Catheter apparatuses having multi-electrode arrays 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 multi-electrode array configured to be delivered to a renal blood vessel. The array is selectively transformable between a delivery or low-profile state (e.g., a generally straight shape) and a deployed state (e.g., a radially expanded, generally helical shape). The multi-electrode array is sized and shaped so that the electrodes or energy delivery elements contact an interior wall of the renal blood vessel when the array is in the deployed (e.g., helical) state. The electrodes or energy delivery elements are configured for direct and/or indirect application of thermal and/or electrical energy to heat or otherwise electrically modulate neural fibers that contribute to renal function or of vascular structures that feed or perfuse the neural fibers.
1. A catheter apparatus, comprising:
an elongated, flexible tubular member extending along a longitudinal axis, wherein the elongated tubular member has a proximal portion, a distal portion, and a central lumen therein, and wherein the tubular member comprises—
a deflection region at the distal portion, wherein the deflection region includes a plurality of slots in a wall of the tubular member and substantially transverse to the longitudinal axis; and
an orientation region adjacent to the deflection region and between the deflection region and a distal end of the proximal portion of the elongated tubular member, wherein the orientation region includes a plurality of slots in the wall of the tubular member and substantially transverse to the longitudinal axis;
wherein the tubular member is selectively transformable between—
a first state in which the deflection region is generally straight extending along the longitudinal axis, and
a second state in which the deflection region comprises a generally helically-shaped structure and the orientation region has an elbow shape such that the distal end of the proximal portion of the tubular member is aimed through an interior of the helix;
a plurality of energy delivery elements carried by the deflection region and including at least a first energy delivery element and a second energy delivery element, wherein, when the tubular member is in the second state, the first and second energy delivery elements are axially and radially spaced from one another about the longitudinal axis; and
a control member operatively engaged with the tubular member to control movement of the flexible tubular member,
wherein the control member comprises a wire disposed in the central lumen, and wherein the wire has a first end portion coupled to the distal portion of the tubular member such that increasing a tension in the wire controls selectively transforms the deflection region of the tubular member between the first state and the second state.
2. The catheter apparatus of claim 1 wherein, in the second state, the deflection region defines a helical axis generally parallel with the longitudinal axis and about which the helical structure revolves to define a plurality of revolutions and a helical diameter of the helical structure, and wherein the helical structure has a distal end and a proximal end spaced along the helical axis to define a helix length.
3. The catheter apparatus of claim 2 wherein the orientation region is configured to substantially axially align the helical axis with the longitudinal axis when the tubular member is in the second state, and wherein the slots of the orientation region are radially offset about the longitudinal axis from the slots of the deflection region.
4. The catheter apparatus of claim 1 wherein the helical shaped structure comprises at least two revolutions to define at least two contact points for engaging a wall of a peripheral blood vessel.
5. The catheter apparatus of claim 1 wherein:
the slots of the deflection region are elongated deflection slots generally parallel to each other along the tubular member, and wherein the deflection slots extend completely through the wall of the tubular member; and
the slots of the orientation region are elongated orientation slots generally parallel to each other along the tubular member, and wherein the orientation slots extend completely through the wall of the tubular member.
6. The catheter apparatus of claim 5 wherein:
center points of each of the orientation slots in the orientation region are spaced apart along a first progressive axis extending along the length of the tubular member; and
center points of each of the deflection slots in the deflection region are spaced apart along a second progressive axis extending along the length of the tubular member and radially offset about the longitudinal axis from the first progressive axis.
7. The catheter apparatus of claim 6 wherein, in the first state:
the first progressive axis is substantially parallel to the longitudinal axis; and
the second progressive axis defines an angle of about 0.5 degrees (0.5°) with respect to a line parallel to the longitudinal axis.
8. The catheter apparatus of claim 6 wherein, in the first state:
the first progressive axis is substantially parallel to the longitudinal axis; and
the second progressive axis defines an angle of about two degrees (2°) with respect to a line parallel to the longitudinal axis.
9. The catheter apparatus of claim 6 wherein, in the first state, the first progressive axis defines an angle of between about 45 degrees (45°) and 90 degrees (90°) with respect to a line parallel to the longitudinal axis.
10. The catheter apparatus of claim 1 wherein the plurality of slots in at least one of the deflection and orientation regions includes at least one opening elongated circumferentially about the longitudinal axis over an angle of about 300°.
11. The catheter apparatus of claim 10 wherein the at least one opening defines an arc length of about 0.04 inch (1.02 mm).
12. The catheter apparatus of claim 10 wherein the at least one opening includes a central region and two end regions disposed about and contiguous with the central region, and wherein the central region and the two end regions each define a width of the opening extending in the direction of the longitudinal axis, the width defined by the two end regions being greater than the width defined by the central region.
13. The catheter apparatus of claim 12 wherein each of the two end regions are substantially circular.
14. The catheter apparatus of claim 12 wherein each of the two end regions and the central region are substantially rectangular, and wherein the two end regions are elongated parallel to the longitudinal axis and the central region is elongated perpendicular to the longitudinal axis.
15. The catheter apparatus of claim 12 wherein each of the two end regions are substantially rectangular and elongated parallel to the longitudinal axis, and the central region defines a circular portion centered about the opening.
16. The catheter apparatus of claim 1 wherein the plurality of slots in the deflection region comprises 30 or fewer deflection slots, and wherein the individual deflection slots are spaced apart from one another by a distance from about 0.03 inch (0.76 mm) to about 0.04 inch (1.02 mm).
17. The catheter apparatus of claim 1 , further comprising a handle assembly at the proximal portion of the tubular member, and wherein a second end portion of the wire is operably coupled to the handle to apply the tension in the wire.