| 摘要 |
A dilator, a method of making the dilator, and a method of using the dilator to compress fatty substances deposited in or on the walls and lumen of the major arteries. The dilator includes a tubular member that has a distal end portion that can be expanded to compress the fatty substances. One embodiment of the dilator has a balloon or inelastic sack formed integrally with side walls of the tubular member and spaced from its distal end. A second embodiment of the dilator utilizes a tubular member formed by first and second spring wire guides encompassing a plurality of dilating wires surrounding a center pull wire. Near the distal end of the dilator, the spring wire guides are spaced from each other to define a buckling region for the dilating wires. When the center wire is pulled, a compressive force is applied on the dilating wires, so that the wires buckle, or expand, in the buckling region. In one modification of this embodiment, a thin elastic membrane encompasses the dilating wires and the buckling region. In another modification, the thin elastic membrane covers substantially the entire length of the dilating wires so that both pneumatic and mechanical compressive forces can be exerted on the fatty substances. The elastic membrane is positioned inside or on the outside of the spring wire guides. A further embodiment of the dilator utilizes a tubular member having a distal end split by longitudinally-extending slits. Rearward movement of a ball member positioned in front of the leading or distal end of the tubular member, after or simultaneously with rearward movement of a sheath encompassing the split end, forces apart the split end thereby dilating the artery and exerting a compressive force on the fatty substances.
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