Phosphodiesterase Type 5 Inhibitors in Postprostatectomy Erectile Dysfunction: A Critical Analysis of the Basic Science Rationale and Clinical Application

Landmarks in erectile function recovery after radical prostatectomy

The description of the nerve-sparing technique of radical prostatectomy by Walsh was one of the major breakthroughs in the surgical treatment of prostate cancer in the 20(th) century. However, despite this advance and consequent technological refinements to nerve-sparing surgery, a large proportion of men still suffer from erectile dysfunction (ED) as a complication of prostatectomy. A plethora of therapeutic approaches have been proposed to optimize erectile function recovery in these patients. Several preclinical and translational studies have shown benefits of therapies including PDE5 inhibitor (PDE5I) treatment, immunomodulation, neurotrophic factor administration, and regenerative techniques, such as stem cell therapy, in animal models. However, most of these approaches have either failed to translate to clinical use or have yet to be studied in human subjects. Penile rehabilitation with PDE5Is is currently the most commonly used clinical strategy, in spite of the absence of solid clinical evidence to support its use.

Effects of tadalafil treatment after bilateral nerve-sparing radical prostatectomy: quality of life, psychosocial outcomes, and treatment satisfaction results from a randomized, placebo-controlled phase IV study

Background

This multicenter, randomized, double-blind, double-dummy, placebo-controlled trial primarily evaluated the efficacy of tadalafil once-daily (OaD) or on-demand (“pro-re-nata”; PRN) treatment, started early post-nsRP. Secondary outcome-measures on quality-of-life (QoL) and treatment satisfaction are reported.

Methods

Patients, aged <68 yrs, with adenocarcinoma of the prostate (Gleason ≤ 7, normal preoperative erectile function [EF]) were randomized post-nsRP 1:1:1 to 9-month treatment with tadalafil 5 mg OaD, tadalafil 20 mg PRN, or placebo, followed by 6-week drug-free washout and 3-month open-label tadalafil OaD treatment (OLT). The main outcome measures were Changes in Expanded Prostate Cancer Index Composite (EPIC-26), Erectile Dysfunction Inventory of Treatment Satisfaction (EDITS), and Self-Esteem and Relationship (SEAR) questionnaires (mixed-model-for-repeated-measures, including terms for treatment, visit, treatment-by-visit interaction, age-group, country, baseline-score). LS means with 95% confidence interval (CI) are reported.

Results

423 patients were randomized to 3 treatment-groups: tadalafil OaD (N = 139), PRN (N = 143), or placebo (N = 141). In each group, 57 (41.0%), 58 (40.6%), and 50 (35.5%) patients were aged 61-68 yrs. At the end of double-blind treatment (DBT), patients’ EPIC sexual domain-scores improved significantly with tadalafil OaD versus placebo (treatment effect [95% CI]: 9.6 [3.1,16.0]; p = 0.004); comparisons of PRN versus placebo at end of DBT, and comparisons of tadalafil OaD and PRN versus placebo after OLT were not significant. Only in older patients (61-68 yrs; age-by-treatment p ≤ 0.1), EPIC urinary incontinence domain-scores also improved significantly with tadalafil OaD versus placebo (overall treatment effect across all visits, 8.3 [0.4,16.1]; p = 0.040). Treatment satisfaction increased significantly in both tadalafil groups, EDITS total-scores increased significantly with OaD and PRN versus placebo during DBT (p = 0.005 and p = 0.041, respectively). At the end of OLT, improvement was significant for tadalafil OaD versus placebo only (p = 0.035). No significant differences were observed for SEAR.

Conclusions

These results suggest that chronic dosing of tadalafil improves QoL of patients post-nsRP. The improvement of urinary incontinence in elderly patients randomized to tadalafil OaD may contribute to this effect.

Trial registration

www.clinicaltrials.gov, NCT01026818.

Electronic supplementary material

The online version of this article (doi:10.1186/s12894-015-0022-9) contains supplementary material, which is available to authorized users.

Is it worth continuing sexual rehabilitation after radical prostatectomy with intracavernous injection of alprostadil for more than 1 year?

Introduction

Intracavernous alprostadil injection (IAI) is a widely used treatment for sexual rehabilitation (SR) after radical prostatectomy (RP). It is unknown whether the continuation of IAI beyond 1 year continues to improve erectile function.

Aims

To assess evolution of sexual function in patients using IAI who are nonresponsive to phosphodiesterase type 5 inhibitors (PDE5i) between 12 (M12) and 24 (M24) months after RP.

Methods

We retrospectively studied 75 men with a nerve-sparing laparoscopic RP, who had normal preoperative erectile function, and who regularly used IAI for SR for at least 24 months. At M12, no patients had responded to PDE5i.

Main Outcome Measures

At 12 and 24 months, sexual function was assessed with the UCLA Prostate Cancer Index (UCLA-PCI), International Index of Erectile Function (IIEF)-15, and erection hardness score (EHS) with and without IAI. We also assessed the satisfaction rate with IAI, injection-related penile pain, and satisfaction of treatment. Statistical analysis was performed by using t-tests for paired data and Spearman's rho correlation coefficients to assess the relationships between scores at M12 and M24.

Results

Improvement of nocturnal erection was noted (UCLA-PCI, question 25); however, no significant difference was found for IIEF-erectile function with (19.60 ± 9.80 vs. 18.07 ± 10.44) and without IAI (4.63 ± 2.93 vs. 4.92 ± 4.15), UCLA-PCI-sexual bother (37.14 ± 21.45 vs. 37.54 ± 19.67), nor the EHS score with (2.97 ± 1.30 vs. 2.57 ± 1.30) and without IAI (0.67 ± 1.11 vs. 0.76 ± 0.10). The rate of satisfaction with treatment decreased over time (66.6% vs. 46.7%, P = 0.013). Improved response to IAI at M12 was not correlated to improvement in spontaneous erections at M24.

Conclusion

The response to IAI remained stable after 2 years of treatment, and no significant improvement of spontaneous erections during intercourse attempts was found between M12 and M24. Patients should be informed of the limited effect of IAI on natural erections after 1 year. Yiou R, Bütow Z, Parisot J, Binhas M, Lingombet O, Augustin D, de la Taille A, and Audureau E. Is it worth continuing sexual rehabilitation after radical prostatectomy with intracavernous injection of alprostadil for more than 1 year? Sex Med 2015;3:42–48.

Penile rehabilitation after radical prostatectomy: does it work?

CONTEXT

Erectile dysfunction (ED) represents one of the most common long-term side effects in patients with clinically localized prostate cancer (PCa) undergoing nerve-sparing radical prostatectomy (RP).

OBJECTIVE

To analyze the role of penile rehabilitation in the recovery of erectile function (EF) after nerve-sparing RP.

EVIDENCE SYNTHESIS

Penile rehabilitation is defined as the use of any intervention or combination with the goal not only to achieve erections sufficient for satisfactory sexual intercourses, but also to return EF to preoperative levels. The concept of rehabilitation is based on the implementation of protocols aimed at improving oxygenation, preserving endothelial structure, and preventing smooth muscle structural alterations. Nowadays, the most commonly adopted approaches for penile rehabilitation after nerve-sparing RP are represented by the administration of phosphodiesterase type-5 inhibitors (PDE5-Is), intracorporeal injection therapy, vacuum erection devices (VED), and the combination of these therapies. Several basic science studies support the rational for the adoption of penile rehabilitation protocols. Particularly, rehabilitation, set as early as possible, seems to be better than leaving the erectile tissues unassisted. On the other hand, results from solid prospective randomized trials finally assessing the long-term beneficial effects of PDE5-Is, intracavernosal injections, or VED on EF recovery after surgery are still lacking.

CONCLUSIONS

Although preclinical evidences support the rationale for penile rehabilitation after nerve-sparing RP, clinical studies reported conflicting results regarding its efficacy on long-term EF recovery. Nowadays, which is the optimal rehabilitation program still represents a matter of debate.

