Emerging periurethral bulking agents for female stress urinary incontinence: is new necessarily better?

Bulking therapy for stress urinary incontinence in women continues to evolve from the standpoint of material science. Several new materials have recently been subjected to clinical trials with the aim of assessing efficacy and safety of these agents for possible device registration. These new additions run the gamut of biologic to synthetic materials, including re-engineered carbon-coated zirconium beads, ethylene vinyl copolymer, calcium hydroxylapatite, silicone, and hyaluronic acid. Trial design and results reporting for bulking agents has also evolved, with the addition of quality-of-life and patient approbation assessments now being included with outcomes for incontinence reduction and adverse events recording. The new agents and recent studies are reviewed within a context of the prior evidence that has supported the use of the bulking strategy for management of symptomatic stress incontinence. Several recent trials have also compared bulking agents with surgical interventions from effectiveness, approbation, and cost vantage points so as to better determine the reasonability of bulking agent use in an era of minimally invasive incontinence surgery.