Coaxial stretch-resistant vaso-occlusive device

Abstract

A filamentous vaso-occlusive implant device includes an elongate, flexible outer member, preferably a microcoil, arranged coaxially around at least one inner member. When the outer member is subjected to axial tension, it elongates axially, while it simultaneously contracts radially. The radial contraction is resisted by the inner member, which thereby limits the elongation of the outer member so that its elastic limit is not exceeded. Therefore, permanent stretching or deformation of the outer member is not permitted. An obturator tip is advantageously provided at the distal end of the device, and a coupling element for detachable attachment of the device to a delivery mechanism is advantageously attached to the proximal end of the device. The inner member may be a microcoil, a hollow tube, a solid filament, a spiral cut tube, a slotted tube, or a tubular braid, and it may be provided with a bioactive agent. In a specific preferred embodiment, the inner member comprises first, second, and third coaxial microcoils.

Dependencies are inferred from the claim text.