Apparatuses for inhibiting renal nerve activity via an intra-to-extravascular approach

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.

1 - 30 . (canceled) 
   
   
       31 . An apparatus for inhibiting renal nerve activity via an intra-to-extravascular approach, the apparatus comprising:
 an intravascular catheter comprising a shaft and a distal section configured for placement within a renal blood vessel proximate to renal nerves; and   a thermal element coupled to the distal section of the shaft,   wherein the thermal element is configured for intravascular delivery and extravascular placement adjacent to renal nerves via an intra-to-extravascular approach, and   wherein the thermal element is configured to thermally inhibit neural signaling along the renal nerves.   
   
   
       32 . The apparatus of  claim 31  wherein the thermal element comprises a needle. 
   
   
       33 . The apparatus of  claim 32  wherein the needle is configured to extend from the distal section of the catheter across the wall of the renal blood vessel and into the extravascular space of the renal blood vessel. 
   
   
       34 . The apparatus of  claim 33  further comprising an electric field generator and wherein the needle comprises an electrode operatively connected to the electric field generator. 
   
   
       35 . The apparatus of  claim 34  wherein the electric field generator is configured to deliver a thermal electric field to the renal nerves via the electrode when the electrode is positioned in the extravascular space of the renal blood vessel. 
   
   
       36 . The apparatus of  claim 35  wherein the thermal electric field delivered by the electric field generator is configured to resistively heat the renal nerves. 
   
   
       37 . The apparatus of  claim 35  wherein the thermal electric field delivered by the electric field generator is configured to thermally ablate the renal nerves. 
   
   
       38 . The apparatus of  claim 35 , further comprising a temperature sensor and wherein data from the temperature sensor controls delivery of the thermal electric field by the electric field generator. 
   
   
       39 . The apparatus of  claim 34  wherein the electrode comprises a monopolar electrode and the electric field generator is configured to deliver a monopolar electric field via the monopolar electrode to an ex vivo ground pad. 
   
   
       40 . The apparatus of  claim 34  wherein the electrode comprises an insulated portion and an uninsulated portion and wherein the uninsulated portion of the electrode is configured to be positioned within the extravascular space of the renal blood vessel. 
   
   
       41 . The apparatus of  claim 33  wherein the needle comprises an infusion needle configured to deliver a thermal fluid to the renal nerves. 
   
   
       42 . The apparatus of  claim 33  wherein the distal section of the catheter comprises a lumen and a side port for delivery and extension of the needle across the wall of the renal blood vessel. 
   
   
       43 . The apparatus of  claim 42  wherein the thermal element comprises a proximal needle and a distal needle and the distal section of the catheter comprises a proximal lumen and side port for intra-to-extravascular delivery and placement of the proximal needle and a distal lumen and side port for intra-to-extravascular delivery and placement of the distal needle. 
   
   
       44 . The apparatus of  claim 33 , further comprising a sensor coupled to the needle. 
   
   
       45 . The apparatus of  claim 33  wherein the distal section of the catheter comprises an expandable positioning element configured to center the catheter within the renal blood vessel and facilitate delivery of the needle into the extravascular space of the renal blood vessel. 
   
   
       46 . The apparatus of  claim 45  wherein the expandable positioning element comprises an inflatable balloon or an expandable basket or cage. 
   
   
       47 . The apparatus of  claim 31  further comprising a cooling element configured to protect the inside of the renal blood vessel from thermal damage. 
   
   
       48 . The apparatus of  claim 31  wherein the thermal element comprises a Peltier element. 
   
   
       49 . An apparatus for reducing renal nerve activity via an intra-to-extravascular approach, the apparatus comprising:
 an intravascular catheter comprising a shaft and a distal section configured for placement within a renal blood vessel proximate to renal nerves; and   an infusion needle extending from the distal section of the shaft,   wherein the infusion needle is configured for intravascular delivery and extravascular placement adjacent to renal nerves via an intra-to-extravascular approach, and   wherein the infusion needle is configured to inhibit neural signaling along the renal nerves.   
   
   
       50 . The apparatus of  claim 49  wherein the infusion needle is configured to deliver a thermal fluid to the renal nerves. 
   
   
       51 . The apparatus of  claim 49  wherein the infusion needle is configured to deliver a neuromodulatory agent to the renal nerves.