Erectile preservation following radical prostatectomy

Repeated Injections of Mesenchymal Stem Cell-Derived Exosomes Ameliorate Erectile Dysfunction in a Cavernous Nerve Injury Rat Model

PURPOSE

To evaluate the therapeutic effect of repeated injections of mesenchymal stem cell (MSC)-derived exosomes on the erectile dysfunction (ED) of bilateral cavernous nerve injury (BCNI) rat model and to identify potential target genes of these injections.

MATERIALS AND METHODS

MSC-derived exosomes were isolated using an aqueous two-phase system. Rats were randomly assigned into four groups: Normal, BCNI, exosome once, and exosome-repeat groups. After four weeks, we measured the intracavernosal pressure (ICP)/mean arterial pressure (MAP) ratio to evaluate erectile function and examined cavernous nerve tissues for histological and molecular analyses. RNA sequencing in penile tissues was used to determine differentially expressed genes and was verified by quantitative polymerase chain reaction. Human umbilical vein endothelial cells (HUVECs) were used for in vitro studies to analyze biological roles.

RESULTS

The ICP/MAP ratios in the exosome-once and exosome-repeat groups were significantly increased compared to those in the BCNI group. Interestingly, the ICP/MAP ratio showed a greater increase in the exosome-repeat group, which also showed significantly increased smooth muscle/collagen ratio, α-smooth muscle actin and neuronal nitric oxide synthase expression, and cyclic guanosine monophosphate level compared to the BCNI and exosome-once groups. Three genes were significantly differentially expressed in the exosome group, among which Ras homolog family member B promoted cell proliferation and angiogenesis of HUVECs.

CONCLUSIONS

Repeated injections of MSC-derived exosomes can be effective in the treatment of rat models with ED induced by cavernous nerve injury.

Penile Rehabilitation after Prostate Cancer Treatment: Which Is the Right Program?

The management of sexual complications after treatment of localized prostate cancer, such as erectile dysfunction, changes in the length of the penis, pain during sexual intercourse, and lack of orgasm, is still an unsolved problem with an important impact on patients’ quality of life. In this review, we summarize the current scientific literature about the rehabilitation of erectile dysfunction after prostate cancer treatment. The therapy for penile rehabilitation includes different types of treatments: the combination of phosphodiesterase type 5 inhibitors (PDE5-I) and the vacuum erectile device (VED) are considered first-line treatment options. When therapy begins, the duration of treatment, the dosage and the drug used all play very important roles in the treatment outcome. Intracavernous injection (ICI) therapy represents the second-line option for patients ineligible for PDE5-I therapy. Technological development has led to the emergence of devices for the stimulation of the penis without the use of drugs, such as penile vibratory stimulation (PVS) for stimulation of ejaculation in spinal cord injury and low-intensity extracorporeal shockwave therapy (LIESWT). The rapid diffusion of the latter, thanks to its easy use, attains good results without side effects. The panorama of penile rehabilitation after PC treatments is vast and many studies are needed, especially on new technologies, to find the best therapeutic regimen possible, personalized to the patient’s characteristics and the type of treatment for PC.

Insulin-Like Growth Factor-1-Loaded Polymeric Poly(Lactic-Co-Glycolic) Acid Microspheres Improved Erectile Function in a Rat Model of Bilateral Cavernous Nerve Injury

BACKGROUND

Previous studies have documented improvement in erectile function after bilateral cavernous nerve injury (BCNI) in rats with the use of pioglitazone. Our group determined this improvement to be mediated by the insulin-like growth factor-1 (IGF-1) pathway.

AIM

To eliminate the systemic effects of pioglitazone and evaluate the local delivery of IGF-1 by polymeric microspheres after BCNI in the rat.

METHODS

Male Sprague-Dawley rats aged 10-12 weeks were assigned at random to 3 groups: sham operation with phosphate buffered saline (PBS)-loaded microspheres (sham group), crush injury with PBS-loaded microspheres (crush group), and crush injury with IGF-1-loaded microspheres (IGF-1 group). Poly(lactic-co-glycolic) acid microspheres were injected underneath the major pelvic ganglion (MPG). IGF-1 was released at approximately 30 ng/mL/day per MPG per rat.

OUTCOMES

Functional results were demonstrated by maximal intracavernosal pressure (ICP) normalized to mean arterial pressure (MAP). Protein-level analysis data of IGF-1 receptor (IGF-1R), extracellular signal-regulated kinase (ERK)-1/2, and neuronal nitric oxide synthase (nNOS) were obtained using Western blot analysis and immunohistochemistry for both the cavernosal tissue and the MPG and cavernous nerve (CN).

