A Pilot Study to Determine Penile Oxygen Saturation Before and After Vacuum Therapy in Patients with Erectile Dysfunction After Radical Prostatectomy

Understanding human aging and the fundamental cell signaling link in age-related diseases: the middle-aging hypovascularity hypoxia hypothesis

Aging-related hypoxia, oxidative stress, and inflammation pathophysiology are closely associated with human age-related carcinogenesis and chronic diseases. However, the connection between hypoxia and hormonal cell signaling pathways is unclear, but such human age-related comorbid diseases do coincide with the middle-aging period of declining sex hormonal signaling. This scoping review evaluates the relevant interdisciplinary evidence to assess the systems biology of function, regulation, and homeostasis in order to discern and decipher the etiology of the connection between hypoxia and hormonal signaling in human age-related comorbid diseases. The hypothesis charts the accumulating evidence to support the development of a hypoxic milieu and oxidative stress-inflammation pathophysiology in middle-aged individuals, as well as the induction of amyloidosis, autophagy, and epithelial-to-mesenchymal transition in aging-related degeneration. Taken together, this new approach and strategy can provide the clarity of concepts and patterns to determine the causes of declining vascularity hemodynamics (blood flow) and physiological oxygenation perfusion (oxygen bioavailability) in relation to oxygen homeostasis and vascularity that cause hypoxia (hypovascularity hypoxia). The middle-aging hypovascularity hypoxia hypothesis could provide the mechanistic interface connecting the endocrine, nitric oxide, and oxygen homeostasis signaling that is closely linked to the progressive conditions of degenerative hypertrophy, atrophy, fibrosis, and neoplasm. An in-depth understanding of these intrinsic biological processes of the developing middle-aged hypoxia could provide potential new strategies for time-dependent therapies in maintaining healthspan for healthy lifestyle aging, medical cost savings, and health system sustainability.

Erectile Dysfunction: Treatments, Advances and New Therapeutic Strategies

Erectile dysfunction (ED) is the inability to get and maintain an adequate penile erection for satisfactory sexual intercourse. Due to its negative impacts on men's life quality and increase during aging (40% of men between 40 and 70 years), ED has always attracted researchers of different disciplines, from urology, andrology and neuropharmacology to regenerative medicine, and vascular and prosthesis implant surgery. Locally and/or centrally acting drugs are used to treat ED, e.g., phosphodiesterase 5 inhibitors (first in the list) given orally, and phentolamine, prostaglandin E1 and papaverine injected intracavernously. Preclinical data also show that dopamine D4 receptor agonists, oxytocin and α-MSH analogues may have a role in ED treatment. However, since pro-erectile drugs are given on demand and are not always efficacious, new strategies are being tested for long lasting cures of ED. These include regenerative therapies, e.g., stem cells, plasma-enriched platelets and extracorporeal shock wave treatments to cure damaged erectile tissues. Although fascinating, these therapies are laborious, expensive and not easily reproducible. This leaves old vacuum erection devices and penile prostheses as the only way to get an artificial erection and sexual intercourse with intractable ED, with penile prosthesis used only by accurately selected patients.

Indications and characteristics of penile traction and vacuum erection devices

A variety of devices are available for the management of patients with erectile dysfunction, Peyronie's disease, penile dysmorphophobia, for support before and after penile prosthesis insertion, and after radical prostatectomy. Traction devices include, but are not limited to, Penimaster PRO (MSP Concept, Berlin, Germany), Andropenis and Andropeyronie (Andromedical, Madrid, Spain), and the Restorex (PathRight Medical, Plymouth, USA). The other type of devices are vacuum devices such the Osbon ErecAid (Timm Medical, MN, USA). Different devices are optimal for different clinical applications, and robust and contemporary clinical data show a variety of strengths and weaknesses for each device. Research currently favours the use of traction devices for improvement of penile curvature and erectile function in patients with Peyronie's disease compared with vacuum devices; Penimaster Pro and Restorex have been shown to be associated with the best outcomes in this indication. Vacuum devices are favoured for treatment of erectile dysfunction and penile length loss after radical prostatectomy; the Osbon ErecAid is the most well-studied device for this indication. Research into other uses of vacuum and traction devices, such as for penile dysmorphophobia or before and after penile prosthesis, is very limited. Compliance, cost and availability remain substantial challenges, and further high-quality evidence is required to clarify the role of traction devices in urology and sexual medicine.

