A self-expandable mechanical clot retrieval device is designed variously to dislodge, engage and retract blood clot from extremely small and tortuous vasculature. The retrieval device comprises an elongate member and a plurality of ring elements. The ring elements may comprise a plurality of struts and crowns interconnected by a tether formed at a distal end of the elongate member or may be a separate component attached thereto. At least one tether may connect each ring element to the elongate member to restrain the ring element in a collapsed configuration during delivery of the retrieval device through an intravascular microcatheter. The tether connecting the ring element to the elongate member disengages when the retrieval device is positioned at the occluded site and the microcatheter is retracted to allow the self-expandable ring elements to reach an expanded configuration.