RESULTS

At 2 weeks after nerve injury, animals treated with IGF-1 demonstrated improved erectile functional recovery (ICP/MAP) at all voltages compared with BCNI (2.5V, P = .001; 5V, P < .001; 7.5V, P < .001). Western blot results revealed that up-regulation of the IGF-1R and ERK-1/2 in both the nervous and erectile tissue was associated with improved erectile function recovery. There were no significant between-group differences in nNOS protein levels in cavernosal tissue, but there was an up-regulation of nNOS in the MPG and CN. Immunohistochemistry confirmed these trends.

CLINICAL TRANSLATION

Local up-regulation of the IGF-1R in the neurovascular bed at the time of nerve injury may help men preserve erectile function after pelvic surgery, such as radical prostatectomy, eliminating the need for systemic therapy.

STRENGTHS & LIMITATIONS

This study demonstrates that local drug delivery to the MPG and CN can affect the CN tissue downstream, but did not investigate the potential effects of up-regulation of the growth factor receptors on prostate cancer tissue.

CONCLUSION

Stimulating the IGF-1R at the level of the CN has the potential to mitigate erectile dysfunction in men after radical prostatectomy, but further research is needed to evaluate the safety of this growth factor in the setting of prostate cancer. Haney NM, Talwar S, Akula PK, et al. Insulin-Like Growth Factor-1-Loaded Polymeric Poly(Lactic-Co-Glycolic) Acid Microspheres Improved Erectile Function in a Rat Model of Bilateral Cavernous Nerve Injury. J Sex Med 2019;16:383-393.

Suprapubic cystostomy for the management of urethral injuries during penile prosthesis implantation

Introduction

Urethral injury is an uncommon surgical complication of penile prosthesis (PP) surgery. Conventional dogma requires abortion of the procedure if the adjacent corporal body is involved or delayed implantation to avert device infection associated with urinary extravasation. Besides the setback of the aborted surgery, this management approach also presents the possible difficulty of encountering corporal fibrosis at the time of reoperation.

Aim

We report an approach using primary urethral repair and temporary suprapubic cystostomy for the management of incidental urethral injuries in a cohort of patients allowing for successful completion of unaborted PP implantation.

Materials and Methods

We performed a retrospective analysis of all patients receiving PPs from 1990 to 2014 in which incidental urethral injuries were repaired and PP implantation was completed with suprapubic cystostomy (suprapubic tube [SPT] insertion). After allowing for urethral healing and urinary diversion via SPT for 4–8 weeks, the PP was activated.

Main Outcome Measures

Successful management was determined by the absence of perioperative complications within 6 months of implantation.

Results

We identified four cases, all receiving inflatable PPs, managed with temporary suprapubic cystostomy. These patients sustained urethral injuries during corporal dissection (one patient), corporal dilation (one patient), and penile straightening (two patients). All patients were managed safely and successfully.

Conclusion

Primary urethral repair followed by temporary suprapubic cystostomy offers a surgical approach to complete PP implantation successfully in patients who sustain urethral injury complications, particularly for complex PP surgeries. Anele UA, Le BV, and Burnett AL. Suprapubic cystostomy for the management of urethral injuries during penile prosthesis implantation.

Penile rehabilitation: the evolutionary concept in the management of erectile dysfunction

A compromise in erectile function is commonly experienced after radical prostatectomy and has been attributed to injury to vascular, neurogenic, and smooth muscle. The concept of rehabilitation after organ injury is not a novel concept and is one that has been applied to all aspects of medicine. Penile rehabilitation has been classically defined as the use of a device or pharmacologic agent to aid erectile function recovery after radical prostatectomy. Here we redefine penile rehabilitation as the use of any device, medication, or intervention to promote male sexual function as a primer before and after any insult to the penile erectile physiologic axis. We also review the epidemiology, rational and current literature on penile rehabilitation after prostatectomy.

Prediction model for penile prosthesis implantation for erectile dysfunction management

OBJECTIVE

Penile prosthesis surgery is indicated based on undesirability, contraindication or ineffectiveness of non-surgical options for erectile dysfunction. This definitive treatment is often delayed after initial diagnosis. Our objective was to develop a prediction tool based on a patient's clinical history to determine likelihood of ultimately receiving a penile prosthesis.

RESEARCH DESIGN AND METHODS

This retrospective analysis used claims data from Commercial and Medicare supplemental databases. Inclusion criteria were 18 years of age with 1 year of continuous enrollment at the first diagnosis of erectile dysfunction. Patients' demographics, co-morbidities and erectile dysfunction therapy were derived based on enrollment, medical and prescription histories.