Optimal vacuum erectile device therapy regimen for penile rehabilitation in a bilateral cavernous nerve crush rat model

BACKGROUND

Vacuum erectile device (VED) therapy has been widely used in penile rehabilitation after radical prostatectomy; however, there is no consensus on the best regimen.

OBJECTIVES

To explore an optimal VED therapy regimen in bilateral cavernous nerve crush (BCNC) rat model.

MATERIALS AND METHODS

Adult male rats were used to measure the effects of different durations (1-30 min) of VED treatment on penile length, penile blood gas analysis, and adverse effects. Forty-eight adult male rats were randomly divided into Sham, BCNC, and VED treatment groups (2-3-2-3 min, 4-3-3 min, 5-5 min, and 10 min). Penile length, erectile function, and side effects were detected after VED treatment. Histopathological staining and Western blotting were performed to explore the cellular and molecular changes.

RESULTS

Prolongation of the duration of VED treatment significantly decreased the penile oxygen saturation, partial oxygen pressure, and arterial blood ratio (P < 0.05). Compared with the BCNC group, all VED treatment regimens partially reversed BCNC-induced penile shortening and erectile dysfunction (P < 0.0001), with the 4-3-3-min and 5-5-min treatment groups exhibiting more significant improvement than the 10-min and 2-3-2-3-min treatment groups (P < 0.0001). The mechanism may be related to the up-regulation of the smooth muscle cell/collagen ratio, endothelial nitric oxide synthase, and α-smooth muscle actin (all P < 0.0001); and the down-regulation of hypoxia-inducible factor-1α, transforming growth factor-β1, and apoptosis (all P < 0.0001). The incidence of adverse effects in the 2-3-2-3-min treatment group was the highest.

DISCUSSION

The commonly used VED therapy regimens maintained erectile function and penile length of BCNC rat by relieving hypoxia and fibrosis, and no further benefits were observed with increased treatment frequency or prolonged treatment duration.

CONCLUSION

Two consecutive 5-min treatments with a short interval is the optimal VED therapy regimen for penile rehabilitation in BCNC rat model.

The management of sexual dysfunction resulting from radiotherapy and androgen deprivation therapy to treat prostate cancer: A comparison of uro-oncology practice according to disease stage

OBJECTIVES

To establish current uro-oncology practice in the management of sexual dysfunction (SD) following radiotherapy (RT) and/or androgen deprivation therapy (ADT) to treat prostate cancer. To identify differences in approach to the management of SD according to disease stage.

SUBJECTS AND METHODS

A 14-question mixed methods survey was designed to assess the current UK practice. Closed- and open-ended questions were used to quantify results while allowing participants to expand on answers. The survey was distributed to members of the British Uro-Oncology Group at the 2019 annual meeting.

RESULTS

Surveys were completed by 63 uro-oncologists attending the annual meeting of the British Uro-Oncology Group (response rate 66%). The major issue highlighted was a difference in approach to managing SD according to disease stage. More than half of the participants (56%) said 'advanced stage of disease' was a barrier to discussing SD. Clinicians were less likely to discuss SD, take baseline assessments, refer to a specialist clinic or offer rehabilitation when dealing with patients with advanced disease. Only a minority said that the management of SD was primarily their responsibility (11%). Nearly all clinicians (92%) had access to SD clinics; however, the majority of clinicians did not routinely refer patients.

CONCLUSIONS

This study shows that men with advanced prostate cancer need better support in managing SD. Patients receiving long-term ADT are less likely to be offered any kind of help or intervention. Specific guidance on managing SD in this cohort may result in improvements in sexual function, emotional well-being, quality of life, mental health and confidence.

