Objectives: To compare, in a multicenter, randomized clinical trial, collagen injections versus surgery with regard to efficacy, quality of life, satisfaction, and complications.
Methods: Of 133 women with stress urinary incontinence, 66 were randomized to collagen injection and 67 to surgery (6 needle bladder neck suspensions, 19 Burch, and 29 slings). After randomization, 15 women refused their allocated treatment. "Intent-to-treat" and "per protocol" analyses were applied. Women assigned to collagen injection could receive up to three injections before it was considered a failure. A "top-up" injection was allowed within 3 months after cure. Success as the primary outcome at 12 months was defined as a dry 24-hour pad test (2.5 g or less of urine) after having received only the allocated intervention.
Results: The per protocol analysis showed that the success rate 12 months after collagen injections (53.1%) was much lower than that after surgery (72.2%). The difference was 19.1% (95% confidence interval -36.2% to -2%). The general and disease-specific quality-of-life scores measured by the Rand Medical Outcomes Study 36-item Health Survey and Incontinence Impact Questionnaire were similar in the two groups (P = 0.306). Women treated by surgery were, on average, more satisfied (79.6%) than those treated by collagen injection (67.2%), but the difference was not significant (P = 0.228). Finally, complications were less frequent and severe with collagen injection: 36 events in 23 subjects for collagen injection versus 84 events in 34 subjects for surgery (P = 0.03).
Conclusions: One year after intervention, the success rate of collagen injection as a treatment for stress urinary incontinence was about 19% lower than that after surgery. This has to be tempered by the similar changes in quality of life and satisfaction in both groups and that the number and severity of complications were much greater after surgery than after collagen injection. The results of this study indicate that collagen injections might be a worthwhile alternative to surgery for the treatment of stress urinary incontinence.