MAIN OUTCOME MEASURES

The Cox proportional hazards model with stepwise selection was used to identify and quantify (using relative risk) factors associated with a future penile prosthesis implant. Co-morbidities and therapies present prior to the index erectile dysfunction diagnosis were analyzed as fixed covariates.

RESULTS

Approximately 1% of the dataset's population (N = 310,303 Commercial, N = 74,315 Medicare, respectively) underwent penile prosthesis implantation during the study period (3928 patients in the overall population: 2405 patients [0.78%] in the Commercial and 1523 patients [2.05%] in the Medicare population). Factors with the greatest predictive strength of penile prosthesis implantation included prostate cancer diagnosis (relative risk: 3.93, 2.29; 95% CI, 3.57-4.34, 2.03-2.6), diabetes mellitus (2.31, 1.23; 2.12-2.52, 1.1-1.37) and previous treatment with first-line therapy (1.39, 1.33; 1.28-1.5, 1.2-1.47) (all P < 0.01).

CONCLUSION

The presence and extent of specific medical history factors at the time of erectile dysfunction diagnosis predict an individual's future likelihood of penile prosthesis. Calculating the likelihood of penile prosthesis implantation based on the weight of these factors may assist clinicians with the definition of a care plan and patient counseling. The precision of the model may be limited by factors beyond medical history information that possibly influence the decision to proceed to surgery.

Peyronie's disease: epidemiology, diagnosis, and management

OBJECTIVE

Peyronie's disease (PD) is a progressive fibrotic disorder of the penis that is characterized by formation of collagen plaques on the tunica albuginea of the penis that may result in penile deformity, pain (typically early in the disease course), and often occurs in conjunction with erectile dysfunction. This review's purpose is to raise awareness of PD among primary care physicians, who are likely to provide the initial diagnosis and information to patients.

METHODS

PubMed was searched for articles related to epidemiology, diagnosis, and management of PD. Reference lists of relevant articles were also examined for further pertinent research. Following the goals of this review, references were selected based on their appropriateness for a primary care audience.

RESULTS

The symptoms of PD may physically limit intercourse and impose a severe physical and psychological burden. The course of PD includes an early 'inflammatory' phase that may last 1-18 months and a subsequent 'stable' phase. In the early phase, patients may experience penile pain as the tunical plaque develops. During the stable phase, the plaque becomes more organized, penile curvature stabilizes, and the pain usually subsides. Currently, there are no US Food and Drug Administration approved therapies that have shown significant efficacy for PD. Nonsurgical treatment options are often used to manage PD with variable success. Most studies of nonsurgical management of PD are small, poorly controlled, and include patients in variable disease stages. Surgical treatment of PD is reserved for stable patients with erectile dysfunction and penile deformity that impairs sexual function.

CONCLUSION

PD is frequently undiagnosed. Even when PD is correctly identified, choice of treatment is problematic, based on the limited currently available clinical data demonstrating clinical benefits associated with treatment. Newer medications in clinical testing seem to offer some potential benefit for men with PD, though further research is necessary.

Comparison of health-related quality of life and emotional distress among Chinese cancer survivors

The purpose of this study is to compare health-related quality of life (HRQoL) and emotional distress among diverse cancer survivors who had completed all treatment within the previous year. A convenience sample of 353 cancers survivors (lung, head and neck, breast and prostate cancers) were recruited to complete a survey, which consisted of (i) Hospital Anxiety and Depression Scales; (ii) Chinese version of the Functional Assessment of Cancer Therapy-General version; and (iii) demographic and clinical data. The HRQoL scores were similar among the four types of survivors. Mild anxiety and depression levels were reported, but no significant difference was noted. Younger females with financial burdens and uncertain prognosis were particularly associated with HRQoL and emotional distress. Further studies are essential to identify specific problems that cancer patients experience after cancer diagnosis that might lead to the early detection of those most at risk of ongoing problems.

Nitric oxide-releasing polymeric microspheres improve diabetes-related erectile dysfunction

INTRODUCTION

We have used a long-acting nitric oxide (NO)-releasing polymer to develop injectable biodegradable microspheres capable of localized NO release over prolonged periods of time.

AIM

The aim of this study was to evaluate the therapeutic potential of these microspheres for diabetes-related erectile dysfunction (ED) in the rat model.

METHODS

NO-releasing microspheres were incubated in physiologic buffer, and in vitro NO release was measured using a Griess assay. To ensure no migration, microspheres were fluorescently tagged and injected into the corpus cavernosum of adult rats, and fluorescent imaging was performed weekly for 4 weeks, at which point rats were sacrificed. To assess physiologic efficacy, diabetes was induced in 40 rats using streptozotocin (STZ), whereas 10 rats were kept as age-matched controls. Diabetic rats were divided into four groups: no treatment, sildenafil, NO-releasing microspheres, and combination therapy. For each rat, the cavernosal nerve (CN) was stimulated at various voltages, and intracavernosal pressure (ICP) and mean arterial pressure (MAP) were measured via corpus cavernosum and carotid artery catheterization, respectively. Long-term efficacy was determined by injecting diabetic rats with microspheres and measuring erectile response at predetermined intervals for up to 5 weeks.