Adding a vacuum erection device to regular use of Tadalafil improves penile rehabilitation after posterior urethroplasty

This study aimed to evaluate whether adding a vacuum erection device (VED) to regular use of Tadalafil could achieve better penile rehabilitation following posterior urethroplasty for pelvic fracture-related urethral injury (PFUI). Altogether, 78 PFUI patients with erectile dysfunction (ED) after primary posterior urethroplasty were enrolled and divided into two treatment groups: VED combined with Tadalafil (Group 1, n = 36) and Tadalafil only (Group 2, n = 42). Changes in penile length, testosterone level, International Index of Erectile Function-5 (IIEF-5) questionnaire, Quality of Erection Questionnaire (QEQ), and nocturnal penile tumescence (NPT) testing were used to assess erectile function before and after 6 months of ED treatment. Results showed that the addition of VED to regular use of Tadalafil preserved more penile length statistically (0.4 ± 0.9 vs −0.8 ± 0.7 cm, P < 0.01). IIEF-5 score and QEQ score in Group 1 were higher than Group 2 (both P < 0.05). After treatment, 21/36 (58.3%) Group 1 patients and 19/42 (45.2%) Group 2 patients could complete vaginal penetration. Group 1 patients also had markedly improved testosterone levels (P = 0.01). Unexpectedly, there was no significant difference in NPT testing between two therapies. For PFUI patients with ED after posterior urethroplasty, the addition of VED to regular use of Tadalafil could significantly improve their conditions – improving erection and increasing penile length – thus increasing patient satisfaction and confidence in penile rehabilitation.

Devices for penile traction: the long and winding road to treating Peyronie's disease

INTRODUCTION

Penile traction therapy (PTT) is increasingly being recognized as a viable nonsurgical approach to Peyronie's disease (PD). The goal of this article is to review the current literature on PTT with attention to traction protocols, devices, and outcomes.

AREAS COVERED

Literature on the pathophysiology of PD, PTT as primary and adjunctive treatment for PD, perioperative use of PTT, and vacuum erection devices are all reviewed. Pertinent literature was obtained from the PubMed database. The key words 'penile traction,' 'mechanotransduction,' and 'Peyronie's disease' were searched and results were narrowed down based on relevance to the review.

EXPERT COMMENTARY

PTT appears beneficial but the true magnitude of effect is difficult to discern. Most studies are not randomized, have small sample sizes, lack control arms, or have varying traction protocols. Patient compliance is critical and new devices and traction protocols are needed to maximize the benefit of PTT.

Does penile rehabilitation have a role in the treatment of erectile dysfunction following radical prostatectomy?

In men undergoing radical treatment for prostate cancer, erectile function is one of the most important health-related quality-of-life outcomes influencing patient choice in treatment. Penile rehabilitation has emerged as a therapeutic measure to prevent erectile dysfunction and expedite return of erectile function after radical prostatectomy. Penile rehabilitation involves a program designed to increase the likelihood of return to baseline-level erectile function, as opposed to treatment, which implies the therapeutic treatment of symptoms, a key component of post–radical prostatectomy management. Several pathological theories form the basis for rehabilitation, and a plethora of treatments are currently in widespread use. However, whilst there is some evidence supporting the concept of penile rehabilitation from animal studies, randomised controlled trials are contradictory in outcomes. Similarly, urological guidelines are conflicted in terms of recommendations. Furthermore, it is clear that in spite of the lack of evidence for the role of penile rehabilitation, many urologists continue to employ some form of rehabilitation in their patients after radical prostatectomy. This is a significant burden to health resources in public-funded health economies, and no effective cost-benefit analysis has been undertaken to support this practice. Thus, further research is warranted to provide both scientific and clinical evidence for this contemporary practice and the development of preventative strategies in treating erectile dysfunction after radical prostatectomy.

Comparison of the effects of extracorporeal shock wave therapy and a vacuum erectile device on penile erectile dysfunction: a randomized clinical trial

BACKGROUND

This randomized clinical trial (October 2012-December 2013) compared extracorporeal shock wave therapy (ESWT) and a vacuum erectile device (VED) for management of erectile dysfunction (ED).

