The effect of platelet-rich plasma on cavernous nerve regeneration in a rat model

The efficacy of platelet rich plasma in the treatment of erectile dysfunction: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Erectile dysfunction (ED) is a common issue among males, and the use of platelet-rich plasma (PRP) therapy for treating ED has gained increasing attention, but there is still no conclusive evidence regarding its efficacy.

AIM

To evaluate the efficacy of PRP therapy for ED.

METHODS

We systematically searched PubMed, Embase, Cochrane Library, and Web of Science databases up to November 2023 to identify randomized controlled trials (RCTs) on PRP therapy for ED. We used Review Manager version 5.4 for data analysis and management.

RESULT

After applying inclusion and exclusion criteria for screening, a total of 4 studies involving 413 patients were finally included in our meta-analysis. According to our analysis, the PRP group showed significant advantages over the placebo group in terms of MCID at the first month (p = 0.03) and sixth months (p = 0.008), while there was no significant difference between the two groups at the third month (p = 0.19). Additionally, in terms of IIEF, PRP showed significantly better efficacy than placebo at the first, third, and sixth months (p < 0.00001).

CONCLUSIONS

PRP shows more effectiveness in treating ED compared to placebo, offering hope as a potential alternative treatment for ED.

Evaluating the efficacy and safety of platelet-rich plasma injection for erectile dysfunction: a systematic review and meta-analysis of randomized controlled trials

INTRODUCTION

Platelet-rich plasma (PRP) is rich in factors that play a role in stem cell recruitment, inflammation modulation, and angiogenesis. With numerous preclinical and clinical studies exploring PRP as a potential treatment for erectile dysfunction (ED), this study focused on assessing the effectiveness of intracorporeal PRP injection for ED patients based on randomized controlled trials (RCTs).

OBJECTIVES

The study sought to evaluate the efficacy and safety of intracorporeal injection of PRP in treating ED through a systematic review and meta-analysis of RCTs.

METHODS

This study adhered to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. A comprehensive search was conducted on online databases (PubMed, Scopus, and ScienceDirect) to identify RCTs comparing PRP with a placebo for ED treatment. The primary outcomes assessed were the proportion of patients achieving the minimal clinically important difference in the International Index of Erectile Function (IIEF) domain and the change in the IIEF domain from baseline. The results were combined as a standardized mean difference between the PRP and placebo groups.

RESULTS

Three RCTs comprising 230 patients were included. The overall effect favored PRP over placebo: total patients attaining minimal clinically important difference in the IIEF domain (odds ratio [OR], 5.64; 95% confidence interval [CI], 2.05 to 15.55; P = .0008), IIEF change from baseline (mean difference [MD], 2.99; 95% CI, 1.74 to 4.24; P = .00001), PSV (MD, 9.34; 95% CI, 0.84 to 17.84; P = .03), end-diastolic volume (standardized MD, 0.50; 95% CI, 0.17 to 0.83; P = .003), Sexual Encounter Profile question 3 (standardized MD, 0.78; 95% CI, 0.45 to 1.12; P = .00001), and visual analog scale score (MD, -0.30; 95% CI, -0.53 to -0.08; P = .008).

CONCLUSION

PRP appears to be a safe and effective treatment for mild-to-moderate ED. However, further support from high-quality RCTs is needed to strengthen these findings.

Platelet-rich plasma intracavernosal injections for the treatment of primary organic erectile dysfunction: a systematic review and meta-analysis of contemporary controlled studies

We aim to summarize the latest evidence on platelet-rich plasma (PRP) intracavernosal injections efficacy in men affected by primary organic erectile dysfunction (ED). We reviewed the literature for randomized controlled trials (RCTs) or prospective and retrospective comparative studies evaluating PRP alone or in combination for ED treatment. A comprehensive search in PubMed, Scopus, Web of Science, and ClinicalTrials.gov was performed for English language full-text articles or conference abstracts. A qualitative and quantitative data synthesis was provided. Overall, seven records were included: three RCTs evaluated PRP vs. placebo, one study separately tested PRP and low-intensity shock wave therapy (Li-SWT), three studies compared Li-SWT or low-intensity pulsed ultrasound alone with their combination with PRP. Of 641 included patients, 320 received PRP. Despite the heterogeneity among inclusion criteria, dose and protocol of PRP administration, and outcomes measured, most studies independently reported better sexual outcomes in patients who received PRP, without significant severe side effects. In meta-analysis, where only placebo-controlled studies were included, patients treated with PRP showed higher International Index of Erectile Function (erectile function domain) score compared to patients who received placebo: pooled mean difference (95% Confidence Interval) of 2.99 (1.86, 4.13) after 1 month (209 patients) vs. 2.85 (1.61, 4.09) after 3 months (204 patients) vs. 3.21 (1.82, 4.60) after 6 months (199 patients) of follow-up. In men affected by primary organic ED, PRP intracavernosal injections demonstrated an objective improvement or at least a tendency in erectile function recovery. Patient numbers, and the short-term follow-up may limit the generalizability of these observations. High quality, large-scale, and standardized controlled trials are needed before recommending its definitive use in clinical practice.

A potential treatment for erectile dysfunction: Effect of platelet-rich plasma administration on axon and collagen regeneration in cavernous nerve injury

Recent studies highlighted the role of platelet-rich plasma (PRP) in progenitor cell homing, migration, and nerve cell regeneration while also inhibiting fibrosis and apoptosis in cavernous nerve injury (CNI). The aim of this study was to investigate the effect of PRP administration on axon and collagen regeneration in CNI. A true experimental study using a post-test-only control group design was conducted. Twenty-five male Wistar rats (Rattus norvegicus), weighing 200-300 grams, were divided into five groups: two control groups (sham procedure and negative control), and three experimental groups receiving local PRP, intraperitoneal PRP, and a combination of local and intraperitoneal PRP. The cavernous nerve was injured with a hemostasis clamp for one minute before 200 µL of 200 PRP was injected locally, intraperitoneally, or both, depending on the group. After four weeks, the rats were euthanized, tissue segments (2 mm) from each cavernous nerve and mid-penis were collected and analyzed for collagen density, axon diameter, and number of myelinated axons. Our study found that collagen growth was slower in CNI group without PRP (sham procedure) compared to all PRP groups (local, intraperitoneal, and combination). The intraperitoneal PRP group had the highest collagen density at 5.62 µm; however, no significant difference was observed in collagen density among all groups (p=0.056). Similar axon diameter was found across the groups, with no statistically significant difference observed (p=0.856). In the number of myelinated axons, a significant difference was found among all groups with significantly more axons in local PRP and combined local and intraperitoneal PRP groups compared to others (p=0.026). In conclusion, PRP administration improved the number of myelinated axons in CNI, suggesting PRP role in CNI regeneration and the potential for an innovative approach to treating erectile dysfunction associated with CNI.

Ultrasound guided platelet rich plasma injections for post-traumatic greater occipital neuralgia following concussion: a pilot randomized controlled trial

Background

Treatment for post-traumatic greater occipital neuralgia (GON) includes serial injections of steroid/anesthetic. While these injections can alleviate pain, effects can be transient, frequently lasting only 1 month. As a potential alternative, platelet-rich plasma (PRP) injections are an emerging biological treatment with beneficial effects in peripheral nerve disorders. We investigated the feasibility, safety, and effectiveness of a single PRP injection for post-traumatic GON in comparison to saline or steroid/anesthetic injection.

Methods

In this pilot randomized, double-blinded, placebo-controlled trial, 32 adults with post-traumatic GON were allocated 1:1:1 to receive a single ultrasound-guided injection of (1) autologous PRP (2) steroid/anesthetic or (3) normal saline. Our primary outcome was feasibility (recruitment, attendance, retention) and safety (adverse events). Exploratory measures included headache intensity and frequency (daily headache diaries) and additional questionnaires (headache impact, and quality of life) assessed at pre-injection, 1 week, 1 month, and 3 months post-injection.

Results

We screened 67 individuals, 55% were eligible and 95% of those participated. Over 80% of daily headache diaries were completed with 91% of participants completing the 3-month outcome questionnaires. No serious adverse events were reported. There were no significant differences between groups for headache intensity or frequency. Headache impact on function test-6 scores improved at 3 month in the PRP (β = -9.7, 95% CI [-15.6, -3.74], p = 0.002) and saline (β = -6.7 [-12.7, -0.57], p = 0.033) groups but not steroid/anesthetic group (p = 0.135).

Conclusion

PRP is a feasible and safe method for treating post-traumatic GON with comparable results to saline and steroid/anaesthetic. Further trials with larger sample sizes are required.Clinical trial registration:https://clinicaltrials.gov/, identifier NCT04051203.

