Therapeutic tissue modulation devices and methods

1. An intraluminal ablation catheter comprising:

a proximal manifold;

an elongate shaft comprising at least one lumen,

wherein the elongate shaft comprises a central longitudinal axis extending along its length;

a first balloon coupled to a distal end portion of the elongate shaft,

wherein the first balloon is adapted to transition between a folded configuration and an expanded, unfolded configuration,

wherein the first balloon comprises four electrodes,

wherein a first electrode and a second electrode of the four electrodes are located in a first circumferential cross-sectional plane along the first balloon and are located in opposite quadrants from each other around the circumference of the first balloon when the first balloon is in the expanded, unfolded configuration,

wherein a third electrode and a fourth electrode of the four electrodes are located within a second circumferential cross-sectional plane along the first balloon and are located in opposite quadrants from each other around the circumference of the first balloon when the first balloon is in the expanded, unfolded configuration, wherein the second circumferential cross-sectional plane is axially offset from the first circumferential cross-sectional plane;

a second balloon located within the first balloon, wherein the second balloon comprises at least one orifice positioned adjacent each of the four electrodes, the at least one orifice being adapted to direct at least one fluid jet toward a respective one of the four electrodes, wherein the at least one lumen comprises at least one fluid delivery lumen in fluid communication with an interior of the second balloon and adapted to deliver coolant within the second balloon.

2. The ablation catheter of claim 1 , wherein the third electrode and the fourth electrode are in different quadrants than the first electrode and the second electrode.

3. The ablation catheter of claim 1 , wherein the third electrode and the fourth electrode are in quadrants that are circumferentially offset by 90 degrees from the quadrants in which the first electrode and the second electrode are located.

4. The ablation catheter of claim 1 , wherein the first electrode and the second electrode are located 180 degrees apart circumferentially from each other about the central longitudinal axis of the elongate shaft.

5. The ablation catheter of claim 4 , wherein the third electrode and the fourth electrode are located 180 degrees apart circumferentially from each other about the central longitudinal axis of the elongate shaft.

6. The ablation catheter of claim 5 , wherein the third and fourth electrodes are each circumferentially offset from the first and second electrodes by 90 degrees.

7. The ablation catheter of claim 1 , wherein the at least one lumen further comprises a first central guidewire lumen adapted to track a guidewire.

8. The ablation catheter of claim 1 , further comprising a nozzle or eductor positioned adjacent the at least one orifice, and wherein the nozzle or eductor is configured to direct the fluid jets toward the respective one of the four electrodes.

9. The ablation catheter of claim 1 , wherein each of the four electrodes is directly mounted on an outer surface of the balloon.

10. The ablation catheter of claim 1 , further comprising two spaced-apart lesion spacing indicators positioned along the elongate shaft to facilitate controlled spacing of lesion zones.

11. The ablation catheter of claim 1 , further comprising a distal tracking segment coupled to a distal end of the balloon, wherein the distal tracking segment is adapted to vary a flexibility of the catheter from distal to proximal.

12. An intraluminal ablation catheter comprising:

a proximal manifold;

an elongate shaft comprising a plurality of lumens,

wherein the plurality of lumens comprises a guidewire lumen and a fluid infusion lumen;

an inner inflatable member surrounding at least one of the plurality of lumens and being coupled to the at least one of the plurality of lumens,

wherein the fluid infusion lumen is configured to infuse cooling fluid into the inner inflatable member;

an outer inflatable member surrounding the inner inflatable member and being coupled to the elongate shaft,

wherein the outer inflatable member comprises a plurality of electrodes;

a plurality of electrical conductors extending from a port of the proximal manifold to each of the plurality of electrodes;

wherein the inner inflatable member comprises a plurality of outlet orifices configured to direct jets of the cooling fluid from the inner inflatable member toward a bottom surface of each of the plurality of electrodes of the outer inflatable member so as to cool the plurality of electrodes.

13. The catheter of claim 12 ,

wherein each electrode of the plurality of electrodes has a surface area between 8 mm 2 and 16 mm 2 ;

wherein each of the outlet orifices has a diameter of between 0.05 mm and 0.25 mm,

wherein an annular gap between the inner inflatable member and the outer inflatable member ranges between 0.05 mm and 1.5 mm,

wherein a length of the outer inflatable member is between 10 mm and 30 mm, and

wherein a flow rate of the cooling fluid per electrode ranges from 0.1 to 1.0 mL/second.

14. The catheter of claim 12 , wherein a width of each of the plurality of electrodes is configured such that the each of the plurality of electrodes lies on an outer surface of a fold when the outer inflatable member is in a non-expanded, folded configuration.

15. The catheter of claim 12 , further comprising a moveable outer sheath coupled along a length of the elongate shaft and moveable with respect to the elongate shaft, wherein translational movement of the moveable outer sheath adjusts a push force on a distal end portion of the catheter or adjusts a flexibility of the elongate shaft.

16. The catheter of claim 12 , wherein the ablation catheter is sized and adapted such that a distal end of the elongate shaft can be advanced to a location within a hepatic artery.

17. The catheter of claim 12 , wherein the inner inflatable member is a first balloon, and wherein the outer inflatable member is a second balloon.

18. The catheter of claim 12 , wherein the plurality of electrodes comprises four electrodes, wherein a first electrode and a second electrode of the four electrodes are located within a first circumferential cross-section along the outer inflatable member at a first axial distance from a distal end of the outer inflatable member and are located in opposite quadrants from each other about a central longitudinal axis of the elongate shaft when the outer inflatable member is in an expanded configuration, and wherein a third electrode and a fourth electrode of the four electrodes are located within a second circumferential cross-section along the outer inflatable member at a second axial distance from the distal end of the outer inflatable member and are located in opposite quadrants from each other about the central longitudinal axis of the elongate shaft when the outer inflatable member is in the expanded configuration, wherein the second axial distance is different from the first axial distance.

19. An intraluminal ablation catheter comprising:

a proximal manifold;

an elongate shaft coupled to the proximal manifold, the elongate shaft comprising multiple lumens extending therethrough,

wherein a first lumen of the multiple lumens comprises a fluid infusion lumen, and

wherein the elongate shaft comprises a central longitudinal axis extending along its length,

an inner expandable member coupled to at least one of the multiple lumens,

wherein the fluid infusion lumen is configured to infuse cooling fluid into the inner expandable member;

an outer expandable member surrounding the inner expandable member and being coupled to a distal end portion of the elongate shaft,

wherein the outer expandable member comprises a plurality of electrodes, and

wherein the inner expandable member comprises a plurality of outlet orifices configured to direct jets of the cooling fluid from the inner expandable member toward a bottom surface of each of the plurality of electrodes of the outer expandable member so as to cool the plurality of electrodes.

20. The ablation catheter of claim 19 :

wherein the inner expandable member and the outer expandable member are configured to be expanded by the cooling fluid,

wherein each electrode of the plurality of electrodes has a surface area between 8 mm 2 and 16 mm 2 ;

wherein a second lumen of the multiple lumens comprises a guidewire lumen configured to facilitate advancement of the intraluminal ablation catheter over a guidewire,

wherein each of the outlet orifices has a diameter of between 0.05 mm and 0.25 mm,

wherein an annular gap between the inner inflatable member and the outer inflatable member ranges between 0.05 mm and 1.5 mm,

wherein a length of the outer inflatable member is between 10 mm and 30 mm, and

wherein a flow rate of the cooling fluid per electrode ranges from 0.1 to 1.0 mL/second.