Collagen injections for genuine stress urinary incontinence: Patient selection and durability

Abstract

The questions of patient selection parameters and durability of response in the use of collagen injections for genuine stress incontinence are addressed. A total of 181 women with a mean age of 64 years (range 26–94) underwent collagen injections for urethral incompetence. Treatment outcome was determined by a change in individual incontinence grades before and after injection. Of the 181 women 42 (23%) are cured, 94 (52%) are improved and 45 (25%) failed. Follow-up in the successful patients, either cured or improved, was a mean of 21 months (range 4–69) after their last collagen injection. No difference in outcome was seen in relation to patient age or pretreatment grade of incontinence. Of the 30 patients with bladder instability, 18 (60%) had a favorable outcome. No significant difference in outcome was seen in patients with or without hypermobility (P=0.2889). Patients with type III incontinence required the largest amount of collagen for a successful outcome. The persistence of continence in 78 patients who were cured for at least 2 months were plotted on a Kaplan-Meier survival curve. The probability of remaining dry without additional collagen was 72% at 1 year, 57% at 2 years and 45% at 3 years. It was concluded that, collagen injection into the urethra is a safe and well-tolerated procedure. Pretreatment bladder instability may be an adverse factor. Patients with or without hypermobility had equal benefit. Long-term durability was seen. If deterioration occurred repeat collagen injections restored success. The current literature is reviewed and the use of collagen relative to other treatments is discussed.