| 摘要 |
This is an implantable vaso-occlusive device. It is typically a vaso-occlusive coil comprising a primary helically wound coil which may then be wound into a secondary shape. Central to the invention is the use of a stretch-resisting member extending through the lumen formed, which stretch-resisting member is fixedly attached, directly or indirectly, to the coil in at least two locations. The stretch-resisting member is preferably somewhat loose within the interior of the lumen so to prevent the coil from collapsing, binding, and therefore stiffening during passage of turns through the human body. The coil should bend easily. In some variations of the invention, the stretch-resisting member may be formed into coil tips at the ends of the coil using simple equipment such as soldering irons or the like. The tips are typically of the same diameter as is the coil body itself. This stretch-resisting member is for the primary purpose of preventing stretching of the coil during movement of that coil, e.g., by retrieval or repositioning after deployment. The device may have a self-forming secondary shape made from a pre-formed primary linear helically wound coil, although it need not have the secondary form. Desirably, the coil is extremely flexible and is controllaby released using a severable or mechanical joint such as an electrolytically detachable joint. External fibers may be attached to the device and affixed to the pre-formed linear member to increase thrombogenicity. The extremely flexible variation of the invention may be hydraulically delivered through the lumen of a catheter and is so flexible that it may be retrievably delivered therethrough a flow-directed catheter. The vaso-occlusive member may be also be covered with a fibrous braid. The device is typically introduced into the body through a catheter. The device is passed axially through the catheter sheath and assumes its secondary form upon exiting the catheter.
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