Aortic filter catheter

Abstract

A aortic filter catheter is used to capture potential emboli within the aorta during heart surgery and cardiopulmonary bypass. An expandable embolic filter assembly having fine filter mesh for capturing macroemboli and microemboli is mounted on a catheter shaft having a perfusion lumen with perfusion ports located upstream of the filter. The embolic filter assembly can be actively or passively deployed within the ascending aortic. The embolic filter assembly includes an aortic occlusion device, which may be a toroidal balloon, an expandable balloon or a selectively deployable external catheter flow control valve. The combined device allows percutaneous transluminal administration of cardiopulmonary bypass and cardioplegic arrest with protection from undesirable embolic events.

What is claimed is:  
     
         1 . An aortic filter catheter comprising: 
 an elongated catheter shaft,    an embolic filter assembly mounted on said catheter shaft, said embolic filter assembly including a porous filter mesh, said embolic filter assembly being expandable to engage an inner surface of a patient's aorta, and    an aortic occlusion device mounted on said elongated catheter shaft.    
     
     
         2 . The aortic filter catheter of  claim 1 , wherein said aortic occlusion device is mounted on said elongated catheter shaft upstream of said embolic filter assembly.  
     
     
         3 . The aortic filter catheter of  claim 1 , wherein said aortic occlusion device comprises a toroidal balloon occlusion device, said toroidal balloon occlusion device having an uninflated state, a first inflated state in which said toroidal balloon occlusion device engages the inner surface of the aorta and in which said toroidal balloon occlusion device has an open central passage permitting fluid flow therethrough, and a second inflated state in which said central passage of said toroidal balloon occlusion device closes preventing fluid flow therethrough.  
     
     
         4 . The aortic filter catheter of  claim 1 , wherein said aortic occlusion device comprises an inflatable balloon expandable to occlude the aortic lumen.  
     
     
         5 . The aortic filter catheter of  claim 4 , wherein said inflatable balloon is mounted on said elongated catheter shaft upstream of said embolic filter assembly.  
     
     
         6 . The aortic filter catheter of  claim 1 , wherein said aortic occlusion device comprises an external catheter flow control valve expandable to occlude the aortic lumen.  
     
     
         7 . The aortic filter catheter of  claim 6 , wherein said external catheter flow control valve is mounted on said elongated catheter shaft upstream of said embolic filter assembly.  
     
     
         8 . The aortic filter catheter of  claim 1 , wherein said embolic filter assembly is configured to expand passively in response to blood flow in the aorta.  
     
     
         9 . The aortic filter catheter of  claim 1 , wherein said embolic filter assembly is resiliently biased toward the expanded state.  
     
     
         10 . The aortic filter catheter of  claim 1 , further comprising a perfusion lumen within said elongated catheter shaft, said perfusion lumen being fluidly connected to a perfusion port located on said elongated catheter shaft upstream of said filter mesh and downstream of said aortic occlusion device.  
     
     
         11 . The aortic filter catheter of  claim 10 , further comprising a distal lumen within said elongated catheter shaft, said distal lumen being fluidly connected to a distal port on said elongated catheter shaft upstream of said aortic occlusion device.  
     
     
         12 . The aortic filter catheter of  claim 1 , wherein said embolic filter assembly is configured with a conical upstream section and an approximately cylindrical extension extending downstream of said conical upstream section.  
     
     
         13 . The aortic filter catheter of  claim 1 , wherein said embolic filter assembly includes a means to actively expand said embolic filter assembly within the aorta.  
     
     
         14 . The aortic filter catheter of  claim 13 , wherein said means to actively expand said embolic filter assembly comprises a plurality of actuation members connected to an outer periphery of said embolic filter assembly.  
     
     
         15 . The aortic filter catheter of  claim 14 , wherein said actuation members comprise a plurality of actuation wires slidably received within at least one actuation wire lumen within said elongated catheter shaft, said actuation wires having distal ends connected to the outer periphery of said embolic filter assembly.  
     
     
         16 . The aortic filter catheter of  claim 13 , wherein said means to actively expand said embolic filter assembly comprises an extendable and retractable support wire circumscribing an outer periphery of said embolic filter assembly.  
     
     
         17 . The aortic filter catheter of  claim 16 , wherein said support wire has a distal end advanceable and retractable through a channel circumscribing said outer periphery of said embolic filter assembly.  
     
     
         18 . The aortic filter catheter of  claim 16 , wherein said support wire forms an expandable and retractable loop circumscribing said outer periphery of said embolic filter assembly.  
     
     
         19 . The aortic filter catheter of  claim 16 , wherein said elongated catheter shaft is approximately tangential to said outer periphery of said embolic filter assembly when said embolic filter assembly is in an expanded state.  
     
     
         20 . The aortic filter catheter of  claim 1 , wherein said embolic filter assembly has an outer periphery and said elongated catheter shaft is approximately tangential to said outer periphery of said embolic filter assembly when said embolic filter assembly is in an expanded state.  
     
