Priapism: New concepts in the pathophysiology and new treatment strategies

Priapism is defined as prolonged and persistent erection of the penis without sexual stimulation. This is a poorly understood disease process, and we have little information on the etiology and pathophysiology of this erectile disorder. Two main types of priapism exist: low-flow (ischemic) and high-flow (nonischemic) priapism. When the physician first diagnoses which type of priapism exists, distinguishing the type of priapic event is paramount in order to choose the correct treatment options. Until recently, we had not sufficiently understood the pathogenesis of this erectile disorder and therefore, could not effectively manage its pathologic consequences of erectile tissue damage and erectile dysfunction. In this review, the proposed pathogenesis of ischemic priapism is reviewed, and a survey regarding novel treatment modalities is given.     

Medical management of ischemic stuttering priapism: a contemporary review of the literature

Priapism is defined as a prolonged and persistent erection of the penis without sexual stimulation. This is a poorly understood disease process with little information on the pathophysiology of this erectile disorder. Complications from this disorder are devastating due to the irreversible erectile damage and resultant erectile dysfunction (ED). Stuttering priapism, though relatively rare, affects a high prevalence of men with sickle-cell disease (SCD) and presents a challenging problem with guidelines for treatment lacking or resulting in permanent ED. The mechanisms involved in the development of priapism in this cohort are poorly characterized; therefore, medical management of priapism represents a therapeutic challenge to urologists. Additional research is warranted, so we can effectively target treatments for these patients with prevention as the goal. This review gives an introduction to stuttering priapism and its clinical significance, specifically with regards to the patient with SCD. Additionally, the proposed mechanisms behind its pathophysiology and a summary of the current and future targets for medical management are discussed.     

Insights of priapism mechanism and rationale treatment for recurrent priapism

Priapism is defined as abnormal prolonged penile erection occurring beyond or unrelated to sexual interest. The disorder is enigmatic yet devastating because of its elusive etiology, irreversible erectile tissue damage, and resultant erectile dysfunction （ED）. Current management strategies suffer from a poor understanding of the pathophysiology, especially at the molecular level. The traditional treatments are based more on empirical rather than evidence-based knowledge. The outcomes for restoration of normal erectile function are poor, especially for stuttering priapism. Therefore, it is critical to understand priapism from a molecular level, to formulate treatment strategies and to establish rational prevention strategies for high-risk populations, such as sickle cell disease （SCD） patients and cases of the stuttering variant. This review focuses on the recent advances at the molecular level in priapism and penile erection, and applies the recent knowledge to the treatment of stuttering priapism.     

Case report of post-traumatic arterial high-flow priapism

Priapism is rare and usually unpredictable. High-flow priapism is caused by unregulated arterial inflow. Antecedent trauma is the most commonly described etiology. This condition does not require emergent treatment. The initial management of high-flow priapism should be observation, because treatment-related erectile dysfunction may appear. We report a case of high-flow priapism by perineal trauma in a 27-year-old man. His corpora were typically tumescent, but not completely rigid. He could not have sexual intercourse. Blood from the corpus cavernosum was normally oxygenated. Color duplex ultrasonography was performed in the lithotomy position, scanned at the perineum, showed pseudoaneurysmal appearance. Selective internal pudendal arteriography showed a right cavernous arterial extravasation. Superselective embolization of right internal pudendal arteries was performed with an autologous clot. After the procedure, detumescence was achieved as well as erectile function. We recommend superselective arterial embolization as the management of high flow priapism to patients who request treatment.     

Priapism

Priapism has been defined by AFUD as a pathological condition which consists in a penile erection that persists moreover or is not related to sexual stimulation. Priapism pathophysiology has remained unknown until differents groups of clinical investigators began to research about this entity in patients complaining of erectile dysfunction, who where receiving treatment with intracavernosal vasoactive molecules. Priapism can be clasified into ischaemic (venocclusive): the most prevalent type, or Arterial (non-ischaemic). The purpose of this revision is to update the pathophysiology of the two types of priapism and to create an algorithm of therapeutical and diagnostic approach.     

Priapism: an avoidable complication of pharmacologically induced erection

Priapism is an alarming complication during treatment of erectile dysfunction with vasoactive drugs, particularly papaverine alone or in combination with phentolamine mesylate. An investigational protocol was designed to identify patients who are more susceptible to priapism after intracavernous injection of papaverine alone or with phentolamine. The protocol was applied in 331 men with impotence of various etiology. The association of a positive response to visual sexual stimulation and penile brachial index of more than 0.8 represented a higher risk for post-injection priapism. We were able to reduce the incidence of this compliance to 1% in the last 101 patients.     