Platelet-rich plasma therapy in erectile dysfunction and Peyronie's disease: a systematic review of the literature

PURPOSE

Platelet-rich plasma (PRP) as a regenerative therapy has gained interest in the field of andrology for the treatment of erectile dysfunction (ED) and Peyronie's disease (PD). This systematic review aims to critically evaluate the current evidence on the use of PRP for these conditions.

METHODS

We performed a systematic literature search according to the PRISMA guidelines using PubMed and Scopus databases in December 2023. Studies were included if they evaluated the effect of PRP therapy for ED or PD in humans.

RESULTS

We identified 164 articles, 17 of which were included, consisting of 11 studies on ED, 5 studies on PD, and 1 study on both. We included four randomized controlled trials, 11 prospective cohort studies, and three retrospective cohort studies including a total of 1099 patients. The studies on ED and PD generally showed small to moderate benefits with mild and transient side effects and no major adverse events were reported. General limitations included variations in PRP protocols, small sample sizes, short follow-up periods, and lack of control groups except in the three randomized trials on ED and the one on PD.

CONCLUSION

The literature on PRP therapy in andrology is limited and difficult to interpret due to variations in protocols and methodological drawbacks. Further research is necessary to determine the optimal preparation and treatment protocols for PRP therapy and clarify its effectiveness in andrology.

Platelet-rich plasma for erectile dysfunction: a review of the current research landscape

INTRODUCTION

Erectile dysfunction (ED) is the inability to achieve or maintain erection for satisfactory sexual performance. ED drastically reduces the quality of life for men and their partners and is commonly linked to comorbid conditions such as diabetes and cardiovascular disease. As a result, clinicians and researchers are working to improve treatments for ED. Current guideline-approved ED treatments include oral phosphodiesterase type 5 inhibitors, intraurethral alprostadil, penile intracavernosal injections, and penile prosthesis surgery. Today, there is increasing interest in restorative therapies such as intracavernosal platelet-rich plasma (PRP) for the management of ED.

OBJECTIVES

This narrative review describes the current trials investigating intracavernosal PRP for ED and proposes future directions to increase the strength of evidence to support use of PRP in this population.

METHODS

A comprehensive literature search of PubMed, Science Direct, and Scopus was performed to identify all randomized clinical trials using PRP for the treatment of ED.

RESULTS

We identified 4 randomized clinical trials investigating the safety and efficacy of PRP for ED. We found significant heterogeneity among study protocols, including collection of PRP, dosing of PRP, and follow-up.

CONCLUSION

While intracavernosal PRP is considered safe, its efficacy for the management of ED remains unknown due to variability among clinical trials.

Platelet-rich plasma for the treatment of erectile dysfunction: a systematic review of preclinical and clinical studies

INTRODUCTION

There has been tremendous growth in regenerative medicine during the last decade. For erectile dysfunction (ED), after the inclusion of low-intensity shockwave therapy as a treatment modality for ED management by the European Association of Urology sexual health guidelines, intracavernosal injection of platelet-rich plasma (PRP) has gained popularity between urologists and patients as a novel ED therapeutic modality with initial promising results. However, limited clinical data exist regarding efficacy and safety in patients with ED. Furthermore, despite numerous preclinical studies in other tissues and organs, the mechanism of action for restoring erectile function remains undetermined.

OBJECTIVES

This systematic review aims to present the current status of preclinical and clinical evidence regarding the use of PRP as treatment option for ED.

METHODS

A systematic literature search was conducted using PubMed, Cochrane, and ScienceDirect databases, until February 2023 for studies exploring the effect of PRP on ED.

RESULTS

We identified 517 articles, 23 of which were included in this review. These were 7 preclinical (of which 1 was a comparative trial and 6 were placebo-controlled randomized controlled trials) and 16 clinical studies (of which 1 was a comparative trial, 5 were randomized trials, and 2 were placebo-controlled randomized controlled trials). Preclinical data support the regenerative role of PRP in erectile tissue, in accordance with existing evidence in other tissues. Randomized clinical studies, as well as the first 2 available randomized, placebo-controlled clinical trials, showed promising efficacy and a lack of any adverse events.

CONCLUSION

As PRP for ED is widely used worldwide, there is an urgent need for high-quality studies with long-term follow-up. Standardization of research protocols, especially on the quality of PRP preparation, is also needed.

Platelet-rich Plasma for the Treatment of Erectile Dysfunction: A Prospective, Randomized, Double-blind, Placebo-controlled Clinical Trial

PURPOSE

We assessed the safety and efficacy of 2 injections of platelet-rich plasma for treating mild to moderate erectile dysfunction by conducting a prospective, randomized, double-blind, placebo-controlled clinical trial.

MATERIALS AND METHODS

Men with mild to moderate erectile dysfunction (International Index of Erectile Function scores 11-25) were randomized to receive either 2 injections of platelet-rich plasma or placebo separated by 1 month. Primary outcome was percentage of men meeting minimum clinically important difference at 1 month after the second injection. Secondary outcomes were change in International Index of Erectile Function at 1, 3, and 6 months, and changes in penile vascular parameters and adverse events at 6 months.

RESULTS

We randomized 61 men: 28 into platelet-rich plasma and 33 into placebo. There was no difference between groups in percentage of men meeting minimum clinically important difference at 1 month: 14 (58.3%) in platelet-rich plasma vs 15 (53.6%) in placebo (P = .730). Mean International Index of Erectile Function-Erectile Function domain changed from 17.4 (95% CI 15.8-19.0) to 21 (17.9-24.0) at 1 month in men receiving platelet-rich plasma, vs 18.6 (17.3-19.8) to 21.6 (19.1-24.1) in the placebo group; however, there was no significant difference between groups (P = .756). There were no major adverse events and only 1 minor adverse event in each group. There were no changes in penile Doppler parameters from baseline to 6 months.

CONCLUSIONS

The results of our prospective, double-blind, randomized, placebo-controlled clinical trial suggest that 2 injections of intracavernosal platelet-rich plasma separated by 1 month in men with mild to moderate erectile dysfunction is safe, but we found no difference in efficacy between platelet-rich plasma and placebo.

Intracavernous injection of platelet-rich plasma reverses erectile dysfunction of chronic cavernous nerve degeneration through reduction of prostate hyperplasia evidence from an aging-induced erectile dysfunction rat model

Age-induced erectile dysfunction (ED) is a convoluted medical condition, and restoring erectile function (EF) under geriatric conditions is highly complicated. Platelet-rich plasma (PRP) treatment is an inexpensive cell-based therapeutic strategy. We have aimed to restore EF in aged-ED rats with PRP as a therapeutic tool. Male rats were grouped into aged and young according to age. The young rats were considered as normal control (NC) and treated with saline. Aged were further divided into 2 groups and treated with intracavernous (IC) PRP and saline. Treatment was scheduled at the 9th and 10th week for NC and 41th and 42th week for aged-ED rats, with EF analysis scheduled on the 12th week for NC and 44th week for aged-ED rats, respectively. Erectile response, immunofluorescence staining, and electron microscopic analyses were performed. IC PRP treatment effectively reduced prostate hyperplasia (PH). EF response indicated a significant increase in crucial EF parameters in PRP-treated aged-ED rats. Histological evidence denoted a rigid and restored development of tunica adventitia of the dorsal artery, decreased vacuolation of the dorsal penile nerve, and structural expansion of the epineurium. Masson's trichrome and immunostaining results affirmed an elevated expression of α-smooth muscle actin (α-SMA) in the corpus cavernosum (CC). Ultrastructure findings revealed that PRP effectively rejuvenated degenerating nerves, preserved endothelium and adherent junctions of corporal smooth muscle, and restored the axonal scaffolds by upregulating neurofilament-H (NF-H) expression. Finally, PRP enhanced neural stability by enhancing the axonal remyelination processes in aged-ED rats. Hence, PRP treatment was proven to restore EF in aged-ED rats, which was considered a safe, novel, cost-effective, and hassle-free strategy for EF restoration in geriatric patients.

Current Knowledge on Radiation-Therapy-Induced Erectile Dysfunction in Prostate-Cancer Patients: A Narrative Review

Prostate cancer is the most frequently diagnosed cancer in men in the United States. Among the different available treatment options, radiation therapy is recommended for localized or even advanced disease. Erectile dysfunction (ED) often occurs after radiation therapy due to neurological, vascular, and endocrine mechanisms resulting in arterial tone alteration, pudendal-nerve neuropraxia, and lastly fibrosis. Considering the influence of quality of life on patients’ treatment choice, radiation-therapy-induced ED prevention and treatment are major issues. In this narrative review, we briefly summarize and discuss the current state of the art on radiation-therapy-induced ED in PCa patients in terms of pathophysiology and available treatment options.

