What is Bulkamid (polydimethylsiloxane) injection?

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Last updated: May 14, 2025View editorial policy

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From the Guidelines

Bulkamoid injection is a viable treatment option for stress urinary incontinence in women, particularly those who wish to avoid more invasive surgical management or have insufficient improvement following an anti-incontinence procedure, as it may provide a mechanical barrier to prevent urine leakage, although repeat injections may be required 1.

Key Considerations

  • The procedure involves injecting a bulking agent, typically polyacrylamide hydrogel, into the urethral tissue surrounding the bladder neck to increase urethral resistance and prevent urine leakage.
  • The standard dosage is 1-4 ml of Bulkamoid injected at 3-4 sites around the urethra using a cystoscope for guidance.
  • Patients can expect immediate results, though some may require a repeat injection after 1-3 months for optimal effect.
  • Recovery is quick with most patients returning to normal activities within 24 hours.
  • Common side effects include temporary discomfort during urination, urinary tract infection, and blood in the urine, which typically resolve within a few days.

Efficacy and Safety

  • The efficacy of Bulkamoid injection is supported by limited long-term data, with calcium hydroxyapatite, polydimethylsiloxane, and polyacrylamide hydrogel (PAHG) showing persistence of effect at 73.2,83, and 96 months, respectively 1.
  • PAHG has been shown to have a lower satisfaction rate compared to TVT, but the majority of women treated with PAHG were considered cured or improved at 3-year follow-up 1.
  • Erosions were not noted in PAHG patients, unlike other bulking agents, in multiple studies 1.

Patient Selection

  • Bulkamoid injection is particularly suitable for elderly patients or those who cannot undergo more invasive surgical procedures.
  • Patients should be counseled on the expected need for repeat injections and the potential risks and benefits of the procedure.
  • The treatment works best for mild to moderate stress incontinence, and patients with more severe incontinence may require alternative treatments.

From the Research

Bulkamid Injection Efficacy

  • Bulkamid injections have been shown to be an effective treatment option for women with stress urinary incontinence (SUI) or stress-predominant mixed urinary incontinence (MUI) 2, 3, 4.
  • Studies have reported significant improvements in patient satisfaction, with 67.1% of patients feeling cured or improved at 7 years follow-up 2, and 63.7% of patients still cured at last follow-up 3.
  • The International Consultation on Incontinence Questionnaire-Short Form (ICIQ-UI SF) scores and Visual Analog Scale Quality of Life (VAS QoL) have also shown significant improvements after Bulkamid injections 2, 4.

Bulkamid Injection Safety

  • Bulkamid injections have been found to be a safe treatment option, with minimal complications 2, 3, 4.
  • Postoperative complications have been reported to be transient, with prolonged bladder emptying time and urinary tract infections being the most common complications 2, 3.
  • The risk of urinary retention and urinary tract infections has been found to be low, with no significant difference between periurethral and transurethral routes of injection 5.

Predictive Factors of Clinical Success

  • Follow-up time has been found to be significantly associated with failure compared to improvement/cure 3.
  • The presence of overactive bladder (OAB) has been found to affect the outcome of Bulkamid injections, with patients with OAB having a lower Patient Global Improvement (PGI) score compared to those without OAB 3.

Comparison with Other Treatments

  • Bulkamid injections have been compared to other treatments, such as midurethral slings (MUS), and have been found to be an effective and safe alternative 4.
  • The choice of treatment depends on various factors, including patient preferences and medical history 4.

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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