Catheter apparatus having an improved shape-memory alloy cuff and inflatable on-demand balloon for creating a bypass graft in-vivo

Abstract

The present invention provides a catheter apparatus, an improved introducer system, and a methodology for creating a bypass on-demand between an unobstructed blood vessel such as the aorta and an obstructed blood vessel such as an obstructed coronary artery in-vivo using a prepared shape-memory alloy cuff and a graft segment in tandem as a shunt. The invention allows the placement and creation of single or multiple bypass grafts without use of a heart-lung machine and without need for stopping the heart of the patient during the coronary artery bypass surgery.

What I claim is:  
     
         1 . A catheter apparatus for creating a bypass on-demand between an unobstructed blood vessel and an obstructed blood vessel in-vivo using a graft segment as a conduit, said bypass catheter apparatus comprising: 
 a catheter suitable for introduction into and extension through the body invivo to a chosen site wherein an unobstructed blood vessel is in anatomic proximity to an obstruction lying within another blood vessel, said catheter being comprised of a hollow tube of fixed axial length having a proximal end, a distal end, and at least one internal lumen of predetermined diameter;    an obturator for on-demand introduction and passage through said catheter to a chosen site on the unobstructed blood vessel in-vivo, said obturator comprising 
 (a) a puncturing headpiece for puncture of and entry into the lumen of an unobstructed blood vessel,  
 (b) a perforating end tip on said puncturing headpiece to facilitate the perforation of a blood vessel wall at the chosen site in-vivo,  
 (c) an elongated shaft of fixed axial length integrated with said puncturing headpiece, said elongated shaft being configured for the carrying and transport of a graft segment within said internal lumen of said catheter to the chosen site on the unobstructed blood vessel in-vivo; and  
   a thermoelastic deformable cuff comprised of a prepared shape-memory alloy in a chosen extant configuration for positioning over said elongated shaft adjacent to said puncturing headpiece of said obturator together with a graft segment, said thermoelastic deformable cuff having a discrete central portion and two discrete end portions 
 (i) wherein, prior to the perforation of the unobstructed blood vessel in-vivo by said puncturing headpiece of said obturator, said central portion of said cuff has been engaged and joined to one end of the graft segment then carried by said elongated shaft of said obturator thereby forming an engaged medial cuff portion and two discrete non-engaged cuff end portions;  
 (ii) and wherein, after the perforation of the unobstructed blood vessel in-vivo by said puncturing headpiece of said obturator, one of said non- engaged cuff end portions is extended into the lumen of the unobstructed blood vessel, and becomes thermoelastically deformed in-situ within the lumen of the unobstructed blood vessel into a prepared memory-shaped end configuration, and is disposed in the prepared memory-shaped end configuration onto an interior surface of the unobstructed blood vessel,  
 (iii) and wherein, after the perforation of the unobstructed blood vessel in-vivo by said puncturing headpiece of said obturator, the other of said non-engaged cuff end portions is positioned adjacent an exterior surface of the unobstructed blood vessel, and becomes thermoelastically deformed in-situ adjacent the exterior surface of the unobstructed blood vessel into another prepared memory-shaped end configuration, and is disposed in the other prepared memory-shaped end configuration onto an exterior surface of the unobstructed blood vessel.  
 (iv) and whereby the end of the graft segment engaged by the central portion of the cuff becomes secured to and placed in blood flow communication with the unobstructed blood vessel and serves as a conduit means for bypassing an obstruction and restoring blood flow from the unobstructed blood vessel to an obstructed blood vessel.  
   
     
     
         2 . A catheter apparatus for creating a bypass on-demand between an unobstructed blood vessel and an obstructed blood vessel in-vivo using a graft segment as a conduit, said bypass catheter apparatus comprising: 
 a catheter suitable for introduction into and extension through the body invivo to a chosen site wherein an unobstructed blood vessel is in anatomic proximity to an obstruction lying within another blood vessel, said catheter being comprised of a hollow tube of fixed axial length having a proximal end, a distal end, and at least one internal lumen of predetermined diameter;    an obturator for on-demand introduction and passage through said catheter to a chosen site on the unobstructed blood vessel in-vivo, said obturator comprising 
 (a) a puncturing headpiece for puncture of and entry into the lumen of an unobstructed blood vessel,  
 (b) a perforating end tip on said puncturing headpiece to facilitate the perforation of a blood vessel wall at the chosen site in-vivo,  
 (c) an elongated shaft of fixed axial length integrated with said puncturing headpiece, said elongated shaft being configured for the carrying and transport of a graft segment within said internal lumen of said catheter to the chosen site on the unobstructed blood vessel in-vivo;  
   an inflatable and deflatable on-demand balloon of prechosen configuration disposed adjacent to said puncturing headpiece on said elongated shaft of said obturator, the girth of said balloon in the deflated state being less than the internal diameter of the graft segment to be used as a conduit; and    a thermoelastic deformable cuff comprised of a prepared shape-memory alloy in an chosen extant configuration for positioning over said elongated shaft adjacent to said puncturing headpiece of said obturator together with a graft segment to be used as a conduit, said thermoelastic deformable cuff having a discrete central portion and two discrete end portions 
 (i) wherein, prior to the perforation of the unobstructed blood vessel in-vivo by said puncturing headpiece of said obturator, said discrete central portion of said cuff has been engaged and joined to one end of the graft segment then carried by said elongated shaft of said obturator thereby forming an engaged central cuff portion and two discrete non-engaged cuff end portions;  
 (ii) and wherein, after the perforation of the unobstructed blood vessel in-vivo by said puncturing headpiece of said obturator, one of said non-engaged cuff end portions is extended into the lumen of the unobstructed blood vessel, and becomes thermoelastically deformed in-situ within the lumen of the unobstructed blood vessel into a prepared memory-shaped end configuration, and is disposed in the prepared memory-shaped end configuration onto an interior surface of the unobstructed blood vessel,  
 (iii) and wherein, after the perforation of the unobstructed blood vessel in-vivo by said puncturing headpiece of said obturator, the other of said non-engaged cuff end portions is positioned adjacent an exterior surface of the unobstructed blood vessel, and becomes thermoelastically deformed in-situ adjacent the exterior surface of the unobstructed blood vessel into another prepared memory-shaped end configuration, and is disposed in the other prepared memory-shaped end configuration onto an exterior surface of the unobstructed blood vessel,  
 (iv) and whereby the end of the graft segment engaged by the central portion of the cuff becomes secured to and placed in blood flow communication with the unobstructed blood vessel and serves as a conduit means for bypassing an obstruction and restoring blood flow from the unobstructed blood vessel to an obstructed blood vessel.  
   
