초록 ▼

A vaso-occlusive device includes inner, intermediate, and outer elements arranged coaxially. The inner element is a filamentous element, preferably a microcoil. The intermediate element is made of a non-metallic material, preferably an expansile polymer. The outer element is substantially non-expans

A vaso-occlusive device includes inner, intermediate, and outer elements arranged coaxially. The inner element is a filamentous element, preferably a microcoil. The intermediate element is made of a non-metallic material, preferably an expansile polymer. The outer element is substantially non-expansile and defines at least one gap or opening through which the intermediate element is exposed. In a preferred embodiment, when the intermediate element is expanded, it protrudes through the at least one gap or opening in the outer element and assumes a configuration with an undulating, convexly-curved outer surface defining a chain of arcuate segments, each having a diameter significantly greater than the diameter of the outer element. The expanded configuration of the intermediate element minimizes friction when the device is deployed through a microcatheter, thereby reducing the likelihood of buckling while maintaining excellent flexibility. The result is a device with enhanced pushability and trackability when deployed through a microcatheter.

대표청구항 ▼

1. A method of occluding a body cavity, comprising: delivering an implant to a vascular abnormality of a body cavity with a delivery device, said implant comprising an open-coiled element surrounding a hydrogel element and defining a gap;expanding said hydrogel element through said gap within said v

1. A method of occluding a body cavity, comprising: delivering an implant to a vascular abnormality of a body cavity with a delivery device, said implant comprising an open-coiled element surrounding a hydrogel element and defining a gap;expanding said hydrogel element through said gap within said vascular abnormality at a controlled rate in response to an environmental parameter; and,detaching said implant from said delivery device. 2. The method of claim 1, wherein said hydrogel element surrounds a microcoil. 3. The method of claim 1, further comprising detaching a coupling element from a proximal end of said implant. 4. The method of claim 1, wherein said environmental parameter is temperature. 5. The method of claim 1, wherein said environmental parameter is pH. 6. The method of claim 1, wherein said expanding said hydrogel element at a controlled rate in response to an environmental parameter further comprises expanding said hydrogel element through gaps of said open-coiled element to form an exterior surface having an undulating configuration defining a chain of convexly-curved arcuate segments. 7. The method of claim 1, wherein said open-coiled element comprises a wire forming a helical configuration. 8. The method of claim 1, wherein said hydrogel element expands volumetrically. 9. A method of occluding a body cavity, comprising: providing an implant; said implant having a first flexible hydrogel element coaxially located within a second flexible element;delivering said implant with a delivery device to a vascular abnormality;exposing said first flexible hydrogel element to fluid through gaps defined by said second flexible element;detaching said implant from said delivery device; and,allowing said first flexible hydrogel element to expand at a controlled rate within said second element responsive to an environmental parameter of said fluid. 10. The method of claim 9, further comprising a microcoil located within said first flexible hydrogel element and made of a biocompatible material selected from a group consisting of metal wire and polymeric filament. 11. The method of claim 9, further comprising expanding said first flexible hydrogel element through said gaps defined by said second flexible member. 12. The method of claim 9, wherein said second flexible element comprises an open-wound, helically-coiled wire. 13. The method of claim 9, wherein said first flexible hydrogel element has a rate of expansion responsive to a change in temperature or pH. 14. The method of claim 9, further comprising uncoupling a proximal end of said implant. 15. A vaso-occlusive device implantable in a vascular abnormality, comprising: an expansile first hydrogel member expandable at a controlled rate in response to an environmental parameter;a second member helically surrounding said first hydrogel member and defining a gap through which the first hydrogel member is exposed; and,wherein said vaso-occlusive device is selectively detachable from a delivery device within a patient. 16. The vaso-occlusive device of claim 15, wherein said environmental parameter is pH. 17. The vaso-occlusive device of claim 15, wherein said environmental parameter is temperature. 18. The vaso-occlusive device of claim 15, wherein said second member is an open-wound helical coil defining said gap. 19. The vaso-occlusive device of claim 15, further comprising a third member located within said expansile first hydrogel member, and wherein said third member is a microcoil. 20. A vaso-occlusive device implantable in a vascular abnormality, comprising: an open-coiled element;an expansile hydrogel element exposed between loops of said open-coiled element and expandable at a controlled rate against said open-coiled element; and,wherein said vaso-occlusive device is selectively detachable from a delivery device within a patient. 21. The vaso-occlusive device of claim 20, wherein said expansile hydrogel element volumetrically expands at a controlled rate in response to an environmental parameter. 22. The vaso-occlusive device of claim 21, wherein said environmental parameter is pH or temperature.