbon dioxide conveying tube, each tube having a first and second end, the first ends adapted for placement in the heart of the animal;

the carbon dioxide conveying tube having a plurality of apertures in the first end for passage of carbon dioxide therethrough into the heart, and the second end being connectable to the outlet of the pressure and flow controlling mechanism

the fluid removal tube having an opening in the first end for passage of fluid therethrough from the heart, and the second end being connectable to a mechanism operable to draw the fluid out of the heart through the fluid removal tube;

wherein the carbon dioxide conveying tube has a smaller inside diameter than the fluid removal tube;

the pressure/flow controlling mechanism is disposed between the gas source and the gas conveying tube; and

the gas source, the pressure/flow controlling mechanism and the gas conveying tube are in fluid flowing communication for conveying the gas therethrough;

and the pressure/flow controlling mechanism is operable to provide a flow of the gas through the system such that when the first end of the gas conveying tube is placed into the heart, the pressure and flow of the gas from the pressure/flow controlling mechanism through the gas conveying tube into the heart is effective to inhibit air from entering the heart, great vessel, or both, or to remove air from the heart, the great vessel, or both.

31. The system according to claim 30, wherein the first end of the fluid removal tube extends beyond the first end of the carbon dioxide conveying tube.

32. The system according to claim 31, wherein the first end of the carbon dioxide conveying tube is about 1-2 inches shorter than the first end of the fluid removal tube.

33. The system according to claim 30, wherein the carbon dioxide conveying tube is terminated with a slanted end.

34. The system according to claim 30, wherein the multiple lumen tube is part of a balloon endoaortic catheter.