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 - 17 . (canceled) 
     
     
         18 . A method for treating a hypertensive human patient, the method comprising:
 intravascularly positioning a thermal apparatus carried by a renal denervation catheter at least proximate to renal nerves of the patient;   delivering thermal energy via the thermal apparatus to modulate a function of the renal nerves via thermal effects; and   intravascularly removing the renal denervation catheter from the patient after delivering the thermal energy to conclude the procedure.   
     
     
         19 . The method of  claim 18  wherein intravascularly positioning a thermal apparatus comprises intravascularly positioning the thermal apparatus within a renal artery of the patient proximate to the renal nerves. 
     
     
         20 . The method of  claim 18  wherein the renal denervation catheter comprises an expandable element at a distal region of the catheter, and wherein the thermal apparatus is carried by the expandable element, and wherein the method further comprises:
 transforming the expandable element from a low-profile delivery configuration to an expanded treatment configuration within a renal artery of the patient after intravascularly positioning the thermal apparatus at least proximate to renal nerves and before delivering thermal energy. 
 
     
     
         21 . The method of  claim 18  wherein intravascularly positioning a thermal apparatus further comprises delivering the thermal apparatus at least proximate to the renal nerves via an intra-to-extravascular approach. 
     
     
         22 . The method of  claim 18  wherein delivering thermal energy via the thermal apparatus comprises directly applying thermal energy to the renal nerves. 
     
     
         23 . The method of  claim 18  wherein delivering thermal energy via the thermal apparatus comprises indirectly applying thermal energy to the renal nerves. 
     
     
         24 . The method of  claim 18  wherein delivering thermal energy via the thermal apparatus further comprises delivering a thermal electric field to the renal nerves via at least one electrode. 
     
     
         25 . The method of  claim 24  wherein delivering a thermal electric field to the renal nerves via at least one electrode further comprises delivering the thermal electric field via at least one wall-contact electrode. 
     
     
         26 . The method of  claim 18 , further comprising monitoring a parameter of at least one of the renal nerves, a non-target tissue, or the renal denervation catheter during modulation of a function of the renal nerves. 
     
     
         27 . The method of  claim 26 , further comprising controlling delivery of the thermal energy via the thermal apparatus in response to the monitored parameter. 
     
     
         28 . The method of  claim 18 , further comprising actively protecting non-target tissue during modulation of the function of the renal nerves via thermal effects. 
     
     
         29 . The method of  claim 28  wherein actively protecting the non-target tissue further comprises reducing a degree of thermal damage induced in the non-target tissue. 
     
     
         30 . The method of  claim 28  wherein actively protecting the non-target tissue further comprises delivering a thermal fluid to a vicinity of the non-target tissue. 
     
     
         31 . The method of  claim 28  wherein actively protecting the non-target tissue further comprises establishing a heat transfer rate discrepancy between the non-target tissue and the renal nerves. 
     
     
         32 . The method of  claim 18  wherein delivering thermal energy via the thermal apparatus comprises delivering high intensity focused ultrasound energy to the renal nerves. 
     
     
         33 . The method of  claim 18  wherein delivering thermal energy via the thermal apparatus comprises delivering ultrasound energy to the renal nerves. 
     
     
         34 . The method of  claim 18  wherein delivering thermal energy via the thermal apparatus comprises cooling the renal nerves via the thermal energy. 
     
     
         35 . The method of  claim 18  wherein delivering thermal energy via the thermal apparatus to modulate a function of the renal nerves results in a therapeutically beneficial reduction in blood pressure of the patient. 
     
     
         36 . The method of  claim 18  wherein delivering thermal energy via the thermal apparatus to modulate a function of the renal nerves comprises reducing afferent and/or efferent renal neural activity. 
     
     
         37 . The method of  claim 18  wherein delivering thermal energy via the thermal apparatus to modulate a function of the renal nerves comprises delivering thermal energy to ablate the renal nerves. 
     
     
         38 . The method of  claim 18  wherein intravascularly positioning a thermal apparatus carried by a renal denervation catheter at least proximate to renal nerves comprises delivering the renal denervation catheter to a renal artery of the patient via a guidewire.