Is Platelet Rich Plasma Safe and Effective in Treatment of Erectile Dysfunction? Randomized Controlled Study

OBJECTIVE

To evaluate the safety and efficacy of platelet rich plasma (PRP) injections as a therapeutic modality for mild to moderate erectile dysfunction.

METHODS

A placebo-controlled study of 100 cases with mild to moderate erectile dysfunction. Participants were allocated to 2 groups; the PRP group received 3 injections (3 mL each corpus) and the interval between injections was 15 days, while the Placebo (Saline) group received 6 mL saline injected intracavernous. Postinjection follow-up lasted 6 months.

RESULTS

Compared to the placebo group, the PRP group demonstrated a significant improvement at the 1 and 3 months follow-up that slightly dropped at the 6 months follow-up (P <.001). The improvement was evident in the duplex parameters, International Index of Erectile Function Erectile Function (IIEF-EF), SEP Q2, and 3. At 1-month post-treatment follow-up (76%) patients in the PRP group had an improved IIEF-EF as they attained a minimal clinically important difference compared to (18%) in the saline group. At the 3-months post-treatment follow-up, (72%) patients achieved a minimal clinically important difference in the PRP group vs (16%) in saline group then dropped to (70%) in the PRP group vs (16%) in saline group at the 6-months post-treatment follow up. Patients' overall and intercourse satisfaction levels were higher in the PRP group than the placebo group as demonstrated with the higher IIEF score Q6, 7, 8, and IIEF score Q13, 14 respectively with the maximum improvement reported at the 3 months follow-up. No reports of plaque formation, subcutaneous bruising, or any other major side effects among participants.

CONCLUSION

PRP is a safe and promising method for the improvement of mild to moderate erectile dysfunction.

An update on the current status and future prospects of erectile dysfunction following radical prostatectomy

BACKGROUND

Radical prostatectomy (RP) and radiation treatment are standard options for localized prostate cancer. Even though nerve-sparing techniques have been increasingly utilized in RP, erectile dysfunction (ED) due to neuropraxia remains a frequent complication. Erectile function recovery rates after RP remain unsatisfactory, and many men still suffer despite the availability of various therapies.

OBJECTIVE

This systematic review aims to summarize the current treatments for post-RP-ED, assess the underlying pathological mechanisms, and emphasize promising therapeutic strategies based on the evidence from basic research.

METHOD

Evaluation and review of articles on the relevant topic published between 2010 and 2021, which are indexed and listed in the PubMed database.

RESULTS

Phosphodiesterase type 5 inhibitors, intracavernosal and intraurethral injections, vacuum erection devices, pelvic muscle training, and surgical procedures are utilized for penile rehabilitation. Clinical trials evaluating the efficacy of erectogenic drugs in this setting are conflicting and far from being conclusive. The use of androgen deprivation therapy in certain scenarios after RP further exacerbates the already problematic situation and emphasizes the need for effective treatment strategies.

CONCLUSION

This article is a detailed overview focusing on the pathophysiology and mechanism of the nerve injury developed during RP and a compilation of various strategies to induce cavernous nerve regeneration to improve erectile function (EF). These strategies include stem cell therapy, gene therapy, growth factors, low-intensity extracorporeal shockwave therapy, immunophilins, and various pharmacological approaches that have induced improvements in EF in experimental models of cavernous nerve injury. Many of the mentioned strategies can improve EF following RP if transformed into clinically applicable safe, and effective techniques with reproducible outcomes.

Erectile dysfunction: Is platelet-rich plasma the new frontier for treatment in patients with erectile dysfunction? A review of the existing evidence

Erectile dysfunction (ED) is one of the commonest disorders in adult males and affects 12–19% of men of reproductive age. Only few studies have evaluated the impact of ED on men and couples with infertility—these studies report higher rates of ED in this sub-group of men compared to the general population, with the prevalence of ED in men diagnosed with male infertility ranging from 6.7 to 61.6%. Nevertheless, ED is considered a rare cause of male infertility, accounting for about 0.4–5% of all causes of male infertility. ED remains a poorly treated condition globally and current therapies, like oral medication, offer only temporary symptomatic relief and do not influence disease progression—patients are potentially on lifelong treatment, with ED worsening over time. In contrast, regenerative medicine may potentially reverse or halt the progression of ED processes. In this article, we review the evidence for intracavernosal injections of platelet-rich plasma (PRP) in the treatment of ED.

Human umbilical cord blood-derived platelet -rich plasma: a new window for motor function recovery and axonal regeneration after spinal cord injury

BACKGROUND

There are complex mechanisms for reducing intrinsic repairability and neuronal regeneration following spinal cord injury (SCI). Platelet-rich plasma (PRP) is a rich source of growth factors and has been used to motivate the regeneration of peripheral nerves in neurodegenerative disorders. However, only a few studies have shown the effects of PRP on the SCI models.

METHODS

We investigated whether PRP derived from human umbilical cord blood (HUCB-PRP) could recover motor function in animals with spinal cord injury. Sixty adult male Wistar rats were randomly divided into 6 groups (n=60) as control, sham (laminectomy without induction of spinal cord injury), SCI, vehicle (SCI+ Platelet-Poor Plasma), PRP2day (SCI+PRP injection 2 days after SCI), and PRP14day (SCI+PRP injection 14 days after SCI). SCI was performed at the T12-T13 level. BBB test was carried out weekly after injury for six weeks. Caspase3 expression was determined using the Immunohistochemistry technique. The expression of GSK3β, CSF-tau, and MAG was determined using the Western blot technique. Data were analyzed by PRISM & SPSS software.

RESULTS

HUCB-PRP treated animals showed a higher locomotor function recovery than those in the SCI group (p<0.0001). The level of caspase3, GSK3β and CSF- Tau reduced and the MAG level in the spinal cord increased by the injection of HUCB-PRP in SCI animals.

CONCLUSION

Injection of HUCB-PRP enhanced hind limb locomotor performance by modulation of caspase3, GSK3β, CSF-tau, and MAG expression. Using HUCB-PRP could be a new therapeutic option for recovering motor function and axonal regeneration after SCI.

Pilot study of intra-cavernous injections of platelet-rich plasma (P-shot®) in the treatment of vascular erectile dysfunction

INTRODUCTION

Intracavernosal injections of platelet-rich plasma (PRP) or P-shot® are increasingly proposed as a curative treatment for organic sexual dysfunction despite the lack of evidence of effectiveness.

OBJECTIVES

We conducted a pilot study to evaluate the safety and efficacy of intracavernous PRP injections in patients with vascular erectile dysfunction (ED).

METHODS

Three intracavernosal injections of PRP were performed 15days apart in 15 patients with vascular ED unresponsive to medical treatment with 5-phosphodiesterase inhibitors and/or prostaglandin E instillations or injections. Questionnaires assessing erectile function (IIEF-EF, EHS, SEP, Sexual discomfort score) were completed prior to treatment and 1, 3 and 6 months after the last injection.

RESULTS

No side effects were noted during the study period. The IIEF-EF score was significantly improved after treatment (P<0.001) with a gain of 5 points at 1month, 4 points at 3months and 3 points at 6months (respectively P=0.001, P=0.003 and P=0.022). The other questionnaires did not change significantly. In total, 20% of patients considered that the erection lasted long enough to have a sexual intercourse (SEP score) before P-shot® versus 26.7% after the treatment (P=1).

CONCLUSION

This study suggests that the effect of P-Shot® remains moderate in cases of ED with vascular origin. Larger clinical studies are needed to determine the real effectiveness of this therapeutic strategy.

LEVEL OF PROOF

2.

Autologous Immune Cell-Based Regenerative Therapies to Treat Vasculogenic Erectile Dysfunction: Is the Immuno-Centric Revolution Ready for the Prime Time?

