Erectile dysfunction following prostatectomy: prevention and treatment

Adipose Derived Mesenchymal Stem Cells-Derived Mitochondria Transplantation Ameliorated Erectile Dysfunction Induced by Cavernous Nerve Injury

PURPOSE

Erectile dysfunction (ED) is a common postoperative complication of pelvic surgery for which there is currently no effective treatment. This study investigated the therapeutic effects and potential mechanisms of adipose derived mesenchymal stem cells-derived mitochondria (ADSCs-mito) transplantation in a rat model of bilateral cavernous nerve injury (CNI) ED.

MATERIALS AND METHODS

We isolated mitochondria from ADSCs and tested their quality. In vivo, twenty male Sprague Dawley rats were randomly divided into four groups: sham operation group and CNI groups that received intracavernous injection of either phosphate buffer solution, ADSCs-mito or ADSCs. Two weeks after therapy, the erectile function of the rats was evaluated and the penile tissues were harvested for histologic analysis and western blotting. In vitro, the apoptosis rate, reactive oxygen species (ROS), mitochondria derived active oxygen (mtROS) and adenosine triphosphate (ATP) levels were detected in corpus cavernosum smooth muscle cells (CCSMCs) after the incubation with ADSCs-mito. In addition, intercellular mitochondrial transfer was visualized by co-culture of ADSCs and CCSMCs.

RESULTS

The ADSCs, ADSCs-mito and CCSMCs were isolated and identified successfully. ADSCs-mito transplantation notably restored the erectile function and smooth muscle content of CNI ED rats. Moreover, the levels of ROS, mtROS and cleaved-caspase 3 were reduced and the levels of superoxide dismutase and ATP were increased after ADSCs-mito transplantation. In CNI ED rats, the mitochondrial structure of cells in penile tissues was destroyed. ADSCs could transfer its own mitochondria to CCSMCs. Pre-treatment with ADSCs-mito could significantly decrease apoptosis rate, ROS levels and mtROS levels as well as restore the ATP level in CCSMCs.

CONCLUSIONS

ADSCs-mito transplantation significantly ameliorated ED induced by CNI, with similar potency to ADSCs treatment. The ADSCs-mito might exert their effects via anti-oxidative stress, anti-apoptosis and modulating energy metabolism of CCSMCs. Mitochondrial transplantation should be a promising therapeutic method for treating CNI ED in the future.

Stem Cell Therapy for Erectile Dysfunction: A Step towards a Future Treatment

Background: The improvement of absent or partial response in the medical treatment of erectile dysfunction (ED) has led to the development of minimally invasive new treatment modalities in the field of regenerative medicine. Methods: A literature review on stem cell therapy for the treatment of ED was performed. We searched for the terms "erectile dysfunction" and "stem cell therapy" in PubMed and Clinicaltrials.gov. Literature searching was conducted in English and included articles from 2010 to 2022. Results: New treatment modalities for ED involving stem cell therapy are not only conceived with a curative intent but also aim to avoid unnecessary adverse effects. Several sources of stem cells have been described, each with unique characteristics and potential applications, and different delivery methods have been explored. A limited number of interventional studies over the past recent years have provided evidence of a safety profile in their use and promising results for the treatment of ED, although there are not enough studies to generate an appropriate protocol, dose or cell lineage, or to determine a mechanism of action. Conclusions: Stem cell therapy is a novel treatment for ED with potential future applications. However, most urological societies agree that further research is required to conclusively prove its potential benefit.

The prostate in women: an updated histological and immunohistochemical profile of the female periurethral glands and their relationship to an implanted midurethral sling

BACKGROUND

There is evidence of glandular tissue in the region of the anterior vaginal wall-female periurethral tissue (AVW-FPT) that has similar morphology and immunohistochemistry to the prostate in men. Surgical injury to this tissue has been suggested as a potential cause of sexual dysfunction following midurethral sling (MUS) procedures. However, the anatomy and embryology of these glands have not been fully resolved. This has led to difficulties in classifying this tissue as a prostate and defining its clinical significance related to MUS procedures.

AIM

To describe the histological and immunohistochemical characteristics of the female periurethral glands using markers of prostate tissue and innervation and to examine their anatomical relationships to an implanted MUS.

METHODS

Using gross and fine dissection, the AVW-FPT was dissected from 9 cadavers. Prior to dissection, 2 cadavers underwent simulation of the MUS procedure by a urogynecologist. Samples were paraffin embedded and serially sectioned. Immunohistochemistry was performed using markers of prostate tissue and innervation.

OUTCOMES

Redundant immunohistochemical localization of markers for prostatic tissue and innervation of the glandular tissue of the AVW-FPT, including the region of MUS implantation.

RESULTS

Female periurethral glands were immunoreactive for markers of male prostatic tissue, including prostate-specific antigen, androgen receptor, HOXB13, and NKX3.1. Markers of innervation (protein gene product 9.5, choline acetyl transferase, and vasoactive intestinal polypeptide) also localized to certain regions of the glandular tissue and associated blood supply. Surgical simulation of the MUS procedure demonstrated that some periurethral glands are located in close proximity to an implanted sling.

CLINICAL TRANSLATION

The AVW-FPT contains glandular tissue in the surgical field of MUS implantation. Iatrogenic damage to the female periurethral glands and the associated innervation during surgery could explain the negative impacts on sexual dysfunction reported following MUS procedures.

STRENGTHS AND LIMITATIONS

This is the first study to characterize the female periurethral glands using markers of prostatic tissue in concert with markers of general and autonomic innervation and characterize their anatomical relationships within the surgical field of MUS implantation. The small sample size is a limitation of this study.

CONCLUSION

We provide further evidence that the AVW-FPT contains innervated glands that are phenotypically similar to the male prostate and may share a common embryonic origin. The microscopic and immunohistochemical features of the periurethral glands may be indicative of their functional capacity in sexual responses. The location of these glands in the surgical field of MUS procedures underscores the clinical significance of this tissue.

Comparison of the therapeutic effects of human umbilical cord blood-derived mesenchymal stem cells and adipose-derived stem cells on erectile dysfunction in a rat model of bilateral cavernous nerve injury

Background: Cavernous nerve injury (CNI) is the leading cause of erectile dysfunction (ED) after radical prostatectomy and pelvic fracture. Transplantation of human adipose-derived stem cells (ASCs) has been widely used to restore erectile function in CNI-ED rats and patients. Umbilical cord blood-derived MSCs (CBMSCs) are similarly low immunogenic but much primitive compared to ASCs and more promising in large-scale commercial applications due to the extensive establishment of cord blood banks. However, whether CBMSCs and ASCs have differential therapeutic efficacy on CNI-ED and the underlying mechanisms are still not clear.