Effect of Tadalafil Once Daily on Penile Length Loss and Morning Erections in Patients After Bilateral Nerve-sparing Radical Prostatectomy: Results From a Randomized Controlled Trial

OBJECTIVE

To report penile integrity measures, including stretched penile length (SPL), from a randomized, double-blind, double-dummy, placebo-controlled trial evaluating treatment with tadalafil initiated after nerve-sparing radical prostatectomy (nsRP).

METHODS

Patients aged ≤ 68 years were randomized after nsRP 1:1:1 to 9-month double-blind treatment (DBT) with tadalafil 5 mg once daily (OaD), 20-mg tadalafil on-demand ("pro-re-nata"; PRN), or placebo, followed by 6-week drug-free washout and 3-month open-label OaD treatment. Secondary outcome measures included the change in SPL from pre-nsRP to the end of DBT (analysis of covariance adjusting for treatment, country, baseline, age, and nerve-sparing score), responses to Sexual Encounter Profile (SEP) questions 1-3 (mixed models for repeated measures adjusting for treatment, country, visit, visit-treatment-interaction, age), and Standardized Morning Erection Question (Cochran-Mantel-Haenszel test adjusted for age and country).

RESULTS

Four hundred twenty-three patients were randomized to tadalafil OaD (N = 139), tadalafil PRN (N = 143), and placebo (N = 141). Greater retainment of SPL was observed with tadalafil OaD vs placebo at the end of DBT (least-square mean [95% confidence interval] difference OaD vs placebo, 4.1 mm [0.4 to 7.8 mm]; P = .032). No significant effects on SPL were found for tadalafil PRN vs placebo, or for the nerve-sparing score. Penile tumescence (SEP1) and ability for vaginal insertion (SEP2) significantly improved vs placebo at the end of double-blind and open-label treatment for patients randomized to tadalafil OaD only. The ability for successful sexual intercourse (SEP3) significantly improved with tadalafil OaD vs placebo only during DBT. The distribution of Standardized Morning Erection Question responses was different at the end of DBT (P = .045); 34.2% of patients on tadalafil OaD, 50.0% on tadalafil PRN, and 56.5% on placebo reported absence of morning erections.

CONCLUSION

These data suggest the early initiation of tadalafil OaD protects from penile length loss and may contribute to protection from structural cavernosal changes after nsRP.

Use of nanoparticles to monitor human mesenchymal stem cells transplanted into penile cavernosum of rats with erectile dysfunction

Purpose

This study was performed to examine the treatment of erectile dysfunction by use of superparamagnetic iron oxide nanoparticles-labeled human mesenchymal stem cells (SPION-MSCs) transplanted into the cavernous nerve injured cavernosa of rats as monitored by molecular magnetic resonance imaging (MRI).

Materials and Methods

Eight-week-old male Sprague-Dawley rats were divided into three groups of 10 rats each: group 1, sham operation; group 2, cavernous nerve injury; group 3, SPION-MSC treatment after cavernous nerve injury. Immediately after the cavernous nerve injury in group 3, SPION-MSCs were injected into the cavernous nerve injured cavernosa. Serial T2-weighted MRI was done immediately after injection and at 2 and 4 weeks. Erectile response was assessed by cavernous nerve stimulation at 2 and 4 weeks.

Results

Prussian blue staining of SPION-MSCs revealed abundant uptake of SPION in the cytoplasm. After injection of 1×10⁶ SPION-MSCs into the cavernosa of rats, T2-weighted MRI showed a clear hypointense signal induced by the injection. The presence of SPION in the corpora cavernosa was confirmed with Prussian blue staining. At 2 and 4 weeks, rats with cavernous nerve injury had significantly lower erectile function than did rats without cavernous nerve injury (p<0.05). The group transplanted with SPION-MSCs showed higher erectile function than did the group without SPION-MSCs (p<0.05). The presence of SPION-MSCs for up to 4 weeks was confirmed by MRI imaging and Prussian blue staining in the corpus cavernosa.

Conclusions

Transplanted SPION-MSCs existed for up to 4 weeks in the cavernous nerve injured cavernosa of rats. Erectile dysfunction recovered and could be monitored by MRI.

Effect of Ginkgo biloba Extract (EGb-761) on Recovery of Erectile Dysfunction in Bilateral Cavernous Nerve Injury Rat Model

OBJECTIVE

To investigate whether the therapeutic effect of Ginkgo biloba extract (GBE) in a rat model can improve erectile dysfunction after bilateral cavernous nerve injury.

METHODS

Forty-three male Sprague-Dawley rats underwent cavernous nerve crush injury and were randomized into 4 groups, including: vehicle only, high-dose GBE, medium-dose GBE, and low-dose GBE. Eight animals underwent sham operation. Four weeks later, erectile function was assessed by cavernous nerve electrostimulation, and penile tissue was collected for histologic analysis.

RESULTS

Significant recovery of erectile function was observed in the high-dose GBE group in a dose-dependent manner as compared with the vehicle-only group (P <.001). The high-dose GBE group had a significant increase in neurofilament-1 expression (P <.001), preservation of neural nitric oxide synthase nerve fibers of the dorsal penile nerve (P <.05), and increased smooth muscle cell content (P <.001) compared with the vehicle-only group. In addition, high-dose GBE markedly augments the smooth muscle-to-collagen ratio (P <.05) and reduces the apoptotic index.

CONCLUSION

Administration of GBE increases neuron survival and preserves the neural nitric oxide synthase nerve fiber and contents of the corpus cavernosum after bilateral cavernous nerve injury. These implications indicate the beneficial effects of GBE use in the repair of the cavernous nerve and recovery of erectile function after radical prostatectomy.

Psychosocial perspectives on sexual recovery after prostate cancer treatment

Many therapies for erectile dysfunction (ED) after prostate cancer treatment improve erectile firmness, yet, most couples stop using aids within 1-2 years. Patients and partners who expect immediate and complete success with their first ED treatment can be demoralized when they experience treatment failure, which contributes to reticence to explore other ED aids. Comprehensive patient education should improve sustainability and satisfaction with ED treatments. Pre-emptive and realistic information should be provided to couples about the probability of recovering natural erections. Beginning intervention early and using a couple-based approach is ideal. Recommendations are provided about the timing of ED treatment, the order of aid introduction, and combination therapies. Renegotiation of sexual activity is an essential part of sexual adaptation. From the outset of therapy, couples should be encouraged to broaden their sexual repertoire, incorporate erection-independent sexual activities, and continue to be sexual despite ED and reduced libido.

Management of erectile dysfunction post-radical prostatectomy

Radical prostatectomy is a commonly performed procedure for the treatment of localized prostate cancer. One of the long-term complications is erectile dysfunction. There is little consensus on the optimal management; however, it is agreed that treatment must be prompt to prevent fibrosis and increase oxygenation of penile tissue. It is vital that patient expectations are discussed, a realistic time frame of treatment provided, and treatment started as close to the prostatectomy as possible. Current treatment regimens rely on phosphodiesterase 5 inhibitors as a first-line therapy, with vacuum erection devices and intraurethral suppositories of alprostadil as possible treatment combination options. With nonresponders to these therapies, intracavernosal injections are resorted to. As a final measure, patients undergo the highly invasive penile prosthesis implantation. There is no uniform, objective treatment program for erectile dysfunction post-radical prostatectomy. Management plans are based on poorly conducted and often underpowered studies in combination with physician and patient preferences. They involve the aforementioned drugs and treatment methods in different sequences and doses. Prospective treatments include dietary supplements and gene therapy, which have shown promise with there proposed mechanisms of improving erectile function but are yet to be applied successfully in human patients.

3D vs 2D laparoscopic radical prostatectomy in organ-confined prostate cancer: comparison of operative data and pentafecta rates: a single cohort study

Background

Currently, men are younger at the time of diagnosis of prostate cancer and more interested in less invasive surgical approaches (traditional laparoscopy, 3D-laparoscopy, robotics). Outcomes of continence, erectile function, cancer cure, positive surgical margins and complication are well collected in the pentafecta rate. However, no comparative studies between 4th generation 3D-HD vision system laparoscopy and standard bi-dimensional laparoscopy have been reported. This study aimed to compare the operative, perioperative data and pentafecta rates between 2D and 3D laparoscopic radical prostatectomy (LRP) and to identify the actual role of 3D LRP in urology.

