Periurethral bulking agents provide a unique, minimally invasive treatment option for stress urinary incontinence in female patients. Although many different injectable agents have been described, the gold standard remains glutaraldehyde cross-linked bovine collagen (Contigen). Limited efficacy and durability have been reported in a significant proportion of patients and presumed to result from collagen loss (eg, by tissue absorption/metabolism and luminal extravasation).
Current 3-D US data Close to two-thirds (62%) of patients who have achieved an initial satisfactory improvement in continence have been shown to have a circumferential distribution of collagen around the urethra, while this configuration was observed in only 20% of patients without satisfactory improvement in continence (Urology 2003; 62:232-6). Eighty percent of patients achieving a durable response (at least 1 year; mean, 2 years) had a circumferential configuration (Urology 2005; 65:60-6).