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Pelvic floor muscle training for erectile dysfunction and climacturia 1 year after nerve sparing radical prostatectomy: a randomized controlled trial

Abstract

This study aimed to determine whether patients with persistent erectile dysfunction (ED), minimum 12 months after radical prostatectomy (RP), experienced a better recovery of erectile function (EF) with pelvic floor muscle training (PFMT) compared with patients without this intervention. Second, we aimed to investigate the effect of PFMT on climacturia. All patients, who underwent RP, with persistent ED of minimum 1 year post operation were eligible. The treatment group started PFMT immediately at 12 months post operation and the control group started at 15 months after RP. All patients received PFMT during 3 months. The sample size needed to detect with 80% power a 6 points-difference regarding the EF-domain of the International Index of Erectile Function (IIEF), was at least 12 subjects per group. Patients were evaluated using the IIEF and questioned regarding climacturia. Differences between groups at 15 months were evaluated with Mann–Whitney U-test and Fisher’s exact test. As a result, the treatment group had a significantly better EF than the control group at 15 months after surgery (P=0.025). Other subdomains of the IIEF remained constant for both groups. The effect of PFMT was maintained during follow-up. At 15 months, a significantly higher percentage of patients in the treatment group showed an improvement regarding climacturia (P=0.004).

Introduction

Erectile dysfunction (ED) is the persistent inability to attain and maintain an erection with sufficient rigidity to perform satisfactory penetrative sexual activity.1

ED remains a significant consequence in 19%–74% patients undergoing a nerve-sparing radical prostatectomy (RP).2 Different treatment options for ED are available. Phosphodiesterase-5-inhibitors (PDE5-i) currently dominate the treatment strategy for ED. However, lack of efficacy leads to discontinuation in >50% of cases.3

Several efficacy studies indicated pelvic floor muscle training (PFMT) as an effective treatment for men with ED without previous pelvic surgery. However, most studies used different programs and small sample sizes.4, 5, 6, 7, 8, 9 Only one randomized controlled trial (RCT) was reported concerning the effect of PFMT on ED in men without an RP.8 In the treatment group (PFMT+lifestyle advice), 40% of the participants attained normal erectile function (EF), 35% showed some improvement and 25% did not improve.8 After RP, only 1 RCT (n=52) and 1 case study were mentioned, suggesting improved EF after PFMT.9, 10 In the treatment group (starting PFMT immediately after catheter removal), 47% of patients recovered potency versus 12.5% in the control group (verbal instructions) at 12 months after surgery.10 Sighinolfi et al.9 offered PFMT for persistent ED, 12–18 months after RP, resulting in improved EF in all three patients. However, no RCT investigated the effect of PFMT for ED, taking into account a period of spontaneous recovery of minimum 12 months.

Climacturia or orgasm-associated incontinence occurred in 22%–43% of post-prostatectomy patients,11, 12, 13 which causes embarrassment and avoidance of sexual activity.

Our primary aim was to determine whether patients, minimum 12 months after RP, with persistent ED experienced a better recovery of ED with PFMT compared with patients without treatment. Our secondary aim was to investigate the effect of PFMT on climacturia.

Patients and methods

Patients

Between September 2010 and July 2011, patients with persistent ED, minimum 1 year after RP, were eligible to participate. Inclusion and exclusion criteria are described in Table 1. Patients with remaining incontinence, other than climacturia, at the time of inclusion were not eligible. All patients signed written informed consent.

Table 1 Overview of inclusion and exclusion criteria

Procedure

Preoperative and 12 months after surgery, patients filled out the International Index of Erectile Function (IIEF), consisting of 15 items regarding EF, orgasmic function, sexual desire, intercourse satisfaction and overall satisfaction.14 Eligible participants were randomized into the treatment group, starting PFMT immediately, or the control group, starting PFMT at 15 months after surgery, to control for further spontaneous recovery of EF. Computerized randomization was performed within each stratum by using permuted blocks (size=4). Strata were age (<65 vs 65) and EF IIEF subdomain (IIEF-EF) score at 12 months post operation (12 vs >12).

Interventions

All patients received equal individual PFMT, manually controlled by the therapist. Exercises were supported with electrostimulation during 10 min (biphasic symmetric current (constant voltage), intensity as high as possible, not painful, frequency: 50 Hz and pulse duration: 600 μs). PFMT was organized once a week (first 6 weeks) and once every fortnight (next 6 weeks). In addition, the patients performed a home PFMT program (60 contractions per day, spread over 2 sessions). The PFMT was focused at improving strength and endurance of the pelvic floor muscles, advanced coordination and analytical exercises, and pelvic floor muscle exercises combined with dual tasks in varying body positions.

