A surgical instrument (30) comprises a handle (32) and an elongate shaft (34), and is operable to remove an anastomotic ring device from a patient. The elongate shaft houses a plurality of ring engaging fingers (38). Each of the fingers comprises sheath (40) housing a wire (46) having a hook (48) at its distal end. Each hook may be advanced beyond the distal end of a respective sheath to engage petals on an anastomotic ring device. Subsequent proximal retraction of the hooks secures the anastomotic ring device to the ring engaging fingers. With the anastomotic ring device secured to the ring engaging fingers, the fingers may be drawn together to collapse the anastomotic ring device from an actuated, hollow rivet-shaped configuration to an unactuated, cylindrically-shaped configuration. The surgical instrument may then contain the collapsed anastomotic ring device, thereby facilitating removal of the anastomotic ring device from the patient.