Early outcomes, patient selection and learning curve of Bulkamid® for female stress urinary incontinence

Periurethral Bulkamid® injections are a minimally invasive treatment option for female stress urinary incontinence. We assessed early outcomes, morbidity, predictors of favorable response, and the learning curve during implementation.

This retrospective single-center cohort included 167 women treated with Bulkamid® for stress or mixed urinary incontinence between July 2021 and February 2024. The primary outcome was favorable patient-reported response at 6 weeks, defined as documented complete or near-complete resolution (>90% improvement) or marked improvement (>50-90%) of stress urinary leakage. Moving-window, CUSUM, and LC-CUSUM analyses assessed outcomes according to operator experience. Predictors of favorable response were assessed using multivariable logistic regression.

At 6 weeks, 57 patients (34.1%) achieved complete or near-complete resolution and 65 (38.9%) marked improvement, yielding a 73.0% favorable response rate. Sequential analyses consistently demonstrated stabilization after approximately 20 procedures. Acute urinary retention occurred in 24.5%, was transient in all cases, and differed between operators (35.3% vs. 2.0%; P<0.001). A positive urethral support test predicted favorable response (adjusted OR: 2.67, 95% CI: 1.01-7.03; P=0.047), whereas detrusor overactivity predicted poorer response (adjusted OR: 0.21, 95% CI: 0.05-0.85; P=0.029).

Bulkamid® provided satisfactory early patient-reported outcomes, with stabilization after approximately 20 procedures. Patient selection appeared important, particularly urethral support and detrusor overactivity. Higher operator-related postoperative retention was not associated with superior clinical outcomes. These findings require prospective validation in larger multicenter cohorts.