Pathophysiology of priapism: dysregulatory erection physiology thesis

Nitric Oxide Resistance in Priapism Associated with Sickle Cell Disease: Mechanisms, Therapeutic Challenges, and Future Directions

Patients with sickle cell disease (SCD) display priapism, a prolonged penile erection in the absence of sexual arousal. The current pharmacological treatments for SCD-associated priapism are limited and focused on acute interventions rather than prevention. Thus, there is an urgent need for new drug targets and preventive pharmacological therapies for this condition. This review focuses on the molecular mechanisms linked to the dysfunction of the NO-cyclic guanosine monophosphate (cGMP)-phosphodiesterase type 5 (PDE5) pathway implicated in SCD-associated priapism. In murine models of SCD, reduced nitric oxide (NO)-cGMP bioavailability in the corpus cavernosum is associated with elevated plasma hemoglobin levels, increased reactive oxygen species levels that inactive NO, and testosterone deficiency that leads to endothelial nitric oxide synthase downregulation. We discuss the consequences of the reduced cGMP-dependent PDE5 activity in response to these molecular changes, highlighting it as the primary pathophysiological mechanism leading to excessive corpus cavernosum relaxation, culminating in priapism. We also further discuss the impact of intravascular hemolysis on therapeutic approaches, present current pharmacological strategies targeting the NO-cGMP-PDE5 pathway in the penis, and identify potential pharmacological targets for future priapism therapies. In men with SCD and priapism, PDE5 inhibitor therapy and testosterone replacement have shown promising results. Recent preclinical research reported the beneficial effect of treatment with haptoglobin and NO donors. SIGNIFICANCE STATEMENT: This review discusses the molecular changes that reduce NO-cGMP bioavailability in the penis in SCD and highlights pharmacological targets and therapeutic strategies for the treatment of priapism, including PDE5 inhibitors, hormonal modulators, NO donors, hydroxyurea, soluble guanylate cyclase stimulators, haptoglobin, hemopexin, and antioxidants.

Novel erectile analyses revealed augmentable penile Lyve-1, the lymphatic marker, expression

Purpose

The pathophysiology of penis extends to erectile dysfunction (ED) to conditions including sexually transmitted diseases (STDs) and cancer. To date, there has been little research evaluating vascular drainage from the penis. We aimed to evaluate penile blood flow in vivo and analyze its possible relationship with the lymphatic maker.

Materials and Methods

We established an in vivo system designed to assess the dynamic blood outflow from the corpus cavernosum (CC) by dye injection. To analyze lymphatic characteristics in the CC, the expression of Lyve-1, the key lymphatic endothelium marker, was examined by the in vitro system and lipopolysaccharide (LPS) injection to mimic the inflammatory conditions.

Results

A novel cavernography methods enable high-resolution morphological and functional blood drainage analysis. The expression of Lyve-1 was detected along the sinusoids. Furthermore, its prominent expression was also observed after penile LPS injection and in the erectile condition.

Conclusions

The current in vivo system will potentially contribute to the assessment of penile pathology from a novel viewpoint. In addition, current analyses revealed inducible Lyve-1 expression for LPS injection and the erection state, which requires further analyses on penile lymphatic system.

Treatment of Refractory Ischemic Priapism: A Case Report and Literature Review

Recurrent priapism is a rare and poorly known entity. It is defined by recurrent episodes of painful erections that last less than four hours. The etiology is similar to that of ischemic priapism. Episodes lasting more than four hours require immediate intervention to prevent penile fibrosis and subsequent erectile dysfunction. A 42-year-old male with no significant chronic-degenerative history was referred to our medical center from his second-level medical unit after a 56-hour history of ischemic priapism with the persistence of tumescence despite medical and surgical treatment. Upon interrogation, the patient reported stuttering (recurrent) episodes of painful erections lasting approximately three to four hours, not associated with sexual activity or arousal, in the past two years, with spontaneous resolution. He denied the use of psychotropics or drugs for erectile dysfunction. As a palliative measure, a left saphenous-cavernous (Grayhack) bypass was performed, with a 90% decrease in tumescence and total resolution of pain during the first 12 hours. There is little information and treatment recommendations for patients with recurrent priapism, and even less for patients who are refractory to conventional medical and surgical treatment. Recurrent or stuttering priapism is a condition with a low incidence and a pathophysiology compatible with low-flow priapism. It is difficult to treat and has a poor prognosis in terms of erectile function. Likewise, it is mostly associated with the use of psychotropic drugs such as cocaine and marijuana, medications for erectile dysfunction such as phosphodiesterase inhibitors, prostaglandin E1 analogues, and hematological malignancies such as sickle cell anemia and multiple myeloma. The aim of this article is to share our experience with a patient refractory to multiple medical and surgical treatments.

Primary Penile Squamous Cell Cancer-Related Malignant Priapism in a Cystectomized Patient: A Case Report

Priapism is one of the most common urologic emergencies and is characterized by a prolonged and painful erectile state unrelated to sexual stimulation or sexual desire. Neoplasm-associated priapism is a rare condition and is usually caused by corporeal metastases of other pelvic area malignancies. Primary penile malignancy-related malignant priapism is extremely rare. In this reported case, an 82-year-old male presented with priapism. The penile doppler ultrasound and pelvic magnetic resonance imaging were compatible with ischemic priapism and corporal mass. Subsequently, the patient underwent total penectomy and bilateral superficial inguinal lymphadenectomy. The pathology report was consistent with primary penile squamous cell cancer (SCC), so the patient underwent adjuvant radiotherapy. However, he developed multiple metastases and could survive for about six months. The patient had undergone radical cystectomy (RC) and urethrectomy 19 and 2 years ago due to urothelial carcinoma, respectively. To the best of our knowledge, this is the second case of malignant priapism due to primary penile SCC and represents one of the longest urethral recurrence periods after RC. When a patient presents with malignant priapism, primary penile malignancies should be considered in differential diagnosis, even if the patient has a history of pelvic area malignancies.

