Radially expandable stents
An expandable, elongate flexible conduit is provided for placement in a tubular body structure. An exemplary conduit includes a plurality of flexible longitudinal members defining in an unexpanded state a lumen, the members being radially expandable at preselected intervals to define a longitudinally oriented array of open-sided cages separated by less-expanded tubular segments, at least one of the open-sided cages having a diameter varying along its length and each of the open-sided cages having a maximum diameter larger than a diameter of the less-expanded tubular segments.
1. An expandable, elongate flexible conduit dimensionally adapted for placement in a tubular body structure, comprising:
a plurality of flexible longitudinal members defining in an unexpanded state a lumen, the members being radially expandable at preselected intervals to define a longitudinally oriented array of open-sided cages separated by less-expanded segments, each member extending through the entire away of open-sided cages, one of the open-sided cages being formed by multiple flexible longitudinal members that do not touch one another along the cage when expanded, at least one of the open-sided cages having a diameter varying along its length and at least one of the open-sided cages having a diameter in an expanded state larger than a diameter of the less-expanded segments; and
at least one end portion biased to be so curled in a resting state as to curl the end portion's lumen as a whole.
2. The conduit of claim 1 , wherein the at least one open-sided cage assumes an undulating shape upon radial expansion.
3. The conduit of claim 1 , wherein an external surface of the array of open-sided cages separated by less-expanded segments defines an undulating shape.
4. The conduit of claim 1 , wherein the less-expanded segments are tubular in shape.
5. The conduit of claim 1 , wherein each of the open-sided cages has a maximum diameter larger than the diameter of the less-expanded segments.
6. The conduit of claim 1 , wherein the at least one curled end portion has a curled shape memory.
7. The conduit of claim 1 , further comprising a filament secured to a distal region of the conduit and extending to a proximal region of the conduit, wherein proximal displacement of the filament transitions the conduit to the expanded state.
8. The conduit of claim 1 , further comprising a filament coupled to a distal region of the conduit and extending to a proximal region of the conduit, wherein distal displacement of the filament transitions the conduit to the unexpanded state.
9. The conduit of claim 8 , wherein the filament is disposed in the lumen.
10. The conduit of claim 1 , wherein the conduit is fabricated from a material that can degrade or dissolve.
11. The conduit of claim 1 , wherein the end portion is J-shaped.
12. A method for draining fluid from an at least partially obstructed tubular body structure, comprising:
inserting a conduit as defined by claim 1 into the tubular body structure in an unexpanded state to bypass at least a portion of an area of obstruction;
radially expanding the members of the conduit so that they do not touch one another at preselected intervals to form the array of open-sided cages separated by less-expanded segments; and
providing through the expanded members of the conduit a drainage path in fluid communication with the fluid.
13. The method of claim 12 , further comprising anchoring the conduit relative to the tubular body structure using the curled end portion.