     
     
         3 . A catheter apparatus for creating a bypass on-demand between an unobstructed blood vessel and an obstructed blood vessel in-vivo using a graft segment as a conduit, said bypass catheter apparatus comprising: 
 a catheter suitable for introduction into and extension through the body invivo to a chosen site wherein an unobstructed blood vessel is in anatomic proximity to an obstruction lying within another blood vessel, said catheter being comprised of a hollow tube of fixed axial length having a proximal end, a distal end, and at least one internal lumen of predetermined diameter;    an obturator for on-demand introduction and passage through said catheter to a chosen site on the unobstructed blood vessel in-vivo, said obturator comprising 
 (a) a puncturing headpiece for puncture of and entry into the lumen of an unobstructed blood vessel,  
 (b) a perforating end tip of said puncturing headpiece to facilitate the perforation of a blood vessel wall at the chosen site in-vivo;  
 (c) an elongated shaft of fixed axial length integrated with said puncturing headpiece, said elongated shaft being configured for the carrying and transport of a graft segment within said internal lumen of said catheter to the chosen site on the unobstructed blood vessel in-vivo;  
   an inflatable and deflatable on-demand balloon of prechosen configuration disposed adjacent to said puncturing headpiece on said elongated shaft of said obturator, the girth of said balloon in the deflated state being less than the internal diameter of the graft segment to be used as a conduit; and    a thermoelastic deformable cuff comprised of a prepared shape-memory alloy in a chosen extant configuration for positioning over said elongated shaft adjacent to said puncturing headpiece of said obturator together with a graft segment 
 (i) wherein, prior to the perforation of the unobstructed blood vessel in-vivo by said puncturing headpiece of said obturator, a portion of said cuff in the extant configuration has been engaged and joined to one end of the graft segment then carried by said elongated shaft of said obturator thereby forming an engaged cuff portion and a plurality of non-engaged cuff end portions,  
 (ii) and wherein, after the perforation of the unobstructed blood vessel in-vivo by said puncturing headpiece of said obturator, at least part of said non-engaged cuff end portion is extended into the lumen of the unobstructed blood vessel and becomes thermoelastically deformed in-situ into a prepared memory-shaped end configuration, and said prepared memory-shaped end configuration of said deformed non-engaged cuff portion becomes disposed onto an interior surface of the unobstructed blood vessel,  
 (iii) and whereby said cuff engaged end of the graft segment becomes secured to and placed in blood flow communication with the unobstructed blood vessel and serves as conduit means for bypassing an obstruction and restoring blood flow from the unobstructed blood vessel to an obstructed blood vessel.  
   
     
     
         4 . The catheter apparatus as recited in  claim 1 ,  2 , or  3  wherein said deformable cuff is comprised of a nickel-titanium alloy.  
     
     
         5 . The catheter apparatus as recited in  claim 1 ,  2 , or  3  wherein said deformable cuff is overlaid with a biocompatible coating.  
     
     
         6 . The catheter apparatus as recited in  claim 1 ,  2 , or  3  wherein said deformable cuff comprises an open meshwork.  
     
     
         7 . The catheter apparatus as recited in  claim 1 ,  2 , or  3  wherein said deformable cuff comprises a solid mass of material.  
     
     
         8 . The catheter apparatus as recited in  claim 1 ,  2 , or  3  wherein said obturator further comprises means for expansion and contraction of said puncturing headpiece on-demand.  
     
     
         9 . The catheter apparatus as recited in  claim 1 ,  2 , or  3  wherein said graft segment comprises a synthetic prosthetic channel section.  
     
     
         10 . The catheter apparatus as recited in  claim 1 ,  2 , or  3  wherein said graft segment comprises a previously excised blood vessel segment.  
     
     
         11 . The catheter apparatus as recited in  claim 2  or  3  wherein said balloon comprises means for conveying fluid.  
     
     
         12 . The catheter apparatus as recited in  claim 2  or  3  wherein said balloon comprises an enclosing sheath.  
     
     
         13 . The catheter apparatus as recited in  claim 2  or  3  wherein said balloon is composed of at least one material selected from the group consisting of elastic and non-elastic substances.