- •Preface
- •Acknowledgments
- •Contents
- •1.1 Introduction
- •1.2 Normal Embryology
- •1.3 Abnormalities of the Kidney
- •1.3.1 Renal Agenesis
- •1.3.2 Renal Hypoplasia
- •1.3.3 Supernumerary Kidneys
- •1.3.5 Polycystic Kidney Disease
- •1.3.6 Simple (Solitary) Renal Cyst
- •1.3.7 Renal Fusion and Renal Ectopia
- •1.3.8 Horseshoe Kidney
- •1.3.9 Crossed Fused Renal Ectopia
- •1.4 Abnormalities of the Ureter
- •1.5 Abnormalities of the Bladder
- •1.6 Abnormalities of the Penis and Urethra in Males
- •1.7 Abnormalities of Female External Genitalia
- •Further Reading
- •2.1 Introduction
- •2.2 Pathophysiology
- •2.3 Etiology of Hydronephrosis
- •2.5 Clinical Features
- •2.6 Investigations and Diagnosis
- •2.7 Treatment
- •2.8 Antenatal Hydronephrosis
- •Further Reading
- •3.1 Introduction
- •3.2 Embryology
- •3.3 Pathophysiology
- •3.4 Etiology of PUJ Obstruction
- •3.5 Clinical Features
- •3.6 Diagnosis and Investigations
- •3.7 Management of Newborns with PUJ Obstruction
- •3.8 Treatment
- •3.9 Post-operative Complications and Follow-Up
- •Further Reading
- •4: Renal Tumors in Children
- •4.1 Introduction
- •4.2 Wilms’ Tumor
- •4.2.1 Introduction
- •4.2.2 Etiology
- •4.2.3 Histopathology
- •4.2.4 Nephroblastomatosis
- •4.2.5 Clinical Features
- •4.2.6 Risk Factors for Wilms’ Tumor
- •4.2.7 Staging of Wilms Tumor
- •4.2.8 Investigations
- •4.2.9 Prognosis and Complications of Wilms Tumor
- •4.2.10 Surgical Considerations
- •4.2.11 Surgical Complications
- •4.2.12 Prognosis and Outcome
- •4.2.13 Extrarenal Wilms’ Tumors
- •4.3 Mesoblastic Nephroma
- •4.3.1 Introduction
- •4.3.3 Epidemiology
- •4.3.5 Clinical Features
- •4.3.6 Investigations
- •4.3.7 Treatment and Prognosis
- •4.4 Clear Cell Sarcoma of the Kidney (CCSK)
- •4.4.1 Introduction
- •4.4.2 Pathophysiology
- •4.4.3 Clinical Features
- •4.4.4 Investigations
- •4.4.5 Histopathology
- •4.4.6 Treatment
- •4.4.7 Prognosis
- •4.5 Malignant Rhabdoid Tumor of the Kidney
- •4.5.1 Introduction
- •4.5.2 Etiology and Pathophysiology
- •4.5.3 Histologic Findings
- •4.5.4 Clinical Features
- •4.5.5 Investigations and Diagnosis
- •4.5.6 Treatment and Outcome
- •4.5.7 Mortality/Morbidity
- •4.6 Renal Cell Carcinoma in Children
- •4.6.1 Introduction
- •4.6.2 Histopathology
- •4.6.4 Staging
- •4.6.5 Clinical Features
- •4.6.6 Investigations
- •4.6.7 Management
- •4.6.8 Prognosis
- •4.7 Angiomyolipoma of the Kidney
- •4.7.1 Introduction
- •4.7.2 Histopathology
- •4.7.4 Clinical Features
- •4.7.5 Investigations
- •4.7.6 Treatment and Prognosis
- •4.8 Renal Lymphoma
- •4.8.1 Introduction
- •4.8.2 Etiology and Pathogenesis
- •4.8.3 Diagnosis
- •4.8.4 Clinical Features
- •4.8.5 Treatment and Prognosis
- •4.9 Ossifying Renal Tumor of Infancy
- •4.10 Metanephric Adenoma
- •4.10.1 Introduction
- •4.10.2 Histopathology
- •4.10.3 Diagnosis
- •4.10.4 Clinical Features
- •4.10.5 Treatment
- •4.11 Multilocular Cystic Renal Tumor
- •Further Reading
- •Wilms’ Tumor
- •Mesoblastic Nephroma
- •Renal Cell Carcinoma in Children
- •Angiomyolipoma of the Kidney
- •Renal Lymphoma
- •Ossifying Renal Tumor of Infancy
- •Metanephric Adenoma
- •Multilocular Cystic Renal Tumor
- •5.1 Introduction
- •5.2 Embryology
- •5.4 Histologic Findings
- •5.7 Associated Anomalies
- •5.8 Clinical Features
- •5.9 Investigations
- •5.10 Treatment
- •Further Reading
- •6: Congenital Ureteral Anomalies
- •6.1 Etiology
- •6.2 Clinical Features
- •6.3 Investigations and Diagnosis
- •6.4 Duplex (Duplicated) System
- •6.4.1 Introduction
- •6.4.3 Clinical Features
- •6.4.4 Investigations
- •6.4.5 Treatment and Prognosis
- •6.5 Ectopic Ureter
- •6.5.1 Introduction
- •6.5.3 Clinical Features
- •6.5.4 Diagnosis
- •6.5.5 Surgical Treatment
