Abstract: Plicator systems may have two telescoping components that when arranged in an open configuration have one or more windows into which tissue of, for example, a tubular organ may be invaginated. The invaginated tissue may be secured in the window when the plicator system transitions to a closed configuration. Closing the window may act to, for example, clamp, pierce of the tubular organ tissue invaginated into the window, thereby securing the invaginated tubular organ tissue into the window. In some instances, an axially-expanding spring may be disposed between two plicator systems and when this assembly is implanted in a tubular organ, axial expansion of the spring may exert a distending force on the tubular organ, which may stimulate growth of the tubular organ.