Nonischaemic priapism associated with selective serotonin‐3 receptor antagonist

Priapism is a rare but severe urological emergency of erection of penis in the absence of physical and psychological sexual stimulation. Priapism is often idiopathic and is commonly associated with medications and underlying medical or traumatic causes. In this report, we present a case of a 70‐year‐old White Caucasian man who developed priapism after the administration of ondansetron, which is a selective serotonin type‐3 (5‐HT3) receptor antagonist. This case is unique, because, to date, there are only two presented cases in literature. The objective of this case report is to highlight the importance of recognising the possibility of priapism with ondansetron because this condition is not commonly seen in clinical practice to be associated with ondansetron and may go unrecognised. Also, potential pathophysiological mechanisms involved in the development of ondansetron‐induced priapism are presented.     

Priapism - etiology, pathophysiology and management

The understanding of erectile physiology has improved the prompt diagnosis and treatment of priapism. Priapism is defined as prolonged and persistent erection of the penis without sexual stimulation and failure to subside despite orgasm. Numerous etiologies of this condition are considered. Among others a disturbed detumescence mechanism, which may due to excess release of contractile neurotransmitters, obstruction of draining venules, malfunction of the intrinsic detumescence mechanism or prolonged relaxation of intracavernosal smooth muscle are postulated. Treatment of priapism varies from a conservative medical to a drastic surgical approach. Two main types of priapism; veno-occlusive low flow (ischemic) and arterial high flow (non-ischemic), must be distinguished to choose the correct treatment option for each type. Patient history, physical examination, penile hemodynamics and corporeal metabolic blood quality provides distinction between a static or dynamic pathology. Priapism can be treated effectively with intracavernous vasoconstrictive agents or surgical shunting. Alternative options, such as intracavernous injection of methylene blue (MB) or selective penile arterial embolization (SPEA), for the management of high and low flow priapism are described and a survey on current treatment modalities is given.     

Stuttering Priapism: Insights into Pathogenesis and Management

Priapism is defined as a persistent, painful erection that continues beyond, or is unrelated to, sexual stimulation. It may be categorized as either ischemic (low/absent flow) or nonischemic (high flow). Stuttering priapism is a variant of the ischemic type that is characterized by repetitive, transient, painful, self-limiting episodes of priapism. It is associated with various hematological disorders, including sickle cell disease and pharmacological treatments. The consequences of ineffective treatment of priapism are erectile dysfunction and impaired quality of life due to chronic pain and physical disfigurement. Many of the existing medical therapeutic options for treatment of stuttering priapism are nonmechanistic and associated with significant adverse effects. However, the scientific knowledge of stuttering priapism has transitioned in the past few years, from a condition that is poorly understood to one that has borne a burst of evolving molecular science. In this review, the pathophysiology of priapism is discussed, with particular emphasis on new molecular effectors and mechanisms. Novel treatment methods, as well as potential future agents, based on the emerging molecular evidence are discussed.     

The actual incidence of papaverine-induced priapism in patients with erectile dysfunction following penile colour Doppler ultrasonography

Penile color Doppler sonography is a valuable method for evaluating erectile dysfunction. However, there are some concerns about the safety of this method due to the intracorporeal pharmacological injection, which may cause priapism as a complication, resulting in penile fibrosis. To evaluate the actual incidence of papaverine-induced priapism in patients with erectile dysfunction (ED) who underwent penile colour Doppler sonography and to determine the safety of this diagnostic tool, a retrospective study was conducted using the database of our institution. A total of 672 men with ED underwent penile color Doppler ultrasonography with the intracorporeal injection of 60 mg papaverine hydrochloride. The patient characteristics of priapism cases were retrospectively evaluated. Priapism in 18 of the 672 patients (2.68%) was successfully treated with blood aspiration, irrigation and injection of an α-agonist medication, when needed. Patients with priapism were younger compared with those without priapism; mean age 45 ± 12.51 (20–68) versus 50.93 ± 12.04 (17–78) ( P  < 0.001). Penile Doppler ultrasound is a safe procedure in evaluating erectile dysfunction. The incidence of priapism, which is the most important complication of this procedure, is low and can be managed successfully with conservative approaches.     

Priapism in the newborn: management and review of literature

Priapism is a pathological condition of a penile erection that persists beyond or is unrelated to sexual stimulation. Priapism is broadly classified into two types: (i) ischaemic priapism (veno-occlusive) (low-flow), (ii) nonischaemic priapism (arterial) (high-flow). We report the case of a newborn presenting with priapism on the first day of life and also review published data on the management and follow-up of this condition.     

