A catheter assembly comprising: a leading end; a trailing end; an expandable device positioned at the leading end, the expandable device having a proximal end and a distal end, the expandable device having a collapsed configuration for endoluminal delivery of the expandable device to a treatment site in a body of a patient, and an expanded configuration having a diameter larger than the diameter of the collapsed configuration; a constraining mechanism extending around the expandable device to releasably constrain the expandable device toward the collapsed configuration, said constraining mechanism comprising an axially displaceable sheath having a lumen extending between the leading end and the trailing end, the expandable device positioned in the lumen towards the leading end such that axial displacement of the sheath away from the expandable device exposes the expandable device; a flexible film sleeve wrapped circumferentially around the expandable device; a coupling member cooperating with a plurality of openings in the sleeve for releasably coupling portions of the sleeve to one another to limit expansion of at least a portion of the expandable device after removal of the constraining mechanism, the sleeve limiting expansion of the expandable device toward an intermediate configuration larger than the collapsed configuration and smaller than the expanded configuration; a pusher disposed in the lumen and axially slidable relative to the sheath to prevent movement of the expandable device with the sheath in response to the axial displacement of the sheath; and a steering line operatively coupled to the sleeve to allow axial bending of the at least a portion of the expandable device while in the intermediate configuration in response to selective displacement of the steering line relative to the catheter. a leading end; a trailing end; an expandable device positioned at the leading end, the expandable device having a proximal end and a distal end, the expandable device having a collapsed configuration for endoluminal delivery of the expandable device to a treatment site in a body of a patient, and an expanded configuration having a diameter larger than the diameter of the collapsed configuration; a constraining mechanism extending around the expandable device to releasably constrain the expandable device toward the collapsed configuration, said constraining mechanism comprising an axially displaceable sheath having a lumen extending between the leading end and the trailing end, the expandable device positioned in the lumen towards the leading end such that axial displacement of the sheath away from the expandable device exposes the expandable device; a flexible film sleeve wrapped circumferentially around the expandable device; a coupling member cooperating with a plurality of openings in the sleeve for releasably coupling portions of the sleeve to one another to limit expansion of at least a portion of the expandable device after removal of the constraining mechanism, the sleeve limiting expansion of the expandable device toward an intermediate configuration larger than the collapsed configuration and smaller than the expanded configuration; a pusher disposed in the lumen and axially slidable relative to the sheath to prevent movement of the expandable device with the sheath in response to the axial displacement of the sheath; and a steering line operatively coupled to the sleeve to allow axial bending of the at least a portion of the expandable device while in the intermediate configuration in response to selective displacement of the steering line relative to the catheter.