Methods and apparatus for thermally-induced renal neuromodulation

Abstract

Methods and apparatus are provided for thermally-induced renal neuromodulation. Thermally-induced renal neuromodulation may be achieved via direct and/or via indirect application of thermal energy to heat or cool neural fibers that contribute to renal function, or of vascular structures that feed or perfuse the neural fibers. In some embodiments, parameters of the neural fibers, of non-target tissue, or of the thermal energy delivery element, may be monitored via one or more sensors for controlling the thermally-induced neuromodulation. In some embodiments, protective elements may be provided to reduce a degree of thermal damage induced in the non-target tissues. In some embodiments, thermally-induced renal neuromodulation is achieved via delivery of a pulsed thermal therapy.

1 . A method for thermally-induced renal neuromodulation, the method comprising: 
 positioning a thermal apparatus at least proximate to a neural fiber that contributes to renal function; and    delivering pulsed energy via the thermal apparatus to modulate a function of the neural fiber via thermal effects.    
   
   
       2 . The method of  claim 1 , wherein positioning the thermal apparatus further comprises delivering the device via an approach chosen from the group consisting of intravascularly, extravascularly, intra-to-extravascularly and combinations thereof.  
   
   
       3 . The method of  claim 1 , wherein delivering the pulsed energy further comprises directly applying pulsed thermal energy to the neural fiber.  
   
   
       4 . The method of  claim 1 , wherein delivering the pulsed energy further comprises indirectly applying pulsed thermal energy to the neural fiber.  
   
   
       5 . The method of  claim 1 , wherein delivering the pulsed energy further comprises delivering a pulsed thermal electric field to the neural fiber via at least one electrode.  
   
   
       6 . The method of  claim 5 , wherein positioning the thermal apparatus further comprises intravascularly delivering the device, and wherein delivering a pulsed thermal electric field to the neural fiber via at least one electrode further comprises delivering the pulsed thermal electric field via at least one wall-contact electrode.  
   
   
       7 . The method of  claim 1  further comprising monitoring a parameter of at least one of the neural fiber, a non-target tissue or the apparatus during thermally-induced modulation of the function of the neural fiber.  
   
   
       8 . The method of  claim 7  further comprising controlling the delivery of the pulsed energy in response to the monitored parameter.  
   
   
       9 . The method of  claim 1  further comprising actively protecting non-target tissue during thermal modulation of the neural fiber.  
   
   
       10 . The method of  claim 9 , wherein actively protecting the non-target tissue further comprises reducing a degree of thermal damage induced in the non-target tissue.  
   
   
       11 . The method of  claim 9 , wherein actively protecting the non-target tissue further comprises delivering a thermal fluid to a vicinity of the non-target tissue.  
   
   
       12 . The method of  claim 9 , wherein actively protecting the non-target tissue further comprises establishing a heat transfer rate discrepancy between the non-target tissue and the neural fiber.  
   
   
       13 . The method of  claim 1 , wherein delivering the pulsed energy further comprises delivering pulsed high intensity focused ultrasound to the neural fiber.  
   
   
       14 . The method of  claim 1 , wherein delivering the pulsed energy further comprises heating the neural fiber via the pulsed thermal energy.  
   
   
       15 . The method of  claim 1 , wherein delivering the pulsed energy further comprises cooling the neural fiber via the pulsed thermal energy.  
   
   
       16 . Apparatus for thermally-induced renal neuromodulation, the apparatus comprising: 
 a pulse generator configured to provide pulsed thermal energy;    a device configured for delivery within a blood vessel to a vicinity of a neural fiber that contributes to renal function; and    a thermal modulation element supported by the device, the thermal modulation element being configured to expand from a first dimension to a second dimension, wherein the thermal modulation element is configured to (a) contact a wall of the blood vessel upon expansion of the thermal modulation element to the second dimension within the blood vessel, and (b) transmit the pulsed thermal energy relative to the neural fiber to thermally induce modulation of a function of the neural fiber upon expansion of the thermal modulation element to the second dimension within the blood vessel.    
   
   
       17 . The apparatus of  claim 16 , wherein the thermal modulation element is configured to self-expand from the first dimension to the second dimension.  
   
   
       18 . The apparatus of  claim 16 , wherein the device further comprises an expandable member that is at least proximate to the thermal modulation element, the expandable member being configured to expand the thermal modulation element from the first dimension to the second dimension.  
   
   
       19 . The apparatus of  claim 16 , wherein the thermal modulation element is configured for direct application of the pulsed thermal energy relative to the neural fiber.  
   
   
       20 . The apparatus of  claim 16 , wherein the thermal modulation element is configured for indirect application of the pulsed thermal energy relative to the neural fiber.  
   
   
       21 . The apparatus of  claim 16 , wherein the thermal modulation element further comprises at least one electrode configured to deliver a pulsed thermal electric field relative to the neural fiber.  
   
   
       22 . The apparatus of  claim 16 , wherein the apparatus further comprises at least one sensor.  
   
   
       23 . The apparatus of  claim 22 , wherein the sensor is configured to monitor a physiological parameter of the neural fiber.  
   
   
       24 . The apparatus of  claim 22 , wherein the sensor is configured to monitor a physiological parameter of non-target tissue.  
   
   
       25 . The apparatus of  claim 22 , wherein the sensor is configured to monitor a parameter of the apparatus.  
   
   
       26 . The apparatus of  claim 22  further comprising a feedback control in communication with the sensor.  
   
   
       27 . The apparatus of  claim 16 , wherein the apparatus further comprises a protective element configured to reduce a degree of thermal damage induced in non-target tissue.  
   
   
       28 . The apparatus of  claim 16 , wherein the thermal modulation element further comprises at least one thermoelectric element configured to deliver the pulsed thermal energy relative to the neural fiber.  
   
   
       29 . The apparatus of  claim 16 , wherein the thermal modulation element further comprises a high intensity focused ultrasound element.  
   
   
       30 . The apparatus of  claim 16 , wherein the thermal modulation element further comprises a thermal fluid.  
   
   
       31 . The apparatus of  claim 27 , wherein the protective element comprises an infusion element configured to infuse a thermal fluid in a vicinity of the non-target tissue.  
   
   
       32 . The apparatus of  claim 16  further comprising an occlusion element configured to temporarily occlude blood flow within the blood vessel.