Recent reports suggest that phosphodiesterase-5 (PDE-5) inhibitors are effective against lower urinary tract dysfunction, including storage dysfunction [1]. There have also been reports that penile rehabilitation using PDE-5 inhibitors influence erectile dysfunction after robot-assisted radical prostatectomy (RARP) [2]. However, the effect of penile rehabilitation on urinary incontinence after RARP and health-related quality of life (QOL) is unclear. In this study, we examined the effects of penile rehabilitation after RARP on incontinence and QOL with adjustment by propensity score matching (PSM).

The study included patients who underwent RARP in our department from October, 2010 to August, 2019. The patients who 1. had an observation period of less than two years, 2. did not answer the International Index of Erectile Function (IIEF) questionnaire preoperatively, or 3. received pre- or post-operative hormone and radiation therapy were excluded. For penile rehabilitation, a PDE-5 inhibitor (tadalafil 20 mg) was administered twice a week for 1–6 months after surgery. We used the Short Form Health Survey (SF)-8 questionnaire, the IIEF questionnaire (question 1 and EF-domain), and the Expanded Prostate cancer Index Composite (EPIC) questionnaire (sexual function subscale (SFS); urinary domain summary score (USS): urinary irritative subscale (UIR); urinary bother subscale (UBS); urinary incontinence subscale (UIN); and urinary function subscale (UFS)). The relevant evaluation items in SF-8 were physical function (PF), role physical (RP), bodily pain (BP), general health (GH), vitality (VT), social functioning (SF), role emotional (RE), mental health (MH), physical component summary (PCS), and mental component summary (MCS). The questionnaires were collected preoperatively and postoperatively at 1, 3, 6, 9, 12, 18 and 24 months. Postoperative urinary incontinence was assessed at scheduled visits 1, 3, 6, 9, 12, 18, and 24 months after the RARP. Patients who used no security liner pads were considered to have urinary continence and those who used one or more security liner pads per day were considered to have urinary incontinence. We investigated the relationship between the presence or absence of penile rehabilitation and pre- and post-operative urinary incontinence, health-related QOL, and erectile function, with adjustment by PSM.

Of the 257 patients who met the enrolment criteria, 95 patients were in the penile rehabilitation group (PR group) and 162 patients were in the nonpenile-rehabilitation group (non-PR group). Patients in the PR group were significantly younger and had a higher preoperative IIEF Q1 score, a higher preoperative IIEF EF-domain score, and a longer total surgical time than the non-PR group. After PSM, there were 156 effective analyses, of which 78 were in the PR group (mean age 64.9 ± 6.0 years) and 78 were in the non-PR group (mean age 64.6 ± 5.2 years). There was no significant difference in demographic factors between the two groups after PSM. In the IIEF Q1 and EF-domain scores, there were no significant differences between the two groups one month postoperatively, but there were significantly higher differences in the PR group 3–18 months and 3–24 months postoperatively as compared to the non-PR group (p < 0.001). The recovery rates for urinary incontinence (the pad free rate) after the RARP were 16.7%, 33.3%, 47.4%, 55.1%, 62.8%, 66.7%, and 72.4% in the non-PR group and 29.5%, 46.2%, 59.0%, 62.8%, 67.5%, 71.1%, and 71.1% in the PR group at 1, 3, 6, 9, 12, 18, and 24 months, respectively. There was no significant difference in the recovery rate of urinary incontinence between the two groups. In EPIC, the SFS score was significantly higher differences in the PR group 3–24 months as compared to the non-PR group (p < 0.001). The USS, UIR, UBS scores were significantly higher in the PR group 3-6 months postoperatively (p < 0.05), and the UBS scores were significantly higher in the PR group 9 months postoperatively (p < 0.05). In SF-8, the GH, VT, SF, RE, MH, and MCS scores were significantly higher in the PR group three months postoperatively (p < 0.05), and the SF, RE, MH, and MCS scores were significantly higher in the PR group six months postoperatively (p < 0.05).

In all patients before PSM, the preoperative IIEF Q1 and EF-domain scores were significantly higher in the PR group than those in the non-PR group. This study was not a randomized trial and patients who requested PR might have had a high level of sexual activity, hence it was likely that the scores would have been high even before surgery and one month postoperatively. After PSM, these groups were no longer significantly different preoperatively and one month postoperatively and the baseline seemed to be consistent. Three months postoperatively, with adjustment by PSM, the values were significantly higher in the PR group and the effect of PR was evident. In addition, this effect was long-lasting, persisting beyond 9 months postoperatively. The rate of improvement in the urinary incontinence of the PR group tended to be slightly better in the early postoperative period, but there was no significant difference between the two groups. However, there were significant improvement in EPIC scores (USS, UIR and UBS) from 3 months postoperatively, indicating that PR may improve urinary-related quality of life. Concerning health-related QOL, some scores were significantly higher in the PR group, and it was considered that PR also improved the health-related QOL.

Our results suggest that PR with PDE-5 inhibitor after RARP improves erectile function, health-related and urinary-related QOL.

Matthias Oelke, et al: European Urology. 2012, 61, 917-925.
Kim S, et al: Sexual Medicine. 2018, 6, 108-114.