Predictors of Sex-Induced Crisis, Sexual Function and Marital Satisfaction in Women with Sickle Cell Disease

BACKGROUND

Sex-induced and orgasm-induced crisis, sexual dysfunction, and marital satisfaction among women with sickle cell disease (SCD) is under-reported.

AIM

This study assessed sexual function in women with SCD and compared sexual function in women with SCD to women without SCD.

METHODS

This was a descriptive and comparative cross-sectional survey that involved 435 women with SCD and 406 women without SCD (as controls).

OUTCOMES

This study demonstrates the predictors of sex-induced crisis, sexual function and marital satisfaction in women with sickle cell disease.

RESULTS

The prevalence of dyspareunia and marital dissatisfaction was higher in women with SCD than those without SCD. In addition, SCD was significantly associated with multiple sexual dysfunctions, with reported symptoms of sexual desire disorder (HSDD), female sexual arousal disorder (FSAD), and female sexual orgasm disorder (FSOD). Genotype, age, age at puberty, dyspareunia, and duration of infertility were the observed independent predictors of sexual dysfunction in women with SCD. Also, most (54.02%) of the SCD subjects experienced sex-induced and orgasm-induced crises. Although water intake before and after sex was reported to be beneficial in preventing sex-induced and orgasm-induced crisis in women with SCD, it was not a predictor of sexual dysfunction.

CLINICAL IMPLICATIONS

SCD patients are at risk of sex-induced and orgasm-induced crisis as well as sexual dysfunction.

STRENGTHS AND LIMITATIONS

No study has ever reported the incidence of sex-and orgasm-induced crisis and sexual dysfunction in women with SCD. Also, we used a reasonably large sample size and utilized widely acceptable validated and reproducible tools like ENRICH Marital Satisfaction (EMS) and Female Sexual Function Index (FSFI) to assess the marital satisfaction and sexual function of the studied participants. This allows for the generalization of our findings. The limitations of the present study include recall bias and the inability to document real-time occurrences of sex-and orgasm-induced crisis and the incidence of female sexual dysfunction. Furthermore, though the risk factors of sexual dysfunction as perceived by women with SCD were elicited, biological risk factors and the possible associated mechanisms were not determined in this study.

CONCLUSION

Our study shows that sex-induced and orgasm-induced crisis and sexual dysfunction are significant morbidities in women with SCD, and fluid/water intake before and after sexual activity may be beneficial.

Current Opinion on the Use of Magnetic Resonance Imaging in Staging Prostate Cancer: A Narrative Review

Accurate staging is critical for treatment planning and prognosis in men with prostate Cancer. Prostate magnetic imaging resonance (MRI) may aid in the staging evaluation by verifying organ-confined status, assessing the status of the pelvic lymph nodes, and establishing the local extent of the tumor in patients being considered for therapy. MRI has a high specificity for diagnosing extracapsular extension, and therefore may impact the decision to perform nerve sparing prostatectomy, along with seminal vesicle invasion and lymph node metastases; however, its sensitivity remains limited. Current guidelines vary significantly regarding endorsing the use of MRI for staging locoregional disease. For high-risk prostate cancer, most guidelines recommend cross sectional imaging, including MRI, to evaluate for more extensive disease that may merit change in radiation field, extended androgen deprivation therapy, or guiding surgical planning. Although MRI offers reasonable performance characteristics to evaluate bone metastases, guidelines continue to support the use of bone scintigraphy. Emerging imaging technologies, including coupling positron emission tomography (PET) with MRI, have the potential to improve the accuracy of prostate cancer staging with the use of novel radiotracers.

Establishment of mouse line showing inducible priapism-like phenotypes

Purpose

Penile research is expected to reveal new targets for treatment and prevention of the complex mechanisms of its disorder including erectile dysfunction (ED). Thus, analyses of the molecular processes of penile ED and continuous erection as priapism are essential issues of reproductive medicine.

Methods

By performing mouse N-ethyl-N-nitrosourea mutagenesis and exome sequencing, we established a novel mouse line displaying protruded genitalia phenotype (PGP; priapism-like phenotype) and identified a novel Pitpna gene mutation for PGP. Extensive histological analyses on the Pitpna mutant and intracavernous pressure measurement (ICP) and liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI/MS)/MS analyses were performed.

Results

We evaluated the role of phospholipids during erection for the first time and showed the mutants of inducible phenotypes of priapism. Moreover, quantitative analysis using LC-ESI/MS/MS revealed that the level of phosphatidylinositol (PI) was significantly lower in the mutant penile samples. These results imply that PI may contribute to penile erection by PITPα.

Conclusions

Our findings suggest that the current mutant is a mouse model for priapism and abnormalities in PI signaling pathways through PITPα may lead to priapism providing an attractive novel therapeutic target in its treatment.

Clinical and penile Doppler outcomes using a modified, tourniquet free, Nesbit plication for severe Peyronie's disease

Background

Penile curvature (PC) can be surgically corrected by plication techniques or Nesbit corporoplasty. These shortening techniques can be complicated by post-operative: penile shortening, recurrent PC, palpable suture knots and erectile dysfunction. Furthermore, Nesbit procedures require the use of a penile tourniquet to avoid intraoperative bleeding. This observational study aims to assess the results of Nesbit modified corporoplasty, avoiding intraoperative use of tourniquet without risk of bleeding. The objective is to reduce penile ischemic anatomical and functional damages such as long-term erectile dysfunction.