About 35% of patients affected by erectile dysfunction (ED) do not respond to oral phosphodiesterase-5 inhibitors (PDE5i) and more severe vasculogenic refractory ED affects diabetic patients. Innovative approaches, such as regenerative therapies, including stem cell therapy (SCT) and platelet-rich plasma (PRP), are currently under investigation. Recent data point out that the regenerative capacity of stem cells is strongly influenced by local immune responses, with macrophages playing a pivotal role in the injury response and as a coordinator of tissue regeneration, suggesting that control of the immune response could be an appealing approach in regenerative medicine. A new generation of autologous cell therapy based on immune cells instead of stem cells, which could change regenerative medicine for good, is discussed. Increasing safety and efficacy data are coming from clinical trials using peripheral blood mononuclear cells to treat no-option critical limb ischemia and diabetic foot. In this review, ongoing phase 1/phase 2 stem cell clinical trials are discussed. In addition, we examine the mechanism of action and rationale, as well as propose a new generation of regenerative therapies, evolving from typical stem cell or growth factor to immune cell-based medicine, based on autologous peripheral blood mononuclear cells (PBMNC) concentrates for the treatment of ED.

Platelet-Rich Plasma Injections for Erectile Dysfunction and Peyronie's Disease: A Systematic Review of Evidence

INTRODUCTION

Erectile Dysfunction (ED) and Peyronie's Disease (PD) are debilitating medical conditions affecting patients' quality of life (QoL). Platelet-rich plasma (PRP) injections are one of the various emerging approaches proposed to treat these medical conditions.

AIM

To describe the evidence of the potential role of PRP injections in ED and PD.

METHODS

The authors conducted a systematic review according to the PRISMA statement using the following databases in November 2019: The National Library of Medicine (PubMed), Ovid Medline, Cochrane, Scopus, Embase, and Embase classic. The search was performed using keywords drawn from studies on the use of PRP in ED and PD in clinical and preclinical studies.

RESULTS

Eighteen articles met the inclusion criteria for review, including 12 studies on the use of PRP in humans and 6 on the use of PRP in rats. Ten studies reported on the efficacy of PRP in ED exclusively, 7 in PD exclusively and one in both conditions. In humans, 6 and 3 studies showed promising results in PD and ED, respectively. No major complications were noted. Unwanted minor side effects were noted by studies reporting on PD, including mild penile bruising, ecchymosis, hematomas as well as transient hypotension noted in 2 out of 90 patients.

CONCLUSION

PRP injections for the treatment of ED may be promising, but no recommendation can be made because of scarce evidence. Safety and effectiveness of this therapy in the treatment of ED and PD require further preclinical and clinical studies with standardized protocols to gain an adequate insight into its potential implications. Patients should be offered to be part of such trials to better understand PRP potential. Alkandari MH, Touma N, Carrier S, Platelet-Rich Plasma Injections for Erectile Dysfunction and Peyronie's Disease: A Systematic Review of Evidence. Sex Med Rev 2022;10:341-352.

Assessment of the intracavernosal injection platelet-rich plasma in addition to daily oral tadalafil intake in diabetic patients with erectile dysfunction non-responding to on-demand oral PDE5 inhibitors

This study aimed to evaluate the effectiveness of ICI of platelet-rich plasma (PRP) in addition to daily oral tadalafil intake in diabetic erectile dysfunction (ED) patients non-responding to PDE5 inhibitors. Overall, 48 patients complaining of ED non-responding to on-demand PDE5 inhibitors were allocated into 2 equal groups, diabetics and non-diabetics that were given a daily dose of 5 mg tadalafil plus vardenafil 20 mg on demand during the study besides being subjected to 3 doses of ICI of PRP, 4 weeks apart. Responses to on-demand PDE5 inhibitors, International index of erectile function-5 (IIEF-5) score, erection hardness scores (EHS) and pharmaco-dynamic duplex studies were assessed. After PRP injections, 33% and 50% of cases were satisfied with on-demand PDE5 inhibitors, respectively, whereas 41% and 66% of them showed improved EHS response. Compared with baseline scores, the mean IIEF-5 scores were significantly improved after PRP therapy in the diabetic ED group (12.1 vs. 8.04, p = 0.003) as well as in the non-diabetic ED group (14.8 vs. 10.2, p = 0.001) linked to pharmaco-penile duplex readings. Both good and fair diabetic control exhibited significant responses to ICI therapy of PRP compared with bad controlled cases. The significant improvement included; the IIEF-5 score increase (86.7%, 126% vs. 16.1%), improved EHS as well as penile duplex readings. Baseline HbA1C demonstrated a significant negative correlation with IIEF-5 score before (p = 0.019) and after PRP therapy (p = 0.002) respectively. It could be concluded that ICI of PRP could be an effective therapy for treating ED patients non-responding to on-demand oral PDE5 treatment.

A review of regenerative therapies as penile rehabilitation in men following primary prostate cancer treatment: Evidence for erectile restoration and cavernous nerve regeneration

Objective

Methods

Results

Conclusion

Regenerative technology to restore and preserve erectile function in men following prostate cancer treatment: evidence for penile rehabilitation in the context of prostate cancer survivorship

Introduction

Erectile dysfunction (ED) following prostate cancer treatment is not uncommon and penile rehabilitation is considered the standard of care in prostate cancer survivorship (PCS), where both patient and his partner desire to maintain and/or recover pre-treatment erectile function (EF). There is a clinical interest in the role of regenerative therapy to restore EF, since existing ED treatments do not always achieve adequate results.

Aim

To review regenerative therapies for the treatment of ED in the context of PCS.

Materials and Methods

A review of the existing PubMed literature on low-intensity extracorporeal shockwave therapy (LIESWT), stem cell therapy (SCT), platelet-rich plasma (PRP), gene therapy, and nerve graft/neurorrhaphy in the treatment of ED and penile rehabilitation, was undertaken.

Results

IESWT promotes neovascularization and neuroprotection in men with ED. While several systematic reviews and meta-analyses showed positive benefits, there is limited published clinical data in men following radical prostatectomy. Cellular-based technology such as SCT and PRP promotes cellular proliferation and the secretion of various growth factors to repair damaged tissues, especially in preclinical studies. However, longer-term clinical outcomes and concerns regarding bioethical and regulatory frameworks need to be addressed. Data on gene therapy in post-prostatectomy ED men are lacking; further clinical studies are required to investigate the optimal use of growth factors and the safest vector delivery system. Conceptually interpositional cavernous nerve grafting and penile re-innervation technique using a somatic-to-autonomic neurorrhaphy are attractive, but issues relating to surgical technique and potential for neural 'regeneration' are questionable.

Conclusion

In contrast to the existing treatment regime, regenerative ED technology aspires to promote endothelial revascularization and neuro-regeneration. Nevertheless, there remain considerable issues related to these regenerative technologies and techniques, with limited data on longer-term efficacy and safety records. Further research is necessary to define the role of these alternative therapies in the treatment of ED in the context of penile rehabilitation and PCS.

Comparison of the efficacy of low-intensity shock wave therapy and its combination with platelet-rich plasma in patients with erectile dysfunction

We aimed to compare the efficacy of low-intensity shock wave therapy (Li-SWT) alone and its combination with platelet-rich plasma (PRP) in the treatment of patients with erectile dysfunction (ED). Between January 2015 and October 2020, patients who did not benefit from the use of phosphodiesterase type 5 inhibitors (PDE5i; 5 mg/day) for at least 3 months and underwent Li-SWT or Li-SWT with PRP were evaluated retrospectively. There were 93 patients who were subjected to Li-SWT only (Group 1) and 91 patients subjected to Li-SWT with PRP (Group 2). Analysis of the International Index of Erectile Function-Erectile Function Area (IIEF-EF) scores showed a significant increase in both the groups post-treatment (Group 1: from 14.33 ± 4.39 to 23.8 ± 4.37, p = .001; Group 2: from 17.82 ± 3.44 to 26.3 ± 2.55, p = .001). When the increase in the IIEF-EF scores was compared pre- and post-treatment between the groups with respect to the ED grades, there was no statistically significant difference between them. Furthermore, while the intravaginal ejaculatory latency time (IELT) in successfully treated patients of Group 1 remained the same, Group 2 presented 1.5-3.5 times (mean, 2.4) prolongation. Their mean IELT score showed an increase from 2.2 (0.8-3.5) min to 5.3 (2.8-10.5) min. Our study shows that combination treatment of Li-SWT with PRP injections is not only safe for patients with ED, but also effective and safe in prolonging the IELT.

