MANUALLY-ACTUATED TISSUE RESECTING INSTRUMENTS

A tissue resecting instrument (10) includes a housing (210), an outer shaft (120) extending distally from the housing and defining a window at a distal end portion thereof, an inner cutting shaft (130) extending through the outer shaft, a drive assembly (250), a trigger (220), and an adjustable resistance mechanism (300). The inner cutting shaft is translatable and/or rotatable relative to the outer shaft. The drive assembly is coupled to the inner cutting shaft and configured to drive the translation and/or rotation thereof. Manual actuation of the trigger actuates the drive assembly to drive the translation and/or rotation of the inner cutting shaft. The adjustable resistance mechanism includes a spring coupled between the trigger and the housing, and a control knob (330) operably coupled to the spring to enable adjustment of a resistance to pivoting of the trigger from an un-actuated position to an actuated position.