BERKELEY, CA (UroToday Inc.) - Despite the availability of effective therapies for stress urinary incontinence (SUI), as many as 80% of women do not seek help for this distressing condition. Many women are unwilling to undergo invasive treatments such as surgery but would be willing to try a less invasive, office based procedure even if the probability of objective cure is reduced.

Urethral injection is a minimally invasive SUI therapy that potentially obviates the need for surgery. Zuidex implacement therapy comprises injection of non-animal stabilized hyaluronic acid/dextranomer (NASHA/Dx) via the Implacer device which was developed to facilitate standardized, guided urethral injection of the gel without the need of cystoscopy. Initial results were promising, and recently the procedure was tested on a larger cohort of female patients with SUI. The results are reported in the September, 2005 issue of European Urology by Chris Chapple and colleagues from a multi-national study group.

In the study, 142 female patients (with a mean age of 55.7 years) with stress urinary incontinence that had been present for greater than 12 months, underwent placement of NASHA/Dx gel delivered by the Implacer system in the office after administration of local anesthetic by injection or via intraurethral gel. The device delivers four 0.7 ml of gel via 50 mm, 21 gauge needles into the mid-urethra. Follow-up visits were scheduled at 4, 8 and 12 weeks, and 6 and 12 months after treatment.

The primary efficacy assessment was provocation test urinary leakage which was assessed after filling the bladder with 300 ml of saline and submitting the patent to a fixed exercise routine (stair-climbing (100 steps up and down), coughing strongly (10 times), running on the spot (1 minute), jumping in one place (1 minute), and jumping jacks (30 seconds)). A positive response to treatment was defined as a reduction in provocation test leakage of ≥ 50% from baseline. Efficacy was also measured by 24-hour pad eight test leakage, and number of incontinence episodes/24 hours. At week 8, all women with persistent leakage were offered a second injection of NASHA/Dx gel.

Analysis of the results showed that the response rate was 78% at week 12, and 77% at month 12. Significant reductions in median provocation test leakage, 24-hour pad-weight test leakage and number of incontinence episodes/24 hours were observed at all time points. At month 12, the median decreases from baseline in these three variables were 93%, 89% and 67%, respectively. The mean reduction in urinary leakage via the provocation test was 38.0 gms at baseline to 2.2 gms after the procedure at 12 months. Sixty-one patients (43%) required a second injection to achieve these results after questioning at the 8 week follow-up visit, and 34 patients (24%) withdrew due to lack of efficacy primarily. Treatment related adverse events side were of a nature expected with urethral injection - most were transient, and of mild or moderate intensity.

In summary, treatment with NASHA/Dx gel via the Implacer device resulted in significant improvement in urinary leakage which was sustained over 12 months. The procedure, which was performed in the office and with only local anesthetic, can be considered a viable treatment option in the treatment of naive cases of SUI.

Eur Urol. 2005 Sept; 48(3): 488-494