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Injectable agents for stress urinary incontinence (SUI)

How do injectable agents for Stress Urinary Incontinence work?

Urethral bulking agents (also known as bioinjectable or injectable agents) such as Bulkamid®, Durasphere®, Macroplastique® are injected via a needle through a telescope into the water pipe (urethra) to improve problems with stress urinary incontinence.

These agents work by a “bulking” effect in the tissues around the urethra that protects against incontinence by increasing the resistance to the outflow of urine and enabling the walls of the urethra to seal better to prevent leakage.

The best results occur when the patient’s incontinence is due to poor urethral function combined with good pelvic muscle support. Injectable agents can be used both in women and men with stress urinary incontinence (SUI).

Top Left = Cystoscope inserted into urethra; Top Right = Bulking agent injected into urethra; Bottom Left = Cross-section of urethra before bulking agent injection; Bottom Right = Cross-section of urethra after bulking agent injection showing coaptation of urethral lining.

Copyright Dr Karen McKertich - Not for use without attribution.

What injectable agents are available in Australia?

Injectable agents available in Australia to treat stress urinary incontinence include:

  • Bulkamid®
  • Durasphere®
  • Macroplastique®

What is Bulkamid®?

Dr McKertich uses Bulkamid® as an injectable bulking agent to treat stress urinary incontinence in women due to its safety and efficacy.

Bulkamid® is a transparent gel injected into the urethra using a fine needle inserted under vision using a telescope (cystoscope) which passes into the water pipe. Bulkamid® is made of a chemical called polyacrylamide gel which is 97.5% water and 2.5% polyacrylamide. Polyacrylamide is a material that has been used in plastic surgery and for the manufacture of contact lenses for over 10 years. The structure of polyacrylamide allows it to stay at the site of implantation without inducing a reaction from the body.

What are the main indications for Bulkamid® injections?

This procedure is most suitable for people with stress urinary incontinence due to “intrinsic sphincter deficiency” where the urethral tissues close poorly and which is generally associated with more severe urine leakage with minimal exertion.

It might also be effective in patients with urethral hypermobility where excessive movement of the urethra predisposes to stress urinary incontinence.

Dr. McKertich will advise patients regarding suitability for Bulkamid® injection depending on the results of investigations including Urodynamic study.

How is the procedure performed?

The Bulkamid® injection procedure can be performed under local or general anaesthetic as a day case procedure using a fine cystoscope (telescope) to inject the Bulkamid® into the urethra (urine pipe taking urine from the bladder).

What are the results Of Bulkamid® in treating Stress Urinary Incontinence in Women?

The result of treatment with Bulkamid® is immediate. One of the advantages of treatment with Bulkamid is that there is no significant restriction in activity after the procedure as is required after sling procedures for stress urinary incontinence. The recovery time is very rapid.

Up to 2/3 of patients who are treated with Bulkamid® are either cured or have significant improvement in their stress urinary incontinence after 2 years.

As there is the potential for absorption or leakage of all injectable bulking agents such as Bulkamid® from the urethra with time, stress urinary incontinence can recur. If stress incontinence recurs, Bulkamid® can be reinjected into the urethra. Around 44% of women will request reinjection.

What are the advantages of Bulkamid® injections?

  • This is the least invasive surgical procedure to treat stress urinary incontinence.
  • It can be performed under local anaesthesia or general anaesthesia/ sedation if preferred.
  • The side-effects and complication rate from Bulkamid® injections are minimal.
  • This procedure may be more acceptable to women who wish to avoid the potential complications associated with more invasive surgery or a general anaesthetic.
  • Having a Bulkamid® injection does not prevent an individual from having more invasive surgery such as a sling procedure in the future.

It may suit:

  • Some women who have only a mild degree of incontinence even after performing pelvic floor physiotherapy.
  • Women who already have difficulty emptying their bladder and who are therefore at risk of emptying their bladder poorly after stress incontinence surgery, as Bulkamid® injections have an extremely low rate of problems with long-term urinary retention.
  • Women who want a procedure that allows them to return rapidly to work and their normal level of activity.
  • Women who are willing to accept the lower cure or significant improvement rate in stress urinary incontinence after treatment with Bulkamid® compared to sling surgery success rates.

What are the disadvantages of Bulkamid® injections?

  • Repeat injections are often required to maintain effectiveness as the Bulkamid® may be reabsorbed by the body. As a result the initial effectiveness of the Bulkamid® injection may decline over time.
  • Please Note: Bulkamid® periurethral injections should not be regarded as a one-time or permanent treatment. Many patients need additional treatments with Bulkamid® to achieve and maintain improvement in incontinence.

Consultation for Stress Urinary Incontinence (SUI)

If you believe you may be experiencing Stress Urinary Incontinence and would like to discuss with Dr McKertich, please call us or make an appointment request. A valid GP or specialist referral is required to make an appointment.