- •6.6 Ureterocele
- •6.6.1 Introduction
- •6.6.3 Clinical Features
- •6.6.4 Investigations and Diagnosis
- •6.6.5 Treatment
- •6.6.5.1 Surgical Interventions
- •6.8 Mega Ureter
- •Further Reading
- •7: Congenital Megaureter
- •7.1 Introduction
- •7.3 Etiology and Pathophysiology
- •7.4 Clinical Presentation
- •7.5 Investigations and Diagnosis
- •7.6 Treatment and Prognosis
- •7.7 Complications
- •Further Reading
- •8.1 Introduction
- •8.2 Pathophysiology
- •8.4 Etiology of VUR
- •8.5 Clinical Features
- •8.6 Investigations
- •8.7 Management
- •8.7.1 Medical Treatment of VUR
- •8.7.2 Antibiotics Used for Prophylaxis
- •8.7.3 Anticholinergics
- •8.7.4 Surveillance
- •8.8 Surgical Therapy of VUR
- •8.8.1 Indications for Surgical Interventions
- •8.8.2 Indications for Surgical Interventions Based on Age at Diagnosis and the Presence or Absence of Renal Lesions
- •8.8.3 Endoscopic Injection
- •8.8.4 Surgical Management
- •8.9 Mortality/Morbidity
- •Further Reading
- •9: Pediatric Urolithiasis
- •9.1 Introduction
- •9.2 Etiology
- •9.4 Clinical Features
- •9.5 Investigations
- •9.6 Complications of Urolithiasis
- •9.7 Management
- •Further Reading
- •10.1 Introduction
- •10.2 Embryology of Persistent Müllerian Duct Syndrome
- •10.3 Etiology and Inheritance of PMDS
- •10.5 Clinical Features
- •10.6 Treatment
- •10.7 Prognosis
- •Further Reading
- •11.1 Introduction
- •11.2 Physiology and Bladder Function
- •11.2.1 Micturition
- •11.3 Pathophysiological Changes of NBSD
- •11.4 Etiology and Clinical Features
- •11.5 Investigations and Diagnosis
- •11.7 Management
- •11.8 Clean Intermittent Catheterization
- •11.9 Anticholinergics
- •11.10 Botulinum Toxin Type A
- •11.11 Tricyclic Antidepressant Drugs
- •11.12 Surgical Management
- •Further Reading
- •12.1 Introduction
- •12.2 Etiology
- •12.3 Pathophysiology
- •12.4 Clinical Features
- •12.5 Investigations and Diagnosis
- •12.6 Management
- •Further Reading
- •13.1 Introduction
- •13.2 Embryology
- •13.3 Epispadias
- •13.3.1 Introduction
- •13.3.2 Etiology
- •13.3.4 Treatment
- •13.3.6 Female Epispadias
- •13.3.7 Surgical Repair of Female Epispadias
- •13.3.8 Prognosis
- •13.4 Bladder Exstrophy
- •13.4.1 Introduction
- •13.4.2 Associated Anomalies
- •13.4.3 Principles of Surgical Management of Bladder Exstrophy
- •13.4.4 Evaluation and Management
- •13.5 Cloacal Exstrophy
- •13.5.1 Introduction
- •13.5.2 Skeletal Changes in Cloacal Exstrophy
- •13.5.3 Etiology and Pathogenesis
- •13.5.4 Prenatal Diagnosis
- •13.5.5 Associated Anomalies
- •13.5.8 Surgical Reconstruction
- •13.5.9 Management of Urinary Incontinence
- •13.5.10 Prognosis
- •13.5.11 Complications
- •Further Reading
- •14.1 Introduction
- •14.2 Etiology
- •14.3 Clinical Features
- •14.4 Associated Anomalies
- •14.5 Diagnosis
- •14.6 Treatment and Prognosis
- •Further Reading
- •15: Cloacal Anomalies
- •15.1 Introduction
- •15.2 Associated Anomalies
- •15.4 Clinical Features
- •15.5 Investigations
- •Further Reading
- •16: Urachal Remnants
- •16.1 Introduction
- •16.2 Embryology
- •16.4 Clinical Features
- •16.5 Tumors and Urachal Remnants
- •16.6 Management
- •Further Reading
- •17: Inguinal Hernias and Hydroceles
- •17.1 Introduction
- •17.2 Inguinal Hernia
- •17.2.1 Incidence
- •17.2.2 Etiology
- •17.2.3 Clinical Features
- •17.2.4 Variants of Hernia
- •17.2.6 Treatment
- •17.2.7 Complications of Inguinal Herniotomy
- •17.3 Hydrocele
- •17.3.1 Embryology
- •17.3.3 Treatment
- •Further Reading
- •18: Cloacal Exstrophy
- •18.1 Introduction
- •18.2 Etiology and Pathogenesis
- •18.3 Associated Anomalies
- •18.4 Clinical Features and Management
- •Further Reading
- •19: Posterior Urethral Valve
