Catheter assemblies comprising a direct heating element for renal neuromodulation and associated systems and methods
Catheter apparatuses, systems, and methods for achieving renal neuromodulation by intravascular access are disclosed herein. One aspect of the present technology, for example, is directed to a treatment device having a direct heating element configured to be delivered to a renal blood vessel. The treatment device is selectively transformable between a delivery or low-profile state and a deployed state. The direct heating element is housed within an occlusion element which is sized and shaped so that the direct heating element contacts an interior wall of the occlusion element, an outer wall of which is simultaneously in contact with the inner wall of a renal blood vessel when the treatment assembly is in the deployed state. The direct heating element is configured to apply thermal energy to heat neural fibers that contribute to renal function.
1. A catheter apparatus, comprising:
an elongated tubular shaft having a proximal portion and a distal portion;
a therapeutic assembly at the distal portion of the elongated tubular shaft and configured to be located at a target location within a renal artery of a patient, the therapeutic assembly comprising:
a control member having a tubular structure and a lumen therethrough and having a pre-formed helical shape;
a direct heating element having one or more heating wires carried by and wrapped around the control member;
a flexible tube having a lumen disposed between the control member and the direct heating element; and
an occlusion element at the distal portion of the elongated tubular shaft in which the control member and the direct heating element are positioned.
2. The catheter apparatus of claim 1 wherein the tubular structure comprises a nitinol multifilar stranded wire.
3. The catheter apparatus of claim 1 wherein the elongated tubular shaft and the therapeutic assembly together define therethrough a guide wire lumen configured to slidably receive a medical guide wire, and
wherein axial movement of the guide wire relative to the therapeutic assembly transforms the control member between (a) a low-profile state and (b) an expanded state having a helical shape set by the control member.
4. The catheter apparatus of claim 1 wherein the occlusion element is selectively transformable between a low-profile configuration in a delivery state and an expanded configuration sized to fit within the renal artery in a deployed state.
5. The catheter apparatus of claim 4 wherein, in the expanded configuration, the occlusion element is sized to occlude the renal artery.
6. The catheter apparatus of claim 1 wherein energy from the direct heating element is sufficient to cause at least partial ablation of at least one renal nerve of the patient.
7. The catheter apparatus of claim 4 wherein the direct heating element is configured to physically contact an inner wall of the occlusion element when the occlusion element is in the expanded configuration and the therapeutic assembly is in the deployed state.
8. The catheter apparatus of claim 1 wherein the occlusion element is an expandable balloon.
9. The catheter apparatus of claim 8 wherein the expandable balloon is configured to be inflated with a fluid selected from: saline, contrast fluid, or a mixture thereof.
10. The catheter apparatus of claim 1 wherein the occlusion element comprises a distal end and a proximal end, and wherein the distal end and the proximal end of the occlusion element are affixed to the control member.
11. The catheter apparatus of claim 1 wherein the occlusion element comprises a distal end affixed to the control member, and a proximal end affixed to the elongated tubular shaft.
12. The catheter apparatus of claim 1 , further comprising one or more sensors at the distal portion of the elongated tubular shaft for monitoring or controlling effects of energy delivery from the direct heating element.
13. The catheter apparatus of claim 12 wherein at least one of the one or more sensors comprises a thermocouple for monitoring temperature.
14. The catheter apparatus of claim 1 , wherein the flexible tube is configured to provide electrical insulation between the direct heating element and the control member.
15. The catheter apparatus of claim 1 , wherein the direct heating element is a slanted ring.
16. A catheter apparatus, comprising:
an elongated tubular shaft having a proximal portion and a distal portion; and
a therapeutic assembly disposed at the distal portion of the elongated shaft and adapted to be located at a target location within a renal artery of a human patient, the therapeutic assembly comprising:
an occlusion element;
a control member comprising a pre-formed helical shape, wherein the control member is a tubular structure having a lumen therethrough; and
a direct heating element that includes a first insulation layer that is in direct contact with the control member, a second insulation layer and a heating wire that is in between the first insulation layer and the second insulation layer, the heating wire being wrapped around the control member, wherein the control member and the direct heating element are within the occlusion element.