METHODS

Consecutive Chinese patients (20-55 years) with ED, abnormal nocturnal penile tumescence and rigidity (NPTR), and international index of erectile function-5 items (IIEF-5) score <22 were randomized to receive ESWT or VED (twice weekly, 4 weeks). Primary outcomes were treatment efficacy and success rate 4 weeks after completion of therapy. Secondary outcomes included changes in IIEF-5 score, sex encounter profile (SEP) score, erection hardness score (EHS) and NPTR assessments 4 weeks post-therapy. All enrolled patients (n = 30 per group) completed the study. At baseline, age, IIEF-5 score, SEP score, EHS, and NPTR assessments were similar between groups.

RESULTS

Four weeks post-therapy, IIEF-5 score increased in the ESWT (15.03 ± 3.00 vs. 11.60 ± 2.28) and VED (15.10 ± 3.06 vs. 11.53 ± 2.27) groups, as did SEP score, EHS, and NPTR measures (all P < .05). Efficacy in the ESWT and VED groups was excellent in 10% and 13.3%, respectively, and moderate in 63.3% and 53.3%, respectively. Treatment success rate in the ESWT and VED groups was 73.3% and 67.7%, respectively.

CONCLUSION

VED use and ESWT have comparable efficacies in the treatment of ED in Chinese patients.

The controversy surrounding penile rehabilitation after radical prostatectomy

Radical prostatectomy (RP) techniques have been refined in the last few decades. Despite nerve-sparing surgery, erectile dysfunction (ED) still seems to be affecting more than half of patients undergoing RP. Penile rehabilitation consists of understanding the mechanisms that affect erectile function (EF) and utilizing pharmacologic agents, devices or interventions to promote male sexual function before and after any insult to the penile erectile physiologic axis. There currently is a limited amount of clinical trials that assess treatments with the goal of recovering post-prostatectomy EF. The goal of this article is to assess a contemporary series of trials that study penile rehabilitation. Although the current evidence lacks to prove its irrefutable effectiveness, advancements in research and technology forecast a promising future in penile rehabilitation management.

Erectile dysfunction treatment and traditional medicine-can East and West medicine coexist?

Erectile dysfunction (ED) is a common sexual problem affecting many men irrespective of cultures, beliefs and nationalities. While medical therapy for ED has been revolutionized by the advent of oral phosphodiesterase type 5 inhibitors and intracavernosal injection of vasoactive agents, recent technological advances such stem cell therapy, low intensity shock wave and newer generation of penile prosthesis implant offer hope to men who do not respond to conventional medical therapy. In contrast, traditional and complementary medicine (TCM) focuses on the restoration and better overall bodily regulation with the use of various herbal and animal products as well as exercises to invigorate qi (energy) in vital organs. Western medicine involves an analysis of ED symptom and underlying causes that contribute to ED, while TCM emphases the concept of holism and harmonization of body organs to achieve natural sexual life. The following article reviews our current understanding regarding the philosophical approach, and evaluates the evidence surrounding various ED therapies between mainstream Western Medicine and TCM.

Vacuum therapy in penile rehabilitation after radical prostatectomy: review of hemodynamic and antihypoxic evidence

Generally, hypoxia is a normal physiological condition in the flaccid penis, which is interrupted by regular nocturnal erections in men with normal erectile function.1 Lack of spontaneous and nocturnal erections after radical prostatectomy due to neuropraxia results in persistent hypoxia of cavernosal tissue, which leads to apoptosis and degeneration of cavernosal smooth muscle fibers. Therefore, overcoming hypoxia is believed to play a crucial role during neuropraxia. The use of a vacuum erectile device (VED) in penile rehabilitation is reportedly effective and may prevent loss of penile length. The corporal blood after VED use is increased and consists of both arterial and venous blood, as revealed by color Doppler sonography and blood gas analysis. A similar phenomenon was observed in negative pressure wound therapy (NPWT). However, NPWT employs a lower negative pressure than VED, and a hypoperfused zone, which increases in response to negative pressure adjacent to the wound edge, was observed. Nonetheless, questions regarding ideal subatmospheric pressure levels, modes of action, and therapeutic duration of VED remain unanswered. Moreover, it remains unclear whether a hypoperfused zone or PO₂ gradient appears in the penis during VED therapy. To optimize a clinical VED protocol in penile rehabilitation, further research on the mechanism of VED, especially real-time PO₂ measurements in different parts of the penis, should be performed.