Methods

Between January 2010 and March 2019, a total of 64 patients with congenital penile curvature (CPC) and Peyronie’s disease (PD) underwent surgical correction with a Nesbit modified technique first time described by Rolle et al., with minimal technical differences. The operation notes were retrospectively reviewed. In particular, we evaluated pre- and post-operative erectile functions using IIEF-5 score, penile Doppler ultrasonography and overall patient satisfaction.

Results

During operations, no intraoperative bleeding was noted, and no short-term complications such as hematomas or neurovascular bundle lesions were reported. At 6 months, no palpable subcutaneous indurations and no sensory change were detected. Post-operative penile shortening was reported in 38 (59.4%) patients (mean 0.83±0.79 cm), but it did not influence the high overall satisfaction rate of 91.4%. Only 2 patients reported a slightly partial recurrence of curvature (<15%) with no need for a redo surgery. Mean IIEF-5 score increased from 17.1±5.2 to 20.8±3.9 at 6 months and 21.8±3.4 at 12 months (P<0.001 in both cases). Mean PSV also significantly increased at the end of follow-up (28.5±6.1 at baseline vs. 31.0±7.1 at 12 months, P=0.03).

Conclusions

Considering the optimal results in terms of erectile functions increasing and absence of PC recurrence (>15°), we think that Nesbit modified corporoplasty without tourniquet application during reconstruction is a safe and effective surgical procedure for all kind of shortening corporoplasty to reduce the time of penile ischemia, preventing even serious consequences for the normal physiology of erection.

Differences in polysomnographic, nocturnal penile tumescence and penile doppler ultrasound findings in men with stuttering priapism and sleep-related painful erections

Men with Stuttering Priapism (SP) and sleep-related painful erections (SRPE) experience bothersome nocturnal painful erections resulting in poor sleep. The aim of this study is to observe common features and differences between men with SP and SRPE based on polysomnography, nocturnal penile tumescence (NPT), and penile doppler ultrasound (PDU). This is a prospective cohort study of 20 participants divided into two groups (Group 1 = SP [n = 12]; Group 2 = SRPE [n = 8]) with bothersome painful nocturnal erections. All participants were referred to the sleep disorder clinic to be assessed and consented for overnight polysomnography with simultaneous NPT recording and to complete validated sleep, sexual dysfunction and health-related quality of life questionnaires. Unstimulated PDU was also performed. Abnormal Polysomnographic findings (reduced sleep efficiency, total sleep time, and awake after sleep onset) were identified in both groups suggesting poor sleep. Men with SP had significantly longer erections (60.0 vs 18.5; p = 0.002) and took longer to detumesce once awake (25.7 vs 5.4 min; p = 0.001) than men with SRPE. They also had significantly higher peak systolic and end diastolic velocities on unstimulated PDU with an abnormal low resistance waveform identified. No sleep pathology was identified in men with SP. This implies a local (penile) etiology in men with SP. Men with SRPE had a normal resting PDU and abnormal sleep architecture with REM awakenings and significantly more Periodic limb movements (p = 0.04) than men with SP suggesting a central (sleep-related) cause in men with SRPE. Sexual dysfunction and poor HR-QoL was identified on validated questionnaires in both groups. SP and SRPE are rare entities that share similar symptoms (painful nocturnal erections and poor sleep) but dissimilar features of nocturnal erection onset, duration and resolution with different polysomnographic features which may allude to a different pathophysiology.

Men with sickle cell disease experience greater sexual dysfunction when compared with men without sickle cell disease

Recurrent ischemic priapism is a common complication of sickle cell disease (SCD). We assessed the burden, characteristics, and types of priapism, including sexual dysfunction, in a cohort of men with and those without SCD, to test the hypothesis that sexual dysfunction is more prevalent in men with SCD. In Kano, Nigeria, we conducted a comparative cross-sectional survey that included 500 and 250 men 18 to 40 years of age, with and without SCD, respectively. The survey used the Priapism Questionnaire and the International Index of Erectile Function for sexual function assessment. All eligible participants approached for the study gave informed consent and were enrolled. Stuttering and major priapism were defined based on the average duration of priapism experiences that lasted ≤4 and >4 hours, respectively. The prevalence of priapism was significantly higher in men with SCD than in those without it (32.6% vs 2%; P < .001). Stuttering priapism accounted for 73.6% of the priapism episodes in men with SCD. Nearly 50% of the participants with SCD-related priapism had never sought medical attention for this complication. The majority of the men with SCD-related priapism used exercise as a coping mechanism. Priapism affected the self-image of the men with SCD, causing sadness, embarrassment, and fear. The percentage of the men with SCD who had erectile dysfunction was more than twofold higher than that of those without SCD who had erectile dysfunction (P = .01). The men with SCD had a higher prevalence of priapism and sexual dysfunction than the men without SCD.

Combination High Flow Priapism With Low Flow Priapism: Case Report

Introduction

Priapism is defined as a persistent penile erection lasting longer than 4 hours and unrelated to sexual activity. It is one of the most common emergencies treated by urologists. Advances in understanding the pathophysiology of various types of priapism have led to targeted management strategies according to type of priapism.

Aim

The aims of this article is report the case of a 24-year-old man who was presented in the emergency department with a combination of high flow priapism with low flow priapism.