Smoking status and the baseline international index of erectile function score can predict satisfactory response to platelet-rich plasma in patients with erectile dysfunction: A prospective pilot study

Erectile dysfunction (ED) is a common condition with a significant impact on the quality of life. Regenerative medicine maladies are intended to repair or replace damaged tissues and organs through different therapeutic mechanisms. Our aim was to study the effect of intra-corporeal injection (ICI) of platelet-rich plasma (PRP) in ED patients. Thirty-four patients' erectile function was evaluated by filling up an abridged form of the international index of erectile function (IIEF-5) before and after PRP therapy. ICI of PRP was done once per week for 2 months. All patients were prescribed PDE5Is for one month after PRP therapy. Penile haemodynamics was assessed using 20 µg of PGE1 before and 3 months after initiating PRP therapy. Interestingly, our study had shown that there was a statistically significant difference in the IIEF-5 score after ICI of PRP (-5.5, ±5.2, p=<0.001). Furthermore, in multiple logistic regression model for PRP responsiveness, smoking and IIEF score before PRP were the only significant independent variables (p = .040, p = .023 respectively). PRP injection for ED patients may be a promising modality as well as baseline IIEF-5, and smoking status can be used as predictors for a satisfactory response to PRP in such patients.

Effects of Platelet-Rich Fibrin/Collagen Membrane on Sciatic Nerve Regeneration

ABSTRACT

Alternative treatment approaches to improve the regeneration ability of damaged peripheral nerves are currently under investigation. The aim of the current study was to evaluate the effects of leucocyte/platelet-rich fibrin (L-PRF) with or without a collagen membrane as a supporter on crushed sciatic nerve healing in a rat model. Recovery of motor function and electrophysiologic measurements were evaluated at 4 weeks postoperatively. The whole number of myelinated axons, peripheral nerve axon density, average nerve fiber diameter (μm), and G-ratio were analyzed and compered among the groups. Functional, electrophysiological, and histological evaluations showed no significant difference among the groups with the exception of the L-PRF with collagen membrane groups that showed relatively positive effects on the functional and histological nerve recovery. In addition, the collagen membrane with L-PRF can be effect in nerve regeneration.

Ultrasound-guided platelet-rich plasma injections for post-traumatic greater occipital neuralgia: study protocol for a pilot randomized controlled trial

BACKGROUND

Post-traumatic headaches (PTH) are a common sequelae of traumatic brain injury (TBI) and greatly impact patient function and quality of life. Post-traumatic greater occipital neuralgia (GON) is a type of post-traumatic headache. Conventional treatment includes steroid/anesthetic injections which typically alleviate pain but have a short duration of effect. Platelet-rich plasma (PRP) is an emerging biological treatment for numerous degenerative disorders, including peripheral nerve disorders. The primary aim of this pilot study is to evaluate whether a randomized control trial of PRP for the treatment of GON in patients with post-traumatic headaches is feasible in regard to recruitment, adherence, retention, and adherence and adverse events. Exploratory aims include improvement in pain, function, and quality of life in patients with post-traumatic GON receiving PRP compared to steroid/anesthetic and normal saline injections.

METHODS

Thirty adults (over 18 years of age) with post-traumatic GON will be randomized into one of three groups: (1) autologous PRP injection, (2) steroid/anesthetic injection (standard care), or (3) placebo injection with normal saline. Injections will be performed to the greater occipital nerve under ultrasound guidance by a trained physician. Daily headache intensity and frequency data will be collected pre-injection and for the duration of the study period. Feasibility will be defined as greater than 30% recruitment, 70% completion of intervention, 70% retention, and less than 2 minor adverse events. Exploratory outcomes will be explored using the Headache Impact Test-6 (HIT-6, a valid and reliable 6-item questionnaire for assessment of the impact of headaches across different diagnostic groups of headaches) and the quality of life in following brain injury questionnaire (QOILIBRI).

DISCUSSION

This pilot study will be the first to evaluate the feasibility of PRP as a potential treatment of GON in patients with post-traumatic headache.

TRIAL REGISTRATION

ClinicalTrials.gov - NCT04051203 (registered August 9, 2019).

Restorative Therapies for Erectile Dysfunction: Position Statement From the Sexual Medicine Society of North America (SMSNA)

INTRODUCTION

Current non-invasive treatments for erectile dysfunction (ED) include oral medications, intracavernosal injections, and vacuum-assisted devices. Though these therapies work well for many, a subset of patients have contraindications or are unsatisfied with these options. Restorative therapies for ED are a new frontier of treatments focused on regenerating diseased tissue and providing a potential "cure" for ED.

AIM

The aim of this position statement is to examine existing clinical trial data for restorative therapies and identify elements that require further research before widespread adoption.

METHODS

A literature review was performed to identify all clinical trials performed with regenerative therapy for ED. This includes treatments such as stem cell therapy (SCT), platelet rich plasma (PRP), and restorative related technologies like low-intensity shockwave therapy (LiSWT).

MAIN OUTCOME MEASURES

Most clinical trials in restorative therapies were assessed for safety, feasibility, or efficacy. This included recording adverse events, changes in sexual function and erectile function questionnaires, and diagnostics measures.

RESULTS

To date there is an absence of robust clinical data supporting the efficacy of restorative therapies regarding ED, though technologies such as LiSWT have established relative safety.

CONCLUSIONS

Restorative therapies are a promising technology that represents a new frontier of treatment geared towards reversing disease pathology rather than just treating symptoms. However, current published clinical studies are limited. Future work needs to be adequately powered, multi-center, randomized, sham/placebo-controlled trials in well-characterized patient populations to ensure safety and demonstrate efficacy. Until these studies are done, restorative therapies should be reserved for clinical trials and not offered in routine clinical practice. Liu JL, Chu KY, Gabrielson AT, et al. Restorative Therapies for Erectile Dysfunction: Position Statement From the Sexual Medicine Society of North America (SMSNA). J Sex Med 2021;9:100343.

Platelet-Rich Plasma (PRP) Improves Erectile Function: A Double-Blind, Randomized, Placebo-Controlled Clinical Trial

BACKGROUND

Animal studies postulate that platelet-rich plasma (PRP) injections improve key elements of the pathophysiologic mechanisms leading to erectile dysfunction (ED).

AIM

To conduct the first double-blind, randomized, placebo-controlled trial assessing the efficacy and safety of PRP injections in patients with mild and moderate ED.

METHODS

Sixty sexually active patients with mild and moderate ED were randomly assigned to two sessions, with a one-month difference, of 10 mL PRP (n = 30) or placebo (n = 30) intracavernosal injections. An FDA-approved separation system was used. Patients were evaluated at 1, 3 and 6 months after completion of the treatment protocol. A per-protocol analysis was applied. All participants withheld any ED treatment during the trial.

OUTCOMES

The achievement of minimal clinically important difference (MCID) in the International Index of Erectile Function - Erectile Domain (IIEF-EF) from baseline to 6 months after final treatment. Erectile function at all time points, as well as safety of PRP injections, were also evaluated.

RESULTS

At 6 months, a MCID was achieved by 20/29 (69%) patients in the PRP group compared to 7/26 (27%) in the placebo group. The risk difference between the two groups was 42% (95%CI: 18-66), P < 0.001 and the baseline-adjusted mean between-group-difference in the IIEF-EF score was 3.9 points (95%CI: 1.8-5.9). Similarly, a statistically significant difference of both the number of participants attaining a MCID and the IIEF-EF score was also observed at the 1- and 3-month evaluation between the two groups. Accordingly, patients receiving PRP were more satisfied with the treatment. No adverse events were observed during the study period.

CLINICAL IMPLICATIONS

Intracavernosal PRP injection therapy used as outlined in this trial appears to be a safe and effective short-term treatment for the management of mild to moderate ED.

STRENGTHS & LIMITATIONS

We conducted the first clinical trial exploring the role of PRP in the management of ED. Conversely, our findings lack external validity due to single-center design. Furthermore, our results cannot be extrapolated to other PRP separation systems.

CONCLUSIONS

PRP intracavernosal injections may be a promising addition to the urologist's armamentarium for the management of ED. Still, further high-quality studies are warranted to corroborate our findings. Evangelos P, Mykoniatis I, Pyrgidis N, et al. Platelet-Rich Plasma (PRP) Improves Erectile Function: A Double-Blind, Randomized, Placebo-Controlled Clinical Trial. J Sex Med 2021;18:926-935.

Anatomy, Pathophysiology, Molecular Mechanisms, and Clinical Management of Erectile Dysfunction in Patients Affected by Coronary Artery Disease: A Review

Erectile dysfunction (ED) has been defined as the inability to attain or maintain penile erection sufficient for successful sexual intercourse. ED carries a notable influence on life quality, with significant implications for family and social relationships. Because atherosclerosis of penile arteries represents one of the most frequent ED causes, patients presenting with it should always be investigated for potential coexistent coronary or peripheral disease. Up to 75% of ED patients have a stenosis of the iliac-pudendal-penile arteries, supplying the male genital organ’s perfusion. Recently, pathophysiology and molecular basis of male erection have been elucidated, giving the ground to pharmacological and mechanical revascularization treatment of this condition. This review will focus on the normal anatomy and physiology of erection, the pathophysiology of ED, the relation between ED and cardiovascular diseases, and, lastly, on the molecular basis of erectile dysfunction.

