Expandable catheter system for vessel wall injection and muscle and nerve fiber ablation

Abstract

A catheter-based/intravascular ablation (denervation) system 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 or/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 needle delivery system is formed with self-expanding materials and include structures, near the end portion of the needles, or using separate guide tubes. 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 . A intravascular nerve ablation system for circumferential delivery of an ablative fluid in or outside the vessel wall of a target vessel comprising:
 a catheter body having a central axis extending in a longitudinal direction having a fluid injection lumen, the fluid injection lumen being in fluid communication with three or more sharpened injection needles, the catheter body further including a distal tip and an outer sheath, the outer sheath having a first closed position where the sheath and the distal tip together enclose the sharpened injection needles, the sheath having a second open position, the open position allowing the injection needles to expand outward into the inside vessel wall of a target vessel;   an external source of ablative fluid in fluid communication with said fluid injection lumen, and   injection egress located near the distal end of the needles adapted to provide circumferential delivery of the ablative fluid from the fluid injection lumen at a prescribed depth of injection.   
     
     
         2 . The system of  claim 1  where the circumferential delivery of the ablative fluid is into a specific volume of tissue selected from:
 the media of the wall of the target vessel, 
 the adventitia of the wall of the target vessel, 
 the volume outside of the adventitia of the wall of the target vessel, 
 The media and adventitia of the wall of the target vessel, 
 The adventitia and the volume outside of the adventitia of the target vessel. 
 
     
     
         3 . The system of  claim 1  where the circumferential delivery includes at least three points of injection egress. 
     
     
         4 . The system of  claim 1  further including a distal balloon to prevent the ablative fluid from flowing downstream in the target vessel. 
     
     
         5 . The system of  claim 1  where said catheter body includes a fixed guide wire attached to its distal end. 
     
     
         6 . The system of  claim 1  configured to be advanced coaxially over a separate guide wire. 
     
     
         7 . The system of  claim 1  where the injection egress is provided by at least one injector tube having an injection needle at its distal end, the injection egress being near the distal end of the injection needle. 
     
     
         8 . The system of  claim 1  further including a distal self-expanding portion. 
     
     
         9 . The system of  claim 8  where the distal self-expanding portion includes the injection egress. 
     
     
         10 . The system of  claim 8  where the distal self-expanding portion includes at least one guide tube, and the injection egress is provided by at least one injector tube having a needle at its distal end, the at least one injector tube adapted to be advanced and retracted through the at least one guide tube. 
     
     
         11 . The system of  claim 8  further including a sheath that when retracted to its most proximal open position allows the distal self-expanding portion to expand outward. 
     
     
         12 . The system of  claim 11  where said sheath has a distal closed position and a proximal open position, where the sheath in the closed position extends in the distal direction so as to completely cover the injection egress. 
     
     
         13 . The system of  claim 11  further including a sheath that includes a radiopaque marker at its distal end. 
     
     
         14 . The system of  claim 8  where the self-expanding portion is formed from NITINOL. 
     
     
         15 . The system as of  claim 1  where said ablative fluid includes at least one of the ablative fluids selected from the group including ethanol, phenol, glycerol, lidocaine, bupivacaine, tetracaine, benzocaine, guenethadine, botulinum toxin. 
     
     
         16 . The system of  claim 1  where said ablative fluid is a heated fluid composition. 
     
     
         17 . The vascular nerve ablation system of  claim 1  where said ablative fluid is a cooled fluid composition. 
     
     
         18 . The vascular nerve ablation system of  claim 1  where said ablative fluid is a form of steam injected through the injection lumen of the catheter body. 
     
     
         19 . A method of treating hypertension, the method including the steps of:
 a. placing an introducer sheath into the femoral artery;   b. placing a guiding catheter through the introducer sheath;   c. engaging the ostium of a renal artery with the distal end of the guiding catheter;   d. advancing a intravascular nerve ablation system in its closed position through the guiding catheter until the distal end of the intravascular nerve ablation system lies within a renal artery distal to the distal end of the guiding catheter, the vascular nerve ablation system including a distal portion with injection egress adapted to provide circumferential delivery of an ablative fluid to ablate the sympathetic nerves in proximity to the renal artery   e. positioning the injection egress for circumferential delivery of the ablative fluid   f. delivering ablative fluid through the injection egress at a prescribed depth;   g. retracting the vascular nerve ablation system into the guiding catheter;   h. repeating steps a through h for the other renal artery as needed; and,   i. removing the vascular nerve ablation system from the body of the patient.   
     
     
         20 . The method of  claim 21  where the injection egress provides circumferential delivery of the ablative fluid targeted to the depth of the media of the renal artery. 
     
     
         21 . The method of  claim 21  where the injection egress provides circumferential delivery of the ablative fluid targeted to the depth of the adventitia of the renal artery. 
     
     
         22 . The method of  claim 21  where the injection egress provides circumferential delivery of the ablative fluid targeted to a depth outside of the adventitia of the renal artery. 
     
     
         23 . An intravascular nerve ablation system for circumferential delivery of an ablative fluid to a volume of tissue in proximity to the vessel wall of a target vessel comprising:
 a catheter body having a central axis extending in a longitudinal direction and a fluid injection lumen;   an external source of ablative fluid in fluid communication with said fluid injection lumen, and   a guide tube having a distal end and a central lumen, the guide tube having a distal self-expanding portion.   an injector tube having an injection lumen in fluid communication with the fluid injection lumen of the catheter body. The injector tube located coaxially inside of the guide tube, the injector tube having a sharpened injection needle with injection egress at its distal end, the injector tube being adapted to slide in the longitudinal direction within the guide tube.   a guide tube handle adapted to control the longitudinal motion of the guide tube.   an injection tube handle located near the proximal end of the catheter body including a port for injection of the ablative fluid, the port being in fluid communication with the fluid injection lumen of the catheter body, the injection handle further adapted to control the longitudinal movement of the injector tube, the injection handle and guide tube handle providing the means to limit the penetration into the vessel wall of a target vessel of the injection egress at the distal end of the injector tubes.   
     
     
         24 . The system of  claim 23  further including a sheath having a sheath located coaxially outside of the catheter body, the sheath having a closed position and an open position, the open position allowing the self-expanding guide tube to expand outward against the inside of the wall of the target vessel.