Methods

This case report documents the case of a patient who presented in the emergency department with a high flow priapism that then became to a ischemic priapism.

Conclusion

Priapism is one of the most common emergencies treated by urologists. Advances in understanding the pathophysiology of various types of priapism have led to targeted management strategies as was shown in our case.

Carvajal A, Benavides JA. Combination High Flow Priapism With Low Flow Priapism: Case Report. Sex Med 2019;7:111–113.

[Priapism: Diagnosis and management]

OBJECTIVE

Our aim was to present a synthesis on the diagnosis and treatment of priapism.

METHODS

For this purpose, a literature search was performed through PubMed to analyze literature reviews and guidelines regarding priapism.

RESULTS

Priapism is an erection that persists more than 4hours. There are 3 types of priapism: ischemic priapism, non-ischemic priapism and recurrent (stuttering) priapism. Ischemic priapism, often idiopathic, is the most frequent. When diagnosed, an urgent management is required to limit erectile dysfunction. Sickle-cell patients are prone to have ischemic and stuttering priapism. Non-ischemic priapism usually occurs after perineal trauma. Priapism management depends on the type of priapism. Medical treatment (corporal aspiration and injection of sympathomimetics) then if failed, surgery are indicated for ischemic priapism. The persistence of a non-ischemic priapism most likely requires a radiologic embolization.

CONCLUSION

Priapism is a condition that often requires emergency treatment to spare erectile function. It appears crucial to know this condition and its management.

Low nitric oxide level is implicated in sickle cell disease and its complications in Ghana

BACKGROUND

Nitric oxide (NO) plays a fundamental role in maintaining normal vasomotor tone. Recent clinical and experimental data suggest that NO may play a role in the pathogenesis and therapy of sickle cell disease (SCD). The aim of this study was to determine NO metabolites (NOx) in SCD patients at steady state and in vaso-occlusive crisis (VOC), as well as those with hemolytic clinical sub-phenotype that includes leg ulcers and priapism.

METHODOLOGY

This was a case-control cross-sectional study conducted on a total of 694 subjects including 148 comparison group HbAA, 208 HbSS SCD patients in steady state, 82 HbSC SCD patients in steady state, 156 HbSS SCD patients in VOC, 34 HbSC SCD patients in VOC, 34 HbSS SCD patients in post VOC, 21 HbSS SCD patients with leg ulcer and 11 HbSS SCD patients with priapism, with age ranging from 15 to 65 years. Laboratory diagnosis of SCD was done at the Sickle Cell Clinic of the Korle-Bu Teaching Hospital. Plasma nitric oxide metabolites were measured using Griess reagent system by ELISA method.

RESULTS

Mean NOx of 59.66±0.75 µMol/L in the comparison group was significantly different from those in steady state (P=0.02). During VOC, there was a significant reduction in mean NOx levels to 6.08±0.81 µMol/L (P<0.001). Mean NOx levels were however, significantly higher (50.97±1.68 µMol/L) (P<0.001) in the immediate postcrisis period. The mean NOx levels in the leg ulcer (21.70±1.18 µMol/L) (P<0.001) and priapism (28.97±1.27 µMol/L) (P<0.001) patients were significantly low as compared to the SCD patients in the steady state and comparison group.

CONCLUSION

This study presents the first report on plasma NOx levels in SCD complication in Ghanaian SCD patients and confirms reduced plasma NOx levels in SCD patients in general.

Management of priapism: an update for clinicians

Priapism is a prolonged erection that persists beyond or is unrelated to sexual stimulation. It is associated with significant morbidity: psychological, socioeconomic, and physical, including pain and potentially irreversible compromise of erectile function. There are three major types of priapism: ischemic, nonischemic, and stuttering. Establishing the type of priapism is paramount to safely and effectively treating these episodes. Ischemic priapism represents a urological emergency. Its treatment may involve aspiration/irrigation with sympathomimetic injections, surgical shunts, and as a last resort, penile prosthesis implantation. Nonischemic priapism results from continuous flow of arterial blood into the penis, most commonly related to penile trauma. This is not an emergency and may be managed conservatively initially, as most of these episodes are self-limiting. Stuttering priapism involves recurrent self-limiting episodes of ischemic priapism. The primary goal of therapy is prevention, but acute episodes should be managed in accordance with guidelines for ischemic priapism. In this paper we review the diagnosis and treatment of the three priapism variants, as well as discuss future targets of therapy and novel targets on the horizon.

Stuttering priapism in a patient with neurosyphilis

We recently encountered a case of stuttering priapism in a 41-year-old patient with neurosyphilis. Priapism very rarely has a neurogenic cause, and to our knowledge, priapism caused by neurosyphilis has not been reported previously in the literature. Our aim was to report this case and systematically review the related literature.

Molecular analysis of erection regulatory factors in sickle cell disease associated priapism in the human penis

PURPOSE

Priapism is a vasculopathy that occurs in approximately 40% of patients with sickle cell disease. Mouse models suggest that dysregulated nitric oxide synthase and RhoA/ROCK signaling as well as increased oxidative stress may contribute to the mechanisms of sickle cell disease associated priapism. We examined changes in the protein expression of nitric oxide synthase and ROCK signaling pathways, and a source of oxidative stress, NADPH oxidase, in penile erectile tissue from patients with a priapism history etiologically related and unrelated to sickle cell disease.