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.

One-Year Efficacy of Platelet-Rich Plasma for Moderate-to-Severe Carpal Tunnel Syndrome: A Prospective, Randomized, Double-Blind, Controlled Trial

OBJECTIVE

To assess the therapeutic effect of platelet-rich plasma (PRP) for moderate-to-severe carpal tunnel syndrome (CTS).

DESIGN

A prospective, randomized, double-blinded, controlled trial (1-year follow-up).

SETTING

Outpatient of local medical center settings.

PARTICIPANTS

Patients (N=26) who were diagnosed with bilateral moderate-to-severe CTS (total 52 wrists) were included. For each patient, one wrist was randomized into either the PRP or control group and the contralateral wrist of the same patient was allocated to another group. Twenty-four patients were included in the final data analysis.

INTERVENTIONS

The wrists in the PRP group received a single ultrasound-guided dose of PRP injection (3.5mL), and the control group received a single ultrasound-guided injection with normal saline (3.5mL).

MAIN OUTCOME MEASURES

The Boston Carpal Tunnel Syndrome Questionnaire (BCTQ) scores were used as the primary outcome. Secondary outcomes encompassed the cross-sectional area of the median nerve and electrophysiological study. Assessments were conducted prior to injection and 1, 3, 6, and 12 months postinjection.

RESULTS

Compared to the control group, the PRP group exhibited significant improvements in BCTQ severity scores at all time points, BCTQ functional scores at the sixth month, and cross-sectional area at the 12th month postinjection (P<.0125).

CONCLUSIONS

A single dose of ultrasound-guided perineural PRP injection can provide therapeutic effect for 1 year postinjection.

Early Clinical Results of the Tolerability, Safety, and Efficacy of Autologous Platelet-Rich Plasma Administration in Erectile Dysfunction

Introduction

Platelet-rich plasma (PRP) is useful in the treatment of different conditions and diseases as it contains concentrated levels of many growth factors.

Aim

The aim of this study was to investigate the effectiveness of autologous PRP application in the treatment of erectile dysfunction (ED) in patients with metabolic syndrome.

Methods

In this prospective study conducted in June 2019, 31 patients with ED were included. The International Index of Erectile Function–Erectile Function domain (IIEF-EF) questionnaires were used to evaluate erectile function (EF). After administering the intracavernous autologous PRP 3 times with an interval of 15 days, IIEF-EFs were evaluated 1, 3, and 6 months later.

Main Outcome Measure

IIEF in the 1st, 3rd, and 6th months and adverse events.

Results

While the mean IIEF-EF was 18 before the application, the mean IIEF-EF was 20 in the first, third, and sixth months after the procedure (P < .001). However, even though IIEF-EF values increased numerically, median value remained within the mild-moderate classification (scores between 17 and 21). Postprocedure sexual satisfaction scores were significantly higher than preprocedure values (8 vs 6, respectively; P = .002). In the first follow-up of a patient after the 3rd injection, a 4-mm diameter fibrotic plaque was observed on the ventral side in the middle of the penis shaft.

Conclusion

In conclusion, our findings suggest that larger studies as well as placebo-controlled studies are needed to add PRP to the treatment protocol in ED.

T Taş,Çakıroğlu, E Arda, et al. Early Clinical Results of the Tolerability, Safety, and Efficacy of Autologous Platelet-Rich Plasma Administration in Erectile Dysfunction. Sex Med 2021;9:100313.

Intracavernous Injection of Autologous Platelet-Rich Plasma Ameliorates Hyperlipidemia-Associated Erectile Dysfunction in a Rat Model

Introduction

Hyperlipidemia is associated with an increased risk of erectile dysfunction (ED) mediated by endothelial damage. Platelet-rich plasma (PRP) contains numerous angiogenic growth factors. Currently, evidence supporting the use of PRP for ED treatment is limited.

Aim

We investigated PRP in a rat model of hyperlipidemia-associated ED.

Methods

Thirty 2-month-old male Sprague–Dawley rats were randomly divided into 3 groups. 20 rats were fed a high-fat diet for 5 months and were randomly divided into 2 groups: (i) rats in the H group received supernatant injection into the corpus cavernosum weekly for 4 weeks; (ii) rats in the H + PRP group received PRP injection into the corpus cavernosum weekly for 4 weeks. 10 rats were fed a standard diet for 5 months and received supernatant injection into the corpus cavernosum weekly for 4 weeks (N group). 7 days after the 4th injection, all rats underwent erectile function testing and then euthanasia.

Main outcome measures

Erectile function was evaluated by measuring intracavernous pressure (ICP) and mean arterial pressure (MAP). Serum and penile tissue were collected for metabolic variable assessment and histochemical examination, respectively.

Results

Intracavernous pressure/MAP and area under the curve/MAP ratios were significantly higher in the N and H + PRP groups than in the H group. Insulin-like growth factor-1, brain-derived neurotrophic factor, and vascular endothelial growth factor levels were significantly higher in the H + PRP group than in the N and H groups. Corporal neuronal nitric oxide synthase, endothelial nitric oxide synthase, and endothelial cells were weakly expressed in the H group compared with the N and H + PRP groups. Intracorporal oxidative stress and apoptotic index were significantly higher in the H group than in the N and H + PRP groups.

Conclusions

This preclinical evidence suggests that clinical trials of PRP in men with ED should be considered. PRP may play a role in ED management.

Huang YC, Wu CT, Chen MF, et al. Intracavernous Injection of Autologous Platelet-Rich Plasma Ameliorates Hyperlipidemia-Associated Erectile Dysfunction in a Rat Model. Sex Med 2021;9:100317.

Alternative Treatment for Erectile Dysfunction: a Growing Arsenal in Men's Health

PURPOSE OF REVIEW

To highlight and review encouraging preliminary studies behind several alternative products and interventions for erectile dysfunction (ED).

RECENT FINDINGS

Alternative treatments for ED are becoming more prevalent with increased consumer interest. "Natural" products are sold online, and numerous clinics offer various off-label and investigational interventions. These alternative treatments have demonstrated varying degrees of efficacy in randomized trials and meta-analyses, but none of these interventions has robust enough evidence to be considered first-line therapy. These treatments may find a role in combination with guideline treatments or may be used in novel penile rehabilitation research protocols. With growing interest in alternative treatment for men's health, an awareness of the literature is imperative for patient counsel. Alternative treatments, like L-arginine, have a growing body of evidence for efficacy in combination with PDE5i, and low-intensity shock wave therapy and stem cell therapy continue to demonstrate encouraging outcomes in ED trials.

Reviewing the evidence for shockwave- and cell-based regenerative therapies in the treatment of erectile dysfunction

Erectile dysfunction (ED) is both a common and complex disease process. Existing ED treatments do not always achieve adequate results. There is clinical interest in employing regenerative therapies, including low-intensity extracorporeal shockwave therapy (Li-ESWT), platelet rich plasma (PRP), and stem cell therapy (SCT), in the treatment of ED as adjunct or alternative treatments. Here, we present evidence for emerging shockwave- and cell-based regenerative therapies for the treatment of ED following a thorough review of the existing PubMed literature pertaining to Li-ESWT, PRP, and SCT in relation to the treatment of ED. Li-ESWT causes microtrauma in tissue that hypothetically upregulates angiogenesis and recruits stem cells. Several large-scale systematic reviews and meta-analyses have reported that Li-ESWT improved ED in humans. Additionally, evidence has commenced to show that Li-ESWT may be effective against two recognized and complex etiologies of ED: diabetic and neurogenic. PRP delivers an autologous sample rich in growth factors to damaged tissue. Animal model studies have demonstrated improved erectile function recovery as well as preservation of cavernous nerve axons. Studies with PRP in humans are limited. SCT utilizes the regenerative potential of stem cells for healing of damaged tissue. In the treatment of ED, SCT has been used in the setting of diabetic and post-prostatectomy ED. Results of human studies are varied, although SCT treatments did result in increased erectile rigidity with some patients recovering the ability to achieve penetration. While these regenerative therapies show potential to augment the current treatment regimen for ED, there is a paucity of evidence to support the safety and efficacy of these treatments. Further research is necessary to define the role of these alternative therapies in the treatment of ED.