Methods

From October 2012 to July 2013, 86 patients with clinically localized prostate cancer [PCa: age ≤ 70 years, prostate-specific antigen (PSA) ≤ 10 ng/ml, biopsy Gleason score ≤ 7] underwent laparoscopic extraperitoneal radical prostatectomy (LERP) and were followed for approximately 14 months (range 12–25). Patients were selected for inclusion via hospital record data, and divided into two groups. Their patient records were then analyzed. Patients were randomized into two groups: the former 2D-LERP (43 pts) operated with the use of 2D-HD camera; the latter 3D-LERP (43 pts) operated with the use of a 3D-HD 4th generation view system. The operative and perioperative data and the pentafecta rates between 2D-LERP and 3D-LERP were compared.

Results

The overall pentafecta rates at 3 months were 47.4% and 49.6% in the 2D- and 3D-LERP group respectively. The pentafecta rate at 12 months was 62.7% and 67% for each group respectively. 4th generation 3D-HD vision system provides advantages over standard bi-dimensional view with regard to intraoperative steps. Our data suggest a trend of improvement in intraoperative blood loss and postoperative recovery of continence with the respect of the oncological safety.

Conclusions

Use of the 3D technology by a single surgeon significantly enhances the possibility of achieving better intraoperative results and pentafecta in all patients undergoing LERP. Potency was the most difficult outcome to reach after surgery, and it was the main factor leading to pentafecta failure. Nevertheless, further studies are necessary to better comprehend the role of 3D-LERP in modern urology.

Current status of penile rehabilitation after radical prostatectomy

Although disease-free survival remains the primary goal of prostate cancer treatment, erectile dysfunction (ED) remains a common complication that affects the quality of life. Even though several preventive and therapeutic strategies are available for ED after radical prostatectomy (RP), no specific recommendations have been made on the optimal rehabilitation or treatment strategy. Several treatment options are available, including phosphodiesterase-5 inhibitors, vacuum erection devices, intracavernosal or intraurethral prostaglandin injections, and penile prostheses. Urologists must consider more effective ways to establish optimal treatments for ED after RP. ED is an important issue among patients with prostate cancer, and many patients hope for early ED recovery after surgery. This review highlights the currently available treatment options for ED after RP and discusses the limitations of each.

Understanding and targeting the Rho kinase pathway in erectile dysfunction

Erectile dysfunction (ED) is a common disorder that affects a quarter of US men, and has many causes, including endothelial impairment, low testosterone levels, prior surgical manipulation, and/or psychogenic components. Penile erection is a complex process requiring neurally mediated relaxation of arteriolar smooth muscle and engorgement of cavernosal tissues, mediated by nitric oxide (NO). Current medical therapies for ED largely seek to maximize endogenous NO signalling. Certain aetiologies, including diabetes, are difficult to treat with current modalities, emphasizing the need for new molecular targets. Research has demonstrated the importance of RhoA-Rho-associated protein kinase (ROCK) signalling in maintaining a flaccid penile state, and inhibition of RhoA-ROCK signalling potentiates smooth-muscle relaxation in an NO-independent manner. The mechanisms and effects of RhoA-ROCK signalling and inhibition suggest that the RhoA-ROCK pathway could prove to be a new therapeutic target for the treatment of ED.

Effects of tadalafil once daily or on demand versus placebo on time to recovery of erectile function in patients after bilateral nerve-sparing radical prostatectomy

Purpose

We report time to erectile function (EF)-recovery data from a multicenter, randomized, double-blind, double-dummy, placebo-controlled trial evaluating tadalafil started after bilateral nerve-sparing radical prostatectomy (nsRP).

Methods

Patients ≤68 years were randomized post-nsRP 1:1:1 to 9-month double-blind treatment (DBT) with tadalafil 5 mg once daily (OaD), 20 mg tadalafil on demand (“pro-re-nata”; PRN), or placebo, followed by 6-week drug-free washout (DFW) and 3-month open-label OaD treatment. Secondary outcome measures included Kaplan–Meier estimates of time to EF-recovery (IIEF-EF ≥ 22) during DBT (Cox proportional hazard model adjusting for treatment, age, and country).

Results

A total of 423 patients were randomized to tadalafil OaD (N = 139), PRN (N = 143), and placebo (N = 141); 114/122/155 completed DBT. The proportion of patients achieving IIEF-EF ≥22 at some point during DBT with OaD, PRN, and placebo was 29.5, 23.9, and 18.4 %, respectively. DBT was too short to achieve EF-recovery (IIEF-EF ≥ 22) in >50 % of patients; median time to EF-recovery was non-estimable. Time for 25 % of patients to achieve EF-recovery (95 % CI) was 5.8 (4.9, 9.2) months for OaD versus 9.0 (5.5, 9.2) and 9.3 (9.0, 9.9) months for PRN and placebo, respectively. Showing a significant overall treatment effect (p = 0.038), the probability for EF-recovery was significantly higher for OaD versus placebo [hazard ratio (HR); 95 % CI 1.9; 1.2, 3.1; p = 0.011], but not for PRN versus placebo (p = 0.140). Of 57 OaD patients (41.0 %) with ED improved (by ≥1 IIEF-EF severity grade) at the end of DBT, 16 (28.1 % of 57) maintained this improvement through DFW and 27 (47.4 %) declined but maintained improvement from baseline after DFW.

Conclusions

Data suggest that the use of tadalafil OaD can significantly shorten the time to EF-recovery post-nsRP compared with placebo.

Electronic supplementary material

The online version of this article (doi:10.1007/s00345-014-1377-3) contains supplementary material, which is available to authorized users.

Post-prostatectomy erectile dysfunction: contemporary approaches from a US perspective

Success of cancer surgery often leads to life-changing side effects, and surgical treatment for malignant urologic disease often results in erectile dysfunction (ED). Patients that undergo surgical prostatectomy or cystoprostatectomy will often experience impairment of erections due to disruption of blood and nerve supply. Surgical technique, nerve sparing status, patient age, comorbid conditions, and pretreatment potency status all have an effect on post-surgical ED. Regardless of surgical technique, prostatectomy results in disruption of normal anatomy and nerve supply to the penis, which governs the functional aspects of erection. A variety of different treatment options are available for men who develop ED after prostatectomy, including vacuum erection device, oral phosphodiesterase 5 inhibitors (PDE5I), intracorporal injections, and penile prosthesis. The vacuum erection device creates an artificial erection by forming a vacuum via suction of air to draw blood into the penis. The majority of men using the vacuum erection device daily after prostatectomy, regardless of nerve-sparing status, have erections sufficient for intercourse. Phosphodiesterase 5 inhibitors remain a common treatment option for post-surgical ED and are the mainstay of therapy. They work through cyclic adenosine monophosphate and cyclic guanine monophosphate pathways and are recommended in all forms of ED. Intracorporal injections or intraurethral use of vasoactive substances may be a good second-line therapy in men who do not experience improvement with oral medications. Surgical placement of a penile prosthesis is typically the treatment strategy of choice after other options have failed. Semi-rigid and inflatable devices are available with high satisfaction rates. With careful patient counseling and proper treatment selection, patient satisfaction and improved erectile function can be achieved. We advise that patients use a vacuum erection device daily in the early postoperative period in combination with an oral PDE5I. For patients who do not respond to a vacuum erection device or PDE5I, consideration should be given to intraurethral alprostadil, intracorporal injections, or a penile prosthesis.