All patients were treated by the same therapist. Patients were not allowed to use PDE5-i or other aids to improve EF during treatment. During follow-up, PDE5-i were allowed if desirable. When evaluated, patients always had to indicate their EF without any interference of PDE5-i.

Assessments

Our primary outcome was the IIEF-EF. Secondary outcomes were all other IIEF subdomains, a visual analog scale assessing erectile quality (hardness, length, tumescence, elevation and persistence) and a yes/no question regarding climacturia during sexual activity. After randomization, patients in both groups filled out the IIEF, visual analog scale and climacturia question (at 12 months) (Figure 1). The treatment group started PFMT immediately; the control group started 3 months later (at 15 months). When the control group started treatment, these patients filled out the IIEF again and answered the same questions. All patients were re-evaluated after 3 months of treatment. Three months after finishing the program, patients were contacted once again for re-evaluation (Figure 1). The IIEF, visual analog scale and the climacturia question were filled out at home and sent back to an independent person.

Figure 1
figure1

Assessment moments. Different assessment moments for each group ((T) treatment group, (C) control group): inclusion, at the start of the treatment, end treatment (after 3 months of treatment), final evaluation (3 months after the end of the treatment).

Sample size and statistical analysis

The required sample size was calculated to have 80% power to detect a difference in change of the IIEF-EF score between the control and treatment group based on a two-sided unpaired Mann–Whitney U-test (α=5%). Information on the s.d. of the scores is available in the literature (for example, see Dorey et al.8); however, estimates on the variability of the changes are lacking. Therefore, a blinded interim analysis after inclusion of 20 subjects was performed. This interim analysis revealed that the s.d. of the differences equaled 5.0. Power calculation revealed that at least 12 subjects per group were needed to detect a difference of 6 points (minimal clinical important difference (MCID)15) with a power of 80%.

Mann–Whitney U-test and Fisher’s exact test were used to compare the changes in scores (IIEF and visual analog scale) and the proportion of patients with an improvement in climacturia between treatment and control group at 15 months, respectively. Changes in scores between first and final PFMT for the whole group were evaluated with Wilcoxon signed rank tests. Analyses were performed using SPSS version 20 (IBM, Armonk, NY, USA; α=0.05).

The procedures of the study received ethical approval from the commission medical ethics of the University Hospitals Leuven responsible for human/animal experimentation (ML7136). Trial registration: Netherlands Trial Register No NTR 3180.

Results

Thirty-three patients were included, with 16 patients randomized to the treatment group and 17 patients to the control group. Three patients were lost to follow-up within the first 6 weeks of treatment (relational problems, moving abroad for an indefinite period and severe lower back pain). One patient was lost to follow-up at 6 months because of incorrect completion of the IIEF. Both groups showed comparable clinical characteristics. Thirty-three patients were included, 16 patients were randomized to the treatment group and 17 to the control group. The mean age of respectively the treatment and the control group was 61.1 and 61.5 years. Furthermore, 13 and 3 patients in the treatment group and 11 and 6 patients in the control group underwent respectively an open and a robot RP. In addition, 7 and 9 patients in the treatment group and 6 and 11 patients in the control group underwent respectively a unilateral and a bilateral nerve-sparing procedure. The mean IIEF-EF score at the preoperative stage and at inclusion were respectively 26.9 and 6.7 for the treatment group and 23.8 and 9.5 for the control group. At inclusion, 14 patients in the treatment group and 12 patients in the control group had an IIEF score 12. At the start of the treatment, nine and eight patients suffered from climacturia in the treatment and the control group, respectively. The mean duration of urinary incontinence was 48 days (median: 48 days) for the control group (range: 7–100 days) and 60 days (median: 36 days) for the treatment group (range: 2–316 days).

First, the efficacy of PFMT in the treatment (n=16) versus the control group (n=17) was investigated. In a second phase, an evaluation of change after PFMT for the whole group (n=33) was made.

Efficacy of PFMT in the treatment versus the control group

Primary outcome

At 15 months, the treatment group scored significantly better than the control group concerning the change in EF (4.1 (5.6) versus −0.2 (2.4), P=0.025). Correction for both stratification factors (age and IIEF-EF at 12 months) gave comparable results (P=0.03).

Secondary outcomes

For all other domains of the IIEF, there was no evidence for a change neither for a difference between both groups in change (Table 2).

Table 2 Mean (s.d.) IIEF domain scores at 12 months and 15 months after surgery (N=33)

At 15 months, the treatment group scored significantly better than the control group regarding the change in hardness, length, tumescence and elevation (Table 3). Persistence of the erection did not significantly differ between both groups.