- •19.1 Introduction
- •19.2 Embryology
- •19.3 Pathophysiology
- •19.5 Clinical Features
- •19.6 Investigations and Diagnosis
- •19.7 Management
- •19.8 Medications Used in Patients with PUV
- •19.10 Long-Term Outcomes
- •19.10.3 Bladder Dysfunction
- •19.10.4 Renal Transplantation
- •19.10.5 Fertility
- •Further Reading
- •20.1 Introduction
- •20.2 Embryology
- •20.4 Clinical Features
- •20.5 Investigations
- •20.6 Treatment
- •20.7 The Müllerian Duct Cyst
- •Further Reading
- •21: Hypospadias
- •21.1 Introduction
- •21.2 Effects of Hypospadias
- •21.3 Embryology
- •21.4 Etiology of Hypospadias
- •21.5 Associated Anomalies
- •21.7 Clinical Features of Hypospadias
- •21.8 Treatment
- •21.9 Urinary Diversion
- •21.10 Postoperative Complications
- •Further Reading
- •22: Male Circumcision
- •22.1 Introduction
- •22.2 Anatomy and Pathophysiology
- •22.3 History of Circumcision
- •22.4 Pain Management
- •22.5 Indications for Circumcision
- •22.6 Contraindications to Circumcision
- •22.7 Surgical Procedure
- •22.8 Complications of Circumcision
- •Further Reading
- •23: Priapism in Children
- •23.1 Introduction
- •23.2 Pathophysiology
- •23.3 Etiology
- •23.5 Clinical Features
- •23.6 Investigations
- •23.7 Management
- •23.8 Prognosis
- •23.9 Priapism and Sickle Cell Disease
- •23.9.1 Introduction
- •23.9.2 Epidemiology
- •23.9.4 Pathophysiology
- •23.9.5 Clinical Features
- •23.9.6 Treatment
- •23.9.7 Prevention of Stuttering Priapism
- •23.9.8 Complications of Priapism and Prognosis
- •Further Reading
- •24.1 Introduction
- •24.2 Embryology and Normal Testicular Development and Descent
- •24.4 Causes of Undescended Testes and Risk Factors
- •24.5 Histopathology
- •24.7 Clinical Features and Diagnosis
- •24.8 Treatment
- •24.8.1 Success of Surgical Treatment
- •24.9 Complications of Orchidopexy
- •24.10 Infertility and Undescended Testes
- •24.11 Undescended Testes and the Risk of Cancer
- •Further Reading
- •25: Varicocele
- •25.1 Introduction
- •25.2 Etiology
- •25.3 Pathophysiology
- •25.4 Grading of Varicoceles
- •25.5 Clinical Features
- •25.6 Diagnosis
- •25.7 Treatment
- •25.8 Postoperative Complications
- •25.9 Prognosis
- •Further Reading
- •26.1 Introduction
- •26.2 Etiology and Risk Factors
- •26.3 Diagnosis
- •26.4 Intermittent Testicular Torsion
- •26.6 Effects of Testicular Torsion
- •26.7 Clinical Features
- •26.8 Treatment
- •26.9.1 Introduction
- •26.9.2 Etiology of Extravaginal Torsion
- •26.9.3 Clinical Features
- •26.9.4 Treatment
- •26.10 Torsion of the Testicular or Epididymal Appendage
- •26.10.1 Introduction
- •26.10.2 Embryology
- •26.10.3 Clinical Features
- •26.10.4 Investigations and Treatment
- •Further Reading
- •27: Testicular Tumors in Children
- •27.1 Introduction
- •27.4 Etiology of Testicular Tumors
- •27.5 Clinical Features
- •27.6 Staging
- •27.6.1 Regional Lymph Node Staging
- •27.7 Investigations
- •27.8 Treatment
- •27.9 Yolk Sac Tumor
- •27.10 Teratoma
- •27.11 Mixed Germ Cell Tumor
- •27.12 Stromal Tumors
- •27.13 Simple Testicular Cyst
- •27.14 Epidermoid Cysts
- •27.15 Testicular Microlithiasis (TM)
- •27.16 Gonadoblastoma
- •27.17 Cystic Dysplasia of the Testes
- •27.18 Leukemia and Lymphoma
- •27.19 Paratesticular Rhabdomyosarcoma
- •27.20 Prognosis and Outcome
- •Further Reading
- •28: Splenogonadal Fusion
- •28.1 Introduction
- •28.2 Etiology
- •28.4 Associated Anomalies
- •28.5 Clinical Features
- •28.6 Investigations
- •28.7 Treatment
- •Further Reading
- •29: Acute Scrotum
- •29.1 Introduction
- •29.2 Torsion of Testes
- •29.2.1 Introduction
- •29.2.3 Etiology
- •29.2.4 Clinical Features
- •29.2.5 Effects of Torsion of Testes
- •29.2.6 Investigations
- •29.2.7 Treatment
