Various treatment options are currently available for the management of female stress urinary incontinence (SUI).  This study was aimed at determining the effectiveness and safety profile of a novel injectable, non-permanent bulking agent based on the bioresorbable polymer polycaprolactone (PCL; Urolon, AQLANE Medical, The Netherlands). As there is a trend towards the use of less invasive and non-permanent materials, this injectable might be a useful addition to the treatment options available.

This retrospective study conducted in five French urogynecology centers between March 2024 and December 2025 included all female patients with stress urinary incontinence (SUI) who received the PCL bulking agent.
A total of 186 patients with SUI have been included in the study (71% SUI; 29% mixed UI). The median age was 52.3 years, and the median follow-up was 9 months. The mean BMI was 26.8 (20 – 34.1) and the mean parity was 2.81 (0 – 6). A total of 94 patients were menopausal, 17 patients received a previous MUS and 22 had a hysterectomy.

All patients were treated using a transurethral submucosal injection using 2.6 ml in 3 points under cystoscopic control. On average, the injection procedure took 13 minutes. Treatment was performed under general anesthesia (n=144; 77%), epidural (n=1; 0.5%) or 42 local anesthesia (n=42; 22%). Urethral hypermobility was found in 94% of patients (n = 174) and 91% (n = 170) had a positive cough test. 10% had an intrinsic insufficiency of the urethral sphincter. At 3-month, 70% of patients (n = 132) achieved clinical success (dry, no symptoms), 25 % (n = 46) improved, and 5.4% (n = 10) reported failure. Regarding complications, acute urinary retention occurred in 14 % of patients (n = 26) and was resolved in 48 H for 98% of the patients. Urinary infections in 2.6% (n = 5), and transient hematuria in 10% (n = 18). 2 patients were identified with moderate urethral pain for 4 months after the injection.

The present large series of patients report on the safety and effectiveness of a novel polycaprolactone-based UBA. Initial results suggest this to be a safe, minimally invasive procedure with good outcomes. 
Based on our experience, the treatment is also suitable for an outpatient setting using local anesthesia, making the procedure more easy and more cost effective. The study will continue until at least 24 months follow up to report on longer-term results.

Initial results suggest the PCL-based injectable to be a safe and effective treatment option for female stress urinary incontinence, especially for women unable or unwilling to undergo more invasive surgical intervention, or are not open to the use of permanent materials. However, additional long-term data and comparative data is required for making a full assessment of the procedure.