Materials and methods: A bilateral cavernous nerve injury (BCNI) rat model was established by crushing the bilateral cavernous nerves. After crushing, ASCs and CBMSCs were intracavernously injected immediately. Erectile function, Masson staining, and immunofluorescence analyses of penile tissues were assessed at 4 and 12 weeks. PKH-26-labeled ASCs or CBMSCs were intracavernously injected to determine the presence and differentiation of ASCs or CBMSCs in the penis 3 days after injection. In vitro experiments including intracellular ROS detection, mitochondrial membrane potential assay, EdU cell proliferation staining, cell apoptosis assay, and protein chip assay were conducted to explore the underlying mechanism of CBMSC treatment compared with ASC treatment.

Results: CBMSC injection significantly restored erectile function, rescued the loss of cavernous corporal smooth muscles, and increased the ratio of smooth muscle to collagen. PKH-26-labeled CBMSCs or ASCs did not colocalize with endothelial cells or smooth muscle cells in the corpus cavernosum. Moreover, the conditioned medium (CM) of CBMSCs could significantly inhibit the oxidative stress and elevate the mitochondria membrane potential and proliferation of Schwann cells. Better therapeutic effects were observed in the CBMSC group than the ASC group both in vivo and in vitro. In addition, the content of neurotrophic factors and matrix metalloproteinases in CBMSC-CM, especially NT4, VEGF, MMP1, and MMP3 was significantly higher than that of ASC-CM.

Conclusion: Intracavernous injection of CBMSCs exhibited a better erectile function restoration than that of ASCs in CNI-ED rats owing to richer secretory factors, which can promote nerve regeneration and reduce extracellular matrix deposition. CBMSC transplantation would be a promising therapeutic strategy for CNI-ED regeneration in the future.

Indications for nerve-sparing surgery for radical prostatectomy: Results from a single-center study

Purpose

To explore the clinical indications of using the nerve-sparing technique in radical prostatectomy.

Patients and methods

We retrospectively analyzed the clinical and pathological data of 101 patients who underwent radical prostatectomy (RP) at our institution. Twenty-five patients underwent open surgery, and 76 patients underwent laparoscopic surgery. The biochemical recurrence (BCR) rate was analyzed by the method of Kaplan–Meier. The distance between the ipsilateral neurovascular bundles (NVBs) and foci of prostate tumor (N-T distance) was measured in postoperative specimens. We defined the N-T distance >2 mm as the threshold to perform nerve-sparing (NS) in RP. Through logistic regression analysis, we determined the preoperative clinical indications for the nerve-sparing technique in RP.

Results

The average BCR-free survival time was 53.2 months in these 101 patients with RP, with the 3- and 5-year BCR-free rates being 87.9% and 85.8%, respectively. The N-T distance was measured in 184 prostate sides from postoperative specimens of 101 patients. Univariate analysis showed that the percent of side-specific biopsy cores with cancer (≥1/3), maximum tumor length in biopsy core (≥5 mm), average percent involvement of each positive core (≥50%), PI-RADS score, and prostate MP-MRI imaging (extra-capsular extension) were associated with the N-T distance (p < 0.003). Furthermore, the percent of side-specific biopsy cores with cancer (≥1/3) (OR = 4.11, p = 0.0047) and prostate MP-MRI imaging (extra-capsular extension) (OR = 3.92, p = 0.0061) were found to be statistically significant independent predictors of the N-T distance in multivariate analysis.

Conclusions

The clinical indications of nerve-sparing RP were <1/3 side-specific biopsy cores with cancer and no extra-capsular extension by prostate MP-MRI examination.

Curcumin slow-release membrane promotes erectile function and penile rehabilitation in a rat model of cavernous nerve injury

Male erectile dysfunction (ED) caused by cavernous nerve injury is a common complication of pelvic surgery, radiotherapy, transurethral surgery or other operations. However, clinical treatment for iatrogenic or traumatic male ED is difficult and not satisfactory. Many studies have shown that curcumin can promote the repair and regeneration of peripheral nerves; however, whether curcumin can rescue cavernous nerve injury is unknown, and the poor bioavailability of curcumin limits its application in vivo. Hence, the study was conducted. A curved slow-release membrane was produced, and the properties were examined. In addition, the effects of the curcumin slow-release membrane on cavernous nerve-injured SD rats were studied. We found that polylactic acid-glycolic acid-polyethylene glycol (PLGA-PEG) can be used as a good carrier material for curcumin, and curcumin-loaded PLGA-PEG membranes can effectively rescue the cavernous nerve in SD rats, restore the continuity of the cavernous nerve, and increase the expression of nNOS mRNA and proteins in penile tissue, which can improve the penile erectile function of injured SD rats, reduce the degree of penile tissue fibrosis, and effectively promote penis rehabilitation. The curcumin slow-release membrane is proposed to be a new therapeutic approach for penile rehabilitation of cavernous nerve injury.

Should We Call It a Prostate? A Review of the Female Periurethral Glandular Tissue Morphology, Histochemistry, Nomenclature, and Role in Iatrogenic Sexual Dysfunction

INTRODUCTION

There is evidence of glandular tissue within the region of the anterior vaginal wall-female periurethral tissue (AVW-FPT) having similar morphology and immunohistochemistry to the prostate in men and having physiological roles in the female sexual response (FSR). Whether this tissue should be called a prostate in women has been debated. Iatrogenic injury to structures of the AVW-FPT, including these glands and the associated neurovasculature, could be a cause of female sexual dysfunction (FSD).

OBJECTIVES

To consolidate the current knowledge concerning the glandular tissue surrounding the urethra in women, evidence was reviewed to address whether: (i) these glands comprise the prostate in women, (ii) they have specific functions in the FSR, and (iii) injury to the AVW-FPT and prostate has sexual dysfunction as a likely outcome.

METHODS

A literature review was conducted using keywords including female prostate, Skene's/paraurethral glands, periurethral tissue, Gräfenberg (G)-spot, female ejaculation, mid-urethral sling (MUS), and sexual dysfunction.

RESULTS

Histological and immunohistochemical studies of the glandular tissue surrounding the urethra support the existence of prostate in women. Evidence suggests this tissue may have physiologically and clinically relevant autonomic and sensory innervation, and during sexual arousal may contribute to secretions involved in ejaculation and orgasm. Gaps in knowledge relating to the functional anatomy, physiological roles, and embryological origins of this tissue have impeded the acceptance of a prostate in women. Injury to the innervation, vasculature, and/or glandular tissue within the surgical field of MUS implantation suggests iatrogenic sexual dysfunction is plausible.

CONCLUSIONS

Continuing to advance our understanding of the morphology, histochemistry, and physiologic capacity of this glandular tissue will clarify the characterization of this tissue as the "prostate" involved in the FSR, and its role in FSD following surgical injury. Tomalty D, Giovannetti O, Hannan J, et al. Should We Call It a Prostate? A Review of the Female Periurethral Glandular Tissue Morphology, Histochemistry, Nomenclature, and Role in Iatrogenic Sexual Dysfunction. Sex Med Rev 2021;XX:XXX-XXX.