Udenafil for the treatment of erectile dysfunction

Erectile dysfunction (ED) is often perceived by both patients and sexual partners as a serious problem that can jeopardize quality of life, psychosocial or emotional well-being, and the partnership in the long term. Since their introduction, oral phosphodiesterase type 5 inhibitors (PDE5Is) have been found to be highly effective and well tolerated, and are available as the first-line therapy for the treatment of ED. Udenafil is one of the selective PDE5Is made available in recent years for the treatment of ED. Udenafil has clinical properties of both relatively rapid onset and long duration of action due to its pharmacokinetic profile, thereby providing an additional treatment option for ED men to better suit individual needs. There is positive evidence that udenafil is effective and well tolerated in the treatment of ED of a broad spectrum of etiologies or severity. Udenafil is as effective in the treatment of diabetes mellitus-associated ED as other PDE5Is. Due to the clinical property of relatively long duration of action, udenafil may be another option in daily dosing treatment for ED, as suggested by its favorable efficacy and safety profile. Most adverse effects reported from clinical trials are mild or moderate in severity, without any serious adverse event, with headache and flushing being the most common. Also, the concomitant use of anti-hypertensive drugs or alpha-1-blockers does not significantly affect the efficacy and safety profile of udenafil. However, additional studies with larger cohorts including prospective, multicenter, comparative studies with patients of different ethnicities are needed to further validate the favorable findings of udenafil in the treatment of ED.

Development of UK recommendations on treatment for post-surgical erectile dysfunction

AIM

To develop a management strategy (rehabilitation programme) for postsurgical erectile dysfunction (ED) among men experiencing ED associated with treatment of prostate, bladder or rectal cancer that is suitable for use in a UK NHS healthcare context.

METHODS

PubMed literature searches of ED management together with a survey of 13 experts in the management of ED from across the UK were conducted.

RESULTS

Data from 37 articles and completed questionnaires were collated. The results discussed in this study demonstrate improved objective and subjective clinical outcomes for physical parameters, sexual satisfaction, and rates of both spontaneous erections and those associated with ED treatment strategies.

CONCLUSION

Based on the literature and survey analysis, recommendations are proposed for the standardisation of management strategies employed for postsurgical ED.

The Efficacy and Safety of Tadalafil 5 mg Once Daily in the Treatment of Erectile Dysfunction After Robot-Assisted Laparoscopic Radical Prostatectomy: 1-Year Follow-up

PURPOSE

To evaluate the efficacy and safety of tadalafil 5 mg once daily use in the treatment of erectile dysfunction (ED) after robot-assisted laparoscopic radical prostatectomy (RALP).

MATERIALS AND METHODS

The study retrospectively evaluated 92 patients who underwent RALP at Dong-A University Hospital. The patients were surveyed by use of the abridged five-item version of the International Index of Erectile Function (IIEF-5) questionnaire, which was self-administered before surgery and at 6 months and 1 year after surgery. The 92 patients were classified into the tadalafil group (n=47) and the non-tadalafil group (n=45). Each group was then classified depending on the nerve-sparing (NS) procedure used: bilateral NS or unilateral NS.

RESULTS

At 6 months, the total IIEF-5 scores of the tadalafil group and the non-tadalafil group were 10.0±3.4 and 7.0±4.0, respectively. At 1 year, the total IIEF-5 score in the tadalafil group was significantly greater than that in the non-tadalafil group (13.2±5.6 vs. 7.7±4.8, p<0.0001). Statistically significant improvements (p<0.05) were observed in the tadalafil group for all 5 domains of the IIEF-5 score, whereas in the non-tadalafil group there was no significant improvement in any of the domains at 1 year. The reported side effects were flushing (8.5%, n=4), headache (4.3%, n=2), and dizziness (2.1%, n=1).

CONCLUSIONS

In ED patients after NS RALP, a once-daily dose of tadalafil 5 mg was well tolerated and significantly improved EF compared with that in the non-tadalafil group.

Comprehensive analysis of sexual function outcome in prostate cancer patients after robot-assisted radical prostatectomy

PURPOSE

The recovery of potency following radical prostatectomy is complex and has a very wide range. In this study, we analyzed in detail the precise pattern of recovery of potency following robot-assisted radical prostatectomy (RARP).

MATERIALS AND METHODS

Prospectively collected database of patients with a minimum follow-up of 1 year after RARP were evaluated retrospectively. Of 503 patients identified, 483 patients completed the sexual health inventory for men (SHIM) preoperatively and postoperatively every 3 months for the first 12 months. Overall potency, usage of phosphodiesterase type-5 (PDE-5) inhibitors, and return to baseline erectile function were evaluated. Potency was defined as having erection that is sufficient for sexual intercourse more than 50% of attempts, while quality potency was defined as being potent without the use of PDE-5 inhibitors.

RESULTS

Preoperatively, the overall potency and quality potency rate were 67.1% and 48.1%, respectively. Postoperatively, the overall potency rate was 61.4%, while the quality potency rate was 37.2%. In multivariate regression analysis, independent predictors of potency recovery were young age (<60), preoperative potency status, and bilateral preservation of neurovascular bundles (NVBs). In men with SHIM>21, the overall potency and quality potency rate were 79.7% and 41.2%, respectively. More importantly, only 21.4% of the men with normal erection preoperatively (SHIM>21) returned to baseline erectile function (SHIM>21) 12 months after surgery.

CONCLUSIONS

This study indicates that young age (<60), preoperative potency, and bilateral preservation of NVBs were positive predictors of potency recovery following RARP. However, an overwhelming majority of men experience a deterioration in the overall quality of erection after RARP.

Effects of tadalafil treatment on erectile function recovery following bilateral nerve-sparing radical prostatectomy: a randomised placebo-controlled study (REACTT)

BACKGROUND

The potential rehabilitative and protective effect of phosphodiesterase type 5 inhibitors (PDE5-Is) on penile function after nerve-sparing radical prostatectomy (NSRP) remains unclear.

OBJECTIVE

The primary objective was to compare the efficacy of tadalafil 5mg once daily and tadalafil 20mg on demand versus placebo taken over 9 mo in improving unassisted erectile function (EF) following NSRP, as measured by the proportion of patients achieving an International Index of Erectile Function-Erectile Function domain (IIEF-EF) score ≥ 22 after 6-wk drug-free washout (DFW). Secondary measures included IIEF-EF, Sexual Encounter Profile question 3 (SEP-3), and penile length.

DESIGN, SETTING, AND PARTICIPANTS

Randomised, double-blind, double-dummy, placebo-controlled trial in men ≤ 68 yr of age with adenocarcinoma of the prostate (Gleason ≤ 7) and normal preoperative EF who underwent NSRP at 50 centres from nine European countries and Canada.

INTERVENTIONS

1:1:1 randomisation to 9 mo of treatment with tadalafil 5mg once daily, tadalafil 20mg on demand, or placebo followed by a 6-wk DFW and 3-mo open-label tadalafil once daily (all patients).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Logistic regression, mixed-effects model for repeated measures, and analysis of covariance, adjusting for treatment, age, and country, were applied to IIEF-EF scores ≥ 22, SEP-3, and penile length.

RESULTS AND LIMITATIONS

Four hundred twenty-three patients were randomised to tadalafil once daily (n=139), on demand (n=143), and placebo (n=141). The mean age was 57.9 yr of age (standard deviation: 5.58 yr); 20.9%, 16.9%, and 19.1% of patients in the tadalafil once daily, on demand, and placebo groups, respectively, achieved IIEF EF scores ≥ 22 after DFW; odds ratios for tadalafil once daily and on demand versus placebo were 1.1 (95% confidence interval [CI], 0.6-2.1; p=0.675) and 0.9 (95% CI, 0.5-1.7; p=0.704). At the end of double-blind treatment (EDT), least squares (LS) mean IIEF-EF score improvement significantly exceeded the minimally clinically important difference (MCID: ΔIIEF-EF ≥ 4) in both tadalafil groups; for SEP-3 (MCID ≥ 23%), this was the case for tadalafil once daily only. Treatment effects versus placebo were significant for tadalafil once daily only (IIEF-EF: p=0.016; SEP-3: p=0.019). In all groups, IIEF-EF and SEP-3 decreased during DFW but continued to improve during open-label treatment. At month 9 (EDT), penile length loss was significantly reduced versus placebo in the tadalafil once daily group only (LS mean difference 4.1mm; 95% CI, 0.4-7.8; p=0.032).

