Method and Apparatus for Preventing Air Embolisms

Abstract

Method and apparatus for preventing air embolisms during surgical procedures which involves providing a fluid source in communication with an aperture extending into an anatomical cavity such that fluid may be delivered into the cavity when a condition of negative pressure exists in the cavity, thereby preventing the introduction of air into the cavity.

1 . (canceled) 
     
     
         2 . A cannula system having multiple conduits for moving blood to and from a circulatory system in opposite directions, the cannula system comprising:
 a body having a first tubular section and a communicating second tubular section; and   a first fluid conduit and second fluid conduit, wherein the first fluid conduit is disposed within an outer surface of the first tubular section and extends at least partially through the first tubular section but not the second tubular section, and the second fluid conduit is disposed within an outer surface of the first and second tubular sections and extends at least partially through both the first and second tubular sections;   wherein the first fluid conduit is in communication with a first aperture located in a distal end of the first tubular section adjacent a proximal end of the second tubular section, and the second fluid conduit is in communication with a second aperture at a distal end of the second tubular section; and   wherein the first and second fluid conduits are configured to simultaneously carry blood in opposite directions and are configured to be advanced through the circulatory system such that blood is drawn into the cannula system at a first location within the circulatory system and expelled by the cannula system at a second location within the circulatory system via the first and second apertures.   
     
     
         3 . The cannula system of  claim 2 , wherein the first fluid conduit is concentric with the second fluid conduit. 
     
     
         4 . The cannula system of  claim 2 , wherein the first tubular section has an outer diameter that is larger than an outer diameter of the second tubular section. 
     
     
         5 . The cannula system of  claim 2 , further comprising a sealing member mounted at a proximal region of the first tubular section, the sealing member comprising an aperture configured to receive an instrument therethrough. 
     
     
         6 . The cannula system of  claim 2 , further comprising a pump configured to draw blood through one of the first and second apertures and expel the blood through one of the first and second apertures. 
     
     
         7 . The cannula system of  claim 2 , further comprising a tapered tubular section between the first and second tubular sections, the second conduit extending through the tapered tubular section. 
     
     
         8 . The cannula system of  claim 2 , further comprising a third tubular section at least partially engaged with a proximal end of the first tubular section. 
     
     
         9 . The cannula system of  claim 2 , further comprising a sensor connected to the cannula system configured to measure at least one of blood pressure, blood flow rate, or blood oxygen content. 
     
     
         10 . A method for removing and delivering blood to and from the circulatory system through a cannula system, the cannula system having a body having a first tubular section and a communicating second tubular section; and a first fluid conduit and second fluid conduit, wherein the first fluid conduit is disposed within an outer surface of the first tubular section and extends at least partially through the first tubular section but not the second tubular section, and the second fluid conduit is disposed within an outer surface of the first and second tubular sections and extends at least partially through both the first and second tubular sections; wherein the first fluid conduit is in communication with a first aperture located in a distal end of the first tubular section adjacent a proximal end of the second tubular section, and the second fluid conduit is in communication with a second aperture at a distal end of the second tubular section; wherein the first and second fluid conduits are configured to simultaneously carry blood in opposite directions and are configured to be advanced through the circulatory system such that blood is drawn into the cannula system at a first location within the circulatory system and expelled by the cannula system at a second location within the circulatory system via the first and second apertures, the method comprising the steps of:
 inserting the cannula system into a circulatory system of a patient; and   pumping blood through the first and second fluid conduits simultaneously in opposite directions.   
     
     
         11 . The method of  claim 10 , wherein the step of pumping comprises moving blood with a pump through the first fluid conduit towards the first aperture while moving blood with the pump from the second aperture towards the pump. 
     
     
         12 . The method of  claim 10 , wherein the first tubular section has a larger tubular diameter than the second tubular section. 
     
     
         13 . The method of  claim 10 , further comprising:
 measuring a parameter of the blood chosen from the group consisting of pressure, flow rate, and oxygen content.   
     
     
         14 . The method of  claim 10 , wherein the step of inserting further comprises inserting the cannula system at least partially into a target vessel proximate to a heart of the patient. 
     
     
         15 . The method of  claim 10 , wherein the step of inserting further comprises inserting the cannula system at least partially into a patient's heart. 
     
     
         16 . The method of  claim 10 , wherein the step of inserting further comprises inserting the cannula system at least partially into one of the left and right atriums of a heart of the patient. 
     
     
         17 . The method of  claim 10 , wherein the step of inserting further comprises inserting the cannula system at least partially into one of the left and right ventricles of a heart of the patient.