| 摘要 |
A self-expansible structure for implantation in a body cavity is provided. The structure has a generally tubular outline, a nominal length, a nominal diameter, and a unique behavior under constraint. The unique behavior is expressed by a transition diameter, at which a constrained behavior of the structure changes so that, at a constraining diameter smaller than the transition diameter, the structure conforms to the constraint by decreasing the structure's diameter, to below the nominal diameter, and elongating beyond the nominal length, while at a constraining diameter larger than the transition diameter but smaller than the nominal diameter, the structure conforms to the constraint by decreasing the structure's diameter below the nominal diameter, while substantially maintaining the nominal length. Thus, the structure is operable for insertion into a body cavity, via a catheter, having a catheter inner diameter smaller than the transition diameter, by decreasing the structure's diameter, and elongating, and the structure is operable for implantation in the body cavity, having a cavity inner diameter greater than the transition diameter but smaller than the nominal diameter, by decreasing the structure's nominal diameter, while substantially maintaining the nominal length. The value of the transition diameter may be varied and controlled by the manner of constraining in the catheter, during insertion. In the preferred embodiment, the structure is formed of two closed wire constructions, shaped as symmetric wings, and has no exposed tips. The structure may be a stent. Alternatively, the structure may be an anchor, for mounting an incorporeal device thereon. |
