An apparatus for mechanically manipulating hollow organs within the body of a subject, or an organ manipulation apparatus, includes a manipulation section. The manipulation section may include a substantially two-dimensional element, which may have a width that exceeds a distance across a portion of the interior of a hollow organ within which the manipulation section is to be positioned. The manipulation section is configured to manipulate at least a portion of a hollow organ from within, which may modify at least one of a shape, orientation, or location of at least part of the hollow organ. Methods for manipulating hollow organs are also disclosed, as are operating techniques, such as left atrial ablation, in which the shapes, orientations, and/or locations of hollow organs are manipulated to move the hollow organs away from the site of the medical procedure, reducing the potential for damage to the hollow organs.