Planned Penile Vibratory Stimulation in the Prevention of Sexual Dysfunction and Urinary Incontinence After Radical Prostatectomy: a Randomized Controlled Study

Hypothesis The study's hypothesis is that vibration therapy, using the stimulation parameters found in the pilot study, will have a beneficial effect on erectile function, orgasm disturbances, penile shortening, and urinary incontinence, both generally and in connection with sexual activity.

Methods The study is conducted as a randomized, controlled non-blinded study. Men undergoing a nerve-sparing operation for prostate cancer are divided into two groups. A total of 100 men will be included in the study. In case a surgery cannot be performed with nerve preservation or if a participant experiences a recurrence of their prostate cancer requiring additional treatment, the participant will be withdrawn from the study.

Randomization and Treatment Overall, we will investigate the effect of vibration stimulation on erectile function, orgasm disturbances, penile shortening, and urinary incontinence, both generally and in connection with sexual activity. In accordance with the hypotheses, this study will offer vibration therapy for a longer duration than before. Both the vibration group and the control group will be offered fixed post-operative treatment with phosphodiesterase-5-inhibitors as per the standard protocol. Participants will be randomized into the two groups through drawing lots for either vibration or no vibration. Randomization will be done using block randomization via a computer-generated list. The "Ferticare 2.0" vibrator (produced by the company Reflexonic LLC, Leesburg VA, USA) will be used in the study, which is a modernized version of the previously used vibrator and is sold as a sexual aid in Denmark. It is safety-approved with European CE marking as a "household appliance" and is sold as a sexual aid in Denmark. Men in the vibration group will be instructed on the stimulation before their prostate surgery. Subsequently, participants will be able to perform the vibration therapy themselves at home. In both groups, participants must undergo a standard pelvic floor training program, and both groups will be offered fixed PDE-5 inhibitor treatment in the form of daily tadalafil, 5 mg, as the standard treatment for erectile difficulties after the operation. In the vibration group, daily stimulation will be directed towards the frenulum for a minimum of 5 minutes, with an amplitude of 1 mm and a frequency of 90 Hz, as found in the pilot study. Participants will start getting used to the vibration 1-4 weeks before the surgery and resume it within 14 days after the operation. The daily stimulation will continue for a period of 9 months, along with the standard treatment. After these 9 months, men in both groups will stop taking tadalafil during a 4-week wash-out period, after which their spontaneous sexual function will be evaluated. This is necessary due to the well-known positive effect of the medication. In comparison to the standard treatment in the department, offering vibration to half of the participants is an addition. Regarding pelvic floor training and medication for erectile difficulties for all study participants, the current standard is to offer these to all men who have undergone nerve-sparing radical prostatectomy. This will proceed as usual, and the only deviation from usual practice is ensuring that the medication offer is consistent for all participants. The mentioned 4-week period without tablet treatment (wash-out) is necessary to assess spontaneous erections. This is a deviation from the normal standard, as such a wash-out is not conducted for patients who do not participate in research, but it will not affect the actual erectile function of the participants in either group.

Data Collection

Standard investigations related to prostate cancer will be conducted according to normal guidelines, with the registration of: