A medical device for closing an opening between the first atrium and second atrium (40) of a heart is disclosed. The opening (58) defines an axis oriented axially through the opening. The medical device has a frame including a central portion with at least a first anchor (204) and a second anchor (206) each extending from the central portion. The central portion is configured to assume a substantially flat configuration oriented substantially parallel to, or extending substantially along, the axis of the opening upon delivery to the internal tissue opening in an intended, as deployed state. The first anchor and the second anchor extend substantially coplanar with the central portion, wherein in the intended, as deployed state, the central portion is positioned in the opening of the tissue structure with the first anchor positioned in the first atrium and the second anchor positioned in the second atrium. A tissue growth promoting member with an elongated structure is attached to the central portion of the frame. The tissue growth promoting member is configured to substantially extend out-of-plane from the substantially flat configuration and the elongated structure configured to be oriented on the frame so as to be transverse to the axis of the opening and extend across a width of the opening in the tissue structure. The tissue growth promoting member configured to enhance tissue growth in the internal tissue opening. A tool (362) used during placement of the medical device and a method for placement is also disclosed.
