Periurethral collagen injection: a long-term follow-up study

To determine the long-term success of the periurethral injection of collagen (Contigen(R), Bard UK) in women with genuine stress incontinence.

Sixty-one women with genuine stress incontinence were enrolled in a trial of periurethral collagen injections between 1 September 1990 and 31 August 1992. They were assessed at 1, 3, 6, 12 and 24 months after the last collagen injection. In 1998, their notes were reviewed, and a standardized questionnaire was sent to 46 women who were still alive and had undergone no further anti-incontinence surgery.

Of the 53 women who were either known failures or who had follow-up information beyond 5 years, 26% were subjectively improved. Women who had a maximum urethral closure pressure of >20 cmH2O and those who had urinary incontinence for <10 years before their first injection were more likely to have had long-term success. There was no correlation between long-term success and the number of previous operations, body mass index, age or preoperative pad loss. Neither the number of injection sessions, total volume of collagen injected nor perceived bulking at the time of surgery affected long-term success rates. Of the 14 women who considered themselves subjectively improved, seven had daily incontinence and only one was completely dry. Urinary retention and urinary tract infection were the most common complications. In addition, one woman reported a flare-up of her skin test and transient 'flu-like symptoms 2 weeks after the injection, and one woman developed a right upper lobe pneumonia 2 weeks after the collagen injection.

The long-term results of periurethral collagen injections are disappointing. We found no evidence to support the use of periurethral collagen injections in women with intrinsic sphincter deficiency, who had a higher failure rate than those with hypermobility. Further research is essential to develop agents that are not immunogenic, produce minimal inflammatory response and yet are durable.