Efficacy and Safety of Polyacrylamide Hydrogel for the Treatment of Female Stress Incontinence: A Randomized, Prospective, Multicenter North American Study

J Urol. 2014 Sep;192(3):843-9. doi: 10.1016/j.juro.2014.03.109. Epub 2014 Apr 2.


Purpose: Bulkamid® is a new polyacrylamide hydrogel bulking agent for stress urinary incontinence that is injected in the urethral submucosa using a specifically designed device. We evaluated the safety and efficacy of Bulkamid vs Contigen® collagen gel for stress urinary incontinence or stress predominant mixed urinary incontinence.

Materials and methods: This was a single-blind, randomized, prospective, 33-center, 2-arm parallel study of hydrogel vs collagen gel with followup to 1 year. At baseline patients underwent physical examination and bladder testing, and completed quality of life questionnaires and bladder diaries. After randomization patients could receive up to 3 injections at 1-month intervals. Patients were assessed 3, 6, 9 and 12 months after bulking. They completed bladder diaries and quality of life questionnaires, and pad weight was tested. At the last visit Valsalva leak point pressure was measured. Subjective and objective incontinence outcomes and adverse events were compared.

Results: Of the 345 women 229 were randomized to hydrogel and 116 were randomized to collagen gel. At 12 months a 50% or greater decrease in leakage and incontinence episodes was seen in 53.2% and 55.4% of patients who received hydrogel and collagen gel, respectively. At 12 months 47.2% of patients with hydrogel and 50% with collagen gel reported zero stress incontinence episodes, and 77.1% and 70%, respectively, considered themselves cured or improved. Major adverse events were rare in each group.

Conclusions: Bulkamid is not inferior to Contigen. It has a favorable, persistent effect on stress urinary incontinence with a low risk of serious adverse events. Bulkamid is a new, simple, office based bulking system that shows promise as a treatment in women with stress urinary incontinence, particularly since Contigen is no longer commercially available.

Keywords: collagen; female; hydrogel; incontinence; stress urinary; urethra.

Publication types

  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acrylic Resins / adverse effects
  • Acrylic Resins / therapeutic use*
  • Adult
  • Aged
  • Aged, 80 and over
  • Biocompatible Materials / therapeutic use*
  • Canada
  • Collagen / therapeutic use*
  • Female
  • Humans
  • Hydrogels / adverse effects
  • Hydrogels / therapeutic use*
  • Middle Aged
  • Prospective Studies
  • Quality of Life
  • Single-Blind Method
  • Surveys and Questionnaires
  • Treatment Outcome
  • United States
  • Urinary Incontinence, Stress / therapy*
  • Young Adult


  • Acrylic Resins
  • Biocompatible Materials
  • Bulkamid
  • Hydrogels
  • glutaraldehyde-cross-linked collagen
  • polyacrylamide gels
  • Collagen