Methods and apparatus for renal neuromodulation

Abstract

Methods and apparatus are provided for renal neuromodulation using a pulsed electric field to effectuate electroporation or electrofusion. It is expected that renal neuromodulation (e.g., denervation) may, among other things, reduce expansion of an acute myocardial infarction, reduce or prevent the onset of morphological changes that are affiliated with congestive heart failure, and/or be efficacious in the treatment of end stage renal disease. Embodiments of the present invention are configured for extravascular delivery of pulsed electric fields to achieve such neuromodulation.

1 - 65 . (canceled) 
     
     
         66 . A method for treating a patient diagnosed with chronic heart failure, the method comprising:
 extravascularly positioning an energy transfer element carried by a catheter adjacent to renal nerves innervating a kidney of the patient; and   ablating the renal nerves innervating the kidney via energy from the energy transfer element,   wherein ablating the renal nerves therapeutically treats the diagnosed chronic heart failure of the patient.   
     
     
         67 . The method of  claim 66  wherein ablating the renal nerves innervating the kidney reduces central sympathetic drive in the patient in a manner that therapeutically treats the diagnosed chronic heart failure. 
     
     
         68 . The method of  claim 66  wherein ablating the renal nerves innervating the kidney via energy from the energy transfer element comprises delivering radio frequency (RF) energy in a monopolar fashion between the energy transfer element and an external ground pad attached to an exterior of the patient. 
     
     
         69 . The method of  claim 66  wherein the catheter comprises a plurality of energy transfer elements, and wherein ablating the renal nerves innervating the kidney via energy from the energy transfer element comprises delivering radio frequency (RF) energy in a bipolar fashion between two or more of the energy transfer elements. 
     
     
         70 . The method of  claim 66  wherein the catheter comprises a plurality of energy transfer elements, and wherein the individual energy transfer elements are dynamically assignable. 
     
     
         71 . The method of  claim 66  wherein ablating the renal nerves innervating the kidney via energy from the energy transfer element comprises ablating afferent renal nerves of the patient via RF energy from the energy transfer element. 
     
     
         72 . The method of  claim 66  wherein ablating the renal nerves innervating the kidney via energy from the energy transfer element comprises ablating both afferent and efferent renal nerves of the patient via RF energy from the energy transfer element. 
     
     
         73 . The method of  claim 66  wherein extravascularly positioning an energy transfer element carried by a catheter adjacent to renal nerves comprises positioning the energy transfer element at or near a renal hilum of the patient. 
     
     
         74 . The method of  claim 66  wherein extravascularly positioning an energy transfer element carried by a catheter adjacent to renal nerves comprises positioning the energy transfer element along a renal vein of the patient. 
     
     
         75 . The method of  claim 66  wherein extravascularly positioning an energy transfer element carried by a catheter adjacent to renal nerves comprises delivering the catheter over a guidewire. 
     
     
         76 . The method of  claim 66  wherein ablating the renal nerves innervating the kidney comprises at least partially denervating the kidney of the patient. 
     
     
         77 . The method of  claim 66 , further comprising monitoring a parameter of the energy transfer element and/or tissue within the patient before and during delivery of energy via the energy transfer element. 
     
     
         78 . The method of  claim 77  wherein monitoring a parameter comprises monitoring power, temperature, and/or impedance. 
     
     
         79 . The method of  claim 77  wherein monitoring a parameter comprises monitoring at least one physiological parameter of the patient. 
     
     
         80 . The method of  claim 79  wherein the monitored physiological parameter comprises plasma renin levels and/or other neurohormones that are indicative of increased sympathetic nervous activity of the patient. 
     
     
         81 . The method of  claim 67 , further comprising varying delivery of the energy via the energy transfer element in response to the monitored parameter. 
     
     
         82 . The method of  claim 66  wherein extravascularly positioning an energy transfer element carried by a catheter comprises delivering a distal segment of the catheter within a probe, and wherein the method further comprises at least partially extending the distal segment of the catheter out from the probe before delivering energy via the energy transfer element. 
     
     
         83 . The method of  claim 66 , further comprising removing the catheter from the patient after delivering the energy to conclude the procedure. 
     
     
         84 . The method of  claim 83  wherein extravascularly positioning an energy transfer element carried by a catheter adjacent to renal nerves innervating a kidney of the patient comprises positioning the energy transfer element under visual guidance. 
     
     
         85 . The method of  claim 83  wherein extravascularly positioning an energy transfer element carried by a catheter adjacent to renal nerves innervating a kidney of the patient comprises extravascularly positioning the energy transfer element under guidance chosen from the group consisting of computed tomographic, radiographic, ultrasonic, angiographic, laparoscopic and combinations thereof.