Fidgetin-like 2 negatively regulates axonal growth and can be targeted to promote functional nerve regeneration

The microtubule (MT) cytoskeleton plays a critical role in axon growth and guidance. Here, we identify the MT-severing enzyme fidgetin-like 2 (FL2) as a negative regulator of axon regeneration and a therapeutic target for promoting nerve regeneration after injury. Genetic knockout of FL2 in cultured adult dorsal root ganglion neurons resulted in longer axons and attenuated growth cone retraction in response to inhibitory molecules. Given the axonal growth-promoting effects of FL2 depletion in vitro, we tested whether FL2 could be targeted to promote regeneration in a rodent model of cavernous nerve (CN) injury. The CNs are parasympathetic nerves that regulate blood flow to the penis, which are commonly damaged during radical prostatectomy (RP), resulting in erectile dysfunction (ED). Application of FL2-siRNA after CN injury significantly enhanced functional nerve recovery. Remarkably, following bilateral nerve transection, visible and functional nerve regeneration was observed in 7 out of 8 animals treated with FL2-siRNA, while no control-treated animals exhibited regeneration. These studies identify FL2 as a promising therapeutic target for enhancing regeneration after peripheral nerve injury and for mitigating neurogenic ED after RP - a condition for which, at present, only poor treatment options exist.

Dual effect of chitosan activated platelet rich plasma (cPRP) improved erectile function after cavernous nerve injury

BACKGROUND

The intracavernosal (IC) injection of chitosan activated platelet rich plasma (cPRP) has shown to improve the erectile dysfunction in cavernous nerve injury rat model. However, the action target of PRP in improving neurogenic erectile dysfunction remains unclear. We aimed to determine the effect of cPRP action at early stage that further mediates its effect on erectile function (EF) recovery in the bilateral cavernous nerve crushing (BCNC) injury rat model.

METHODS

Fifty-four rats were randomly divided into two equal groups: intracavernosal ( IC) injection of saline after BCNC (group 1) and IC injection of cPRP after BCNC (group 2). Five animals in each group were euthanized at 3, 7 and 14 day (d) post-injection, and the tissues were harvested to conduct transmission electron microscopy and histological assays. Six animals in each group were used to determine the recovery of EF at 14 and 28 d post-injury.

RESULTS

IC injections of cPRP increased all EF parameters at 28 d and 14 d post-injury (p < 0.05). cPRP injections simultaneously prevented the loss of neuronal nitric oxide synthase-positive neurons (p < 0.05) and nerve fibers (p < 0.05) in the major pelvic ganglion and cavernous nerve (CN), respectively, compared with saline injections. This simultaneous accelerated the regeneration of myelinated axons of the CN, reduced apoptosis, and enhanced the proliferation of the corporal smooth muscle cells at an earlier stage.

CONCLUSION

These results suggest that the application of cPRP was beneficial to restore EF via neuroprotective and tissue-protective effects at early stage.

Enhanced effects of salidroside on erectile function and corpora cavernosa autophagy in a cavernous nerve injury rat model

We explored the efficacy and mechanisms of salidroside treatment for erectile dysfunction induced by bilateral cavernous nerve injury (BCNI). Forty male rats were divided into four groups as follows: sham (cavernous nerves exposed only) (S); BCNI (M); BCNI + rapamycin (M + rapamycin); and BCNI + salidroside (M + salidroside). Erectile function in the rats was measured by intracavernosal pressure. Penile tissue was harvested for transmission electron microscopy, immunohistochemistry, immunofluorescence, Masson's trichrome staining, haematoxylin-eosin staining, TdT-mediated dUTP Nick End Labeling and western blotting. The M group exhibited a decrease in erectile responses and increased apoptosis and fibrosis compared to these in the S group. Meanwhile, nerve content and the penile atrophy index were also decreased in the M group. Treatment with salidroside and rapamycin for 3 weeks partially restored erectile function and significantly attenuated corporal apoptosis, fibrosis, nerve content and penile atrophy in the M group. Moreover, the autophagy level was further enhanced in the M + salidroside group, which was the same as that in the positive observation group (M + rapamycin). Salidroside treatment not only improved erectile function in rats with BCNI, but also inhibited apoptosis and fibrosis and ameliorated the loss of nerve content and endothelial and corpus cavernosum smooth muscle cells by promoting protective autophagy.

Effect of platelet-derived growth factor-BB on gap junction and connexin43 in rat penile corpus cavernosum smooth muscle cells

We explored whether platelet-derived growth factor (PDGF)-BB regulates corpus cavernosum smooth muscle cell gap junctions and can ameliorate erectile dysfunction and how it modulates connexin43 (CX43) after bilateral cavernous neurectomy. Primary cultured rat corpus cavernosum smooth muscle cells were treated with PDGF-BB with or without a PDGFR inhibitor, Akt siRNA or the depletion or promotion of β-catenin. PDGF-BB improved CCSMCs gap junction coupling and increased CX43 and PDGFRβ expression; inhibition of PDGFR activity down-regulated CX43 and decreased Akt and nuclear β-catenin. Knockdown or promotion of β-catenin down-regulated and up-regulated CX43 expression respectively. Moreover, β-catenin activation induced CX43 nuclear accumulation, which impeded CX43 down-regulation induced by PDGFR inhibition, suggesting that CX43 expression is positively correlated with nuclear β-catenin expression. Furthermore, CX43 promoter luciferase and chromatin immunoprecipitation assays indicated that β-catenin regulates CX43 transcription by directly interacting with its promoter. Male rats underwent bilateral cavernous neurectomy. After 12 weeks, they were injected with PDGF-BB, CX43 and PDGFRβ expression was significantly lower than in the control group, which was reversed by PDGF-BB injection. These results suggested that PDGF-BB contributed to the improvement of gap junction intracellular communication among corpus cavernosum smooth muscle cells, increased CX43 through PDGFRβ/Akt/nuclear β-catenin signalling, and ameliorated cavernous nerve injury-induced erectile dysfunction.

Penile Rehabilitation Therapy Following Radical Prostatectomy: A Meta-Analysis

BACKGROUND

Penile rehabilitation, defined as the use of any drug or device at or after radical prostatectomy to maximize erectile function recovery, is commonly used for post-prostatectomy erectile dysfunction; however, conflicting results based on each study make it difficult to give a recommendation for clinical practice.

AIM

To clarify the effect of oral phosphodiesterase type 5 inhibitors (PDE5is), vacuum erection devices, intracorporeal injection therapy, and the combination of these treatments on penile rehabilitation.

METHODS

A comprehensive publication search was done through the PubMed and Embase databases up to February 8, 2017. The reference lists of the retrieved studies also were investigated. Data were analyzed using STATA 12.0. A fixed- or random-effects model was used to calculate the overall combined odds ratio (OR) or standard mean differences (SMDs). Publication bias was assessed using the Begg and Egger tests.

OUTCOMES

Change in sexual function before and after treatment.