MATERIALS AND METHODS

Human penile erectile tissue was obtained from 5 patients with sickle cell disease associated priapism and from 6 with priapism of other etiologies during nonemergent penile prosthesis surgery for erectile dysfunction or priapism management and urethroplasty. Tissue was also obtained from 5 control patients without a priapism history during penectomy for penile cancer. Samples were collected, immediately placed in cold buffer and then frozen in liquid nitrogen. The expression of phosphodiesterase 5, endothelial nitric oxide synthase, neuronal nitric oxide synthase, inducible nitric oxide synthase, RhoA, ROCK1, ROCK2, p47(phox), p67(phox), gp91(phox) and β-actin were determined by Western blot analysis. Nitric oxide was measured using the Griess reaction.

RESULTS

In the sickle cell disease group phosphodiesterase 5 (p <0.05), endothelial nitric oxide synthase (p <0.01) and RhoA (p <0.01) expression was significantly decreased, while gp91(phox) expression (p <0.05) was significantly increased compared to control values. In the nonsickle cell disease group endothelial nitric oxide synthase, ROCK1 and p47(phox) expression (each p <0.05) was significantly decreased compared to control values. Total nitric oxide levels were not significantly different between the study groups.

CONCLUSIONS

Mechanisms of sickle cell disease associated priapism in the human penis may involve dysfunctional nitric oxide synthase and ROCK signaling, and increased oxidative stress associated with NADPH oxidase mediated signaling.

Testosterone replacement with 1% testosterone gel and priapism: no definite risk relationship

INTRODUCTION

Although testosterone replacement therapy (TRT) is the preferred treatment for hypogonadism, information for patients using testosterone includes too frequent or prolonged erections as a potential side effect.

AIM

To assess the frequency and risk of priapism or related adverse events (AEs) in hypogonadal men treated with a 1% testosterone gel.

METHODS

Safety and tolerability data for AndroGel 1% were assessed, including three randomized, controlled clinical trials in varying populations of hypogonadal or near hypogonadal men. Study 1 was a Phase 3 trial of AndroGel 1% 5 g, 7.5 g, or 10 g once daily for 6 months (N = 227). Study 2 was a Phase 2 trial of AndroGel 1% 7.5 g once daily titrated as needed vs. placebo for 26 weeks in men with type 2 diabetes (N = 180). Study 3 was a Phase 4 trial of AndroGel 1% 5 g once daily vs. placebo for 12 weeks in men previously unresponsive to sildenafil 100 mg monotherapy and receiving concomitant sildenafil 100 mg (N = 75). Postmarketing AndroGel pharmacovigilance reporting data from 2001 to 2011 was searched for events coded as priapism.

MAIN OUTCOME MEASURES

The incidence of priapism and/or related symptoms reported as urogenital or reproductive system AEs.

RESULTS

In the 283 men exposed to AndroGel 1% over the three trials, mean exposure ranged from 84 days to 149 days. No AEs described as priapism or related symptoms were reported in the three trials. In the postmarketing data, representing 40 million units sold, eight cases described as priapism were reported. Of the six cases with accompanying data, all were judged as possibly related to AndroGel.

CONCLUSIONS

Safety data from the clinical trials for AndroGel 1% did not report any cases of priapism, and its incidence in the postmarketing pharmacovigilance data is extremely low, indicating a minimal risk of inducing priapism.

How I manage priapism due to sickle cell disease

Priapism due to sickle cell disease is a common but less well characterized complication of the disorder. It represents a "medical emergency" with the key determinant of outcome being the duration of penile ischaemia and time to detumescence of <4 h associated with a successful treatment outcome. Management can be outpatient-based and consists of pre-emptive strategies for early stuttering attacks based on prior health education of the association between the 2 disorders, non pharmacological management, outpatient penile aspiration and irrigation with or without instillation of alpha and beta adrenergic agonists for acute episodes and secondary prophylaxis to prevent the high rates of recurrences. The evidence to recommend medical prophylaxis is sparse but based on a consensus of experts and small phase 2 or III clinical trials. A clearer understanding of the molecular mechanism(s) involving normal and dysregulated erectile physiology, scavenger haemolysis and nitric oxide pathway paves way for the use of phosphodiesterase type 5 inhibitors in medical prophylaxis of stuttering attacks. These agents will need to be studied in multi-centre randomized phase III trials before they become standard of care. A multidisciplinary team approach is required to enhance "sexual wellness" and prevent erectile dysfunction in this sexually vulnerable group.

Priapism: pathophysiology and the role of the radiologist

Priapism is defined as a penile erection that persists for 4 h or longer and is unrelated to sexual activity. Its identification is important as lack of timely treatment (particularly of the low flow/ischaemic subgroup) can result in persisting erectile dysfunction as a consequence of irreversible corporal fibrosis. This review describes the physiology and anatomy of the normal erection, the aetiology and pathophysiology of the different types of priapism, and the role of the radiologist in the management of the condition. The treatment of iatrogenic priapism following intracavernosal injection of pharmacostimulant is discussed.

Sickling cells, cyclic nucleotides, and protein kinases: the pathophysiology of urogenital disorders in sickle cell anemia

Sickle cell anemia is one of the best studied inherited diseases, and despite being caused by a single point mutation in the HBB gene, multiple pleiotropic effects of the abnormal hemoglobin S production range from vaso-occlusive crisis, stroke, and pulmonary hypertension to osteonecrosis and leg ulcers. Urogenital function is not spared, and although priapism is most frequently remembered, other related clinical manifestations have been described, such as nocturia, enuresis, increased frequence of lower urinary tract infections, urinary incontinence, hypogonadism, and testicular infarction. Studies on sickle cell vaso-occlusion and priapism using both in vitro and in vivo models have shed light on the pathogenesis of some of these events. The authors review what is known about the deleterious effects of sickling on the genitourinary tract and how the role of cyclic nucleotides signaling and protein kinases may help understand the pathophysiology underlying these manifestations and develop novel therapies in the setting of urogenital disorders in sickle cell disease.

