The document relates to an anti-extrusion tool/assembly, and a sealing system. The an anti-extrusion assembly has an elongated backup member having a hollow body having a first end portion, a second end portion, an inner surface and an outer surface, and a plurality of elongated fingers provided at the second end portion of the hollow body, the plurality of elongated fingers extending axially parallel to the longitudinal axis of the backup member, and being movable between a first un-deployed configuration and a second deployed configuration; and a cam member having an elongated portion configured for insertion into the backup member or for receiving the backup member, and a cam portion having a cam surface and an engagement surface, the cam surface is configured to contact the ends of the plurality of elongated fingers; and adjacent elongated fingers are configured to be in contact with each other in the deployed configuration.