RESULTS

After screening, 11 randomized controlled trials and 5 case-control studies were included. The overall meta-analysis showed that penile rehabilitation with PDE5is, vacuum erection devices, and intracorporeal injection significantly increased the number of patients with erectile function improvement (OR = 2.800, 95% CI = 1.932-4.059, P = .000) and International Index of Erectile Function (IIEF) score (SMD = 5.896, 95% CI = 4.032-7.760, P = .000). In subgroup analysis based on study design, randomized controlled trials and case-control studies showed that penile rehabilitation increased the number of patients with erectile function improvement (randomized controlled trials: OR = 2.154, 95% CI = 1.600-2.895, P = .000; case-control studies: OR = 2.800, 95% CI = 1.932-4.059, P = .000). Subgroup analysis for PDE5i treatment also only demonstrated an increased patient response rate (OR = 2.161, 95% CI = 1.675-2.788, P = .000) and IIEF scores (SMD = 0.922, 95% CI = 0.545-1.300, P = .000). However, after PDE5i washout, there was no improvement of spontaneous erectile function (OR = 1.027, 95% CI = 0.713-1.478, P = .610).

CLINICAL TRANSLATION

This study provides information about the efficacy of penile rehabilitation that can help clinicians decide treatment strategies.

STRENGTHS AND LIMITATIONS

This meta-analysis has higher statistical power than each study. Preoperative patient characteristics, various treatment methods, and different follow-up times might bring bias to pooled effects.

CONCLUSION

Our meta-analysis confirmed that administration of PDE5is, vacuum erection devices, and intracorporeal injection after radical prostatectomy can increase erection function during treatments. However, current evidence does not support that penile rehabilitation with PDE5is can improve recovery of spontaneous erectile function. Further studies with adequate follow-up and larger samples should be conducted to generate a comprehensive conclusion. Liu C, Lopez DS, Chen M, Wang R. Penile Rehabilitation Therapy Following Radical Prostatectomy: A Meta-Analysis. J Sex Med 2017;14:1496-1503.

Topical alprostadil (Vitaros©) in the treatment of erectile dysfunction after non-nerve-sparing robot-assisted radical prostatectomy

OBJECTIVE

The aim of the study is the evaluation of the efficacy and safety of the treatment with topical alprostadil (Vitaros^©) in post-robot assisted radical prostatectomy (RARP) rehabilitation therapy of patients with erectile dysfunction (ED).

METHODS

Seventy-four patients were enrolled and underwent non-nerve-sparing RARP.

INCLUSION CRITERIA

age <75, preoperatively International Index of Erectile Function (IIEF-5) >16, erection hardness score (EHS) ⩾2, weekly sexual intercourse ⩾1, affirmative answers to Sexual Encounter Profile Question (SEP-Q) 2 and SEP-Q3, Charlson Comorbidity Index (CCI) ⩽5, Eastern Cooperative Oncology Group (ECOG) performance status ⩽1, no moderate/severe cardiovascular disease.

RESULTS

Vitaros was administered ⩾2 twice a week. At month 6, the IIEF-5 decreased from 20.5 preoperative to 18.1 post-treatment. EHS score decreased from a mean of 3.3 to a mean of 3.0. The quality of life score decreased from an average of 5.1 to 2.3. Weekly sexual intercourse decreased from an average of 2.1 to 1.7. Six patients dropped out; 89.7% patients showed a positive SEP-Q2 and 77.8% a positive SEP-Q3. All patients responded positively to Global Assessment Questions (GAQ)-1 and 97% to GAQ-2. Of all 68 analyzed patients, 13 (17.6%) switched to intracavernous injection therapy.

CONCLUSIONS

In conclusion, Vitaros may become a viable alternative to common injective therapies in well-selected patients after RARP.

The Protective Effect of Salidroside on Hypoxia-Induced Corpus Cavernosum Smooth Muscle Cell Phenotypic Transformation

Salidroside, a major active ingredient isolated from Rhodiola rosea, has a long application in Chinese medical history. It has widely demonstrated effects on fatigue, psychological stress, and depression and exhibits potential antihypoxia activity. Emerging evidence shows that hypoxia is an important independent risk factor for erectile dysfunction (ED). The aim of this study was to clarify the effect of salidroside on hypoxia-induced phenotypic transformation of corpus cavernosum smooth muscle cells (CCSMCs). Our results showed that salidroside decreased the hypoxia-induced expression of collagen and content of vimentin, a corpus cavernosum smooth muscle synthetic protein, in vitro. Simultaneously, salidroside increased expression of the CCSMC contractile proteins, α-smooth muscle actin (α-SMA) and desmin. In vivo, similarly, the expressions of collagen and hypoxia-inducible factor-1α were increased in bilateral cavernous neurectomy (BCN) rats while they were decreased in the salidroside group. Among the phenotypic proteins, α-SMA and desmin increased and vimentin decreased after treating BCN rats with salidroside compared with the BCN alone group. Overall, our results demonstrate that salidroside has the ability to oppose hypoxia and can inhibit the CCSMC phenotypic transformation induced by hypoxia. Salidroside may provide a new treatment method for ED.

Let’s rethinking about the safety of phosphodiesterase type 5 inhibitor in the patients with erectile dysfunction after radical prostatectomy

As the radical prostatectomy (RP) for the patient diagnosed as localized prostate cancer has been increasing, erectile dysfunction (ED) associated with RP is increased and ED after RP is a significant risk factor to reduce the quality of life for the patient after RP. Therefore, the treatment concept called penile rehabilitation was introduced and phosphodiesterase type 5 inhibitor (PDE5I) is used widely for the prostate cancer patient after RP. Generally PDE5I is considered as safe and effective drug for the prostate cancer patient after RP. Recently, a report against the general opinion that PDE5I use is safe in the patient with prostate cancer was reported and the analysis of 5-yr biochemical recurrence-free survival after RP between the PDE5I users and non-PDE5I users after bilateral nerve sparing RP showed decreased 5-yr biochemical recurrence-free survival in the PDE5I users. In addition, a longitudinal cohort study reported that sildenafil, a kind of PDE5I, use might be associated with the development of melanoma and this result suggested the possibility of adverse effect of PDE5I on some kinds of cancers as well as prostate cancer. Moreover, the studies to evaluate the influence of nitric oxide (NO) and guanosine monophosphate (cGMP) signaling pathway associated with PDE5 showed both cancer reduction and cancer development. Therefore, the role of NO and cGMP signaling pathway in cancer was reviewed based on the previous studies and suggested the necessity of further clinical studies concerning about the safety of PDE5I in prostate cancer.

Current Perspectives on Stem Cell Therapy for Erectile Dysfunction

INTRODUCTION

Erectile dysfunction (ED) is a common sexual disorder that affects the lives of millions of male patients and their partners. Various medical and surgical therapies exist, with the most common being oral intake of phosphodiesterase 5 inhibitors. One therapeutic strategy in preclinical development to treat ED is stem cell transplantation.

AIM

To examine the studies that have investigated stem cells for the treatment of ED.

METHODS

A literature review was performed through PubMed focusing on stem cells and ED.

MAIN OUTCOME MEASURES

An assessment of different types of stem cells and how they may be applied therapeutically in the treatment of ED.