Table 3 Mean scores (s.d.) on the VAS scale for hardness/length/tumescence/elevation/persistence of the erection at 12 months and 15 months after surgery (n=33)

Furthermore, at 15 months, a significantly higher percentage of patients in the treatment group showed an improvement of climacturia (6/14 versus 0/17, P=0.004).

Figure 2 represents the individual evolutions concerning EF over time in the treatment and control group separately. The effect of treatment regarding IIEF-EF was maintained in both groups during follow-up; the difference in EF score between the end of treatment and the last follow-up evaluation (P=0.925 for both groups combined) was not significant.

Figure 2
figure2

Individual evolution of EF over time for the treatment and control group.

Evaluation of change after PFMT for the whole group (n=33)

During treatment, 4/14 (29%) and 5/16 (31%) patients ameliorated by 6 points in the treatment and delayed treatment group, respectively (Figure 2).

After 3 months of treatment, EF changed significantly between the first and final treatment for the whole group (P=0.001).

Table 4 represents the number of patients in each IIEF-EF category preoperative, at the start and at the end of the intervention. None of the patients with an IIEF-EF score at final treatment ≤12 (severe–moderate ED) (n=18) could have sexual intercourse. Eight of these 18 patients tried PDE5-i during follow-up. Only one patient had been able to penetrate once with PDE5-i, all other patients recorded a lack of effect and several side effects. Both patients with mild-to-moderate ED (13–18) at the final treatment were able to have sexual intercourse, but indicated better erections with PDE5-i. The 5 patients with mild ED (19–24) were able to have sexual intercourse, but only 2 of them used PDE5-i during follow-up to extend persistence of the erection. Finally, zero of five patients without ED (25–30) used additional medication.

Table 4 Evolution of the number of patients per IIEF-EF category between preoperative, first and final treatment (n=33)

Satisfaction during sexual intercourse for the whole group (n=33) improved significantly between the first and last treatment (P=0.007). Orgasmic function (P=0.580), sexual desire (P=0.192) and overall satisfaction (P=0.056) remained constant.

Hardness, length, tumescence, elevation and persistence were all significantly improved between the first and final treatment for the whole group (P0.01).

Finally, after 3 months of PFMT, climacturia was significantly decreased between the first (17/33) and final (5/30) treatment for the whole group (P=0.001). In addition, comparing the change in EF, due to therapy in patients who recovered from climacturia and those who did not, revealed that there was no significant difference (P= 0.529) between both groups.

Discussion

Patients with ED 12 months after RP were treated with PFMT during a period of 3 months.

In a first phase, the efficacy of PFMT in treatment versus control group was investigated. Our primary outcome EF improved significantly more in the treatment group than in the control group at 15 months. In addition, a significantly higher percentage of patients in the treatment group showed an improvement in climacturia.

In a second phase, the changes after PFMT for the whole group were evaluated. After 3 months of PFMT, EF and intercourse satisfaction were significantly changed between the first and final treatment. Other IIEF domains remained unchanged. Hardness, length, tumescence, elevation and persistence of erection significantly improved between the first and final treatment. Climacturia was significantly decreased between the first and final PFMT. Comparison of the change in EF, due to therapy in patients who recovered from climacturia against those who did not, revealed that there was no significant difference between both groups, indicating that recovery from climacturia was not the reason for a better EF.

After PFMT, 5/30 patients obtained normal erections. Seven more patients were able to have sexual intercourse, although their erection was not always sufficient. Eighteen patients had no functional erections and still had moderate-to-severe ED. However, we cannot conclude that patients with an initial IIEF-EF score 12 are not eligible for physiotherapy, as 5 of them improved to scores of 18, 20, 21, 21 and 29, respectively.

A major strength of our study is that this is the first RCT evaluating the effect of PFMT in men with persistent ED after RP. Second, a simple treatment scheme during 3 months was used. Prota et al.10 also offered PFMT for ED after RP, but they started PFMT immediately after catheter withdrawal. In our study, all patients received PFMT immediately after RP, to alleviate incontinence. PFMT was continued until total continence (defined as 3 consecutive days of 0 g urine loss, weighted on a balance with an accuracy of 1 g) was achieved.16 Mean duration until total continence for the control and the treatment group was 48 and 60 days, respectively. In the current study, we offered a new series of PFMT, starting at 12 months after surgery for the treatment group and at 15 months after surgery for the control group. Third, the possibility that improvement in EF was caused by time itself was controlled by a waiting period of 3 months before starting PFMT for the control group. The results confirmed that the patients in the control group made no significant progress in this period. Consequently, until now only one case study was available concerning the effect of PFMT on climacturia.9 Furthermore, besides the IIEF, erectile quality and climacturia were asked to obtain an overall picture of the patient’s progress. Finally, our dropout rate was low compared with previous research.8

