A sealing system for use in a tubular body, comprising (a) an anti-extrusion assembly and (b) a deformable sealing element, characterized by: (a) the anti-extrusion assembly comprising: an elongated backup member with a hollow body that has end portions(16a, 16b), an inner surface, and an outer surface, and a plurality of elongated fingers attached at one of the end portions (16a. 16b) of the hollow body, the plurality of elongated fingers extending axially relative to the longitudinal axis of the backup member, the plurality of elongated fingers being movable between an un-deployed configuration and a deployed configuration; and a cam member having an elongated portion configured for insertion into the backup member or for receiving the backup member, and an angled cam portion having a cam surface and an engagement surface, wherein the cam surface is configured to contact ends of the plurality of elongated fingers; and (b) the deformable sealing element being adapted for contacting the engagement surface of the cam portion of the cam member; wherein upon application of an axial compression force on the anti-extrusion assembly, the sealing element is deformed into sealing contact with a wall of the tubular body, and the cam surface of the cam portion causes the plurality of elongated fingers to move into the deployed configuration by rotating the plurality of elongated fingers circumferentially, relative to the one of the end portions (16a, 16b) of the hollow body at which the plurality of elongated fingers attach, around the longitudinal axis to slide relative to one another and flex radially, wherein when in the deployed configuration adjacent of the plurality of elongated fingers contact each other and the ends of the plurality of elongated fingers contact the cam surface and the wall of the tubular body to plug an extrusion gap between the cam member and the tubular body. (a) the anti-extrusion assembly comprising: an elongated backup member with a hollow body that has end portions(16a, 16b), an inner surface, and an outer surface, and a plurality of elongated fingers attached at one of the end portions (16a. 16b) of the hollow body, the plurality of elongated fingers extending axially relative to the longitudinal axis of the backup member, the plurality of elongated fingers being movable between an un-deployed configuration and a deployed configuration; and a cam member having an elongated portion configured for insertion into the backup member or for receiving the backup member, and an angled cam portion having a cam surface and an engagement surface, wherein the cam surface is configured to contact ends of the plurality of elongated fingers; and an elongated backup member with a hollow body that has end portions(16a, 16b), an inner surface, and an outer surface, and a plurality of elongated fingers attached at one of the end portions (16a. 16b) of the hollow body, the plurality of elongated fingers extending axially relative to the longitudinal axis of the backup member, the plurality of elongated fingers being movable between an un-deployed configuration and a deployed configuration; and a cam member having an elongated portion configured for insertion into the backup member or for receiving the backup member, and an angled cam portion having a cam surface and an engagement surface, wherein the cam surface is configured to contact ends of the plurality of elongated fingers; and (b) the deformable sealing element being adapted for contacting the engagement surface of the cam portion of the cam member; wherein upon application of an axial compression force on the anti-extrusion assembly, the sealing element is deformed into sealing contact with a wall of the tubular body, and the cam surface of the cam portion causes the plurality of elongated fingers to move into the deployed configuration by rotating the plurality of elongated fingers circumferentially, relative to the one of the end portions (16a, 16b) of the hollow body at which the plurality of elongated fingers attach, around the longitudinal axis to slide relative to one another and flex radially, wherein when in the deployed configuration adjacent of the plurality of elongated fingers contact each other and the ends of the plurality of elongated fingers contact the cam surface and the wall of the tubular body to plug an extrusion gap between the cam member and the tubular body.