Neuromodulation cryotherapeutic devices and associated systems and methods

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.