A marker delivery (550) device includes a grip (566), a cannula (562), a push rod (568), and a marker element (514). The cannula extends distally from the grip. The push rod is configured to move within the cannula and includes a distal end with one or more seals configured to seal against an interior of the cannula. The marker element includes one or more barbs (516). The push rod is configured to generate a pressure within the cannula between the one or more seals and the marker element to eject the marker element from the cannula.