Histological response to implantation of microstimulators on the bladder wall: short term results

Small wireless microstimulators were implanted on the bladder wall serosa in three cats. The microstimulators were secured with a single polypropylene suture. Two to three microstimulators were implanted in each animal. The stimulators were implanted for eight weeks, and gross observation revealed encapsulation of the microstimulators with no perforation into the bladder lumen or migration from the bladder wall. Histological evaluation confirmed that all the microstimulators were encapsulated with a thin connective tissue sheath and a thickened subserosal layer. Only two microstimulators in one cat revealed a moderate to severe inflammatory response confined to a small area around the stimulator. These results indicate that the microstimulator can be further evaluated for implantation and stimulation of the urinary bladder