Penile rehabilitation following prostate cancer treatment: review of current literature

Radical prostatectomy (RP) and radiotherapy (RT) are highly effective in improving prostate cancer survival. However, both have a detrimental effect on erectile function (EF). Penile rehabilitation consists of understanding the mechanisms that cause erectile dysfunction (ED) and utilizing pharmacologic agents, devices or interventions to promote male sexual function. For the past decade, many researchers have pursued to define effective treatment modalities to improve ED after prostate cancer treatment. Despite the understanding of the mechanisms and well-established rationale for postprostate treatment penile rehabilitation, there is still no consensus regarding effective rehabilitation programs. This article reviews a contemporary series of trials that assess penile rehabilitation and explore treatment modalities that might play a role in the future. Published data and trials related to penile rehabilitation after RP and RT were reviewed and presented. Although recent trials have shown that most therapies are well-tolerated and aid in some degree on EF recovery, we currently do not have tangible evidence to recommend an irrefutable penile rehabilitation algorithm. However, advancements in research and technology will ultimately create and refine management options for penile rehabilitation.

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.

Manufacturers' data show increasing implanted cylinder sizes and measured corporal lengths in inflatable penile implants

INTRODUCTION

We sought to determine whether measured corporal length (MCL) or implanted device size (IDS) has changed.

METHODS

Data were obtained from the two major penile implant companies from the years of 2005-2010 and analyzed. While we requested similar data, companies supplied information at their discretion with MCL provided by American Medical Systems and IDS provided by Coloplast. Intra-patient corporal discrepancies, disease state effects, rear tip extenders (RTEs) use and place of implantation were also provided in some part by companies.

RESULTS

MCL and IDS increased during the study period. Despite the general trend of MCL/IDS, clinically significant (0.5 cm or greater) decreases in MCLs were noted in patients with Peyronie's disease (PD) or a history of radical pelvic surgery (excludes prostatectomy). In only 2.7 % of cases was there an intra-patient discrepancy in cylinder size (>1 cm). IDS was longer in the USA (US, 19.4 cm) compared to outside the US (OUS, 17.7 cm, p < 0.0001). Cylinders were implanted without RTEs in 48.3 % of US cases and 73.7 % of OUS cases (p < 0.0001). In Coloplast devices there was an overall statistically significant change in the use of 16 cm (less utilized) and 20 and 22 cm (more utilized) cylinder lengths during the study period in US implants.

CONCLUSION

MCL and IDS increased during the study period. Men with a history of PD or radical pelvic surgery are at highest risk to have shorter MCL and to possibly receive shorter implants. Intra-patient IDS inconsistency is rare and should prompt investigation.

Landmarks in erectile function recovery after radical prostatectomy

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

Psychosocial perspectives on sexual recovery after prostate cancer treatment

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

Development of UK guidance on the management of erectile dysfunction resulting from radical radiotherapy and androgen deprivation therapy for prostate cancer

AIM

To develop a management strategy (rehabilitation programme) for erectile dysfunction (ED) after radiotherapy (RT) or androgen deprivation therapy (ADT) for prostate cancer that is suitable for use in a UK NHS healthcare context.

METHODS

PubMed literature searches of ED management in this patient group together with a survey of 28 experts in the management of treatment-induced ED from across the UK were conducted.

RESULTS

Data from 19 articles and completed questionnaires were collated. The findings discussed in this article confirm that RT/ADT for prostate cancer can significantly impair erectile function. While many men achieve erections through PDE5-I use, others need combined management incorporating exercise and lifestyle modifications, psychosexual counselling and other erectile aids. This article offers a comprehensive treatment algorithm to manage patients with ED associated with RT/ADT.

CONCLUSION

Based on published research literature and survey analysis, recommendations are proposed for the standardisation of management strategies employed for ED after RT/ADT. In addition to implementing the algorithm, understanding the rationale for the type and timing of ED management strategies is crucial for clinicians, men and their partners.

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.