Penile vibratory stimulation in the recovery of urinary continence and erectile function after nerve-sparing radical prostatectomy: a randomized controlled trial

摘要

Objective class="unordered" style="list-style-type:disc">To examine the effect of penile vibratory stimulation (PVS) in the preservation and restoration of erectile function and urinary continence in conjunction with nerve-sparing radical prostatectomy (RP).Patients and Methods class="unordered" style="list-style-type:disc">The present study was conducted between July 2010 and March 2013 as a randomized prospective trial at two university hospitals. Eligible participants were continent men with an International Index of Erectile Function-5 (IIEF-5) score of at least 18, scheduled to undergo nerve-sparing RP.Patients were randomized to a PVS group or a control group. Patients in the PVS group were instructed in using a PVS device (FERTI CARE® vibrator).Stimulation was performed at the frenulum once daily by the patients in their own homes for at least 1 week before surgery. After catheter removal, daily PVS was re-initiated for a period of 6 weeks.Participants were evaluated at 3, 6 and 12 months after surgery with the IIEF-5 questionnaire and questions regarding urinary bother. Patients using up to one pad daily for security reasons only were considered continent. The study was registered at ().Results class="unordered" style="list-style-type:disc">Data from 68 patients were available for analyses (30 patients randomized to PVS and 38 patients randomized to the control group).The IIEF-5 score was highest in the PVS group at all time points after surgery with a median score of 18 vs 7.5 in the control group at 12 months (P = 0.09), but the difference only reached borderline significance.At 12 months, 16/30 (53%) patients in the PVS group had reached an IIEF-5 score of at least 18, while this was the case for 12/38 (32%) patients in the control group (P = 0.07).There were no significant differences in the proportions of continent patients between groups at 3, 6 or 12 months. At 12 months 90% of the PVS patients were continent, while 94.7% of the control patients were continent (P = 0.46).Conclusion class="unordered" style="list-style-type:disc">The present study did not document a significant effect of PVS. However, the method proved to be acceptable for most patients and there was a trend towards better erectile function with PVS. More studies are needed to explore this possible effect further. class="kwd-title">Keywords: erectile dysfunction, penile rehabilitation, penile vibratory stimulation, prostate cancer, radical prostatectomy, urinary incontinence class="head no_bottom_margin" id="__sec5title">IntroductionRadical prostatectomy (RP) is a commonly employed treatment for localized prostate cancer. Unfortunately, a substantial proportion of patients will experience adverse effects in the form of urinary incontinence and erectile dysfunction (ED) after the surgery . The cavernous nerves are responsible for inducing the physiological erection, and as these nerves run in close proximity to the prostate gland, they are in danger of being damaged during RP. Thus, it is well accepted that the main pathophysiological mechanism behind post-prostatectomy ED is damage to the cavernous nerves. To improve erectile function after surgery, nerve-sparing procedures have therefore been developed, and whenever tumour characteristics allow it, these are routinely employed . However, even when the cavernous nerves are left anatomically intact, it is likely that they are affected by mechanical manipulation, heating, ischaemic effects and local inflammation ^,. This is believed to cause neuropraxia, defined as a temporary block of nerve transmission despite an anatomically intact nerve fibre. Postoperative incontinence can be caused by damage to the urinary sphincter and changes in the course of the urethra after surgery. However incontinence can also occur if these structures are not compromised, which could be connected to changes in the closing pressure of the urinary sphincter and sometimes reduced bladder capacity . In these cases, it is likely that nerve damage plays a pathophysiological role. Rehabilitation of patients' sexual function is often attempted with various regimens of phosphodiesterase type 5 (PDE5) inhibitors, vacuum erection devices and/or injection therapy ^–. Meanwhile, rehabilitation regarding urinary continence is routinely performed by instructing patients in pelvic floor exercises before or after their surgery. Unfortunately, these rehabilitation attempts are often unsuccessful and new methods are needed ^,. One possible reason that current methods have generally shown disappointing results in preserving erectile function and continence is that they do not target the pelvic nerves.It has previously been shown that one can stimulate the nerves of the pelvic floor by means of penile vibratory stimulation (PVS). Thus PVS is capable of inducing ejaculations in ≈90% of men with spinal cord injuries and the treatment is known to increase the pressure in the external urethral sphincter as well as the bladder capacity in this patient group ^,. In addition, mechanical nerve stimulation through vibration applied at the perineum has shown promise in treating urinary incontinence in women, with 24/33 (74%) women experiencing complete resolution of symptoms after 6 weeks of stimulation . Therefore it is feasible that this method can improve nerve function and thereby prevent or minimize the occurrence of incontinence and ED after pelvic surgery. The purpose of the present study is to examine the effect of PVS in the preservation and restoration of erectile function and urinary continence in conjunction with nerve-sparing RP.