Bioabsorbable endoprosthesis having elongate axial reservoir for by-product collection

(New) A bioabsorbable endoprosthesis comprising:

• an elongate element wound about an axis to define a tubular structure having a predetermined radius and length when in an unloaded state, said elongate element having an outer surface, including a bioabsorbable polymer adapted to undergo degradation in vivo, and including an elongate, axially extending reservoir portion adapted to collect a by-product of the degradation of the bioabsorbable polymer;
• wherein the element occupies a total element volume including a reservoir volume occupied by the reservoir portion, and the reservoir volume is at least about ten percent of the total element volume;
• and
• wherein the elongate element is adapted for a simultaneous axial elongation and radial reduction, whereby the tubular structure is radially compressible into a reduced-radius, extended-length state to facilitate an intraluminal delivery of the structure to a selected treatment site within a body lumen, said elongate element having sufficient structural strength to withstand post-delivery confinement in the body lumen and to exert a radial force against a wall defining the body lumen, said structural strength tending to diminish as said degradation progresses.

(New) A bioabsorbable endoprosthesis comprising:

• a tubular structure comprising a first elongate element having an outer surface and wound helically about an axis in a first direction, the tubular structure further comprising a second elongate element wound helically about the axis in a second direction different from the first direction to form crossings with the first elongate element, wherein each of the first and second elements includes a bioabsorbable polymer adapted to undergo degradation in vivo;
• wherein each of the first and second elongate elements occupies a total element volume including an elongate, axially extending open reservoir volume for receiving a by-product of the degradation of the bioabsorbable polymer, and the reservoir volume is at least about ten percent of the total element volume;
• and
• wherein the first and second elements are adapted for a simultaneous axial elongation and radial reduction whereby the tubular structure is radially compressible into a reduced-radius, extended-length state to facilitate an intraluminal delivery of the structure to a selected treatment site within a body lumen, said first and second elements having a sufficient structural strength to withstand confinement in the body lumen and to exert a radial force against a wall defining the body lumen, said structural strength tending to diminish as said degradation progresses.