Several limitations have to be considered. Other research hypothesized that patients with post-prostatectomy ED might benefit from protection from structural changes by using PDE5-i.17 In our study, only two patients (one in every group) systematically used a daily low-dosage PDE5-i from 3 months post operation until the start of the study. Other patients used PDE5-i on demand (n=5) or not at all (n=26) in the first postoperative year. Second, it is noteworthy that no correction for multiple testing was considered for the secondary outcomes. Main interest in the exploration of these results was to verify a general pattern of improvement. Consistent with the main finding for IIEF-EF, several secondary outcomes (hardness, length, tumescence and so on) were also significantly ameliorated after 3 months of PFMT.

Some patients improved considerably on the IIEF-EF, but still needed additional medication during sexual intercourse. Future research has to reveal whether combining PFMT and medication could lead to lower dosages of PDE5-i, less side effects and better adherence.

Other studies mentioned positive results of PFMT for ED; however, this was in patients without a history of RP,4, 5, 6, 7, 8 or PFMT offered immediately after catheter withdrawal.4, 5, 6, 7, 8 In the last study, it was however not clear how much of the effect could be attributed to spontaneous recovery.10 The rationale behind the success of PFMT can be found in the decrease of venous outflow. Contraction of the pelvic floor muscles results in a higher pressure at the base of the penis, in particular the bulbocavernosus and the ischiocavernosus muscles encircle 33%–50% of the base of the penis and are responsible for preventing blood from escaping during an erection by exerting pressure on the deep dorsal vein. In addition, starting therapy with the least invasive option seems a logical strategy. Pelvic floor muscle exercises do not involve any risks and they are painless. The dropout rate is less than for other interventions and treatment modalities. If treatment is successful, the erection is spontaneous, and this in contrast to medication, injection therapy, the use of a vacuum pump or penile prosthesis.7, 8

Climacturia was reported in 22%–43% of the patients after RP.12 Only one case study indicated a significant decrease of climacturia after PFMT.9

To date, five RCTs evaluated the impact of the early use of PDE5-i in post-prostatectomy men with persistent ED.18, 19, 20, 21, 22 Only one study18 found a marked increase in return of normal spontaneous erections, but was stopped early. All other studies indicated no sustained effect on unassisted EF. As only a minority of patients, equally divided over both groups, used PDE5-i in the first postoperative year, this only had a small impact on our study.

Power calculation was based on Goldstein et al.,15 who defined an IIEF-EF difference of six points as the minimal clinical important difference.18 The mean IIEF-EF score at baseline was 11.5 points in their study and they only included men with ED without previous RP. Our patients were assigned to the control and treatment group at 12 months after RP. The mean IIEF-EF scores at baseline were 9.5 and 7.5, respectively. A 6-pointimprovement corresponds to an improvement of minimum 52% (6/11.5) in Goldstein et al.15 This criterion might have been too ambitious for post-prostatectomy patients. In fact, 6/9.5 and 6/7.5 correspond to a minimal improvement of 63% and 80%, respectively, to be clinically relevant. A recent study of Rosen et al.,23 indicated that the receiver operating characteristic-based minimal clinical important difference is only four points. Maybe this is a more realistic measure in men after RP. In our trial, 6/14 (43%) in the treatment group and 7/16 (44%) in the delayed treatment group improved with 4 or more points during treatment. Rosen et al.23 further specified that minimal clinical important differences varied significantly according to baseline ED severity (mild:2, moderate: 5 and severe: 7). In our study, this would mean that 4/14 (28.5%) in the treatment group (mild (n=1), moderate (n=0) and severe (n=3)) and 8/16 (50%) in the delayed treatment group (mild (n=4), moderate (n=1) and severe (n=3)) ameliorated according to the ED severity.

In conclusion, patients, minimum 12 months after RP, with persistent ED experienced a better recovery of EF with PFMT compared with patients without PFMT. In addition, PFMT had a beneficial effect on climacturia.

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Acknowledgements

We acknowledge Miss K Sterckx and Miss H Lemkens for their help in the data collection. No funding was obtained for this study.

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Correspondence to I Geraerts.

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Geraerts, I., Van Poppel, H., Devoogdt, N. et al. Pelvic floor muscle training for erectile dysfunction and climacturia 1 year after nerve sparing radical prostatectomy: a randomized controlled trial. Int J Impot Res 28, 9–13 (2016). https://doi.org/10.1038/ijir.2015.24

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