Apparatuses 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 . An apparatus for renal neuromodulation, the apparatus comprising:
 an electric field generator; and   an electrode configured for extravascular placement proximate a renal nerve in a patient,   wherein the electrode is electrically coupled to the electric field generator, and wherein the electrode is configured to deliver an electric field to the renal nerve while the electrode is located proximate the renal nerve.   
     
     
         2 . The apparatus of  claim 1 , wherein the electrode is configured for placement adjacent to a renal vasculature. 
     
     
         3 . The apparatus of  claim 2 , wherein the electrode is configured for percutaneous placement adjacent to the renal vasculature. 
     
     
         4 . The apparatus of  claim 2 , wherein the electrode is configured to be arranged in (a) a reduced delivery configuration for placement adjacent to the renal vasculature and (b) an expanded treatment configuration for delivering the electric field to the renal nerve. 
     
     
         5 . The apparatus of  claim 4 , wherein the electrode is configured to at least partially encircle the renal vasculature in the expanded treatment configuration. 
     
     
         6 . The apparatus of  claim 1 , wherein the electrode is configured to at least partially encircle a renal artery of the patient. 
     
     
         7 . The apparatus of  claim 2 , wherein the electrode is configured for placement in an annular space between renal fascia and renal vasculature. 
     
     
         8 . The apparatus of  claim 2 , wherein the apparatus is configured to orient a longitudinal portion of the electric field with a longitudinal dimension of at least one of the renal nerve and the renal vasculature. 
     
     
         9 . The apparatus of  claim 1 , wherein the electrode comprises a bipolar electrode pair. 
     
     
         10 . The apparatus of  claim 1 , wherein the electrode comprises an active electrode, and wherein the apparatus further comprises a ground electrode located remote the renal nerve, such that the active electrode is configured to deliver the electric field to the renal nerve in a monopolar fashion. 
     
     
         11 . The apparatus of  claim 10 , wherein the ground electrode is configured for exterior attachment to the patient. 
     
     
         12 . The apparatus of  claim 1 , wherein the electric field generator is configured to produce a pulsed electric field that induces irreversible electroporation in the renal nerve. 
     
     
         13 . The apparatus of  claim 1 , wherein the electric field generator is configured to produce a pulsed electric field that induces electrofusion in the renal nerve. 
     
     
         14 . The apparatus of  claim 1 , wherein the electrode and the electric field generator are further configured to deliver a stimulation electric field to the renal nerve. 
     
     
         15 . The apparatus of  claim 1 , wherein the apparatus comprises an element for monitoring the response of at least one physiological parameter to stimulation of the renal nerve. 
     
     
         16 . The apparatus of  claim 15 , wherein the element is chosen from the group consisting of ultrasound sensors, electrodes, thermocouples, pressure sensors, imaging modalities, electrical impedence sensors and combinations thereof. 
     
     
         17 . The apparatus of  claim 1 , wherein the electrode is chosen from the group consisting of basket-shaped electrodes, cup-shaped electrodes, spiral electrodes, helical electrodes, ring electrodes, cuff electrodes, fan-shaped electrodes, space-occupying electrodes, undulating electrodes, sinusoidal electrodes, coil electrodes, wire electrodes, arcuate electrodes, concave electrodes, curved electrodes, ribbon electrodes, braid electrodes, composite electrodes, expandable electrodes and combinations thereof. 
     
     
         18 . The apparatus of  claim 1 , wherein the apparatus further comprises an infusion element configured to create a working space to facilitate placement of the electrode. 
     
     
         19 . The apparatus of  claim 1  further comprising an implanted subcutaneous element electrically coupled to the electrode via tunneled leads. 
     
     
         20 . The apparatus of  claim 19 , wherein the implanted subcutaneous element comprises a subcutaneous electrical contact, the apparatus further comprising a transcutaneous probe electrically coupled to the electric field generator and configured for reversible placement across skin of the patient for electrically coupling the transcutaneous probe to the subcutaneous electrical contact. 
     
     
         21 . The apparatus of  claim 19 , wherein the implanted subcutaneous element comprises a transcutaneous energy transfer receiving element, the apparatus further comprising a transcutaneous energy transfer transmission element electrically coupled to the pulse electric field generator and configured to non-invasively transmit energy transcutaneously to the receiving element. 
     
     
         22 . The apparatus of  claim 19 , wherein the implanted subcutaneous element comprises the electric field generator. 
     
     
         23 . The apparatus of  claim 22 , wherein the implanted subcutaneous element further comprises an energy storage device electrically coupled to the electric field generator. 
     
     
         24 . The apparatus of  claim 23 , wherein the energy storage device is configured for recharging. 
     
     
         25 . The apparatus of  claim 24  further comprising an external charger configured to transcutaneously recharge the energy storage device. 
     
     
         26 . The apparatus of  claim 23 , wherein the implanted subcutaneous element further comprises a controller. 
     
     
         27 . The apparatus of  claim 26 , wherein the controller further comprises a programmable controller. 
     
     
         28 . The apparatus of  claim 27  further comprising an external programmer configured to transcutaneously program the controller. 
     
     
         29 . The apparatus of  claim 1  further comprising a probe configured for percutaneous insertion in proximity to the renal nerve under guidance. 
     
     
         30 . The apparatus of  claim 29 , wherein the guidance comprises guidance chosen from the group consisting of visual, computed tomographic, radiographic, ultrasonic, angiographic, laparoscopic and combinations thereof. 
     
     
         31 . The apparatus of  claim 29 , wherein the probe is electrically coupled to the electric field generator, and wherein the electrode is attached to the probe. 
     
     
         32 . The apparatus of  claim 29 , wherein the electrode is configured for extravascular placement through the probe proximate the renal nerve. 
     
     
         33 . The apparatus of  claim 29 , wherein the probe is chosen from the group consisting of needles, trocars and combinations thereof. 
     
     
         34 . The apparatus of  claim 29  further comprising a catheter configured for advancement through the probe, wherein the electrode is attached to the catheter. 
     
     
         35 - 57 . (canceled) 
     
     
         58 . An apparatus for renal neuromodulation, the apparatus comprising:
 an electric field generator; and   a device configured for percutaneous placement under Computed Tomography-guidance at an extravascular location within a patient proximate to a sympathetic neural path associated with renal function,   wherein the device comprises an electrode electrically coupled to the electric field generator for delivering a pulsed electric field to the sympathetic neural path while the device is at the extravascular location.   
     
     
         59 . (canceled) 
     
     
         60 . The apparatus of  claim 1 , wherein the apparatus further comprises a mechanical element configured to create a working space to facilitate placement of the electrode. 
     
     
         61 . The apparatus of  claim 1 , wherein the electrode further comprises at least three electrodes. 
     
     
         62 . The apparatus of  claim 61 , wherein at least one of the electrodes is configured for monitoring. 
     
     
         63 - 65 . (canceled)