Exploratory trial of urethral submucosa injection therapy of deflux for stress urinary incontinence after radical prostatectomy

Background: After robot-assisted laparoscopic radical prostatectomy (RARP) for localized prostate cancer, post-operative stress urinary incontinence (SUI) impacts patient quality-of-life (QOL). A simple and less invasive treatment for SUI in these patients is urgently needed. Deflux is a viscous gel that consists of a mixture of sodium hyaluronate and dextranomer beads. It is administered by transurethral approach for the treatment of vesicoureteral reflux. In this study, we aim to establish a minimally invasive treatment for post-prostatectomy SUI through transurethral Deflux injection. Methods: We will perform a single-center, exploratory clinical trial to evaluate the safety and efficacy of transurethral injection of Deflux for SUI after RARP. Inclusion criteria are patients with SUI, a urine leakage volume between 15 and 500 g in a 24-h pad test, and those who use more than two pads per day. Five patients are scheduled to be enrolled in this pilot study. Deflux is injected endoscopically at the 3 o'clock and 9 o'clock positions in the submucosa until coaptation of submucosal bulking is achieved from both intraurethral sides. The primary endpoint is safety following Deflux injection. The secondary endpoint is efficacy on both SUI volume and patients' QOL. Discussion: The importance of this clinical trial is to propose a new minimally invasive treatment option for male SUI patients after RARP.