Liquid cooled, powered surgical handpiece

A powered surgical handpiece for use with a micro-cutting instrument, especially a bone-drilling device useful for ENT/head/neck procedures. The powered surgical handpiece includes a motor contained within a housing. The housing includes a motor enclosure surrounding the motor and a sleeve placed about the motor enclosure. At least a portion of the sleeve has an inner diameter greater than an outer diameter of a corresponding portion of the motor enclosure, such that the housing defines an internal gap or internal passage. Finally, the sleeve forms inlet and outlet ports that are fluidly connected to the internal passage. During use, a cooling fluid, such as de-ionized water or saline, is forced into the internal passage via the inlet port. The motor is sealed relative to the cooling fluid by the motor enclosure. Thus, the cooling fluid does not directly contact the motor, but instead serves as a heat exchange medium through which heat generated by the motor is thermally transferred to the cooling fluid via the motor enclosure. The now heated fluid exits the housing at the outlet port. As a result of the thermal transfer of heat from the motor to the cooling fluid, and the subsequent evacuation of the now-heated fluid away from the handpiece, heat transfer to an outer surface of the housing, otherwise handled by the surgeon, is minimized. In an alternative embodiment, the housing is configured to define a serpentined or specifically routed internal fluid path to optimize heat transfer.