A tissue resecting instrument includes an end effector assembly having a proximal hub housing, outer and inner shafts extending therefrom, and an inner core drive assembly to rotate and reciprocate the inner shaft relative to the outer shaft. The inner core drive assembly includes a proximal receiver that receives a rotational input and rotates in response and includes a seal member disposed thereon. The rotation of the proximal receiver effects rotation of a connector and reciprocation of the connector between a proximal position and a distal position. The connector is operably coupled to the inner shaft such that the rotation and reciprocation of the connector effects the rotation and reciprocation of the inner shaft. In the proximal position, the connector and the seal member establish a seal that blocks outflow. In the distal position, the connector is displaced from the seal member to permit outflow.