Management of Priapism in Adult Men

This study aims to present the management of priapism in adult men in Port Harcourt, Nigeria. All patients who presented with priapism in 2 hospitals in Port Harcourt from July 2007 to April 2014 were prospectively studied. Treatment was assigned based on clinical presentation. Data analyzed included: age on clinical presentation, risk factor, mode, and outcome of management. There were 18 patients aged 17 to 60 years (median age: 30 years). Three patients (16.7%) presented with stuttering priapism. Most of the patients presented after 24 hours of onset. Sixteen patients (89.9%) had hematological disorders. Five patients (27.8%) took suspected aphrodisiac medications. Seven patients (38.9%) were managed conservatively. The rest achieved detumescence following glandulo-cavernous shunting. Erectile function after treatment was satisfactory in 5 patients (27.8%). The commonest cause of priapism in Port Harcourt was hematological disorder. Most of the patients presented late. Prevalence of erectile dysfunction after treatment was high.Key words: Priapism, Sickle cell anemia, TumescencePriapism is a potentially painful medical condition in which the erect penis or clitoris does not return to its flaccid state, despite the absence of both physical and psychological stimulation, within 4 hours.¹ Priapism has been described as a genuine erectile dysfunction in which erection persists without sexual stimulation.² It is a rare condition with overall incidence of 1.5 cases per 100,000 person-years.³ However, it is an important urologic emergency because erectile tissue damage may occur leading to loss of functional erections.⁴ The time interval between the onset of symptoms and presentation for medical intervention impacts on the outcome of management.Priapism is associated with various risk factors such as: antipsychotics drugs, local aphrodisiacs; hematologic malignancies, and congenital vascular disorders. Hemoglibinopathies constitute the major cause in countries where sickle cell disease (SCD) is endemic.⁵Depending on the predisposing factor, priapism may be ischemic, nonischemic, or stuttering. Ischemic priapism is also referred to as veno-occlusive or low flow priapism. Ischemic priapism is characterized by painful persistent erection, reduced or absent cavernosal blood flow, and abnormal cavernous blood gases. The corpora cavernosa are rigid and painful.^2,3Nonischemic priapism is of arterial origin and is said to be a high-flow type. It is due to unregulated cavernous arterial inflow. The phallus in this case may not be rigid or painful and may not require emergency surgical intervention.²In stuttering priapism, the patient has an unwanted painful erection which occurs repeatedly with periods of detumescence. These patients are thought to have recurrent ischemic priapism.^4,5Studies on priapism in the African populations focused on risk factors. This article is to present the results of a 7-year prospective study of priapism in 2 institutions in Port Harcourt, Nigeria, with the aim of documenting the relationship between the outcome of treatment and interval between onset of priapism and intervention in an African population.     

The incidence and management of priapism in Western Australia: a 16 year audit

The objective of the study was to conduct a retrospective audit of patients who presented with priapism in Western Australia during the years 1985-2000. We searched the records of the teaching hospitals in metropolitan Perth and those of the Keogh Institute for Medical Research for the diagnostic code for priapism. A total of 82 episodes of priapism in 63 patients occurred over this 16 year period. In all, 62 episodes occurred after intracavernosal injections (ICI) and 20 were due to other causes. Treatment of priapism included simple aspiration of blood, intracavernosal injection of alpha-adrenergic agents and surgical shunt procedures. Priapism occurring outside the setting of ICI was more likely to require surgery; seven of 20 episodes. After ICI therapy, eight of 62 episodes required shunts. The use of prostaglandin E1 as the drug of choice in ICI therapy in 1989 led to a fall in the incidence of ICI-induced priapism. Priapism is a major side effect of ICI therapy and an uncommon, although important, side effect of other conditions. The incidence of priapism has fallen with the introduction of prostaglandin E1 monotherapy as the favoured drug for ICI therapy of erectile failure.     

Priapisme induit par la chlorpromazine: A propos de deux cas

Priapism is a rare but serious side effect seen with many α-adrenergic antagonists, including both typical and atypical antipsychotics.We report here two cases of priapism associated with chlorpromazine. The first one concerns a young man who was admitted for a manic episode in the context of bipolar disorder. The second one was admitted for behaviour disorders. Upon admission, treatment was begun with chlorpromazine. They presented a priapism. The immediate decision was to stop the antipsychotic agents and to adress both patients in the Urologic Surgery department. They were treated with aspiration and irrigation of the corpora cavernosa with intracavernous injection of sympathomimetic drugs followed by a surgical distal cavernoglanular shunt.This study illustrates two cases of priapism associated with chlorpromazine. It is a urologic emergency. This iatrogenic effect of the chlorpromazine is rare but has to be known by the clinicians to prevent the erectile side-effects.     