     
         21 . The aortic filter catheter of  claim 20 , wherein said elongated catheter shaft has a distal end that is curved toward a center of an inlet end of said embolic filter assembly.  
     
     
         22 . The aortic filter catheter of  claim 1 , further comprising a light emitting means for directing a beam of light through a wall of the aorta.  
     
     
         23 . The aortic filter catheter of  claim 22 , wherein said light emitting means is positioned on an outer periphery of said embolic filter assembly.  
     
     
         24 . The aortic filter catheter of  claim 1 , wherein said embolic filter assembly comprises a first portion of porous filter mesh having a first porosity and a second portion of porous filter mesh having a second porosity different from said first porosity.  
     
     
         25 . The aortic filter catheter of  claim 24 , wherein said first portion of porous filter mesh is an upstream portion of the porous filter mesh and said second portion of porous filter mesh is a downstream portion of the porous filter mesh.  
     
     
         26 . The aortic filter catheter of  claim 24 , wherein said first portion of porous filter mesh is separated from said second portion of porous filter mesh along a longitudinally oriented dividing line.  
     
     
         27 . The aortic filter catheter of  claim 1 , wherein said filter mesh has a convoluted configuration when said embolic filter assembly is in the expanded state.  
     
     
         28 . The aortic filter catheter of  claim 27 , wherein said filter mesh has a circumferentially convoluted configuration.  
     
     
         29 . The aortic filter catheter of  claim 27 , wherein said filter mesh has a longitudinally convoluted configuration.  
     
     
         30 . The aortic filter catheter of  claim 27 , wherein said filter mesh has a helically convoluted configuration.  
     
     
         31 . An aortic filter catheter comprising: 
 an elongated catheter shaft,    an embolic filter assembly having a porous filter mesh mounted on said catheter shaft, said embolic filter assembly being expandable to engage an inner surface of a patient's aorta, said embolic filter assembly having an inlet end that is open to fluid flow when said embolic filter assembly is in an expanded state, and    a toroidal balloon occlusion device mounted at said inlet end of said embolic filter assembly, said toroidal balloon occlusion device having an uninflated state, a first inflated state in which said toroidal balloon occlusion device engages the inner surface of the aorta and in which said toroidal balloon occlusion device has an open central passage permitting fluid flow therethrough, and a second inflated state in which said central passage of said toroidal balloon occlusion device closes preventing fluid flow therethrough.    
     
     
         32 . The aortic filter catheter of  claim 31 , wherein said elongated catheter shaft is approximately tangential to said inlet end of said embolic filter assembly when said embolic filter assembly is in the expanded state.  
     
     
         33 . The aortic filter catheter of  claim 31 , wherein said inlet end of said embolic filter assembly is connected to said elongated catheter shaft by a plurality of struts.  
     
     
         34 . The aortic filter catheter of  claim 31 , further comprising a perfusion lumen within said elongated catheter shaft, said perfusion lumen being fluidly connected to a perfusion port located on said elongated catheter shaft upstream of said filter mesh and downstream of said toroidal balloon occlusion device.  
     
     
         35 . The aortic filter catheter of  claim 34 , further comprising a distal lumen within said elongated catheter shaft, said distal lumen being fluidly connected to a distal port on said elongated catheter shaft upstream of said toroidal balloon occlusion device.  
     
     
         36 . A method comprising: 
 introducing an elongated tubular shaft of an aortic filter catheter into a patient's aorta;    positioning an embolic filter assembly having a porous filter mesh mounted on said elongated tubular shaft within the patient's ascending aorta;    expanding said embolic filter assembly to engage an inner surface of the patient's ascending aorta; and    occluding the patient's ascending aorta with an aortic occlusion device mounted on said elongated tubular shaft.    
     
     
         37 . The method of  claim 36 , wherein said aortic occlusion device is mounted on said elongated catheter shaft upstream of said embolic filter assembly.  
     
     
         38 . The method of  claim 36 , further comprising perfusing oxygenated blood through a perfusion lumen within said elongated tubular shaft into the patient's aorta.  
     
     
         39 . The method of  claim 36 , further comprising perfusing oxygenated blood through a perfusion lumen within said elongated tubular shaft into the patient's aorta upstream of said porous filter mesh and downstream of said aortic occlusion device.  
     
     
         40 . The method of  claim 36 , further comprising introducing a cardioplegic agent into the patient's coronary arteries to induce cardioplegic arrest by infusing the cardioplegic agent into the patient's aorta upstream of said aortic occlusion device.  
     
     
         41 . The method of  claim 36 , further comprising monitoring the position and deployment state of said aortic filter catheter by directing a beam of light from said aortic filter catheter through a wall of the patient's aorta and observing the transmitted light beam external to the aorta.  
     
     
         42 . The method of  claim 36 , wherein said aortic occlusion device comprises an inflatable balloon expandable to occlude the aortic lumen.  
     
     
         43 . The method of  claim 36 , wherein said aortic occlusion device comprises an external catheter flow control valve expandable to occlude the aortic lumen.