A guide wire comprising: a core member about a longitudinal axis of the guide wire and comprising a distal end; an outer coil disposed about the core member and comprising a proximal end and a distal end disposed proximal of the distal end of the core member, the outer coil extending longitudinally along a majority of a length of the guide wire and being longitudinally movable relative to the core member between a retracted position and an advanced position, the distal end of the outer coil being longitudinally spaced from the distal end of the core member by a greater distance in the retracted position than in the advanced position, wherein the outer coil comprises an outer diameter of between about 0.8 mm (0.032 inches) and about 1.0 mm (0.038 inches);. an anchor member comprising an elongate wire extending longitudinally between the distal end of the outer coil and the distal end of the core member and comprising a proximal end attached to the distal end of the outer coil and a distal end attached to the distal end of the core member, whereby, in response to longitudinal movement of the outer coil relative to the core member, the anchor member is movable between a delivery configuration and a deployed configuration, at least a portion of the anchor member being positioned radially away from the longitudinal axis of the guide wire by a greater distance in the deployed configuration than in the delivery configuration; and a retaining mechanism comprising a tubular member removably positionable about the core member and in abutting contact with a proximal end of the outer coil, the retaining mechanism being engageable with the core member to inhibit longitudinal movement of the outer coil proximally relative to the core member. a core member about a longitudinal axis of the guide wire and comprising a distal end; an outer coil disposed about the core member and comprising a proximal end and a distal end disposed proximal of the distal end of the core member, the outer coil extending longitudinally along a majority of a length of the guide wire and being longitudinally movable relative to the core member between a retracted position and an advanced position, the distal end of the outer coil being longitudinally spaced from the distal end of the core member by a greater distance in the retracted position than in the advanced position, wherein the outer coil comprises an outer diameter of between about 0.8 mm (0.032 inches) and about 1.0 mm (0.038 inches);. an anchor member comprising an elongate wire extending longitudinally between the distal end of the outer coil and the distal end of the core member and comprising a proximal end attached to the distal end of the outer coil and a distal end attached to the distal end of the core member, whereby, in response to longitudinal movement of the outer coil relative to the core member, the anchor member is movable between a delivery configuration and a deployed configuration, at least a portion of the anchor member being positioned radially away from the longitudinal axis of the guide wire by a greater distance in the deployed configuration than in the delivery configuration; and a retaining mechanism comprising a tubular member removably positionable about the core member and in abutting contact with a proximal end of the outer coil, the retaining mechanism being engageable with the core member to inhibit longitudinal movement of the outer coil proximally relative to the core member.