The present invention generally provides improved medical devices, systems, and methods. Embodiments may be particularly well suited for the treatment of dermatological and/or cosmetic defects, and alternative embodiments may be configured for treatment of a wide range of target tissues. Some embodiments of the present invention apply cooling with at least one small, tissue-penetrating probe, the probe often comprising a needle having a size suitable for inserting through an exposed surface of the skin of a patient without leaving a visible scar. The cooling may remodel one or more target tissue so as to effect a desired change in a composition of the target tissue and/or a change in its behavior. Exemplary embodiments make use of replaceable needle probes supported by a probe body handle, with small needle probes often being replaced during treatment of a single patient. Unlike the large format cryogenic cooling systems of the past, small cryogenic cooling needle probes may dull or be damaged by insertion. Careful control over the control of cryogenic cooling fluid into a needle probe can allow the length of the active cooling to be controlled through depletion of liquid from an evaporating cryogenic cooling flow. Hence, even needles having similar external structures may provide differing lengths of an iceball along the needle axis. Surprisingly, small cryogenic cooling needles and/or other cryogenic cooling probes having a lubricious coating will allow safe removal of the probe from the treatment region while at a least a portion of the tissue remains frozen, significantly decreasing the overall time for a procedure involving many insertion/freeze/removal cycles.
