Endoscopic silicone injection for female stress urinary incontinence due to intrinsic sphincter deficiency: impact of coexisting urethral mobility on treatment outcome.

OBJECTIVES: To evaluate periurethral silicone injection in the treatment of female stress urinary incontinence due to intrinsic sphincter deficiency (ISD) and assess whether coexisting urethral hypermobility has an impact on treatment outcome.

METHODS: A total of 29 female patients with stress urinary incontinence underwent endoscopic periurethral silicone injection. Using abdominal leak point pressure measurement, ISD was shown preoperatively in all cases. In addition, urethral hypermobility was demonstrated in 14 cases by cotton-swab testing. Treatment outcome was assessed at 3 and 24 months by questionnaire and classified as cure, improvement, or failure.

RESULTS: The morbidity of the procedure was minimal. The median follow-up was 29 months (range 24 to 36). For the entire group, the cure rate was 55% and 45% at 3 and 24 months, respectively. Depending on the existence of urethral hypermobility, the treatment outcome differed significantly. At 3 months, cure was achieved in 73% of the patients with pure ISD and in 36% with urethral hypermobility (P = 0.04). At 24 months, 67% with pure ISD remained continent, but only 21% with urethral hypermobility (P = 0.02).

CONCLUSIONS: In our experience, periurethral silicone injection was a safe treatment for female stress urinary incontinence and provided a moderately successful and durable therapeutic effect in those with sphincter deficiency and good anatomic support. Unsatisfactory results in those with both anatomic incontinence and sphincter deficiency highlight the need for careful preoperative assessment of urethral mobility to exclude such patients from injection therapy.