CONCLUSIONS

Tadalafil once daily was most effective on drug-assisted EF in men with erectile dysfunction following NSRP, and data suggest a potential role for tadalafil once daily provided early after surgery in contributing to the recovery of EF after prostatectomy and possibly protecting from penile structural changes. Unassisted EF was not improved after cessation of active therapy for 9 mo.

TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT01026818.

Nightly vs on-demand sildenafil for penile rehabilitation after minimally invasive nerve-sparing radical prostatectomy: results of a randomized double-blind trial with placebo

OBJECTIVES

To clarify the role of phosphodiesterase type 5 (PDE5) inhibitors in post-prostatectomy penile rehabilitation (PPPR). To compare nightly and on-demand use of PDE5 inhibitors after nerve-sparing minimally invasive radical prostatectomy (RP).

PATIENTS AND METHODS

We conducted a single-institution, double-blind, randomized controlled trial of nightly vs on-demand 50-mg sildenafil citrate after nerve-sparing minimally invasive RP. A total of 100 preoperatively potent men, aged <65 years, with scores on the Erectile Function domain of the International Index of Erectile Function (IIEF-EF) ≥26, underwent nerve-sparing surgery. The patients were randomized to either nightly sildenafil and on-demand placebo (nightly sildenafil group), or on-demand sildenafil and nightly placebo (on-demand sildenafil group; maximum on-demand dose six tablets/month) for 12 months. Patients then underwent a 1-month washout period. Validated measures of erectile function (IIEF-EF score and the Expanded Prostate Cancer Index Composite [EPIC]) were compared between treatment groups over the entire 13-month time course, using multivariable mixed linear regression models.

RESULTS

The treatment groups were well matched preoperatively (mean age 54.3 vs 54.6 years, baseline IIEF-EF score 29.4 vs 29.3, for the nightly vs the on-demand sildenafil groups, respectively). No significant differences were found in erectile function between treatments (nightly vs on-demand sildenafil) at any single timepoint after RP, after adjusting for potential confounding factors. When evaluated over all timepoints simultaneously, no significant effects of treatment group (nightly vs on-demand sildenafil) were found on recovery of potency, as assessed by absolute IIEF-EF scores (P = 0.765), on percentage of men returning to an IIEF-EF score >21 (P = 0.830), or on IIEF-EF score recovery to a percentage of baseline value (P = 0.778). When evaluated over all timepoints simultaneously, no significant effects of treatment group were found on secondary endpoints such as assessment of potency (including EPIC item 59 response 'erections firm enough for intercourse'), attempted intercourse frequency or confidence.

CONCLUSIONS

Erectile recovery up to 1 year after RP does not differ between previously potent men who use sildenafil nightly compared to on-demand. This trial does not support chronic nightly sildenafil as being any better than on-demand sildenafil for use in penile rehabilitation after nerve-sparing minimally invasive RP.

Synergistic effects of BAY 60-4552 and vardenafil on relaxation of corpus cavernosum tissue of patients with erectile dysfunction and clinical phosphodiesterase type 5 inhibitor failure

INTRODUCTION

Overall efficacy rates of phosphodiesterase type 5 inhibitors (PDE5-i) for erectile dysfunction (ED) are 60-70%. PDE5-i treatment failures currently have to resort to invasive treatment options for restoration of erectile function. AIMS.: To assess changes in the nitric oxide (NO)/cyclic guanosine monophosphate (cGMP)/protein kinase (PKG) pathway in human corpus cavernosum (HCC) of PDE5-i nonresponders compared with healthy controls. To evaluate the effects of BAY 60-4552, a stimulator of soluble guanylate cyclase (sGC), and vardenafil on relaxation of HCC strips from PDE5-i nonresponders.

MAIN OUTCOME MEASURES

mRNA expression, morphological localization of the NO/cGMP/PKG pathway, and relaxant capacity of both compounds alone or combined. Analysis of variance, t-test or Mann-Whitney test based upon number of groups and normality of data.

METHODS

HCC tissues were harvested after consent from individuals undergoing penile prosthesis implantation (patients) and potent patients undergoing transurethral surgery (healthy controls, needle biopsy). HCC tissues of patients were compared with those of healthy controls for the expression of mRNA coding for PDE5A, eNOS, PKGα1, PKG2, sGCα1, sGCα2, sGCβ1, sGCβ2, α-smooth muscle actin (aSMA) and β-actin by quantitative polymerase chain reaction (qPCR). The respective proteins were localized using immunofluorescence. Tissue strips of patients were precontracted with phenylepinephrine followed by incubation with 1 μM of either vardenafil or BAY 60-4552, or both simultaneously.

RESULTS

The main targets in the NO/cGMP/sGC pathway were downregulated in PDE5-i nonresponders. The pathway was morphologically located to HCC smooth muscle, of which the overall content was preserved in ED patients based on aSMA expression. BAY 60-4552 and vardenafil have synergistic effects on relaxation of HCC of PDE5-i nonresponders. The main limitation is the small amount of control tissue precluding functional testing on these samples.

CONCLUSION

Despite downregulation of the NO/cGMP/PKG pathway, combining BAY 60-4552 with vardenafil significantly enhanced relaxation HCC strips of PDE5-i nonresponders.

Comparison of efficacy and satisfaction profile, between penile prosthesis implantation and oral PDE5 inhibitor tadalafil therapy, in men with nerve-sparing radical prostatectomy erectile dysfunction

WHAT'S KNOWN ON THE SUBJECT? AND WHAT DOES THE STUDY ADD?: Erectile dysfunction after nerve-sparing radical retropubic prostatectomy constitutes a challenge to the urologist. The mainstay of medical treatment after radical prostatectomy to restore spontaneous erectile function remains phosphodiesterase (PDE5) inhibitors, despite the fact that data from animal studies suggesting that PDE5 inhibitors can prevent smooth muscle apoptosis and fibrosis have not yet been extrapolated to humans because of a lack of standardized protocols. If the above treatment fails, second-line therapies such as intraurethral prostaglandins, penile injection therapy and vacuum devices are offered. When less invasive therapies are ineffective, interventions that preserve sexual function such as penile prosthesis implantation become the treatment of choice. Our study reveals the alternative of penile prosthesis implantation as first-line treatment in erectile dysfunction after nerve-sparing radical prostatectomy. It also highlights its superiority to the oral PDE5 inhibitor treatment, regarding the erection, frequency, firmness, maintenance and penetration ability. This suggests that a concept of an early penile intervention in the future would be promising for those patients who wish to remain sexually active without depending on oral formulations with doubtful and delayed results.

OBJECTIVE

To evaluate the outcome of penile prosthesis surgery in comparison to oral phosphodiesterase type 5 (PDE5) inhibitor administration, in men with erectile dysfunction after nerve-sparing radical prostatectomy, as early penile intervention therapy.

PATIENTS AND METHODS

A total of 174 patients treated by nerve-sparing retropubic radical prostatectomy (RRP) for clinically localized prostate cancer, between January 2006 and September 2009 enrolled in the study, 153 patients fulfilled the inclusion criteria, and 69 (45%) patients presented with post-RRP erectile dysfunction 6 months after primary surgery. Fifty-four patients were disease-free and subdivided into two arms according to treatment modality, either tadalafil three times/week or penile prosthesis implantation. All patients were evaluated using the International Index of Erectile Function (IIEF) questionnaire preoperatively and at 6, 12 and 24 month postoperatively. Repeated measurements analysis of variance was conducted to evaluate the effect of time and group on IIEF total score.

RESULTS

There was a significant reduction in IIEF score from preoperative values to the first measurement after surgery in both treatment groups. The overall degree of change from the first time point immediately after surgery to 2 years was greater in the penile prosthesis group than the tadalafil group (20.4 ± 1.3 vs 8.1 ± 2.4, P < 0.001).

CONCLUSIONS

The efficacy and satisfaction results of both treatment types are considered acceptable. However, regarding the erection frequency, firmness, penetration ability, maintenance and erection confidence it seems that penile prosthesis implantation is superior to oral treatment. The concept of early penile intervention should be considered and is promising for all patients with post-RRP erectile dysfunction.

