Particle migration after transurethral injection of carbon coated beads for stress urinary incontinence

Purpose: Despite 20 years of experience with injectable bulking agents for stress urinary incontinence results are rather disappointing. The satisfyin g initial results of collagen injection are rapidly decreasing with time, w hereas synthetic bulking agents have shown problems with migration and bioc ompatibility. The ideal bulking agent would be permanent with a good clinic al long-term success rate. We report our experience with Durasphere (Carbon Medical Technologies, Inc., St. Paul, Minnesota), a new injectable bulking agent containing carbon coated beads. Materials and Methods: Seven men and 13 women with a mean age of 62.5 years underwent transurethral submucosal injection. The 13 female patients had b een diagnosed with type III stress urinary incontinence and each had underg one at least 1 unsuccessful previous operation for urinary incontinence. Th ere were iatrogenic and traumatic sphincter lesions in 6 and 1 of the male patients, respectively. Mean volume injected per treatment was 6.0 cc. Mean followup was 10 months. Results: After 6 months 76.9% of the female patients were improved but afte r 12 months the success rate decreased to 33%. In the male patients after 6 months the success rate was 66%, which decreased to 33% after 12 months. A t the 6-month followup we observed significant migration of the carbon coat ed beads into the local and distant lymph nodes as well as into the urethra l mucosa. Conclusions: Due to limited success and proved particle migration, carbon c oated beads do not show any improvement over existing bulking materials. Th e clinical effect of bead migration must be determined before extended use of this substance.