Stent delivery system

A stent deliverysystem for implanting a flexible, generally cylindrical, self-expanding stent, comprising:

• a catheter having distal and proximal ends and an outer surface, said catheter defining at least one lumen extending therethrough;
• a flexible, self-expandable coiled stent in a form of a continuous helical coil with a uniform wining direction and voids defined between opposing turns of said coil, said stent having proximal and distal end section separated by an intermediate section, said stent being wound circumferentially around said catheter defining a wound position with turns of the coil in both the proximal and distal sections being more closely wound with a narrower spacing between opposing turns than a winding and spacing between opposing turns in an other portion of said stent, said other portion of said stent including at least said intermediate section and having a predetermined longitudinal length when in said wound position;
• said stent releasably secured to said catheter with said stent releasable from said wound position to an expanded position in a sequence with said proximal and distal sections released first from said catheter and expanded radially outward in response to said release before said other portion of said stent is expanded radially outward, wherein said intermediate section is released from said catheter after said distal and proximal sections are released from said catheter, wherein a longitudinal length of said stent in said expanded position is not substantially less than said predetermined longitudinal length of said other portion of said stent;
• and
• said catheter including grooves formed on the outer surface of the catheter, the grooves corresponding to at least a section of the coil of the stent.

A method for deploying a stent using a delivery system, the delivery system including a catheter having a distal end and a proximal end, the catheter including a stent mounting location adjacent the distal end, the delivery system also including a coil stent mounted at the mounting location, the stent having a distal end and a proximal end, the stent including coils having a first spacing adjacent the proximal end of the stent and also including coils at an intermediate location having a second spacing, the first spacing being narrower than the second spacing, the delivery system also including a first release wire extending longitudinally through the catheter for releasing the proximal end of the stent from the catheter and a second release wire extending longitudinally through the catheter for releasing the distal end of the stent from the catheter, the method comprising:

• delivering the stent with the catheter to a delivery site within a patient;
• releasing the proximal end of the stent by pulling back the first release wire;
• after the proximal end of the stent has been released, self-expanding the stent with the expansion of individual coils of the stent starting at the proximal end and moving along a length of the stent toward the distal end;
• and
• releasing the distal end of the stent after the stent has been self-expanded by pulling back the second release wire.

A delivery system comprising:

• a catheter having a proximal end and a distal end, the catheter including a stent mounting location positioned adjacent the distal end, the catheter defining at least one lumen extending longitudinally there through, the catheter also defining at least one stent mounting opening defined adjacent to the stent mounting location, the stent mounting opening extending from the lumen to an outer surface of the catheter;
• a self-expandable stent mounted at the stent mounting location of the catheter;
• a stent retaining member for securing the stent to the catheter, the stent retaining member having a first end connected to the catheter adjacent to the stent mounting location, the retaining member also including a free end that loops over a portion of the stent and extends inwardly through the stent mounting opening to the lumen of the catheter;
• and
• a release wire that extends longitudinally through the lumen and that connects to the free end of the stent retaining member, where the stent is released from the catheter by pulling back on the release wire such that the release wire disengages from the stent retaining member thereby allowing the stent to self expand.