Injection therapy for stress incontinence in women.

Periurethral bulking agents have been used to treat intrinsic sphincter deficiency for decades. Currently available agents include polytetrafluoroethylene, glutaraldehyde cross-linked collagen, autologous fat and silicone microimplants. Polytetrafluoroethylene has never been approved by the United States Food and Drug Administration for periurethral injection because of the risk of particle migration. Early results have reported subjective cure rates of up to 95% with collagen injections. However, collagen may cause allergic reactions and long-term results are still awaited. Periurethral fat injection has a reported success rate ranging from 23% to 65%. It is simple and avoids the use of foreign materials, but the main disadvantage relates to the variability of resorption and connective tissue replacement. Silicone microimplants need further study to evaluate their efficacy and safety. The best material has not yet been defined. Long-term studies are still necessary to define the optimal injectable agent.