A minimally invasive temporary cavernoso-saphenous shunt in the management of priapism after failed conservative treatment

Priapism is an urological emergency with detrimental consequences, if not managed expeditiously. Though a rare condition with an incidence between 0.3 and 1.5 per 100,000 population, its management options are limited and decision making could be challenging. We present a case of late presenting priapism for which the initial routine clinical care (aspiration, intracavernosal injection, and distal shunt) failed to relieve erection. Subsequently, the patient was successfully treated by a temporary cavernoso-saphenous shunt using carotid shunt and repeated heparin flushes. This novel surgical treatment offers an alternate method of relieving priapism, avoiding the long-term undesired effects associated with permanent proximal shunts such as cavernoso-venous grafts. Moreover, interval flushes (and/or repeated aspirations) with heparin ensures patency of this new shunt during the perioperative period. The patient recovered without any complications and the shunt was removed after one week. He has regained partial erection, however refused to have further treatment. Temporary cavernoso-saphenous shunt using carotid shunt offers an alternate option of management of priapism in patients with failed initial conservative treatment and distal shunts.

Role of adenosine signaling in penile erection and erectile disorders

INTRODUCTION

Penile erection is a hemodynamic process, which results from increased flow and retention of blood in the penile organ due to the relaxation of smooth muscle cells. Adenosine, a physiological vasorelaxant, has been shown to be a modulator of penile erection.

AIM

To summarize the research on the role of adenosine signaling in normal penile erection and erectile disorders.

MAIN OUTCOME MEASURES

Evidence in the literature on the association between adenosine signaling and normal and abnormal penile erection, i.e., erectile dysfunction (ED) and priapism.

METHODS

The article reviews the literature on the role of endogenous and exogenous adenosine in normal penile erection, as well as in erectile disorders namely, ED and priapism.

RESULTS

Adenosine has been shown to relax corpus cavernosum from various species including human in both in vivo and in vitro studies. Neuromodulatory role of adenosine in corpus cavernosum has also been demonstrated. Impaired adenosine signaling through A(2B) receptor causes partial resistance of corpus cavernosum, from men with organic ED, to adenosine-mediated relaxation. Increased level of adenosine has been shown to be a causative factor for priapism.

CONCLUSION

Overall, the research reviewed here suggests a general role of exogenous and endogenous adenosine signaling in normal penile erection. From this perspective, it is not surprising that impaired adenosine signaling is associated with ED, and excessive adenosine signaling is associated with priapism. Adenosine signaling represents a potentially important diagnostic and therapeutic target for the treatment of ED and priapism.

In vitro and in vivo animal models in priapism research

INTRODUCTION

Priapism is an enigmatic yet devastating clinical phenomenon. In the last two decades, the use of various animal models to study this disorder has dramatically advanced our understanding of this mysterious disorder.

AIM

This report reviews various animal models used to study ischemic priapism and informs basic science researchers the broad view of priapism research.

METHODS

Retrospective review of pertinent literature from the last two decades via PubMed search using the keywords "ischemic priapism" and "priapism model."

MAIN OUTCOME MEASURES

  Findings on the animal models used in ischemic priapism research and its advantages and limitations.

RESULTS

In vitro and in vivo animal models varying from dogs, cats, rabbits, rats to mice were used in priapism research. In vitro models included: (i) corpora cavernosa smooth muscle (CCSM) strip in organ bath; (ii) corporal tissue binding assay; (iii) CCSM cell culture under hypoxia/anoxia. In vivo models could be categorized as: (i) pharmacologically induced by corpus cavernosum medicine injection; (ii) ventilation induced by tidal volume control; (iii) mechanical induced by a constrictor band placed around the base of the penis combined with induced erection; (iv) genetic engineered by intracorporal gene transfer, transgenic, or gene knock-out.

CONCLUSIONS

The ischemic priapism animal models are shifting from pharmaceutically or mechanically induced to genetically engineered. The knowledge generated by those models is enhancing our understanding and management of this clinical challenge.

Androgen blockade for the treatment of high-flow priapism

INTRODUCTION

High-flow priapism (HFP) may occur secondary to perineal trauma, congenital arterial malformations, and iatrogenic insults. In cases that do not resolve spontaneously, standard management is by selective embolization, resulting in resolution rates as high as 78%; however, erectile dysfunction (ED) is a frequent complication, occurring in up to 39% of cases.

AIM

We report our use of androgen blockade (AB) to suppress nocturnal erections as an alternative treatment for HFP.

METHODS

A retrospective review of all patients treated at our institution for HFP was undertaken. Included in this study were any patients treated with single- or combination-agent AB for HFP. Operative reports and medical records were examined to determine patient characteristics and outcomes. Treatment efficacy, side effects, and residual ED were assessed using a questionnaire.

MAIN OUTCOME MEASURES

The primary clinical outcomes assessed were resolution of HFP, tolerability, and side effects of treatment.

RESULTS

Seven patients with HFP were treated with AB. Priapism was a result of trauma in three patients and a persistent high-flow state after shunt procedures in four. Mean follow-up was 2 years (range 4 to 64 months). Therapy consisted primarily of 7.5 mg intramuscular monthly leuprolide injections, although bicalutamide and ketoconazole were also utilized as adjunct treatments. Therapy duration ranged from 2 months to 6 months and was discontinued after symptom resolution. One patient discontinued daily ketoconazole after 1 week because of severe hot flashes. The remaining six patients reported complete resolution of HFP. The primary complaints during therapy were decreased libido and fatigue. All patients reported some degree of ED during therapy. There was no reported residual ED or other hypogonadal symptoms on withdrawal of therapy.

