A surgical instrument configured to be coupled to a transducer configured to produce vibrations. The surgical instrument comprises an end effector comprising an ultrasonic blade, a protective sheath, and outer tube and an aperture. The ultrasonic blade extends along a longitudinal axis of the end effector and is configured to be coupled to a transducer. The protective sheath extends at least partially around the ultrasonic blade. The outer tube extends at least partially along the longitudinal axis. The aperture defines a channel extending at least partially through the end effector along the longitudinal axis.