MAIN OUTCOME MEASURES

Erectile response was determined via calculation of mean peak ICP/MAP and area under curve (AUC) for each experimental group.

RESULTS

Under physiologic conditions in vitro, microspheres continued NO release for up to 4 weeks. Fluorescent imaging revealed no detectable signal in tissues besides cavernosal tissue at 4 weeks postinjection. Upon CN stimulation, peak ICP/MAP ratio and AUC of diabetic rats improved significantly (P < 0.05) in microsphere and combination therapy groups compared with no treatment and sildenafil groups. In long-term efficacy studies, microspheres augmented the effect of sildenafil for 3 weeks following injection (P < 0.05).

CONCLUSIONS

NO-releasing microspheres significantly improved erectile response in diabetic rats for 3 weeks and hence offer a promising approach to ED therapy, either as monotherapy or combination therapy.

Current penile-rehabilitation strategies: Clinical evidence

We review the current strategies used for penile rehabilitation (PR) after a radical prostatectomy, where PR is defined as the attempt to restore spontaneous erectile function so that the patient can generate erections with no need for erectile aids. We searched PubMed for relevant reports, using the keywords ‘radical prostatectomy’, ‘penile rehabilitation’, ‘phosphodiesterase inhibitors’, ‘vacuum erection device’, ‘injection therapy’, ‘urethral suppository’, and ‘erectile dysfunction’. In all, 155 articles were identified and reviewed, and had a level of evidence ranging from 1b-4. The use of PR strategies should be based on the patient’s goals after a thorough explanation of realistic expectations, and the risks and consequences of the various treatment options. While a multitude of studies suggest a benefit with PR strategies, there are no established, proven regimens. Further research is needed to establish the optimal approaches to PR.

Long-term satisfaction and predictors of use of intracorporeal injections for post-prostatectomy erectile dysfunction

PURPOSE

Intracorporeal injections have low use rates and high discontinuation rates. We examined factors associated with intracorporeal injection use, long-term satisfaction with intracorporeal injection and reasons for discontinuation in men treated with radical prostatectomy.

MATERIALS AND METHODS

Between October 2000 and September 2003, 731 men who underwent open radical retropubic prostatectomy were enrolled in a prospective outcomes study. The 8-year followup evaluation included the UCLA-PCI, and a survey capturing intracorporeal injection use, satisfaction and reasons for discontinuation. Logistic regression was used to determine associations between intracorporeal injection use and preoperative variables.

RESULTS

The 8-year self-assessment was completed by 368 (50.4%) men. Of these men 140 (38%) indicated prior or current intracorporeal injection use, with only 34 using intracorporeal injection at 8 years. Overall, 44% of the men were satisfied with intracorporeal injections. Reasons for discontinuation included dislike (47%), pain (33%), return of erection (19%), inefficacy (14%) and no partner (6%). Men trying intracorporeal injections had greater preoperative UCLA-PCI sexual function scores (75.2 vs 65.62, p = 0.00005) as well as greater decreases in this score at 3 months (p = 0.0002) and 2 years (p = 0.003). Higher preoperative sexual function scores were independently associated with the use of intracorporeal injections in a model adjusted for age, marital status, nerve sparing status and body mass index (OR 1.021, 95% CI 1.008-1.035).

CONCLUSIONS

Men pursuing intracorporeal injections have better baseline erectile function and experience greater deterioration in erectile function during the early postoperative period. Despite the high efficacy of injections, many men discontinue intracorporeal injections due to dislike or discomfort. Satisfaction rates for intracorporeal injections indicate their long-term role in restoring sexual function in men with post-prostatectomy erectile dysfunction.

Sexuality and Intimacy After Definitive Treatment and Subsequent Androgen Deprivation Therapy for Prostate Cancer

There are more than 2 million prostate cancer survivors in the United States. Primary therapy with surgery or radiation results in permanent changes in sexual function. More than half of these men are subsequently treated with androgen deprivation therapy (ADT) at some point. The addition of ADT further compromises sexuality, intimacy, and a couple's relationship. This review will highlight the challenges faced by patients and couples and reveal the tremendous need for better education of physicians, patients, and couples as well as for more research in sexuality and intimacy with the goal of improving quality of life for this large population of survivors. Suggestions for clinicians to better help patients and their partners regarding sexuality and intimacy are offered.