Optimizing postoperative sexual function after radical prostatectomy

Erectile dysfunction (ED) is one of the complications associated with pelvic surgery. The significance of ED as a complication following pelvic surgery, especially radical prostatectomy (RP), lies in the negative impact that it has on patients' sexual and overall life. In the literature, rates of ED following RP range from 25% to 100%. Such variety is associated with pelvic dissection and conservation of neurovascular structures. Another important factor impacting on postoperative ED is the preoperative erectile function of the patient. Advances in the knowledge of pelvic anatomy and pathological mechanisms led to a refinement of pelvic surgical techniques, with attention to the main structures that if damaged compromise erectile function. These improvements resulted in lower postoperative ED rates and better erectile recovery, especially in patients undergoing RP. Furthermore, surgery alone is not sufficient to prevent this complication, and thus, several medical strategies have been tested with the aim of maximizing erectile function recovery. Indeed it seems that prevention of postoperative ED must be addressed by a multimodal approach. The aim of this review is to give a picture of recent knowledge, novel techniques and therapeutic approaches in order to reach the best combination of treatments to reduce the rate of ED after pelvic surgery.

Separate or combined treatments with daily sildenafil, molsidomine, or muscle-derived stem cells prevent erectile dysfunction in a rat model of cavernosal nerve damage

INTRODUCTION

Long-term daily administration of phosphodiesterase type 5 (PDE5) inhibitors in the rat prevents or reverses corporal veno-occlusive dysfunction (CVOD) and smooth muscle cell (CSMC) loss and fibrosis, in both aging and bilateral cavernosal nerve resection (BCNR) models for erectile dysfunction. In the aging rat model, corporal implantation of skeletal muscle-derived stem cells (MDSC) reverses CVOD. Nitric oxide (NO) and cyclic guanosine monophosphate can modulate stem cell lineage.

AIM

To investigate in the BCNR model the effects of sildenafil at lower doses, alone or in combination with MDSC or the NO donor molsidomine, on CVOD and the underlying corporal histopathology.

MAIN OUTCOMES MEASURES

CVOD, histological, and biochemical markers in rat corporal tissue. Methods.  Rats subjected to BCNR were maintained for 45 days either untreated, or received sildenafil in the water or retrolingually at 10, 2.5, and 1.25 mg/kg/day (medium, low, and very low doses), or intraperitoneal molsidomine, or MDSC implantation into the corpora cavernosa separately or in combination. Cavernosometry evaluated CVOD. Histopathology was assessed on penile sections by Masson trichrome, immunohistochemistry for α-smooth muscle actin (ASMA), or immunofluorescence for neuronal nitric oxide synthase (nNOS)/neurofilament 70, and in fresh tissue by Western blot for various markers and picrosirius red for collagen.

RESULTS

All treatments normalized erectile function (drop rate), and most increased the CSMC/collagen ratio and ASMA expression in corporal tissue sections, and reduced collagen content in the penile shaft. MDSC also increased nNOS and brain-derived neurotrophic factor. The combination treatment was not superior to MDSC or sildenafil given alone, and upregulated PDE5.

CONCLUSIONS

Lowering the dose of a continuous long-term sildenafil administration still maintained the prevention of CVOD in the BCNR rat previously observed, but it was less effective on the underlying histopathology. As in the aging rat model, MDSC also counteracted CVOD, but supplementation with very low-dose sildenafil did not improve the outcome.

Sildenafil promotes neuroprotection of the pelvic ganglia neurones after bilateral cavernosal nerve resection in the rat

OBJECTIVE

To determine the gene expression profile of pelvic ganglia neurones after bilateral cavernosal nerve resection (BCNR) and subsequent treatment with sildenafil in relation to neurotrophic-related pathways.

MATERIALS AND METHODS

Fisher rats aged 5 months were subjected to BCNR or sham operation and treated with or without sildenafil (20 mg/kg body-weight in drinking water) for 7 days. Total RNA isolated from pelvic ganglia was subjected to reverse transcription and then to quantitative reverse transcriptase-polymerase chain reaction (PCR) with the RAT-neurotrophic array. Results were corroborated by real-time PCR and western blotting. Another set of animals were injected with a fluorescent tracer at the base of the penis, 7 days before BCNR or sham operation, and were sacrificed 7 days after surgery. Sections of pelvic ganglia were used for immunohistochemistry with antibodies against neurturin, neuronal nitric oxide synthase, tyrosine hydroxylase and glial cell line-derived neurotrophic factor receptor α2.

RESULTS

A down-regulation of the expression of neuronal nitric oxide synthase accompanied by changes in the level of cholinergic neurotrophic factors, such as neurturin and its receptor glial cell line-derived neurotrophic factor receptor α2, artemin, neurotrophin-4 and cilliary neurotrophic factor, was observed 7 days after BCNR in pelvic ganglia neurones. Treatment with sildenafil, starting immediately after surgery, reversed all these changes at a level similar to that in sham-operated animals.

CONCLUSIONS

Sildenafil treatment promotes changes in the neurotrophic phenotype, leading to a regenerative state of pelvic ganglia neurones. The present study provides a justification for the use of phosphodiesterase 5 inhibitors as a neuroprotective agent after BCNR.

Prevention and management of postprostatectomy sexual dysfunctions. Part 1: choosing the right patient at the right time for the right surgery

CONTEXT

Sexual dysfunction is common in patients following radical prostatectomy (RP) for prostate cancer (PCa).

OBJECTIVE

To review the available literature concerning prevention and management strategies for post-RP erectile function (EF) impairment in terms of preoperative patient characteristics and intra- and postoperative factors that may influence EF recovery.

EVIDENCE ACQUISITION

A literature search was performed using Google and PubMed database for English-language original and review articles either published or e-published up to November 2011.

EVIDENCE SYNTHESIS

The literature demonstrates great inconsistency in what constitutes normal EF before surgery and what a man may consider a normal erection after RP. The use of validated psychometric instruments with recognised cut-offs for normalcy and severity during the pre- and postoperative evaluation should be routinely considered. Therefore, a comprehensive discussion with the patient about the true prevalence of postoperative erectile dysfunction (ED), the concept of spontaneous or pharmacologically assisted erections, and the difference between "back to baseline" EF and "erections adequate enough to have successful intercourse" clearly emerge as key issues in the eventual understanding of the prevention of ED and promotion of satisfactory EF recovery post-RP. Patient factors (including age, baseline EF, and status of comorbid conditions), cancer selection (unilateral vs bilateral nerve sparing), type of surgery (ie, intra- vs inter- vs extrafascial surgeries), surgical techniques (ie, open, laparoscopic, and robot-assisted RP), and surgeon factors (ie, surgical volume and surgical skill) represent the key significant contributors to EF recovery.

CONCLUSIONS

The complexity of the issues discussed throughout this review culminates in the simple concept that optimal outcomes are achieved by the careful choice of the correct patient for the correct type of surgery.

Prevention and management of postprostatectomy sexual dysfunctions part 2: recovery and preservation of erectile function, sexual desire, and orgasmic function

CONTEXT

Sexual dysfunction is common in patients who undergo radical prostatectomy (RP) for prostate cancer (PCa).

OBJECTIVE

Review the available literature concerning prevention of, and management strategies for, post-RP sexual dysfunction in terms of postoperative treatments for erectile function (EF), sexual desire (SD), and orgasmic function (OF) impairment.

EVIDENCE ACQUISITION

A literature search was performed using Google and PubMed databases for English language original and review articles either published or e-published up to November 2011.

EVIDENCE SYNTHESIS

We propose a rational description of many of the clinically available preventive and therapeutic strategies for the preservation and recovery of post-RP EF. A huge amount of preclinical data show that tissue damage ultimately leads to structural alterations, and the literature stresses that rehabilitation and treatment are undoubtedly better than leaving the erectile tissue to its unassisted fate; likewise, the timing of any rehabilitation and treatment is of major clinical importance. However, no specific recommendation emerges regarding the structure of the optimal rehabilitation or treatment regimen. The role of postoperative erectile dysfunction (ED) treatment of those patients who received a non-nerve-sparing RP was also extensively discussed. The literature almost completely lacks a systematic and comprehensive debate about SD (ie, low libido) and OF (ie, decreased intensity of orgasm, dysorgasmia, and climacturia) in patients undergoing RP. Psychological and sexual counseling is of major importance to improve any rehabilitation and treatment of postoperative EF, SD, and OF impairment.

