A system for performing minimally invasive procedures in a working space within a body lumen of a patient including a flexible catheter configured to receive a working instrument therethrough. The flexible catheter has a working space expanding system positioned at the distal portion, the working space expanding system including first and second flexible elements movable from a non-expanded insertion position to an expanded position forming an expanded region to expand the working space within the body. The first and second flexible elements are connected at a distal region by a coupling structure. A stabilizing member stabilizes the distal portion of the flexible catheter.