RESULTS

The stem cell types that have been investigated for the treatment of ED include bone marrow-derived mesenchymal, adipose-derived, muscle-derived, testes, urine-derived, neural crest, and endothelial progenitor. Depending on the cell type, research has demonstrated that with transplantation, stem cells exert a paracrine effect on penile tissue, and can differentiate into smooth muscle, endothelium, and neurons.

CONCLUSION

Multiple stem cell lines are currently being studied for their potential to treat ED. To date, stem cells have proven safe and effective in both animal and human models of ED. More research is needed to understand their full therapeutic potential.

Pharmacologic and surgical therapies for sexual dysfunction in male cancer survivors

The recent recognition that many men experience sexual dysfunction following their diagnosis and treatment of genitourinary cancers, has led to the development multiple varied strategies that attempt to restore or preserve that function. In this manuscript we review the understanding of why it happens, highlight novel management strategies and discuss the concept of penile rehabilitation (PR) following prostate cancer (PCa) treatment, glans preserving strategies among men diagnosed with penile cancer and address the controversial issue of testosterone therapy in men with PCa.

Nightly sildenafil use after radical prostatectomy has adverse effects on urinary convalescence: Results from a randomized trial of nightly vs on-demand dosing regimens

INTRODUCTION

This is a report on urinary function results from a randomized trial of nightly versus on-demand sildenafil after nerve-sparing radical prostatectomy (RP), a secondary objective. We analyzed the effects of these sildenafil administration schemes on urinary health-related quality of life after RP.

METHODS

In total, 100 potent men were equally randomized to nightly and on-demand sildenafil 50 mg after minimally-invasive RP for 1 year. Health-related quality of life questionnaires were administered at various postoperative intervals. Urinary function was assessed using appropriate expanded prostate cancer index composite (EPIC) subscales. Analyses of covariance and linear mixed-effects modeling were used to compare the effects of treatment over time on urinary recovery, controlling for age, nerve-sparing score, and time from surgery.

RESULTS

The nightly (n = 50) and on-demand (n = 50) sildenafil groups were well-matched at baseline. Nightly sildenafil patients had worse EPIC urinary bother and urinary irritative/obstructive subscale scores at 3 and 6 months after RP, even after controlling for multiple variables. On mixed-model analyses, the differences between groups for these EPIC subscales (4.9 and 2.5, respectively) were greater than documented thresholds for clinical significance. Increasing nerve-sparing score was associated with improvements in EPIC urinary summary, bother, incontinence, and function scores; time from surgery was associated with improvements in all EPIC urinary health-related quality of life subscales.

CONCLUSIONS

In this specific population and drug dose, we found that on-demand short-acting phosphodiesterase-5 inhibitor (PDE5i) dosing may be more effective after RP to maximize early urinary health-related quality of life. In preoperatively potent men, nightly sildenafil 50 mg impaired urinary health-related quality of life more than on-demand use in the early months after nerve-sparing RP, independent of effects on urinary continence.

Erectile function following brachytherapy, external beam radiotherapy, or radical prostatectomy in prostate cancer patients

BACKGROUND AND PURPOSE

For localized prostate cancer, treatment options include external beam radiotherapy (EBRT), radical prostatectomy (RP), and brachytherapy (BT). Erectile dysfunction (ED) is a common side-effect. Our aim was to evaluate penile erectile function (EF) before and after BT, EBRT, or RP using a validated self-administered quality-of-life survey from a prospective registry.

MATERIAL AND METHODS

Analysis included 478 patients undergoing RP (n = 252), EBRT (n = 91), and BT (n = 135) with at least 1 year of follow-up and EF documented using IIEF-5 scores at baseline, 6 weeks, 6 months, 1 year, and annually thereafter.

RESULTS

Differences among treatments were most pronounced among patients with no or mild initial ED (IIEF-5 ≥ 17). Overall, corrected for baseline EF and age, BT was associated with higher IIEF-5 scores than RP (+ 7.8 IIEF-5 score) or EBRT (+ 3.1 IIEF-5 score). EBRT was associated with better IIEF-5 scores than RP (+ 4.7 IIEF-5 score). In patients undergoing EBRT or RP with bilateral nerve sparing (NS), recovery of EF was observed and during follow-up, the differences to BT were not statistically significant. Overall age had a negative impact on EF preservation (corrected for baseline IIEF).

CONCLUSION

In our series, EF was adversely affected by each treatment modality. Considered overall, BT provided the best EF preservation in comparison to EBRT or RP.

Emerging drugs for the treatment of erectile dysfunction

INTRODUCTION

Erectile dysfunction adversely affects the lives of millions of men, and is the most commonly treated sexual disorder today. The erectile process has been extensively investigated, with major advances made in elucidating many of the complex molecular pathways involved. These advances have allowed researchers to design and study drug formulations that target various aspects of this complex process. The initial culmination of this research was the introduction of phosphodiesterase 5-inhibitors. While effective in many patients, they are not satisfactory for all afflicted men. As a result, researchers are developing novel drugs that target different molecular pathways.

AREAS COVERED

The paper will review these pathways, and the potential agents that target them. More specifically, first dopaminergic and melanocortin receptor agonists that act centrally will be covered. Then, the paper will examine the "second-generation" phosphodiesterase 5-inhibitors, soluble guanylate cyclases, rho-kinase inhibitors, and maxi-k channel activators that act peripherally.

EXPERT OPINION

Most of these novel drugs have yet to reach Phase III studies. However, it is likely that in years to come, patients will be selectively treated with these novel agents as a monotherapy or in combination with others acting in a synergistic manner.

Clinical Efficacy and Safety of Vitaros©/Virirec© (Alprostadil Cream) for the Treatment of Erectile Dysfunction

Erectile dysfunction (ED) is a very common disorder with a deep impact on patients and their partners. Several options are now available for treating ED; oral pharmacotherapy with phosphodiesterase-5 (PDE5) inhibitors currently represents the first-line option for many ED patients. Vitaros©/Virirec© is new topical, non-invasive treatment for ED that offers the combination of an active drug (alprostadil, a synthetic PGE1) with a skin enhancer that improves its local absorption directly at the site of action. Vitaros©/Virirec© has a favorable pharmacodynamic profile and is poorly absorbed in systemic circulation. This makes it suitable in any circumstances and results in a reduced risk of adverse events (AEs), being systemic AEs reported in only 3% of the treated population. Its clinical efficacy has been demonstrated in both phase II and III trials, showing a global efficacy up to 83% with the 300 μg dose in patients with severe ED significantly better than placebo. Its fast onset of action together with its favorable toxicity profile and lack of interactions with other drugs makes Vitaros©/Virirec© a first-line therapeutic option for patients with ED, particularly for individuals who are reluctant to take systemic treatments or with AEs. It may also have an important role in patients not responding to PDE5 inhibitors, particularly those with ED after radical prostatectomy.

