A vaso-occlusive device (10) includes a microcoil (12) formed into a minimum energy state secondary configuration comprising a plurality of curved segments (14a,14b,24), each defining a discrete axis (16), whereby the device, in its minimum energy state configuration, defines multiple axes. In a preferred embodiment, the minimum energy state secondary configuration comprises a plurality of tangentially-interconnected, substantially circular loops (14a,14b) defining a plurality of discrete axes (16). In an alternative embodiment, the minimum energy state secondary configuration defines a wave-form like structure comprising a longitudinal array of laterally-alternating open loops (24) defining a plurality of separate axes (16). In either embodiment, the device (10), in its minimum energy state secondary configuration, has a dimension that is substantially larger than the largest dimension of the vascular site in which the device is to be deployed. Thus, when the device (10) is deployed in an aneurysm (40) , the confinement of the device (10) within the aneurysm (40) causes the device (10) to assume a three-dimensional configuration that has a higher energy state than the minimum energy state.
