Several different materials have been studied, collagen being one however does not sustain. Polydimethylsiloxane is a solid silicone elastomer suspended in a gel. It has been studied and shown to be non allergenic.
This is a post-market approval study of the use of a urethral bulking agent, polydimethylsiloxane, for stress urinary incontinence. This is a prospective, multicenter study in patients who completed 3 years of follow up post injection. 276 subjects were enrolled and 70 subjects completed all 3 years of follow up.
Subjects were treated with up to two injections. The study enrollment period was October 2008-August 2017. Subjects were then followed at 3,12, 24, and 36 months. Stamey grade (0= continent, 1= incontinence with vigorous activity, 2= incontinence with minimal activity and 3= total incontinence) and I-QoL questionnaire divided into 3 subscales were assessed at baseline, 12, 24,and 36 months post injection. Patient Global Impression of Satisfaction (PGI-S) was assessed at 36 months. They defined success as an improvement to Stamey grade 0 or 1 at 36 months.
They found the majority of patients were white (n=67) with mean age 63.3 years.
At the end of the 3 years or 36 months, 21/70 (30%) of patients reported Stamey score 0 and 28/70 (40%) had Stamey score 1. The composite success rate was 51.4% at 36 months.. The quality of life total score and subscales significantly improved from baseline to12 months, then progressing to 24 and 36 months the quality of life maintained itself. 27/70 (38.5%) patients report very satisfied on PGI-S at 36 months vs 32/68 (47%) at 12 months. Overall satisfaction was 68% at 36 months and 72% at 12 months.
The most common adverse events occurred within the first 3 months as transient dysuria 3.2%, hematuria 6%, pain at the injection site 1.6% and urinary tract infection 2 %. They did not report any serious adverse events. The composite scored is assumed to be lower than overall as patients may have altered their physical activity therefore not capturing a subjective improvement.
At 3 years, Macroplastique urethral bulking agent is safe and efficacious for the treatment of stress incontinence from intrinsic sphincter deficiency. The overall satisfaction is sustained from baseline to 3 years post injection.
Presented by: Mashrin Lira Chowdhury, DO, The University of California Irvine Department of Urology