Ultrasound-guided platelet-rich plasma injection and multimodality ultrasound examination of peripheral nerve crush injury

Ultrasound-guided platelet-rich plasma (PRP) injection is able to make up for the limitations of applying a single growth factor. The goal of this study was to investigate the effects of serial ultrasound-guided PRP injections of the appropriate concentration on the treatment of sciatic nerve crush injury, and explore the value of multimodality ultrasound techniques in evaluating the prognosis of crushed peripheral nerve. In vitro, optimal concentration of PRP (from 150%, 250%, 450%, and 650%) was screened due for its maximal effect on proliferation and neurotrophic function of Schwann cells (SCs). In vivo, ninety rabbits were equally and randomly divided into normal control, model, PRP-2.5×, PRP-4.5×, and PRP-6.5× groups. The neurological function and electrophysiological recovery evaluation, and the comparison of the multimodality ultrasound evaluation with the histological results of sciatic nerve crush injury were performed to investigate the regenerative effects of PRP at different concentrations on the sciatic nerve crush injury. Our results showed that the PRP with a 4.5-fold concentration of whole blood platelets could significantly stimulate the proliferation and secretion of SCs and nerve repair. The changes in stiffness and blood perfusion were positively correlated with the collagen area percentage and VEGF expression in the injured nerve, respectively. Thus, serial ultrasound-guided PRP injections at an appropriate concentration accelerates the recovery of axonal function. Multimodality ultrasound techniques provide a clinical reference for prognosis by allowing the stiffness and microcirculation perfusion of crush-injured peripheral nerves to be quantitatively evaluated.

Availability of platelet-rich plasma for treatment of erectile dysfunction and associated costs and efficacy: A review of current publications and Canadian data

INTRODUCTION

Platelet-rich plasma (PRP) is an increasingly used unconventional treatment option for erectile dysfunction (ED). The validity of PRP as a potential treatment for ED has been proposed in limited human trials. Furthermore, the costs associated with PRP for ED treatment are not readily promoted to patients. The goal of this review was to determine the efficacy and costs of PRP based on currently available literature and Canadian data.

METHODS

A comprehensive literature review of available PRP studies and current published data pertaining to cost, availability, and provider clinics globally was conducted using the PubMed database. Physicians offering genital PRP in Canada were identified using internet searches and PRP provider directories. Physician qualifications, clinic locations, and cost information were obtained from provider websites and telephone calls to identified clinics.

RESULTS

Availability of PRP injections offered for treating ED is increasing globally. There are currently no peer-reviewed publications to substantiate anecdotal evidence pertaining to the efficacy of PRP as a viable treatment option for ED patients. Our results indicate 19 providers for PRP injections in Canada, costing on average $1777 CAD per injection. No providers were affiliated with academic institutions and providers varied in their area of clinical speciality and training.

CONCLUSIONS

To our knowledge, there is currently no research underway investigating the clinical efficacy of PRP for ED treatment despite its broad availability and significant cost. Patients should be informed of the lack of substantiated efficacy and safety data, as the reliability of PRP treatments requires further evaluation.

Effect of Platelet-Rich Plasma Injection on Mild or Moderate Carpal Tunnel Syndrome: An Updated Systematic Review and Meta-Analysis of Randomized Controlled Trials

Objective

To evaluate efficacy of platelet-rich plasma (PRP) injection in carpal tunnel syndrome (CTS), we conducted this meta-analysis, as well as proposed a protocol for its application in curative processes.

Methods

All randomized controlled trials (RCTs) of PRP for the management of mild or moderate CTS were included in this study. Database search was conducted from study inception to July 2020, including PubMed, Embase, Web of Science, and Cochrane Library. We used visual analogue scores (VAS) and the Boston Carpal Tunnel Questionnaire (BCTQ) as evaluation tools for primary outcomes. Second outcomes comprised cross-sectional area (ΔCSA) and electrophysiological indexes including distal motor latency (DML), sensory peak latency (SPL), motor nerve conduction velocity (MNCV), sensory nerve conduction velocity (SNCV), compound muscle action potential (CMAP), and sensory nerve action potential (SNAP). The pooled data were analyzed using RevMan 5.3. Subgroup and sensitivity analyses were conducted with the evidence of heterogeneity. Egger' test was used to investigate publication bias.

Results

9 RCTs were finally screened out with 434 patients included. Control groups comprised corticosteroid injection in 5 trials, saline injection in 1 trial, and splint in 3 trials. At the 1st month after follow-up, only ΔCSA between the PRP group and the control group showed significant difference (P < 0.05). In the 3rd month, there were statistically significant differences in VAS, BCTQ, SPL, SNCV, and ΔCSA between two groups (P < 0.05), while no statistically significant differences were found in the remaining outcomes. In the 6th month, there were statistically significant differences at BCTQ (P < 0.05) in primary outcomes and ΔCSA (P < 0.05) in secondary outcomes between two groups. As to adverse events in PRP injection, only one study reported increased pain sensation within 48 h after injections.

Conclusion

This systematic review and meta-analysis demonstrates that the PRP could be effective for mild to moderate CTS and superior to traditional conservative treatments in improving pain and function and reducing the swelling of the median nerve for a mid-long-term effect. To some extent, the electrophysiological indexes also improved after PRP injection compared with others conservative treatments.

Platelet-rich plasma in umbilical cord blood reduces neuropathic pain in spinal cord injury by altering the expression of ATP receptors

BACKGROUND

Neuropathic pain following injury or dysfunction of the peripheral or CNS is one of the most important medical challenges to treat. Humane platelet-rich plasma (HPRP), which is a rich source of growth factors, may be able to treat and reduce pain caused by spinal cord injury (SCI). In this study, the effect of HPRP on neuropathic pain caused by SCI was investigated.

METHODS

Sixty adult male Wistar rats were randomly divided into 6 groups: control, sham, SCI, vehicle (SCI+platelet-poor plasma), SCI+ PRP2day (injection 48 hrs after SCI) and SCI+PRP14day (injection 14 days after SCI). SCI was induced at the T12-T13 level. Behavioral tests were conducted weekly after injury for six weeks. Allodynia and hyperalgesia were assessed using acetone drops, plantar test and von Frey filament. Cavity size and the number of fibroblasts were determined by H&E stain, and the expression of mTOR, p-mTOR, P₂×₃R and P₂Y₄R were determined using the western blot technique. Data were analyzed using PRISM & SPSS software.

RESULTS

PRP injection showed a higher pain threshold in mechanical allodynia (p<0.0001), cold allodynia (p<0.0001) and thermal hyperalgesia (p<0.0001) than those in the spinal. Animals treated with PRP also reduced cavity size, fibroblast number, p-mTOR/mTOR ratio, and P₂×₃R expression, and increased P₂Y₄R expression. The difference between the two groups was not statistically significant.

CONCLUSIONS

The results showed that PRP reduced SCI-induced allodynia and hyperalgesia by regulating ATP signaling. Using HPRP can open a new window in the treatment of pain caused by damage to the nervous system.

Platelet-Rich Plasma and Cellular Therapies for Sexual Medicine and Beyond

INTRODUCTION

Efforts to understand and unlock the body's potential for regeneration have increased dramatically in recent years. So-called "biohacking" hopes to improve functionality and reverse disease processes.

OBJECTIVES

This review will seek to summarize the available data for the use of platelet-rich plasma, cellular therapies, and other novel therapeutics within sexual medicine.

METHODS

The PubMed database search was performed using the keywords "Stem cell therapy in Erectile dysfunction (ED)", "Gene therapy in ED", "Novel therapeutics for ED", and "Biohacking". Popular news articles for regulation of stem cell therapy were reviewed.

RESULTS

Research efforts have managed to produce an array of novel therapeutics, including stem cell therapy and platelet-rich plasma. Although the use of these items has been largely focused within specialties other than urology, applications involving sexual medicine have been documented and appear to be increasing.

CONCLUSION

Despite evidence of these technologies being adopted within clinical practices as revenue-generators, quality data to support efficacy are quite limited. Matz EL, Scarberry K, Terlecki R, Platelet-Rich Plasma and Cellular Therapies for Sexual Medicine and Beyond. Sex Med Rev 2020;XX:XXX-XXX.

Efficacy of platelet-rich plasma injection in mild and moderate carpal tunnel syndrome: randomized control study

Background

Carpal tunnel syndrome (CTS) is the most common peripheral entrapment neuropathy. Typical symptoms and signs include numbness, tingling, pain, or burning sensation in the digits supplied by the median nerve and/or nocturnal paresthesia. Treatments of CTS range from conservative measures to surgical decompression of the median nerve.

