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 cryotherapeutic device, comprising:
an elongated shaft having a distal portion, the shaft being configured to locate the distal portion intravascularly at a treatment site proximate a renal artery or renal ostium;
a supply lumen along at least a portion of the shaft, the supply lumen being configured to receive liquid refrigerant; and
a cooling assembly at the distal portion, the cooling assembly having a delivery state and a deployed state, the cooling assembly including an orifice and an applicator including an elongated balloon having a length, a balloon proximal portion, a balloon middle portion, and a balloon distal portion along the length, the balloon being curved along the length such that the balloon has a first wall portion having a generally concave curvature along the length and a second wall portion having a generally non-concave curvature along the length in the deployed state, wherein the balloon middle portion is configured to contact the renal artery and/or renal ostium generally along the second wall portion and generally not along the first wall portion in the deployed state, the balloon has a heat-transfer portion in fluid communication with the orifice, wherein the second wall portion at the balloon middle portion at least partially defines the heat-transfer portion, and wherein the heat-transfer portion has a heat-transfer rate in the deployed state while the cooling assembly receives refrigerant sufficient to cause therapeutically-effective, cryogenic renal-nerve modulation.
2. The cryotherapeutic device of claim 1 , wherein the cooling assembly has a length, and wherein the heat-transfer portion is non-circumferential at longitudinal segments along the length of the cooling assembly.
3. The cryotherapeutic device of claim 1 , wherein the first wall portion at the balloon middle portion has a first thickness, and wherein the second wall portion at the balloon middle portion has a second thickness less than the first thickness.
4. The cryotherapeutic device of claim 1 , wherein the balloon distal portion is configured to contact the renal artery and/or renal ostium generally along the first wall portion and generally not along the second wall portion in the deployed state.
5. The cryotherapeutic device of claim 4 , wherein the first wall portion at the balloon distal portion at least partially defines the heat-transfer portion.
6. The cryotherapeutic device of claim 5 , wherein the balloon proximal portion is configured to contact the renal artery and/or renal ostium generally along the first wall portion and generally not along the second wall portion in the deployed state.
7. The cryotherapeutic device of claim 6 , wherein the first wall portion at the balloon proximal portion at least partially defines the heat-transfer portion.
8. A method for treating a patient, comprising:
locating an applicator of a cooling assembly of a cryotherapeutic device intravascularly at a treatment site proximate a renal artery or an ostium of the renal artery, wherein the applicator is at a distal portion of an elongated shaft;
deploying the cooling assembly from a delivery state to a deployed state, the applicator including an elongated balloon having a length, a balloon proximal portion, a balloon middle portion, and a balloon distal portion along the length, the balloon being curved along the length such that the balloon has a first wall portion having a generally concave curvature along the length and a second wall portion having a generally non-concave curvature along the length in the deployed state, the balloon middle portion being configured to contact the renal artery and/or renal ostium generally along the second wall portion and generally not along the first wall portion in the deployed state, the balloon being at least partially collapsed in the delivery state; and
cooling a portion of the treatment site through the second wall portion at the balloon middle portion by transitioning liquid refrigerant into gaseous refrigerant within the cooling assembly and thereby causing therapeutically-effective, cryogenic renal-nerve modulation, the portion of the treatment site being generally non-circumferential in generally any plane perpendicular to a length of the renal artery.
9. The method of claim 8 , wherein the portion of the treatment site is a first portion of the treatment site, and the method further comprises cooling a second portion of the treatment site through the first wall portion at the balloon distal portion thereby causing therapeutically-effective, cryogenic renal-nerve modulation, wherein the second portion of the treatment site is generally non-circumferential in generally any plane perpendicular to the length of the renal artery.
10. The method of claim 9 , further comprising cooling a third portion of the treatment site through the first wall portion at the balloon proximal portion thereby causing therapeutically-effective, cryogenic renal-nerve modulation, wherein the third portion of the treatment site is generally non-circumferential in generally any plane perpendicular to the length of the renal artery.