Hypothesis / aims of study
Urethral bulking with polyacrylamide hydrogel (PAHG) is an alternative to mesh-based mid-urethral slings and other procedures for stress urinary incontinence (SUI). Symptomatic improvement after PAHG is variable with retreatment often required [1,2].
The primary aim was to determine the success rate of PAHG urethral bulking for SUI treatment in patients at a medium-term follow-up interval (1 to 3 years).
Secondary aims were to describe clinical predictors of treatment success with PAHG and to determine rates of urinary retention, retreatment, urinary tract infections, de novo urinary urgency, and any differences based on procedural location.
Study design, materials and methods
This was a cross-sectional study of adult women that underwent PAHG urethral bulking between January 2022 to December 2023 at 3 geographically similar tertiary health centers. Participants were identified by CPT code (51715 or L8606), with electronic medical records (EMR) reviewed to determine eligibility. Surveys were distributed via the EMR and completed online or by phone. Patients were excluded who were non-English speaking, had concomitant POP surgery, or history of prior surgical or procedural treatment of SUI. Survey and subsequent chart review obtained demographic and perioperative data, including retreatment rates.
The primary outcome was a composite measurement of SUI treatment success at the time of survey completion. Success was defined by meeting both the objective and subjective criteria. Objective success (from EMR) was no procedural retreatment of SUI. Subjective success (from survey) included the following: (1) score of 3 or less (“better”) on the Patient Global Impression of Improvement (PGI-I), (2) would choose the PAHG procedure again, (3) 75% or greater SUI symptom improvement, and (4) a score of 0, 1, or 2 on UDI-6 stress-specific question “Do you usually experience urine leakage related to coughing, sneezing or laughing?”. Secondary outcomes included perioperative outcomes and comparisons between PAHG administration in an office or operating room setting. Multivariable logistic regression was performed to identify potential predictors of treatment success and potential confounders.
Results
112 patients were included in the analysis. Surveys were completed a median of 24.3 months from the initial PAHG procedure [interquartile range (IQR) 8.8-41.1]. 104 (93%) of patients self-identified as white (Table 1). For the primary outcome, 38 (34%) of patients had treatment success. Improved patients were more likely to use hormone replacement therapy (HRT) (21% vs 4.1%, p = 0.012) and use vaginal estrogen (29% vs 12%, p = 0.045). Retreatment rate with either PAHG or mid-urethral sling following index PAHG procedure was 29% (32 patients) with 22 patients (20% of total cohort) opting for retreatment with PAHG (Table 2). Outcomes did not differ based on procedural location. Multivariate logistic regression modeling revealed prior cancer related radiation therapy as predictive of treatment failure (OR 0.04, 95% CI 0-0.4), while use of HRT was predictive of success (OR 7.02, 95% CI 1.68-39.6).
Interpretation of results
In this cohort of patients undergoing PAHG urethral bulking as a primary procedural treatment for SUI, treatment success was 34% at median follow-up of 2 years. Treatment success was more likely for patients using HRT or vaginal estrogen and less likely with prior radiation therapy. Success rates may be limited by the strict outcome criteria, though this reflects a comprehensive and patient-centered approach to symptom assessment. There was heterogeneity in follow-up duration, which may underestimate true medium-term outcomes.