Expandable catheter system for fluid injection into and deep to the wall of a blood vessel

Abstract

A catheter-based/intravascular fluid injection system with application to renal denervation includes a multiplicity of needles which expand open around a central axis to engage the wall of a blood vessel, or the wall of the left atrium, allowing the injection of a cytotoxic and/or neurotoxic solution for ablating conducting tissue, or nerve fibers around the ostium of the pulmonary vein, or circumferentially in or just beyond the outer layer of the renal artery. The expandable delivery system includes expandable components that facilitate positioning of a multiplicity of injection needles against the inside wall of a blood vessel from where they can be advanced. The system also includes means to limit and/or adjust the depth of penetration of the ablative fluid into the tissue of the wall of the targeted blood vessel.

1 - 30 . (canceled) 
     
     
         31 . An ablation system comprising:
 a catheter body having a central axis;   a first guide tube and a second guide tube, wherein the first guide tube assumes a pre-shaped curve when extending outward from the catheter body, wherein the second guide tube assumes a pre-shaped curve when extending outward from the catheter body, the first guide tube and the second guide tube configured to have a maximum diameter of outward extension; and   a first injector and a second injector, the first and second injectors located coaxially inside of the first and second guide tubes, respectively,   wherein the first injector and the second injector are configured to advance relative to the first guide tube and the second guide tube, respectively, to penetrate tissue.   
     
     
         32 . The ablation system of  claim 31 , wherein the first injector and the second injector are configured for simultaneous movement. 
     
     
         33 . The ablation system of  claim 31 , wherein the first guide tube and the second guide tube are configured for simultaneous movement. 
     
     
         34 . The ablation system of  claim 31 , wherein the first guide tube comprises a two layer tube. 
     
     
         35 . The ablation system of  claim 31 , wherein the first guide tube comprises a plastic material. 
     
     
         36 . The ablation system of  claim 31 , wherein the first guide tube comprises a stiff material in the portion that bends and extends outward. 
     
     
         37 . The ablation system of  claim 31 , wherein the first guide tube is configured to navigate a nearly right angle bend through the catheter body. 
     
     
         38 . The ablation system of  claim 31 , wherein the first guide tube extends outward without inflation of a balloon. 
     
     
         39 . The ablation system of  claim 31 , wherein the first injector and the second injector are configured to parallel the pre-shaped curve of the first guide tube and the second guide tube. 
     
     
         40 . An ablation system comprising:
 a catheter body having a central axis;   a first guide tube and a second guide tube, the first guide tube and the second guide tube configured to curve toward a vessel wall, the first guide tube and the second guide tube having a memory configuration with a maximum memory diameter; and   a first injector and a second injector, the first and second injectors located coaxially inside of the first and second guide tubes, respectively,   wherein the first injector and the second injector are configured to advance relative to the first guide tube and the second guide tube, respectively, to penetrate tissue.   
     
     
         41 . The ablation system of  claim 40 , wherein the maximum memory diameter of the first guide tube and the second guide tube is between 3 mm and 10 mm. 
     
     
         42 . The ablation system of  claim 40 , wherein the diameter of the catheter body is less than 2 mm. 
     
     
         43 . The ablation system of  claim 40 , wherein the first injector and the second injector are between 25 gauge and 35 gauge. 
     
     
         44 . The ablation system of  claim 40 , wherein the first and second guide tubes are configured to press against, but not penetrate, the vessel wall at the maximum memory diameter. 
     
     
         45 . The ablation system of  claim 40 , wherein the first injector and the second injector extend beyond the maximum memory diameter to penetrate tissue. 
     
     
         46 . An ablation system comprising:
 a catheter body having a central axis;   a first guide tube and a second guide tube, the first guide tube and the second guide tube extendable from the central axis having a pre-set maximum extension with the first guide tube and the second guide tube flaring outward to point close to perpendicular to the central axis; and   a first injector and a second injector, the first and second injectors located coaxially inside of the first and second guide tubes respectively,   wherein the first injector and the second injector are configured to advance relative to the first guide tube and the second guide tube, respectively, to penetrate tissue.   
     
     
         47 . The ablation system of  claim 46 , wherein the advancement of the first injector and the second injector are controlled by a single injector handle. 
     
     
         48 . The ablation system of  claim 46 , wherein the advancement of the first guide tube and the second guide tube are controlled by a single guide tube handle. 
     
     
         49 . The ablation system of  claim 46 , wherein the first injector comprises a radiopaque material. 
     
     
         50 . The ablation system of  claim 46 , wherein the first guide tube comprises a radiopaque material.