Stent delivery and retention apparatus
A stent delivery system comprises an inner member and an expandable balloon mounted in a collapsed state on the inner member, the expandable balloon having a first and a second end. A compressible stent having a first diameter is mounted in a compressed state around the expandable balloon between the first and second ends of the balloon. At least a first retainer pillow is formed in the expandable balloon at its first end and has an outer diameter which is at least substantially equal to the diameter of the compressed stent. A first pillow support member is mounted on the inner member and supports the first retainer pillow to maintain the pillow's outer diameter.
1. A stent delivery system, comprising:
an inner member;
an expandable balloon mounted in a collapsed state on said inner member, said expandable balloon having a first end and a second end;
a compressible stent mounted in a compressed state around said expandable balloon between said first and second ends, said compressible stent in said compressed state having a first diameter;
at least a first retainer pillow formed in said expandable balloon at said first end and having a first outer diameter at least substantially equal to said first diameter; and
at least a first pillow support member mounted on said inner member for supporting said first retainer pillow to maintain said first outer diameter; said first pillow support member comprising a coiled spring member having a first section of a second diameter for engaging said inner member, and a second section of a third diameter being greater than said second diameter of said first section,for supporting said at least a first retainer pillow.
2. A stent delivery system according to claim 1 further comprising:
at least a second retainer pillow formed in said expandable balloon at said second end and having a second outer diameter at least substantially equal to said first diameter; and
at least a second support member mounted on said inner member for supporting said second retainer pillow to maintain said second outer diameter.
3. A stent delivery system according to claim 2 wherein said first outer diameter is greater than said first diameter.
4. A stent delivery system according to claim 1 wherein said coiled spring member is made of a memory alloy.
5. A stent delivery system according to claim 4 wherein said memory alloy is nickel-titanium.