Newer concepts in neural anatomy and neurovascular preservation in robotic radical prostatectomy

With more than 60% of radical prostatectomies being performed robotically, robotic-assisted laparoscopic prostatectomy (RALP) has largely replaced the open and laparoscopic approaches and has become the standard of care surgical treatment option for localized prostate cancer in the United States. Accomplishing negative surgical margins while preserving functional outcomes of sexual function and continence play a significant role in determining the success of surgical intervention, particularly since the advent of nerve-sparing (NS) robotic prostatectomy. Recent evidence suggests that NS surgery improves continence in addition to sexual function. In this review, we describe the neuroanatomical concepts and recent developments in the NS technique of RALP with a view to improving the “trifecta” outcomes.

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.

Topically applied NO-releasing nanoparticles can increase intracorporal pressure and elicit spontaneous erections in a rat model of radical prostatectomy

INTRODUCTION

Patients undergoing radical prostatectomy (RP) suffer from erectile dysfunction (ED) refractory to phosphodiesterase 5 inhibitors, which act downstream of cavernous nerve (CN)-mediated release of nitric oxide (NO). Direct delivery of NO to the penis could potentially circumvent this limitation.

AIM

This study aimed to determine if topically applied NO-releasing nanoparticles (NO-NPs) could elicit erections in a rat model of RP through increased blood flow.

METHODS

Twenty-six Sprague Dawley rats underwent bilateral transection of the CN. One week later, NO-NPs were applied topically to the penile shaft in dimethylsulfoxide (DMSO) gel (10 animals) or coconut oil (6 animals). Control animals were treated with empty NPs. Erectile function was determined through the intracorporal pressure/blood pressure ratio (ICP/BP). The effect of the NO-NPs on blood flow was determined using a hamster dorsal window chamber.

MAIN OUTCOME MEASURES

Animals were investigated for spontaneous erections, onset and duration of erectile response, and basal ICP/BP ratio. Microcirculatory blood flow was determined through measurements of arteriolar and venular diameter and red blood cell velocity.

RESULTS

Eight of 10 animals treated with NO-NPs suspended in DMSO gel had significant increases in basal ICP/BP, and 6 out of these 10 animals demonstrated spontaneous erections of approximately 1 minute in duration. Time to onset of spontaneous erections ranged from 5 to 37 minutes, and they occurred for at least 45 minutes. Similar results were observed with NO-NPs applied in coconut oil. No erectile response was observed in control animal models treated with empty NPs. The hamster dorsal window chamber experiment demonstrated that NO-NPs applied as a suspension in coconut oil caused a significant increase in the microcirculatory blood flow, sustained over 90 minutes.

CONCLUSIONS

Topically applied NO-NPs induced spontaneous erections and increased basal ICP in an animal model of RP. These effects are most likely due to increased microcirculatory blood flow. These characteristics suggest that NO-NPs would be useful in penile rehabilitation of patients following RP.

Phenotypic modulation of corpus cavernosum smooth muscle cells in a rat model of cavernous neurectomy

Background

Patients undergoing radical prostatectomy (RP) are at high risk for erectile dysfunction (ED) due to potential cavernous nerve (CN) damage during surgery. Penile hypoxia after RP is thought to significantly contribute to ED pathogenesis.

Aim

We previously showed that corpora cavernosum smooth muscle cells (CCSMCs) undergo phenotypic modulation under hypoxic conditions in vitro. Here, we studied such changes in an in vivo post-RP ED model by investigating CCSMCs in bilateral cavernous neurectomy (BCN) rats.

Methods

Sprague-Dawley rats underwent sham (n = 12) or BCN (n = 12) surgery. After 12 weeks, they were injected with apomorphine to determine erectile function. The penile tissues were harvested and assessed for fibrosis using Masson trichrome staining and for molecular markers of phenotypic modulation using immunohistochemistry and western blotting. CCSMC morphological structure was evaluated by hematoxylin-eosin (H&E) staining and transmission electron microscopy (TEM).

Results

Erectile function was significantly lower in BCN rats than in sham rats. BCN increased hypoxia-inducible factor-1α and collagen protein expression in corpora cavernous tissue. H&E staining and TEM showed that CCSMCs in BCN rats underwent hypertrophy and showed rough endoplasmic reticulum formation. The expression of CCSMC phenotypic markers, such as smooth muscle α-actin, smooth muscle myosin heavy chain, and desmin, was markedly lower, whereas vimentin protein expression was significantly higher in BCN rats than in control rats.

Conclusions

CCSMCs undergo phenotype modulation in rats with cavernous neurectomy. The results have unveiled physiological transformations that occur at the cellular and molecular levels and have helped characterize CN injury–induced ED.

Sexual dysfunction after cystectomy and urinary diversion

Erectile dysfunction (ED) in men and sexual dysfunction in men and women are common after cystectomy and urinary diversion. Research has focused on both qualifying the prevalence of ED following cystectomy and identifying surgical approaches to limit sexual dysfunction after surgery, but most studies have been limited by small patient populations, an absence of control groups, and a lack of adjustment for confounding factors. Similarly, quality of life (QoL) research studies have also emerged in the context of bladder cancer and cystectomy, and increase our understanding of sexual outcomes associated with cystectomy. A number of instruments for collection of patient-reported outcomes among patients with bladder cancer treated with cystectomy are available for the assessment of condition-specific and procedure-specific QoL. However, other factors that negatively affect sexual function after removal of the bladder, such as psychological issues, age, and health-related competing risks for ED, body image, partner response, and change in life course and sexual priorities, have received less attention. Nevertheless, ED and sexual dysfunction are important complications of cystectomy and urinary diversion. Although changes in the approach to surgery, such as nerve-sparing cystectomy, might improve outcomes, evaluation and management of the source factors of ED and sexual dysfunction are necessary to optimize recovery of function.

Improving sexual health in men with prostate cancer: randomised controlled trial of exercise and psychosexual therapies

Background

Despite being a critical survivorship care issue, there is a clear gap in current knowledge of the optimal treatment of sexual dysfunction in men with prostate cancer. There is sound theoretical rationale and emerging evidence that exercise may be an innovative therapy to counteract sexual dysfunction in men with prostate cancer. Furthermore, despite the multidimensional aetiology of sexual dysfunction, there is a paucity of research investigating the efficacy of integrated treatment models. Therefore, the purpose of this study is to: 1) examine the efficacy of exercise as a therapy to aid in the management of sexual dysfunction in men with prostate cancer; 2) determine if combining exercise and brief psychosexual intervention results in more pronounced improvements in sexual health; and 3) assess if any benefit of exercise and psychosexual intervention on sexual dysfunction is sustained long term.

Methods/Design

A three-arm, multi-site randomised controlled trial involving 240 prostate cancer survivors will be implemented. Participants will be randomised to: 1) ‘Exercise’ intervention; 2) ‘Exercise + Psychosexual’ intervention; or 3) ‘Usual Care’. The Exercise group will receive a 6-month, group based, supervised resistance and aerobic exercise intervention. The Exercise + Psychosexual group will receive the same exercise intervention plus a brief psychosexual self-management intervention that addresses psychological and sexual well-being. The Usual Care group will maintain standard care for 6 months. Measurements for primary and secondary endpoints will take place at baseline, 6 months (post-intervention) and 1 year follow-up. The primary endpoint is sexual health and secondary endpoints include key factors associated with sexual health in men with prostate cancer.

