Postprostatectomy incontinence (PPI), defined as involuntary urine loss following radical prostatectomy (RP) or transurethral resection of the prostate (TURP), is a well-recognized and bothersome complication. Platelet-rich plasma (PRP) has been utilized for tissue repair and regeneration in many medical aspects. This study aimed to evaluate the therapeutic efficacy and durability of multiple PRP injections into the urethral sphincter for managing PPI.

A total of 71 patients with PPI refractory to conservative treatments were prospectively enrolled. Each patient received four monthly PRP injections into the urethral sphincter at five sites for four consecutive months. The primary endpoint was the Global Response Assessment (GRA) score of satisfaction after PRP treatment, along with the identification of predictive factors for a successful outcome. Secondary endpoints included changes in the stress urinary incontinence (SUI) visual analog scale (VAS), Urogenital Distress Inventory (UDI-6), Incontinence Impact Questionnaire (IIQ-7), pad usage, and urodynamic parameters, assessed from baseline to the end of follow-up at 3 months.

The mean age of the patients was 71.0 ± 7.2 years (range: 53–87), with a mean SUI duration of 35.5 ± 36.8 months (range: 12–180). The baseline demographics and parameters after PRP injections were shown in Table 1. After four PRP injections, the mean GRA score was 1.21 ± 1.14 (range: -1 to +3). Fourteen (19.7%) patients became completely dry, 42 (59.1%) had significant improvement, while 15 (21.1%) failed the treatment. Significant improvements were observed in the VAS score for SUI (from 7.1 ± 1.8 to 5.2 ± 2.3, p < 0.001), UDI-6 score (from 5.38 ± 2.3 to 3.86 ± 2.3, p < 0.001), and abdominal leak point pressure in patients who still had SUI after PRP treatment (from 109.42 ± 46.9 to 133.9 ±65.9 cmH₂O, p = 0.014). The baseline lower VAS of SUI (p = 0.002) and higher cystometric bladder capacity (CBC) were identified as significant predictors of a successful outcome (p = 0.047). (Table 2) The increase in abdominal leak point pressure (ALPP) from baseline to end-point was significantly greater in the successful group than failed group (49.3 ± 78.3 cmH2O v.s. 4.9± 52.4 cmH2O; p = 0.028). (Table 3)

PRP injection into the urethral sphincter is effective in male patients with postprostatectomy urinary incontinence. A total of 78.8% patients had very satisfactory or moderately satisfactory (40.8%) or mildly satisfactory (38%) to treatment outcome. The SUI symptom and abdominal leak point pressure showed improvement after PRP injection. Patients with a successful outcome had a less severe stress urinary incontinence and large cystometric bladder capacity than those who failed treatment, suggesting a less incompetent bladder outlet and stable bladder might benefit from PRP injections. The subjective treatment outcome is also  confirmed by the change of objective urodynamic parameter such as abdominal leak point pressure, which was significantly increased in patients with a successful treatment outcome.

Four repeated PRP urethral sphincter injections significantly reduced SUI severity and increased ALPP, demonstrating their potential as an effective and durable novel treatment for PPI. Moreover, patients with a lower VAS of SUI and greater CBC at baseline tend to achieve better treatment outcomes, suggesting a higher urethral resistance at baseline may benefit more from this minimally invasive treatment for PPI.