A system for reducing a compass of an opening or structure in a mammalian body comprises an anchor having a central aperture, a tensioner having a plurality of openings, and a plurality of filaments, each including a retaining member affixed to a distal portion of the filament. The tensioner is receivable within the anchor central aperture. A proximal portion of each filament is receivable within a tensioner opening. A method of reducing a compass of a lumen or structure in a mammalian body comprises delivering the anchor to a first location proximate target tissue, delivering the filaments to a second location proximate the target tissue, threading the filaments through the anchor and the tensioner openings, positioning the tensioner in the anchor aperture, retaining the filaments in the tensioner, and rotating the tensioner to twist the filaments, thereby shortening the length of the filaments and increasing the tension across the system.