Tricorporal priapism postradical cystoprostatectomy: First sign of recurrent urogenital malignancy

Priapism usually involves the whole length of a corpus or two corpora. Rarely is priapism segmental, especially proximally, and seldomly does it involve all three corpora. The causes of priapism are varied, but priapism due to solid malignancy is an extremely uncommon entity. The usual malignancy is urogenital. The disorder is frequently a manifestation of extensive pelvic extension of the primary disease; less commonly, it is associated with pelvic recurrence after seemingly curative surgery. In cases of malignant recurrence, priapism is rarely the first sign of such recurrence. We report a case of proximal tricorporal priapism, secondary to penile metastasis of a bladder malignancy postradical cystoprostatectomy. In this case, priapism was the first sign of disease recurrence and occurred in the absence of pelvic recurrence. This is the first such report of which we are aware.     

A rare case of penile metastasis of testicular cancer presented with priapism

Priapism is thought as a condition of penile erection that persists beyond or is unrelated to sexual stimulation. Commonly two different entities of priapism are known, one is low-flow priapism and the other is high-flow priapism. It is important to distinguish these two conditions for the subsequent different treatments. We report a rare case of an indistinguishable priapism caused by penile metastasis of testicular cancer.     

Priapism secondary to leukemia: Effective management with prompt leukapheresis

Priapism is a urological emergency; without prompt treatment the corpora cavernosa undergoes necrosis and fibrosis that may result in erectile dysfunction. Treatment initially involves conservative measures, such as corporeal aspiration and irrigation with saline or dilute phenylephrine. If this fails, embolization or surgical shunting is usually required. Hyperviscosity resulting from leukemia is a rare cause of priapism. We report a case of a 19-year-old man with an 18-hour history of priapism secondary to undiagnosed chronic myeloid leukaemia. We discuss the method of leukapheresis (mechanical white cell depletion) to reduce viscosity and achieve detumescence after failed aspiration.     

Priapism: current principles and practice

Priapism, a pathologic condition of persistent penile erection in the absence of sexual excitation, is a true erectile disorder. Although it may seem to affect only a small population of male individuals, it carries major significance. Possible complications of the disorder include penile fibrosis and permanent erectile dysfunction. All health care professionals should appreciate the importance of the disorder and be prepared to follow current principles of diagnosis and treatment to reduce or avert its complications.     

European Association of Urology Guidelines on Priapism

ContextPriapism is defined as a penile erection that persists beyond or is unrelated to sexual interest or stimulation. It can be classified into ischaemic (low flow), arterial (high flow), or stuttering (recurrent or intermittent).ObjectiveTo provide guidelines on the diagnosis and treatment of priapism.Evidence acquisitionSystematic literature search on the epidemiology, diagnosis, and treatment of priapism. Articles with highest evidence available were selected to form the basis of these recommendations.Evidence synthesisIschaemic priapism is usually idiopathic and the most common form. Arterial priapism usually occurs after blunt perineal trauma. History is the mainstay of diagnosis and helps determine the pathogenesis. Laboratory testing is used to support clinical findings. Ischaemic priapism is an emergency condition. Intervention should start within 4–6 h, including decompression of the corpora cavernosa by aspiration and intracavernous injection of sympathomimetic drugs (e.g. phenylephrine). Surgical treatment is recommended for failed conservative management, although the best procedure is unclear. Immediate implantation of a prosthesis should be considered for long-lasting priapism. Arterial priapism is not an emergency. Selective embolization is the suggested treatment modality and has high success rates. Stuttering priapism is poorly understood and the main therapeutic goal is the prevention of future episodes. This may be achieved pharmacologically, but data on efficacy are limited.ConclusionsThese guidelines summarise current information on priapism. The extended version are available on the European Association of Urology Website (www.uroweb.org/guidelines/).Patient summaryPriapism is a persistent, often painful, penile erection lasting more than 4 h unrelated to sexual stimulation. It is more common in patients with sickle cell disease. This article represents the shortened EAU priapism guidelines, based on a systematic literature review. Cases of priapism are classified into ischaemic (low flow), arterial (high flow), or stuttering (recurrent). Treatment for ischaemic priapism must be prompt in order to avoid the risk of permanent erectile dysfunction. This is not the case for arterial priapism.     

The etiology,diagnosis, and treatment of priapism: review of the American Foundation for Urologic Disease Consensus Panel Report

Priapism is an important medical condition that requires immediate evaluation, and depending on etiology, may require emergency management. Based on the classification scheme offered by a recent consensus panel, priapism can be subdivided into ischemic and nonischemic types. The nonischemic type, usually the result of perineal trauma, can be treated with conservative therapy, whereas the nonischemic type, which arises from many varied causes, mandates immediate intervention. Corporal fibrosis and permanent erectile dysfunction can result from ischemic priapism that fails to resolve with therapy.