An electro-cauterizing cannula assembly for use in a power-assisted liposuction instrument having a hand-holdable housing and a mechanism for reciprocating the cannula assembly. The electro-cauterizing cannula assembly includes an inner and an outer cannula, each having a distal and proximal end and at least one aspiration aperture about the distal end. The inner cannula is disposed within the outer cannula and the inner and outer aspiration apertures are in at least partial registration to form an effective aspiration aperture. During aspiration of tissue, high-voltage RF power signals are supplied to the inner and outer cannulas to effect hemostasis about the reciprocating aspiration aperture. Such hemostasis is achieved by causing protein molecules within aspirated tissue to coagulate in response to the high-voltage RF signals being supplied across the reciprocating cannulas. The cannula assembly is releasably detachable from the hand-holdable housing to facilitate cleaning and sterilization of the same.