Objective To assess the short-and medium-term efficacy of periurethral collagen injection in women with urethral sphincter incompetence and to determine if urodynamic variables can elucidate the mechanism of action.
Patients and methods Sixty women (mean age 64 years, range 20–90) with genuine stress incontinence received periurethral collagen injections under local anaesthesia; 55 had undergone previous continence surgery. A total of three injection sessions were allowed. Subjective and urodynamic assessments were obtained at 1, 3, 6, 12 and 24 months after injection to evaluate success and long-term effects of collagen.
Results Subjective success rates were 86% at 3 months, 77% at 12 months and 68% at 24 months. Objective cure rates were 61% at 3 months, 54% at 12 months and 48% at 24 months. Low urethral pressures and decreased bladder neck mobility did not affect the outcome. Collagen injections significantly increased stress maximum urethral closure pressures and functional urethral length; increase in the latter and clinical assessment of bulking at the time of injection appeared to predict medium-term success. There were some minor early complications and none in the medium-term.
Conclusions Periurethral collagen injections continued to be effective at the 2-year follow-up, although there was a time-dependent decline. In comparison with more complicated procedures used in patients with previous failed continence surgery, periurethral collagen injection is a simple, acceptable, day case procedure which improves the quality of life in physically fit or frail patients, with few complications.