A vaso-occlusive device and delivery system to a selected site of the vessel in a manner allowing the vaso-occlusive device to substantially assumes a diameter of an inner surface of the vessel or aneurism sac at the site of the embolization procedure is disclosed. The vaso-occlusive device or embolic coil has specific properties for conforming to the diameter of the aneurysm sac thereby enabling retractability and rapid disconnect detachment .The vaso-occlusive device or embolic coil has a predetermined shape requiring fewer embolic coils per embolization procedure advantageously improving patient risk, and the cost and time of the procedure. A method for deploying the embolic coil with such specific properties to the site of an aneurysm using a delivery system configured for deploying the embolic coil features inserting, and/or reconnecting for positioning and reinserting the embolic coil is disclosed.
