Symptom Relief and Practice Setting Variation in Bulkamid Injections for Stress Urinary Incontinence

INTRODUCTION: Bulkamid™ transurethral injection is a minimally invasive treatment for stress urinary incontinence (SUI) and mixed urinary incontinence (MUI). While effective, predictors of repeat injection, progression to sling, and the influence of anesthesia type on treatment efficacy remain incompletely defined. METHODS: We retrospectively reviewed 284 women who underwent Bulkamid™ injection for SUI/MUI. Baseline demographics, comorbidities, and symptom scores were collected. Outcomes were assessed with paired Wilcoxon signed-rank tests. Univariate logistic regression identified predictors of repeat injection and progression to sling. Subgroup analysis compared outcomes by anesthesia use. RESULTS: The cohort had a median age of 63.5 years (IQR 50-72) and BMI of 28.3 kg/m² (24.0-31.7). Most were White (82.4%), with 77.8% having SUI and 22.2% MUI. Comorbidities included diabetes (21.1%), hypertension (48.2%), and prior hysterectomy (44.0%). Median follow-up was 6.7 months (IQR 1.1-17.4). Bulkamid™ significantly improved continence and quality-of-life measures. Median pad use decreased from 2.0 to 1.0 per day (p < 0.001). UDI-6 total scores declined from 45.8 to 16.7 (p < 0.001), with improvements in frequent urination, urgency leakage, physical activity leakage, difficulty emptying, and pain/discomfort (all p < 0.001). Comparison by anesthesia type (general/sedation vs none) showed similar pad reduction and UDI-6 score improvements, but differences in voiding outcomes. Symptom score improvements were otherwise comparable, though those without anesthesia had shorter UDI-6 follow-up intervals (84 vs. 218 days, p = 0.002) and longer overall follow-up (13.4 vs. 6.2 months, p = 0.016). On logistic regression, repeat injection was required in 16.5% at a median of 7.6 months, with procedure done without general/sedative anesthesia as strong predicator for repeat injection (OR 2.82, 95% CI 1.33-5.79, p = 0.005). Seventeen patients (6.0%) progressed to sling, with younger age predicting progression (OR 0.95 per year, 95% CI 0.91-0.98, p = 0.007). CONCLUSIONS: Bulkamid™ injection is a safe, effective, and minimally invasive treatment for stress and mixed urinary incontinence, offering significant symptom improvement with low rates of repeat injection and sling conversion. Younger age was associated with progression to sling, while procedures performed without general/sedative anesthesia were associated with higher likelihood of repeat injection. Bulkamid™ remains a valuable option for women seeking alternatives to sling surgery.