Neuromodulation cryotherapeutic devices and associated systems and methods
Neuromodulation cryotherapeutic devices and associated systems and methods are disclosed herein. A cryotherapeutic device configured in accordance with a particular embodiment of the present technology can include an elongated shaft having distal portion and a supply lumen along at least a portion of the shaft. The shaft can be configured to locate the distal portion intravascularly at a treatment site proximate a renal artery or renal ostium. The supply lumen can be configured to receive a liquid refrigerant. The cryotherapeutic device can further include a cooling assembly at the distal portion of the shaft. The cooling assembly can include an applicator in fluid communication with the supply lumen and configured to deliver cryotherapeutic cooling to nerves proximate the target site when the cooling assembly is in a deployed state.
1. A method for treating a patient, comprising:
locating a cryotherapeutic applicator intravascularly at a treatment site within or otherwise proximate a renal artery, wherein the applicator includes a balloon at a distal portion of an elongated shaft;
transporting liquid refrigerant distally through a supply tube extending along a length of the shaft;
expanding the refrigerant through orifices longitudinally spaced apart along a portion of the supply tube within the balloon; and
exhausting gaseous refrigerant proximally through an exhaust passage within the balloon,
wherein the portion of the supply tube within the balloon is helically wound around the exhaust passage such that expanding the refrigerant through the orifices directs the refrigerant toward a helical region of the balloon and thereby cools an adjacent helical region of tissue at the treatment site.
2. The method of claim 1 , wherein the helical region of tissue is non-circumferential in any plane perpendicular to the length of the renal artery.
3. The method of claim 1 wherein exhausting the gaseous refrigerant includes exhausting the gaseous refrigerant via an exhaust opening at a distal end of the exhaust passage.
4. The method of claim 1 wherein exhausting the gaseous refrigerant includes exhausting the gaseous refrigerant via an exhaust opening positioned between coils of the portion of the supply tube helically wound around the exhaust passage.
5. The method of claim 1 , wherein:
the helical region of the tissue is a first helical region of the tissue;
the helical region of the balloon is a first helical region of the balloon; and
the method further comprises thermally insulating a second helical region of the tissue via a second helical region of the balloon.
6. The method of claim 5 , wherein thermally insulating the second helical region of the tissue includes thermally insulating the second helical region of the tissue with a thermally-insulative member disposed along the second helical region of the balloon.
7. The method of claim 6 , further comprising introducing a filler material into a filler lumen operably connected to the thermally-insulative member to expand the thermally-insulative member from a collapsed configuration to an expanded configuration intravascularly.
8. The method of claim 5 wherein thermally insulating the second helical region of the tissue includes thermally insulating the second helical region of the tissue via a recess at the second helical region of the balloon.
9. The method of claim 5 wherein thermally insulating the second helical region of the tissue includes thermally insulating the second helical region of the tissue via a thick wall portion at the second helical region of the balloon.