CONCLUSIONS

Despite the great number of possible rehabilitation approaches proposed, these approaches should be considered only as strategies, since incontrovertible evidence of their effectiveness for improving natural EF recovery is limited. Conversely, numerous effective therapeutic options are available for treating post-RP ED. SD and OF have not yet been fully assessed in patients who underwent RP.

Both immediate and delayed intracavernous injection of autologous adipose-derived stromal vascular fraction enhances recovery of erectile function in a rat model of cavernous nerve injury

BACKGROUND

Intracavernous injection of cultured adipose-derived stem cells (ADSCs) effectively restores erectile function in cavernous nerve (CN)-injured rats when administered at the time of injury. However, culturing exposes ADSCs to the risk of contamination and dedifferentiation.

OBJECTIVE

Explore the effect of uncultured autologous adipose-derived stromal vascular fraction (SVF) on improving erectile function in a rat model of CN injury when administered at the time of injury or 4 wk after injury.

DESIGN, SETTING, AND PARTICIPANTS

Eighty-nine male Sprague Dawley rats were randomly divided into four groups. CN injury or sham surgery was performed at the start of the study, and rats were treated with either SVF or vehicle. Functional testing and histologic analysis were performed 12 wk after CN crush or sham surgery.

INTERVENTION

We used intracavernous injection of saline immediately after CN crush (n=23), intracavernous injection of SVF immediately after CN crush (n=17), intracavernous injection of SVF 4 wk after CN crush (n=23), or sham surgery (n=26).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

We studied intracavernous pressure (ICP) response to CN electrostimulation and performed histologic examination of midpenile cross-sections. Data were analyzed using one-way analysis of variance followed by the Tukey-Kramer test.

RESULTS AND LIMITATIONS

Both immediate and delayed treatment with SVF resulted in a significantly increased ICP-to-mean arterial pressure ratio compared with the vehicle-treated group. Both immediate and delayed treatment with SVF significantly increased expression of neuronal nitric oxide synthase and neurofilament in dorsal penile nerves compared to the vehicle group. Furthermore, the smooth muscle-to-collagen ratio within the corpus cavernosum was significantly improved in both of the SVF groups compared to vehicle-treated rats. The main limitation of the study is the lack of determination of the SVF components.

CONCLUSIONS

Uncultured autologous SVF injected immediately or 4 wk after CN crush improved erectile function, promoted nerve regeneration, and prevented fibrosis of the corpus cavernosum following CN injury.

Neuronal nitric oxide signaling regulates erection recovery after cavernous nerve injury

PURPOSE

Nitric oxide is the major neuronal mediator of penile erection but its role in erectile function status after cavernous nerve injury is uncertain. We determined the function of neuronal nitric oxide signaling in the pathobiology of erectile function recovery after partial cavernous nerve injury using genetic and pharmacological mouse experimental paradigms.

MATERIALS AND METHODS

Erectile function was evaluated in 5 to 7 wild-type and neuronal nitric oxide synthase-α knockout mice per group 1, 3 and 7 days after unilateral crush or sham injury, at day 7 in wild-type mice treated with the nitric oxide synthase inhibitor L-NAME (l-nitro arginine methyl ester) (Sigma-Aldrich®) at baseline and for 6 days after unilateral crush injury. Apoptosis in the penis was evaluated by Western blot analysis of p-Akt-S473, 3-nitrotyrosine and caspase-3 after bilateral crush injury.

RESULTS

Intracavernous pressure was significantly decreased at 1, 3 and 7 days in wild-type mice but only at day 1 in knockout mice after unilateral crush injury compared with sham treatment values (p <0.05). L-NAME treated wild-type mice had improved erectile function compared with the vehicle treated group at day 7 after unilateral crush injury (p <0.05). In penes p-Akt-S473 was significantly decreased in vehicle treated (p <0.05) but not in L-NAME treated wild-type mice. In penes 3-nitrotyrosine was significantly decreased in L-NAME treated wild-type and vehicle treated knockout mice (p <0.05). Caspase-3 in penes was significantly increased in vehicle treated (p <0.05) but not in L-NAME treated wild-type mice and vehicle treated knockout mice.

CONCLUSIONS

Neuronal nitric oxide signaling regulates erectile function recovery early after partial cavernous nerve injury, exerting an inhibitory role via the induction of apoptotic change in penile tissue. Therapeutic strategies to improve erectile function recovery after radical prostatectomy may consider targeting pathogenic sites of nitric oxide neurobiology.

Erectile preservation following radical prostatectomy

Prostate cancer is the most common cancer among men, representing approximately 25% of all new cancer diagnoses in the USA. For clinically localized prostate cancer, the gold standard for therapy remains radical prostatectomy. One of the main adverse effects of this procedure is erectile dysfunction, which can have a significant impact on the patient's quality of life. There are several mechanisms of erectile dysfunction postprostatectomy, including arteriogenic, venogenic and neurogenic types, as well as the potentially heightened risk of postprostatectomy patients to develop Peyronie's disease. The purpose of this review is to explain the various treatment options available, including phosphodiesterase type 5 inhibitors, intracavernosal injections, intraurethral alprostadil suppositories, vacuum erection devices, and penile prostheses. The role of these therapies in an erectile-dysfunction-treatment function, as well as in penile rehabilitation, will be discussed. Finally, a review of research on novel therapies will also be presented. A comprehensive literature review was performed using the PubMed database. Articles were chosen based on topical relevance and assessed for methodology and major findings. There are data to support the use of each of the therapeutic options in both treatment and rehabilitative roles. More study is needed, however, specifically in regard to penile rehabilitation, to confirm its benefits, as well as to determine optimal rehabilitation protocols.

A randomized trial of internet-based versus traditional sexual counseling for couples after localized prostate cancer treatment

BACKGROUND

After treatment for prostate cancer, multidisciplinary sexual rehabilitation involving couples appears more promising than traditional urologic treatment for erectile dysfunction (ED). The authors of this report conducted a randomized trial comparing traditional or internet-based sexual counseling with waitlist (WL) control.

METHODS

Couples were randomized adaptively to a 3-month WL, a 3-session face-to-face format (FF), or an internet-based format (WEB1). A second internet-based group (WEB2) was added to examine the relation between web site use and outcomes. At baseline, post-WL, post-treatment, and 6-month, and 12-month follow-up assessments, participants completed the International Index of Erectile Function (IIEF), the Female Sexual Function Index (FSFI), the Brief Symptom Inventory-18 to measure emotional distress, and the abbreviated Dyadic Adjustment Scale.

RESULTS

Outcomes did not change during the WL period. Of 115 couples that were randomized to FF or WEB1 and 71 couples in the WEB2 group, 34% dropped out. Neither drop-outs nor improvements in outcomes differed significantly between the 3 treatment groups. In a linear mixed-model analysis that included all participants, mean ± standard deviation IIEF scores improved significantly across time (baseline, 29.7 ± 17.9; 12 months, 36.2 ± 22.4; P < .001). FSFI scores also improved significantly (baseline, 15.4 ± 8.5; 12 months, 18.2 ± 10.7; P = .034). Better IIEF scores were associated with finding an effective medical treatment for ED and normal female sexual function at baseline. In the WEB2 group, IIEF scores improved significantly more in men who completed >75% of the intervention.

CONCLUSIONS

An internet-based sexual counseling program for couples was as effective as a brief, traditional sex therapy format in producing enduring improvements in sexual outcomes after prostate cancer.

