A tissue resecting end effector includes a housing, a shaft extending from the housing, and a drive assembly operably coupled to the shaft such that a rotational input provided to the drive assembly effects the rotation and reciprocation of the shaft relative to the housing. The assembly includes a proximal portion translationally fixed and rotatably coupled to the housing and configured to receive the rotational input and to rotate relative to the housing in response thereto, a distal portion translationally and rotatably coupled to the housing and operably coupled to the proximal portion such that the rotation of the proximal portion relative to the housing effects rotation and reciprocation of the distal portion relative to the housing to thereby rotate and reciprocate the first shaft relative to the housing, and a seal member disposed on the proximal portion or the distal portion and configured to selectively establish a seal therebetween.
