Coiled stent with locking ends

DETAILED DESCRIPTION The present invention is directed to a stent, adapted to be inserted within a body lumen, and designed to expand and lock in an enlarged diameter form.
The stent of the present invention is designed so that the central portion of the stent body can be reversibly expanded at a selected site within a vessel lumen.
Stent deployment can be accomplished by means of a two-stage process which allows the physician to abort the procedure if desired or if a complication develops.
In the first stage, the body of the stent is expanded and then evaluated for such criteria as location relative to the stenosis and size relative to the vessel in which it resides.
At this stage expansion is reversible and the decision to implant the stent can be aborted.
The second stage expands and locks the ends of the stent in place so that the stent remains permanently implanted.
During intravascular surgery, the physician can often only estimate the placement and sizing of the stent when treating a particular lesion.
With the present invention, the means for locking the stent into place can be radiopaque.
This allows the physician to readily determine the position of the stent relative to the lesion during deployment.
The radiopaque ends of the stent allow the stent to be traced without blocking visualization of the lesion, allowing the physician to determine whether the stent is correctly sized to cover the entire lesion.
When the physician is satisfied with the stent placement, the ends of the stent are designed to lock the stent in its expanded configuration.
The stent body may be any geometric design that expands in the center when the ends are either twisted or brought closer together.
The first and second stages of stent expansion may be accomplished by a number of methods.
The stent of the present invention comprises a variety of embodiments.
In some embodiments of the stent, the stent is locked in an expanded state by means of a locking ring attached to each end of the stent.
In another embodiment of the stent the locking device comprises a plurality of slots and tabs with teeth such that the slots receive the tabs