MICROCOIL VASO-OCCLUSIVE DEVICE WITH MULTI-AXIS SECONDARY CONFIGURATION

摘要

A vaso-occlusive device includes a microcoil formed into a secondary configuration comprising a plurality of curved segments, each defining a discrete axis. The secondary configuration may comprise a plurality of interconnected closed loops or laterally-alternating open loops, defining a plurality of discrete axes. Alternatively, the secondary configuration may form a series of closed loops, wherein the entire structure subtends a first angle, and wherein each adjacent pair of loops defines a second angle; or the secondary configuration may form a logarithmic spiral. The device, in its secondary configuration, has a dimension that is larger than the largest dimension of the aneurysm in which it is to be deployed. Thus, confinement of the device within an aneurysm causes it to assume a configuration with a higher energy state than the minimum energy state of the secondary configuration. Because the minimum energy state configuration is larger (in at least one dimension) than the aneurysm, the deployed device is constrained by the aneurysm from returning to its minimum energy state configuration, and the containment of the device minimizes its shifting due to blood flow.