The National Institute for Clinical Excellence is examining intramural urethral bulking procedures for stress urinary incontinence in women and will publish guidance on their safety and efficacy to the NHS in England, Wales and Scotland. The Institute's Interventional Procedures Advisory Committee has considered the available evidence and the views of Specialist Advisors, who are consultants with knowledge of the procedures. The Advisory Committee has made provisional recommendations about intramural urethral bulking procedures for stress urinary incontinence in women.

This document summarises the procedures and sets out the provisional recommendations made by the Advisory Committee. It has been prepared for public consultation. The Advisory Committee particularly welcomes:

• comments on the preliminary recommendation
• the identification of factual inaccuracies
• additional relevant evidence.

Note that this document is not the Institute's formal guidance on these procedures. The recommendations are provisional and may change after consultation.

The process that the Institute will follow after the consultation period ends is as follows:

• The Advisory Committee will meet again to consider the original evidence and its provisional recommendations in the light of the comments received during consultation.
• The Advisory Committee will then prepare draft guidance which will be the basis for the Institute's guidance on the use of the procedures in the NHS in England, Wales and Scotland.

For further details, see the Interventional Procedures Programme manual, which is available from the Institute's website (www.nice.org.uk/ipprogrammemanual).

Closing date for comments: 26 January 2005

Target date for publication of guidance: 27 April 2005

Note that this document is not the Institute's guidance on this procedure. The recommendations are provisional and may change after consultation.

Current evidence suggests that there are no major safety concerns and that intramural urethral bulking procedures for stress urinary incontinence are efficacious in the short term. However, evidence on the long-term efficacy does not appear adequate for these procedures to be used without special arrangements for audit, consent and clinical governance.

Clinicians wishing to undertake intramural urethral bulking procedures for stress urinary incontinence should take the following action.

• Inform the clinical governance leads in their Trusts.
• Ensure that patients understand the uncertainty about efficacy and provide them with clear written information. Use of the Institute's Information for the Public is recommended.
• Audit and review clinical outcomes of all patients having intramural urethral bulking procedures for stress urinary incontinence. Clinicians should submit data to the British Association of Urological Surgeons registry (available from www.baus.org.uk/HomePage/MenuPage.asp) or the British Society of Urogynaecologists registry (for further information contact BSUG@rcog.org.uk).

Publication of safety and efficacy outcomes will be useful. The Institute may review the procedures upon publication of further evidence.

Stress urinary incontinence is the involuntary leakage of urine during exercise or movements such as coughing, sneezing and laughing. It is usually caused by weak or damaged muscles and connective tissues in the pelvic floor, or by weakness of the urethral sphincter itself. It is estimated that 10-52% of adult women have some form of incontinence.

Typically, first-line treatment is conservative and includes pelvic floor muscle training, electrical stimulation, and biofeedback. If the condition does not improve, surgical alternatives in women may include colposuspension, tension-free vaginal tape, transobturator foramen procedures, or traditional suburethral slings.

Intramural urethral bulking aims to augment the urethral wall and increase the resistance to urinary flow. A cystoscope is inserted into the urethra to locate the areas where the bulking agent should be introduced. Several millilitres of bulking agent are then injected into the submucosal tissue at the level of the proximal urethra just distal to the bladder neck. The injections are administered under local anaesthesia, either transurethrally through the cystoscope or para-urethrally via small perineal incisions.

A small randomised controlled trial reported that 53% (34/64) of patients treated by urethral bulking with collagen were cured at 12 months compared with 72% (39/54) treated by conventional open surgery.

One case series of patients treated with collagen reported that, after 12 months, 42% (38/90) were cured or had an improvement in symptoms, as measured objectively using cystometry and abdominal leak point pressure. One case series of patients treated with silicone particles reported that 68% (69/102) were either cured or markedly improved after a mean follow-up of 3 months. This proportion decreased to 48% (40/84) after a mean follow-up of 18 months. Four randomised controlled trials reported no difference in efficacy between different bulking agents. For more details, refer to the sources of evidence.

The Specialist Advisors noted that the efficacy may depend on patient selection, the bulking agent used and the injection technique.

Five case series reported safety data on a total of 389 patients. The most commonly reported adverse events were urinary tract infection, affecting 1% (1/102) to 12% (11/90) of patients, and urinary retention, affecting 0 (0/40) to 11% (10/90) of patients. Other reported complications included abscess at the injection site, urgency of micturition, and prolonged pain. For more details, refer to the sources of evidence.

The Specialist Advisors stated that migration of the bulking agent, voiding difficulties, urinary tract infection and allergic reaction are potential adverse events. Haemorrhage was listed as a rare potential adverse event.

The following document, which summarises the evidence, was considered by the Interventional Procedures Advisory Committee when making its provisional recommendations.

Interventional procedure overview of intramural urethral bulking procedures for stress urinary incontinence in women, August 2004

Available from: www.nice.org.uk/262overview