Alleviation of post-radical prostatectomy cavernosal fibrosis: future directions and potential utility for PDE5 inhibitors

Reversion of cavernosal fibrosis remains a controversial issue. The relative smooth muscle cells' loss that happens with cavernosal nerve damage and their impact on deterioration of erectile function were demonstrated in several studies. Furthermore, chronic ischemia that occurs with aging and medical co-morbidities is associated with the reduction of nitric oxide-cyclic guanosine monophosphate and ultimately cavernosal fibrosis. Despite the encouraging recent results of the role of phosphodiesterase type 5 inhibitors in the prevention of post-prostatectomy erectile dysfunction, debate regarding the exact mechanism of PDE5 inhibitors in prevention, amelioration and reversion of penile fibrosis still exists. Recently, several reports suggested that PDE5 inhibitors may improve endothelial function and decrease arterial stiffness, introducing this class of compounds as potential drugs for the treatment of erectile dysfunction-associated penile fibrosis. In this editorial, we intended to address the role of PDE5 inhibitors as a promising treatment to alleviate or reverse ED associated-cavernosal fibrosis.

Recruitment of intracavernously injected adipose-derived stem cells to the major pelvic ganglion improves erectile function in a rat model of cavernous nerve injury

BACKGROUND

Intracavernous (IC) injection of stem cells has been shown to ameliorate cavernous-nerve (CN) injury-induced erectile dysfunction (ED). However, the mechanisms of action of adipose-derived stem cells (ADSC) remain unclear.

OBJECTIVES

To investigate the mechanism of action and fate of IC injected ADSC in a rat model of CN crush injury.

DESIGN, SETTING, AND PARTICIPANTS

Sprague-Dawley rats (n=110) were randomly divided into five groups. Thirty-five rats underwent sham surgery and IC injection of ADSC (n=25) or vehicle (n=10). Another 75 rats underwent bilateral CN crush injury and were treated with vehicle or ADSC injected either IC or in the dorsal penile perineural space. At 1, 3, 7 (n=5), and 28 d (n=10) postsurgery, penile tissues and major pelvic ganglia (MPG) were harvested for histology. ADSC were labeled with 5-ethynyl-2-deoxyuridine (EdU) before treatment. Rats in the 28-d groups were examined for erectile function prior to tissue harvest.

MEASUREMENTS

IC pressure recording on CN electrostimulation, immunohistochemistry of the penis and the MPG, and number of EdU-positive (EdU+) cells in the injection site and the MPG.

RESULTS AND LIMITATIONS

IC, but not perineural, injection of ADSC resulted in significantly improved erectile function. Significantly more EdU+ ADSC appeared in the MPG of animals with CN injury and IC injection of ADSC compared with those injected perineurally and those in the sham group. One day after crush injury, stromal cell-derived factor-1 (SDF-1) was upregulated in the MPG, providing an incentive for ADSC recruitment toward the MPG. Neuroregeneration was observed in the group that underwent IC injection of ADSC, and IC ADSC treatment had beneficial effects on the smooth muscle/collagen ratio in the corpus cavernosum.

CONCLUSIONS

CN injury upregulates SDF-1 expression in the MPG and thereby attracts intracavernously injected ADSC. At the MPG, ADSC exert neuroregenerative effects on the cell bodies of injured nerves, resulting in enhanced erectile response.

Combination of BAY 60-4552 and vardenafil exerts proerectile facilitator effects in rats with cavernous nerve injury: a proof of concept study for the treatment of phosphodiesterase type 5 inhibitor failure

BACKGROUND

Radical prostatectomy (RP) is frequently responsible for erectile dysfunction (ED). Post-RP patients often show a failure to respond to phosphodiesterase type 5 (PDE5) inhibitors.

OBJECTIVE

The acute effect of BAY 60-4552, the soluble guanylate cyclase (sGC) stimulator, and vardenafil were evaluated alone or in combination on erectile responses to electrical stimulation of the cavernous nerve (ES CN) in rats with cavernous nerve (CN) crush injury-induced ED.

DESIGN, SETTING, AND PARTICIPANTS

Male adult Sprague-Dawley rats underwent laparotomy (sham, n=10) or bilateral CN crush injury (n=56). After 3 wk of recovery, erectile function was evaluated under urethane anaesthesia following ES CN at different frequencies.

MEASUREMENTS

The acute effects of intravenous (IV) injection of vehicle, vardenafil 0.03 mg/kg, BAY 60-4552 0.03 mg/kg or 0.3 mg/kg, or a BAY 60-4552 0.03 mg/kg plus vardenafil 0.03 mg/kg combination were evaluated in CN-crushed rats.

RESULTS AND LIMITATIONS

Bilateral CN crush injury followed by a 3-wk recovery period decreased erectile responses to ES CN by about 50%. In CN-crushed rats, IV vardenafil 0.03 mg/kg and BAY 60-4552 (0.03 or 0.3 mg/kg) increased erectile responses to ES CN to the same extent: Δ intracavernosal pressure/mean arterial pressure (ICP/MAP) at 10 Hz ES CN was 21±1% after vehicle, 25±3% (p<0.001) after vardenafil, and 26±5% and 27±5% after BAY 60-4552 0.03 mg/kg (p<0.01) and 0.3 mg/kg (p<0.001), respectively. The combination of vardenafil with BAY 60-4552 in CN-crushed rats totally restored erectile responses to ES CN equivalent to sham rats (ΔICP/MAP at 10 Hz ES CN: 34±4% after BAY 60-4552/vardenafil combination vs 39±4% in sham rats; not significant).

CONCLUSIONS

The present study supports the concept that the combined administration of a sGC stimulator, BAY 60-4552, and vardenafil provides synergistic beneficial effects and might therefore salvage patients who experience treatment failures with PDE5 inhibitors after RP.

Erectile dysfunction after radical prostatectomy: treatment options

Erectile dysfunction is a common problem after radical prostatectomy, with almost all men experiencing this complication for at least a short period after such surgery. There is evidence that early use of phosphodiesterase type 5 inhibitors, intracavernous vasoactive drugs, intraurethral alprostadil or vacuum devices can improve the recovery of postoperative erectile function. The same therapeutic modalities can be used to treat erectile dysfunction after radical prostatectomy. Physicians must be active and counsel patients and partners to improve adherence to penile rehabilitation or erectile dysfunction treatment.

Erectile function rehabilitation after radical prostatectomy: practice patterns among AUA members

INTRODUCTION

Despite a growing body of evidence supporting erectile function (EF) rehabilitation after radical prostatectomy (RP), there are no guidelines on this subject.

AIM

To explore EF rehabilitation practice patterns of American Urological Association (AUA) urologists.

METHODS

A 35-question instrument was constructed assessing physician demographics, training, and EF rehabilitation practices after RP, and was e-mailed to AUA members by the AUA Office of Education. Data were acquired by the AUA and analyzed by the investigators.

MAIN OUTCOME MEASURE

Percentage of responders who recommend EF rehabilitation practices following RP, characterization of prevalent rehabilitation practices.

RESULTS

Of the 618 urologists who completed the survey, 71% were in private practice, 28% considered themselves as sexual medicine specialists, although only 4% were fellowship-trained, 43% were urologic oncology specialists (14% fellowship-trained), 86% performed RP, and 86% of responders recommended rehabilitation practices. Being a sexual medicine or a urologic oncology specialist was not predictive of rehabilitation employment. Forty-three percent rehabilitate all patients, 57% only selected patients. Selection for rehabilitation was dependent upon preop EF by 66%, nerve-sparing status by 22%, and age by 5%. Eleven percent started rehab immediately after RP, 97% within 4 months. 24%, 45% and 18% ceased rehab at <12, 12-18, and 18-24 months, respectively. Eighty-nine percent of RP surgeons performed rehabilitation vs. only 66% who do not perform RP (P < 0.0001). Eighty-seven percent prefer phosphodiesterase type 5 inhibitors (PDE5i) as their primary strategy followed (in order) by vacuum erection device (VED), intracavernosal injection (ICI), and urethral suppositories.

CONCLUSIONS

Among the respondents, penile rehabilitation is a common practice. Urologic oncologists and RP surgeons are more likely to use rehabilitation practices. The most commonly employed strategy is regular PDE5i use for 12-18 months after RP. .