Discussion

Sexual dysfunction is one of the most prevalent and distressing consequences of prostate cancer. Despite this, very little is known about the management of sexual dysfunction and current health care services do not adequately meet sexual health needs of survivors. This project will examine the potential role of exercise in the management of sexual dysfunction and evaluate a potential best-practice management approach by integrating pharmacological, physiological and psychological treatment modalities to address the complex and multifaceted aetiology of sexual dysfunction following cancer.

Trial registration

Australian New Zealand Clinical Trials Registry ACTRN12613001179729.

Systematic review and meta-analysis of the use of phosphodiesterase type 5 inhibitors for treatment of erectile dysfunction following bilateral nerve-sparing radical prostatectomy

Prostate cancer is relatively common cancer occurring in males. Radical prostatectomy (RP) is the most effective treatment for a localized tumor but erectile dysfunction (ED) is common complication, even when bilateral nerve-sparing RP (BNSRP) is performed. Clinical trials have shown varied effectiveness of phosphodiesterase type-5 inhibitors (PDE5-Is) for treatment of post-BNSRP ED, but there remains controversy over the application of this treatment and no formal systematic review and meta-analysis for the use of PDE5-Is for this condition has been conducted. This review was to systematically assess the efficacy and safety of oral PDE5-Is for post-BNSRP ED. A database search was conducted to identify randomized controlled trials (RCTs). The comparative efficacy of treatments was analyzed by fixed or random effect modeling. Erectile function was measured using the International Index of Erectile Function (IIEF), Sexual Encounter Profile (SEP) question-2, 3 and the Global Assessment Question (GAQ). The rate and incidence of adverse events (AEs) were determined. The quality of included studies was appraised using the Cochrane Collaboration bias appraisal tool. Eight RCTs were included in the analyses. PDE5-Is were effective for treating post-BNSRP ED compared to placebo when erectile function was determined using the IIEF score [mean difference (MD) 5.63, 95% confidence interval (CI) (4.26-6.99)], SEP-2 [relative risk (RR) 1.63, 95% CI (1.18-2.25) ], SEP-3 [RR 2.00, 95% CI (1.27-3.15) ] and GAQ [RR 3.35, 95% CI (2.68-4.67) ]. The subgroup analysis could find a trend that longer treatment duration, higher dosage, on-demand dosing, sildenafil and mild ED are associated with more responsiveness to PDE5-Is. PDE5-Is were overall well tolerated with headache being the most commonly reported AE. Our data provides compelling evidence for the use of PDE5-Is as a primary treatment for post-BNSRP ED. However, further studies are required to optomize usage parameters (such as dosage and duration of treatment).

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.

Exercise therapy for sexual dysfunction after prostate cancer

Sexual dysfunction is one of the most common, distressing and persistent adverse effects of prostate cancer treatment, and has a profound effect on quality of life for the patient and his partner. Current health-care provisions are inadequate to address the demand for the management of sexual dysfunction, with approximately half of prostate cancer survivors reporting unmet sexual health-care needs. Management strategies predominately involve pharmacological interventions to address the direct physiological effects of prostate cancer treatment on erectile function. However, the aetiology of sexual dysfunction is multifaceted and considerable physiological and psychological adverse effects of prostate cancer treatments, which are not addressed by pharmacological intervention, contribute to sexual dysfunction. Exercise has established efficacy for improving many of these factors in men with prostate cancer, including changes in body composition (especially to counteract body feminization), fatigue, physical function, risk of comorbid conditions, depression, anxiety and quality of life. Emerging evidence indicates that exercise also has a positive effect on sexual desire and sexual activity in men with prostate cancer.

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.

Bilateral nerve sparing robotic-assisted radical prostatectomy is associated with faster continence recovery but not with erectile function recovery compared with retropubic open prostatectomy: the need for accurate selection of patients

Robotic-assisted radical prostatectomy (RARP) shows measurable advantages, compared to conventional open surgery, even if some aspects are, still, under debate. The aim of this study was to compare the potency recovery rate of patients with clinically localised prostate cancer treated by bilateral nerve-sparing (BNS) RARP or retropubic radical prostatectomy (RRP), and secondarily, the urinary continence recovery evaluation and the oncological efficacy. All patients treated with BNS-RARP or BNS-RRP for clinically localised prostate cancer, performed by a single dedicated surgeon, between January 2004 and December 2008, were enrolled in this non-randomised prospective comparative study. The International Index of Erectile Function (IIEF) and erection hardness score (EHS), in the form of a questionnaire, were self-administered to each patient pre-operatively and after 12 months. The presence of surgical margins was considered as oncological outcome measure. Eighty-two patients underwent BNS-RARP while 48 underwent BNS-RRP. For BNS-RARP and BNS-RRP the median operative time was 221 and 103 min, respectively (P<0.001; df=128; t=721.43),and intra-operative blood loss was 280 and 565 ml, respectively (P<0.001; df=128; t=1742.44). At a mean follow-up period of 12.4±2.3 months, 12 patients (25%) in the BNS-RRP group and 22 (26.8%) in the BNS-RARP group were considered potent with or without drugs (P=0.81). Moreover, we did not find any statistically significant difference between the 2 groups in terms of IEFF and EHS scores after treatment (17.21 vs. 16.98; P=0.16 and 2.1 vs. 2.0; P=0.54). On the other hand, statistically significant differences between the 2 groups were found in terms of faster urinary continence recovery and the presence of positive surgical margins (P<0.001, P=0.009). Shorter catheterization duration (7 vs. 3 days) and post-operative hospital stays (8 vs. 4 days; P<0.001) were found in the BNS-RARP group compared to the BNS-RRP group. In conclusion, our results demonstrate that BNS-RARP does not improve erectile function recovery compared to open radical prostatectomy; however, it significantly improves urinary continence and decreases the presence of positive surgical margins.

Penile rehabilitation after radical prostatectomy: patients' attitude and feasibility in China

Objective

To investigate the behavior of Chinese erectile dysfunction (ED) patients after radical prostatectomy (RP) who were offered the penile rehabilitation and to assess their attitude and feasibility of rehabilitation after RP in China.

Materials and methods

Comprehensive medical and sexual histories of 187 evaluable PCa patients for RP were obtained together with their attitude towards penile rehabilitation. The rehabilitation data was compared between patients who accepted this treatment or not. The successful intercourse rate six months after treatment was also compared among three rehabilitation interventions, including phosphodiesterase type 5 inhibitor (PDE-5i), vacuum erection device (VED) and combination of both.