Results

The PRP group showed a statistically significant reduction in the visual analog scale, Boston Carpal Tunnel Syndrome Questionnaire, for the severity and the functional capacity scores, and cross-sectional area of the median nerve compared to those of control group 3 months post-treatment (p < 0.05).

Conclusions

Platelet-rich plasma injection in CTS relieves pain and symptom severity and improves functional status but not significantly improve the electrophysiological parameters.

Drug delivery options and therapeutic advances in the management of erectile dysfunction

INTRODUCTION

Erectile dysfunction (ED) is defined as the inability to achieve or maintain an erection sufficient for satisfactory sexual performance. It is estimated that 20-30% of adult men will have at least one episode of ED during their lifetime and the prevalence increases with age. ED is known to have significant negative psychological implications for men, resulting in impaired functional status and a greater prevalence of anxiety and depression.

AREAS COVERED

Medications for the treatment of erectile dysfunction largely revolve around oral, injection, and topical therapies. Though all three modalities are widely used, each delivery option has its own advantages and specific indications. Likewise, there are several new developing treatments for ED that may change the landscape of treatment. The goal of this review is to summarize contemporary drug delivery options used in the treatment of ED and highlight future promising pharmacological developments.

EXPERT OPINION

There are a myriad of new developments on the horizon including new PDE5Is and drug targets, nanotechnology enhancements, stem cell and gene therapy, shockwave therapy, and platelet-rich plasma injections. These are all promising new methods to not only treat ED but also to address the pathology and prevent or eliminate further damage.

Platelet-rich Plasma and Mesenchymal Stem Cells Local Infiltration Promote Functional Recovery and Histological Repair of Experimentally Transected Sciatic Nerves in Rats

Introduction

Platelet-rich plasma (PRP) products and mesenchymal stem cells (MSCs) seem to have a significant potential as neurogenic therapeutic modulator systems. This study aimed to investigate such biological blood derivatives that could enhance nerve regeneration when applied locally in the primary repair of peripheral nerve transection of an experimental rat model.

Methods

A total of 42 two-month-old male Wistar rats were divided into three “treatment” groups (control, PRP, and MSCs). All the subjects were operated under anesthesia, and the surgical site was infiltrated with either normal saline, PRP derived from the animal’s peripheral blood, or MSCs derived from the animal’s femoral bone marrow. All three groups were also sub-divided into two sub-groups based on the post-operative administration of Non-steroidal anti-inflammatory drugs (NSAIDs) or not in order to evaluate the effect of NSAIDs on the final outcome. Three months post-surgery, electromyography evaluation of both hind limbs (right operated and left non-operated) was performed. The animals were euthanized, and nerve repair specimens were prepared for histology.

Results

PRP group had a significant effect (p<0.05) on the sciatic nerve repair when compared with the control group, whereas the MSC group had a positive effect but was not statistically significant (p=0.2). The number of counted neural axons at the area distal to the nerve repair site were significantly repetitive (p<0.05) in both the PRP and MSC groups when compared with the control group.

Conclusions

Both PRP and MSCs appear to play an essential role in the enhancement of nerve repair in terms of functionality and histology. MSCs group demonstrated a positive effect, whereas the PRP group showed statistically significant better results.

Restoration of Neurological Function Following Peripheral Nerve Trauma

Following peripheral nerve trauma that damages a length of the nerve, recovery of function is generally limited. This is because no material tested for bridging nerve gaps promotes good axon regeneration across the gap under conditions associated with common nerve traumas. While many materials have been tested, sensory nerve grafts remain the clinical “gold standard” technique. This is despite the significant limitations in the conditions under which they restore function. Thus, they induce reliable and good recovery only for patients < 25 years old, when gaps are <2 cm in length, and when repairs are performed <2–3 months post trauma. Repairs performed when these values are larger result in a precipitous decrease in neurological recovery. Further, when patients have more than one parameter larger than these values, there is normally no functional recovery. Clinically, there has been little progress in developing new techniques that increase the level of functional recovery following peripheral nerve injury. This paper examines the efficacies and limitations of sensory nerve grafts and various other techniques used to induce functional neurological recovery, and how these might be improved to induce more extensive functional recovery. It also discusses preliminary data from the clinical application of a novel technique that restores neurological function across long nerve gaps, when repairs are performed at long times post-trauma, and in older patients, even under all three of these conditions. Thus, it appears that function can be restored under conditions where sensory nerve grafts are not effective.

The good, bad, and the ugly of regenerative therapies for erectile dysfunction

Erectile dysfunction (ED) is a common condition which reduces quality of life of both patients and their partners, and is a significant health care expense every year. Although phosphodiesterase type-5 inhibitors are the current first-line treatment for men with ED, they are limited by their on-demand dosing, intolerance, and variable efficacy in complex patient populations such as men with multiple medical comorbidities or ED after pelvic surgery. Regenerative medicine has been introduced and investigated in andrology as an encouraging strategy to restore diseased erectile tissue structure and function. Novel regenerative therapies for ED are controversial but are perceived to offer a durable and safe tissue restorative approach to act as a long-term solution to this cumbersome disease process. Here, we review platelet-rich plasma, amniotic fluid membranes, low-intensity extracorporeal shockwave therapy, and stem cell therapy as regenerative strategies to treat ED. Most of these approaches have preclinical and occasionally clinical data to support their ongoing investigation; however, none of these treatments are currently supported for use in ED patients outside of clinical trials.

Efficacy of platelet-rich plasma as an adjuvant to surgical carpal ligament release: a prospective, randomized controlled clinical trial

The purpose of this study is to evaluate the efficiency of local platelet-rich plasma (PRP) injection as an adjuvant treatment after carpal ligament release. We conducted a prospective randomized, triple-blinded, controlled trial. Fifty participants with mild to extreme carpal tunnel syndrome (CTS) were randomly assigned either to the PRP (n = 25) or the platelet-poor plasma (PPP, n = 25) group. After performing open surgical release of the carpal ligament, the inside of the carpal tunnel was irrigated with 3 mL of PRP or PPP according to each participant’s group allocation. The primary outcome was hand grip strength (HGS). Secondary outcomes were the time taken off work after surgery (in days) and scores on the Wong–Baker Faces Scale, Boston Carpal Tunnel Questionnaire, and Southampton Wound Assessment Scale. We evaluated patients before treatment and at 6-weeks. As expected, the pain levels, symptom severity, and functional status improved in all the patients after surgery. However, intragroup analysis revealed that only the participants in the PRP group had regained their pre-operative HGS levels at 6-weeks follow-up. These findings indicate that PRP is an effective adjuvant treatment in patients with mild to severe CTS who require surgery.

Platelet-Rich Plasma Combined with Low-Dose Ultrashort Wave Therapy Accelerates Peripheral Nerve Regeneration

Finding treatments that accelerate peripheral nerve regeneration, prolongation, and functional recovery remains a challenging task. Platelet-rich plasma (PRP) contains numerous growth factors and active proteins, and low-dose ultrashort waves (USWs) stimulate the formation of nerve-nourishing vessels, which are powerful for nerve regeneration. The goal of this study was to evaluate the synergistic effects of serial ultrasound-guided PRP injections combined with low-dose USWs radiation on peripheral nerve regeneration in a crush injury model. Fifty rabbits were equally and randomly divided into normal control, model, USW, PRP, and PRP+USW groups. The neurological function, electrophysiological recovery, and histological and morphological evaluation of regenerated nerves, as well as a targeted muscle recovery assessment, were performed to investigate the regenerative effect of PRP combined with USW therapy. Our results showed that the PRP+USW group had the better early axonal regeneration and displayed the earliest positive compound muscle action potential among the treatment groups. At postintervention week 12, a histological evaluation showed similar expression of the S-100 protein in the PRP+USW and normal control groups. Moreover, the morphological assessment revealed a significant increase in the myelinated nerve fiber density and diameter and myelin sheath thickness compared with the USW and PRP groups. The morphometry of the target muscles indicated the lowest reduction in the percent volume in the PRP+USW group, and an ultrasound examination of the targeted muscle showed the best improvement in stiffness and perfusion parameters at 12 weeks after crush injury. Thus, serial ultrasound-guided PRP injections combined with low-dose USW radiation exert a synergistic effect on accelerating functional axon recovery and decreasing atrophy of the target muscles in a crush injury model. Impact Statement This research describes that the application of platelet-rich plasma combined with low-dose ultrashort waves treatment exert a synergistic effect on accelerating peripheral nerve regeneration. With the extensive use of platelet-rich plasma and physical factors in regenerative medicine or clinical rehabilitation medicine, our findings may help establish effective strategies for repairing peripheral nerve injury.