Aortic occluder with associated filter and methods of use during cardiac surgery

Abstract

A balloon arterial cannula and methods for filtering blood. The devices generally include a mesh for filtering blood flowing within a blood vessel, particularly within an artery such as the aorta, a structure adapted to open and close the mesh within the blood vessel, a means to actuate the structure, and a balloon occluder which typically includes a flexible material enclosing a chamber. The methods generally include the steps of introducing a mesh into a blood vessel to capture embolic material, adjusting the mesh, if necessary, during the course of filtration, inflating the balloon occluder to occlude the vessel upstream of the mesh, and thereafter deflating the balloon occluder and removing the mesh and the captured foreign matter from the blood vessel. Additionally, visualization techniques are used to ensure effective filtration.

1 . A balloon cannula comprising: 
 a filtration assembly; and    an cannula with a collapsible section configured to accommodate the filtration assembly.    
   
   
       2 . A balloon cannula of  claim 1 , wherein the cannula includes an elongate member with a tubular wall, said collapsible section including a portion of the tubular wall that is inwardly collapsible toward an axis of the elongate tubular wall member.  
   
   
       3 . A balloon cannula of  claim 2 , wherein the collapsible section is comprised of an elastomeric material.  
   
   
       4 . A balloon cannula of  claim 3 , wherein the collapsible section includes a balloon.  
   
   
       5 . A balloon cannula of  claim 4 , wherein the collapsible section includes a double-walled balloon.  
   
   
       6 . A balloon cannula of  claim 2 , wherein the collapsible section is comprised of a flexible memory material.  
   
   
       7 . A balloon cannula of  claim 2 , wherein the filtration assembly includes a filter and the collapsible section is configured to collapse inwardly a sufficient amount to allow the filter, in a collapsed condition, to have a diameter smaller than an adjacent, non-collapsible portion of the tubular wall.  
   
   
       8 . A balloon cannula of  claim 7 , wherein the filtration assembly includes a filter seal and wherein collapsible section is configured to collapse inwardly a sufficient amount to allow the filtration assembly, in a collapsed condition, to have a diameter smaller than an adjacent, non-collapsible portion of the tubular wall  
   
   
       9 . A balloon cannula of  claim 8 , wherein the collapsible section begins just proximal to the filter seal when the filter is in a collapsed state.  
   
   
       10 . A balloon cannula of  claim 9 , wherein the collapsible section has a length at least equal to the filter and filter seal.  
   
   
       11 . A balloon cannula of  claim 10 , wherein the length of the collapsible section extends to a distal tip of the cannula.  
   
   
       12 . A balloon cannula of  claim 1 , wherein the collapsible section is comprised of a flexible memory material.  
   
   
       13 . A balloon cannula of  claim 12 , wherein the collapsible section is configured to return to a non-collapsed state when the filter assembly is expanded.  
   
   
       14 . A balloon cannula of  claim 13 , wherein the collapsible section is configured to expand when pressurized blood flow occurs in the cannula.  
   
   
       15 . A method of preparing a filtration assembly and cannula for insertion into a patient, the method comprising: 
 collapsing a section of the cannula; and    collapsing a filtration assembly against an outer wall of the collapsed section of the cannula.    
   
   
       16 . A method of  claim 15 , further comprising expanding the filtration assembly and expanding the collapsed section of the cannula by flowing blood therethrough.