Role of 3D ultrasound in the treatment of stress urinary incontinence with polyacrylamide hydrogel (Bulkamid®) – a pilot study

Abstract Introduction and Hypothesis Polyacrylamide hydrogel (PAHG) is a bulking agent used in treatment of stress urinary incontinence (SUI) in women. Some women experience an improvement or cure in stress urinary incontinence (SUI) symptoms lasting only a few weeks after the injection of the bulking agent. The aim of this study was to use three-dimensional ultrasound (3DUS) to describe the changes in volume, number of deposits and echogenicity of the bulking agent 3 months after PAHG injection. Methods Prospective cohort study of fourteen women with SUI or mixed primarily SUI, who underwent an injection of PAHG. The subjective outcome was evaluated with Patient Global Impression of Improvement questionnaire. 3DUS was performed in all patients immediately after injection of PAHG and again at 3 months follow-up. Results The study found a mean 36.5% loss in bulking agent volume during the study period. A total of 53 PAHG deposits were found by ultrasound immediately after injection. At 3 months follow-up 41 PAHG deposits were left. All deposits were hypoechogenic immediately after injection and only 24% of demonstrated PAHG collections had a hypoechoic echogenicity at 3 months follow-up. Conclusions More than 1/3 of volume of injected PAHG and 23% of deposits could not be found by 3DUS at 3 months follow-up. Only 24% of PAHG injections in our patients had hypo-echoic echogenicity at 3 months follow-up. Larger 3DUS studies with longer follow-up and focus on exact location of the PAHG injections are important future studies.