CONCLUSION

AB is a successful option for treating HFP with acceptable side effects and return to baseline potency on treatment withdrawal.

Evaluation and management of priapism: 2009 update

Priapism is defined as a persistent penile erection (typically 4 h or longer) that is unrelated to sexual stimulation. Priapism can be classified as either ischemic or nonischemic. Ischemic priapism, the most common subtype, is typically accompanied by pain and is associated with a substantial risk of subsequent erectile dysfunction. Prompt medical attention is indicated in cases of ischemic priapism. The initial management of choice is corporal aspiration with injection of sympathomimetic agents. If medical management fails, a cavernosal shunt procedure is indicated. Stuttering (recurrent) ischemic priapism is a challenging and poorly understood condition; new management strategies currently under investigation may improve our ability to care for men with this condition. Nonischemic priapism occurs more rarely than ischemic priapism, and is most often the result of trauma. This subtype of priapism, which is generally not painful, is usually initially managed with conservative treatment.

High-flow priapism due to a malignant glomus tumor (glomangiosarcoma) of the corpus cavernosum

INTRODUCTION

The major cause of non-ischemic high-flow priapism is post-traumatic vascular injury leading to an arterio-lacunar fistula. However, rare causes such as tumors may induce priapism. This is the first report of a malignant glomus tumor localized in the corpora cavernosa.

AIM

The aim of this case is to emphasize the importance of the initial management of priapism and to suggest new tracks on the tests to be performed when the usual exams are not sufficient.

METHOD

We report the case of a hypervascular penile tumor responsible for high-flow priapism as the first clinical symptom of a metastatic glomus tumor. The persistent penile tumescence was initially considered to be a stuttering priapism and treated using an oral α-adrenergic as no provoking event nor fistula was found. After a 2-week reluctance, a penile magnetic resonance imaging (MRI) was performed.

RESULTS

The MRI showed a hypervascular lesion at the proximal part of the right corpora. The lesion was considered as a fistula, and a selective embolization was performed. Two weeks after embolization, the patient came back to the emergency room because of syncopes and dyspnea. Examination by cardiac ultrasound and chest computed tomography revealed the presence of cardiac, pulmonary, and subcutaneous malignant glomus tumors (glomangiosarcoma). Patient received three lines of chemotherapy, and the penile tumor was surgically removed because of persistent erectile dysfunction and perineal pain.

CONCLUSION

This case supports the use of corporal body blood gas analysis in difficult cases to discriminate high- and low-flow priapism and penile MRI when clinical history, physical examination, and aspiration are not contributory.

Increased adenosine contributes to penile fibrosis, a dangerous feature of priapism, via A2B adenosine receptor signaling

Priapism is a condition of persistent penile erection in the absence of sexual excitation. Of men with sickle cell disease (SCD), 40% display priapism. The disorder is a dangerous and urgent condition, given its association with penile fibrosis and eventual erectile dysfunction. Current strategies to prevent its progression are poor because of a lack of fundamental understanding of the molecular mechanisms for penile fibrosis in priapism. Here we demonstrate that increased adenosine is a novel causative factor contributing to penile fibrosis in two independent animal models of priapism, adenosine deaminase (ADA)-deficient mice and SCD transgenic mice. An important finding is that chronic reduction of adenosine by ADA enzyme therapy successfully attenuated penile fibrosis in both mouse models, indicating an essential role of increased adenosine in penile fibrosis and a novel therapeutic possibility for this serious complication. Subsequently, we identified that both mice models share a similar fibrotic gene expression profile in penile tissue (including procollagen I, TGF-beta(1), and plasminogen activator inhibitor-1 mRNA), suggesting that they share similar signaling pathways for progression to penile fibrosis. Thus, in an effort to decipher specific cell types and underlying mechanism responsible for adenosine-mediated penile fibrosis, we purified corpus cavernosal fibroblast cells (CCFCs), the major cell type involved in this process, from wild-type mice. Quantitative RT-PCR showed that the major receptor expressed in these cells is the adenosine receptor A(2B)R. Based on this fact, we further purified CCFCs from A(2B)R-deficient mice and demonstrated that A(2B)R is essential for excess adenosine-mediated penile fibrosis. Finally, we revealed that TGF-beta functions downstream of the A(2B)R to increase CCFC collagen secretion and proliferation. Overall, our studies identify an essential role of increased adenosine in the pathogenesis of penile fibrosis via A(2B)R signaling and offer a potential target for prevention and treatment of penile fibrosis, a dangerous complication seen in priapism.-Wen, J., Jiang, X., Dai, Y., Zhang, Y., Tang, Y., Sun, H., Mi, T., Phatarpekar, P. V., Kellems, R. E., Blackburn, M. R., Xia, Y. Increased adenosine contributes to penile fibrosis, a dangerous feature of priapism, via A(2B) adenosine receptor signaling.

Increased cavernosal relaxations in sickle cell mice priapism are associated with alterations in the NO-cGMP signaling pathway

INTRODUCTION

Priapism is defined as prolonged and persistent penile erection, unassociated with sexual interest or stimulation, and is one of the many serious complications associated with sickle cell disease (SCD).

AIM

The aim of this study was to evaluate the role of the NO-cGMP signaling pathway in priapism in Berkeley murine model of SCD (SS).

