Abstract: The present application provides an occluder, for use in occluding a defect in a vascular system. The occluder comprises a first occlusion disc, a second occlusion disc, and a tightening wire; the first occlusion disc and the second occlusion disc are used for covering different openings of a defect, respectively; a connector is provided on the first occlusion disc; the connector is provided with a wire passing hole; the tightening wire passes through the wire passing hole of the connector; two ends of the tightening wire pass through the second occlusion disc, and form an adjustment wire knot on the side of the second occlusion disc facing away from the first occlusion disc; the distance between the first occlusion disc and the second occlusion disc can be adjusted by the ends of the tightening wire. The present application also provides an occlusion system having the occluder.

Abstract: Disclosed is an occluder for occluding a defect in a vasculature. The occluder includes: two occluding disks and a tightening element. The two occluding disks is configured for covering different openings of the defect; wherein the tightening element includes a tightening thread, the tightening thread passing through the defect and being connected to the two occluding disks, the tightening thread has a length between the two occluding disks and the length is adjustable by means of a free end of the tightening thread. Further provided are an occluding system provided with the occluder, a knotting method for the tightening element of the occluder and a method for occluding an oval foramen with the occluder.