Results

141 (75.4%) patients reported being sexually active in the six months before RP.122 (65.2%) patients wished to preserve sexual activity and 80 (42.8%) had interest in penile rehabilitation after RP. Penile rehabilitation rate was 30.5%. The patients with younger age (P<0.001), higher IIEF-5 score preoperatively (P=0.03) and no adjuvant therapy post-RP (P=0.01) were more acceptable for rehabilitation. Main reasons for refusal of rehabilitation included lack of sexual interest followed by high cost of treatment. The successful intercourse rate was not significantly different among three rehabilitation interventions (P=0.32).

Conclusions

Less than one-third of Chinese RP patients accepted penile rehabilitation postoperatively. Patients’ attitude towards rehabilitation was conservative because of many reasons from traditional Chinese culture, doctors and patients themselves. Penile rehabilitation was feasible and effective in Chinese RP patients.

The resurgence of the vacuum erection device (VED) for treatment of erectile dysfunction

INTRODUCTION

Vacuum erection devices (VEDs) have been approved in the United States since 1982 and offer a viable alternative to oral phosphodiesterase type 5 inhibitors (PDE5i), injections and transurethral suppositories. Studies have demonstrated efficacy in erectile dysfunction (ED) associated with a variety of conditions. More recently, this modality has been evaluated in initial phosphodiesterase inhibitor nonresponders as well as for post-prostatectomy penile rehabilitation.

AIM

This article provides a detailed overview of the history of VEDs, a review of the literature, and a concise description of their new applications in modern urological practice.

METHODS

A retrospective review of publications relevant to the field of VEDs.

MAIN OUTCOME MEASURES

Review of the historical milestones, evolution, and modern utilization of VEDs in modern urological protocols.

RESULTS

Studies have demonstrated efficacy in ED associated with a variety of conditions. Early penile rehabilitation after surgery for prostate cancer with the VED appears to improve erectile function and penile length. Adverse events are transient and not serious.

CONCLUSIONS

The VED has continued to show efficacy for treatment of ED due to various etiologies and should be considered an attractive second-line therapy. In select cases such post-prostatectomy penile rehabilitation, as well as in men who cannot use a PDE5i, the vacuum device should be considered first-line treatment.

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.

Nursing care program for erectile dysfunction after radical prostatectomy

The prevalence of erectile dysfunction (ED) in 114 patients with prostate cancer treated with radical prostatectomy was examined to determine the efficacy of an ED care program in which nurse-provided education plays a fundamental role in the detection and follow-up of ED as well as in treatment compliance. The nursing program consists of four visits during which specific treatment-related information, education and support, active listening, and selection of the treatment best suited to each patient (in consultation with the healthcare team) are provided. One month following bladder catheter removal, 77 of the 114 patients (69%) in the study had ED, with a majority suffering from severe ED. A nursing care program could help minimize ED and enable patients to adapt to their new situation.

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.

Prostate cancer and sexual function

Prostate cancer is now ranked fifth in incidence among cancers in Korean adult males. This is attributable to the more Westernized dietary style which increases the morbidity of prostate cancer and the development of cancer diagnostic technologies, such as prostate-specific antigen and advanced medical systems, increasing the rate of prostate cancer diagnosis. Prostate cancer effects include not only erectile dysfunction caused by the disease itself, but also by psychiatric disorders caused by prostate cancer or its treatments. Prostate cancer by itself reduces sexual desire and the frequency of sexual intercourse. Additionally, surgery or hormonal therapy to block testosterone further increases the frequency of erectile dysfunction. Erectile dysfunction following radical prostatectomy is primarily attributable to nerve injury caused by intraoperative nerve traction, thermal injury, ischemic injury, and local inflammatory reactions. Additionally, the absence of nocturnal penile tumescence causes persistent hypoxia of the corpus cavernosum, which, secondarily, causes anatomical and functional changes in the corpus cavernosum. Preservation of erectile function is one of the most significant issues for patients with local prostate cancer. Erectile dysfunction following radical prostatectomy is known to have various prognoses, depending on preservation of the neurovascular bundle, patient age, and preoperative erectile status. Intracavernosal injections, PDE5 inhibitors, and penile rehabilitation therapy using a vacuum constriction device after radical prostatectomy are known to improve the recovery of erectile function. Recently, testosterone replacement therapy has also drawn attention as a treatment method.

Effects of sildenafil and/or muscle derived stem cells on myocardial infarction

Background

Previous studies have shown that long-term oral daily PDE 5 inhibitors (PDE5i) counteract fibrosis, cell loss, and the resulting dysfunction in tissues of various rat organs and that implantation of skeletal muscle-derived stem cells (MDSC) exerts some of these effects. PDE5i and stem cells in combination were found to be more effective in non-MI cardiac repair than each treatment separately. We have now investigated whether sildenafil at lower doses and MDSC, alone or in combination are effective to attenuate LV remodeling after MI in rats.

Methods

MI was induced in rats by ligature of the left anterior descending coronary artery. Treatment groups were: “Series A”: 1) untreated; 2) oral sildenafil 3 mg/kg/day from day 1; and “Series B”: intracardiac injection at day 7 of: 3) saline; 4) rat MDSC (10⁶ cells); 5) as #4, with sildenafil as in #2. Before surgery, and at 1 and 4 weeks, the left ventricle ejection fraction (LVEF) was measured. LV sections were stained for collagen, myofibroblasts, apoptosis, cardiomyocytes, and iNOS, followed by quantitative image analysis. Western blots estimated angiogenesis and myofibroblast accumulation, as well as potential sildenafil tachyphylaxis by PDE 5 expression. Zymography estimated MMPs 2 and 9 in serum.

Results

As compared to untreated MI rats, sildenafil improved LVEF, reduced collagen, myofibroblasts, and circulating MMPs, and increased cardiac troponin T. MDSC replicated most of these effects and stimulated cardiac angiogenesis. Concurrent MDSC/sildenafil counteracted cardiomyocyte and endothelial cells loss, but did not improve LVEF or angiogenesis, and upregulated PDE 5.

Conclusions

Long-term oral sildenafil, or MDSC given separately, reduce the MI fibrotic scar and improve left ventricular function in this rat model. The failure of the treatment combination may be due to inducing overexpression of PDE5.

Chronic low dosing of phosphodiesterase type 5 inhibitor for erectile dysfunction

Oral phosphodiesterase type 5 (PDE5) inhibitors have provided non-invasive, effective, and well-tolerated treatments for patients with erectile dysfunction (ED). However, many patients with ED are unresponsive to 'on-demand' PDE5 inhibitors. In addition, the lack of spontaneity and naturalness of the on-demand regimen could be a reason for decreased compliance with PDE5 inhibitors. Recently, tadalafil and udenafil were approved for low-dose daily administration for the treatment of ED. Since the introduction of the concept of daily administration of PDE5 inhibitors, several reports have supported the potential benefits of this therapy for disease modification, improvement of the treatment response in difficult-to-treat populations, spontaneity, and safety, although further research is needed to better address these hypotheses. In this article, we reviewed the daily administration of PDE5 inhibitors in terms of pharmacokinetics, safety, efficacy, and distinct features.