METHODS

SS mice and C57BL/6 mice (control) penile tissues were removed and the erectile tissue within the corpus cavernosum (CC) was surgically dissected free. The strips were mounted in 10 mL organ baths containing Krebs solution at 37 degrees C (95% O(2), 5% CO(2), pH 7.4), and vertically suspended between two metal hooks.

MAIN OUTCOME MEASURES

Cumulative concentration-response curves were constructed for acetylcholine (ACh; endothelium-dependent responses), sodium nitroprusside (SNP; endothelium-independent relaxations) and BAY 41-2272 (a potent activator of NO-independent site of soluble guanylate cyclase) in CC precontracted with phenylephrine. Cavernosal responses induced by frequency-dependent electrical field stimulation (EFS) were also carried out to evaluate the nitrergic cavernosal relaxations.

RESULTS

In SS mice, ACh-induced cavernosal relaxations were leftward shifted by 2.6-fold (P < 0.01) that was accompanied by increases in the maximal responses (78 +/- 5% and 60 +/- 3% in SS and C57B6/6J mice, respectively). Similarly, SNP- and BAY 41-2272-induced CC relaxations were leftward shifted by approximately 3.3- and 2.2-fold (P < 0.01) in SS mice, respectively. A significant increase in maximal responses to SNP and BAY 41-2272 in SS mice was also observed (113 +/- 6% and 124 +/- 5%, respectively) compared with C57B6/6J mice (83 +/- 4% and 99 +/- 2%, respectively). The EFS-induced cavernosal relaxations were also significantly higher SS mice.

CONCLUSION

These results showed that SS mice exhibit amplified corpus carvenosum relaxation response mediated by NO-cGMP signaling pathway. Intervention in this signaling pathway may be a potential therapeutic target to treat SCD priapism.

Anxiety disorders in patients with idiopathic priapism: risk factor and pathophysiologic link?

INTRODUCTION

A scientific explanation remains elusive for many presentations of recurrent ischemic priapism.

AIM

The aim of this article was to evaluate the possible clinical association between idiopathic priapism and anxiety disorders.

METHODS

Twenty-one patients without identifiable, presumed etiologies for their priapism disorders presented consecutively to a single practitioner's clinical practice and underwent clinical history evaluation and management over a 2(1/2)-year interval.

MAIN OUTCOME MEASURES

The main outcome is the documentation of patient demographics and clinical profiles relating to medical history and priapism presentations.

RESULTS

Anxiety disorders including generalized anxiety, attention-deficit hyperactivity disorder, and obsessive-compulsive disorder were self-reported in 10 patients.

CONCLUSIONS

The possible association between idiopathic priapism and anxiety disorders lends support for a central neurobiologic pathophysiology for the erectile disorder. Further neuropsychiatric studies of this clinical population is required to confirm the hypothesis.

Oral phosphodiesterase type 5 inhibitors alleviate recurrent priapism complicating thalassemia intermedia: a case report

INTRODUCTION

Recurrent ischemic priapism still remains a serious and difficult to treat complication of certain hematological disorders. Elucidation of the underlying pathophysiologic mechanisms and application of new effective prophylactic treatments are needed.

AIM

To present the efficacy of phosphodiesterase type 5 inhibitors (PDE5is) as a preventive measure against ischemic priapism recurrences complicating thalassemia intermedia.

METHODS

We report on the case of a 19-year-old Caucasian man with thalassemia intermedia complicated by recurrent episodes of priapism following therapeutic splenectomy. After failure of conventional measures to control recurrences, a trial of long-term PDE5is use was initiated.

MAIN OUTCOME MEASURES

PDE5is efficacy based on clinical patient history.

RESULTS

Within 2 months of PDE5i preventive strategy, priapism recurrences nearly resolved. At 6 months, prophylaxis was discontinued. At 12 months, the patient reported clear improvement and satisfaction, experiencing rare episodes of priapism and a physiologic erectile function.

CONCLUSIONS

PDE5 dysregulation seems to be an underline pathogenetic mechanism of thalassemia intermedia-associated priapism. It appears that PDE5is might have a role in the clinical management of such patients and their preventive efficacy warrants further testing in clinical trials.

Excess adenosine in murine penile erectile tissues contributes to priapism via A2B adenosine receptor signaling

Priapism, abnormally prolonged penile erection in the absence of sexual excitation, is associated with ischemia-mediated erectile tissue damage and subsequent erectile dysfunction. It is common among males with sickle cell disease (SCD), and SCD transgenic mice are an accepted model of the disorder. Current strategies to manage priapism suffer from a poor fundamental understanding of the molecular mechanisms underlying the disorder. Here we report that mice lacking adenosine deaminase (ADA), an enzyme necessary for the breakdown of adenosine, displayed unexpected priapic activity. ADA enzyme therapy successfully corrected the priapic activity both in vivo and in vitro, suggesting that it was dependent on elevated adenosine levels. Further genetic and pharmacologic evidence demonstrated that A2B adenosine receptor-mediated (A2BR-mediated) cAMP and cGMP induction was required for elevated adenosine-induced prolonged penile erection. Finally, priapic activity in SCD transgenic mice was also caused by elevated adenosine levels and A2BR activation. Thus, we have shown that excessive adenosine accumulation in the penis contributes to priapism through increased A2BR signaling in both Ada -/- and SCD transgenic mice. These findings provide insight regarding the molecular basis of priapism and suggest that strategies to either reduce adenosine or block A2BR activation may prove beneficial in the treatment of this disorder.