Probe based low temperature lesion formation apparatus, systems and methods include, in one embodiment, a surgical probe having a relatively short shaft (e.g., between 3-12 cm) defining a distal portion and a proximal portion, an inflatable cryogenic element, defining an exterior surface, associated with the distal portion of the shaft and at least one temperature sensor on the exterior of the inflatable cryogenic element. In another embodiment, a method of forming a lesion in a tissue structure includes the steps of positioning an inflatable cryogenic element on the tissue structure with a temperature sensor between a portion of the inflatable cryogenic element and a portion of the tissue surface, supplying cryogenic fluid to the inflatable cryogenic element, maintaining pressure within the inflatable cryogenic element below about 100 mm Hg, and measuring tissue temperature with the temperature sensor.
