An endoluminal prosthesis (10) for placing in a body passage of a patient, includes a ureteral stent (12), the ureteral stent comprising a generally tubular housing (14) having a proximal end (16) and a distal end (18) and a lumen (20) longitudinally disposed therethrough, with cation-exchange resin beads (22) disposed within the tubular housing, and at least one anchoring mechanism (24) disposed on a distal end of the tubular housing, where at least one retention screen (26) is disposed within the lumen of the ureteral stent configured to retain the plurality of beads.