- •29.3 Torsion of the Testicular or Epididymal Appendage
- •29.3.1 Introduction
- •29.3.2 Embryology
- •29.3.3 Clinical Features
- •29.3.4 Investigations and Treatment
- •29.4.1 Introduction
- •29.4.2 Etiology
- •29.4.3 Clinical Features
- •29.4.4 Investigations and Treatment
- •29.5 Idiopathic Scrotal Edema
- •29.6 Testicular Trauma
- •29.7 Other Causes of Acute Scrotum
- •29.8 Splenogonadal Fusion
- •Further Reading
- •30.1 Introduction
- •30.2 Imperforate Hymen
- •30.3 Vaginal Atresia
- •30.5 Associated Anomalies
- •30.6 Embryology
- •30.7 Clinical Features
- •30.8 Investigations
- •30.9 Management
- •Further Reading
- •31: Disorders of Sexual Development
- •31.1 Introduction
- •31.2 Embryology
- •31.3 Sexual and Gonadal Differentiation
- •31.5 Evaluation of a Newborn with DSD
- •31.6 Diagnosis and Investigations
- •31.7 Management of Patients with DSD
- •31.8 Surgical Corrections of DSD
- •31.9 Congenital Adrenal Hyperplasia (CAH)
- •31.10 Androgen Insensitivity Syndrome (Testicular Feminization Syndrome)
- •31.13 Gonadal Dysgenesis
- •31.15 Ovotestis Disorders of Sexual Development
- •31.16 Other Rare Disorders of Sexual Development
- •Further Reading
- •Index
23.9 Priapism and Sickle Cell Disease |
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through increasing levels of cyclic GMP (cGMP). This results in smooth muscle relaxation, vasodilatation of penile arteries, increased blood flow and penile erection. This effect is regulated by phosphodiesterase type 5 (PDE-5) which degrades cGMP.
•SCA patients have elevated free hemoglobin concentrations compared to normal volunteers as a result of hemolysis. This will result in increase in NO scavenging with subsequent prevention of vasodilation.
•Other associated risk factors for priapism include Lactate dehydrogenase (LDH), bilirubin and reticulocyte count which are elevated in patients with SCA and priapism.
•Chronic scavenging of NO results in a decreased expression of downstream regulatory molecules including PDE5 that normally degrades cGMP, the second messenger in NO signaling.
•The combination of chronically decreased PDE5 and normal cGMP generation following nerve stimulation may result in an unregulated, prolonged erection.
•In patients with SCA, there is:
–Reduction in NO bioavailability
–A significant down regulation of PDE-5
–Uncontrolled cGMP activity.
–Elevated levels of adenosine in the penis may also contribute to the pathogenesis of priapism but this has not been well established.
•Risk factors for priapism in SCA patients include:
–Prolonged sexual activity
–Fever
–Dehydration
–Exposure to alcohol
–The use of marijuana
–The use of cocaine, psychotropic drugs, and testosterone
•In priapism these new concepts have specific implications, as the physiologic mechanisms of erection are specifically controlled by nitric oxide.
•Notably, priapism is more frequent in the severe forms of SCD, with an association to pulmonary hypertension (up to five times more common than in other SCD patients) and strokes.
•Episodes of priapism are also linked to a rise in serum markers of hemolysis, such as increase of reticulocytes, indirect bilirubin, and lactate dehydrogenase (LDH).
23.9.5 Clinical Features
•Priapism may occur at any age. The mean age of onset is 12–15 years but has been reported in children.
•70–90 % of affected patients report their first episode prior to 20 years of age.
•The exact prevalence of priapism is not known but it has been estimated to range from 6 to 45 %.
•Priapism has been reported in various hemoglobinopathies. Commonly it is seen in sickle cell anemia (homozygous sickle cell) but has been reported in patients with hemoglobin SC disease, sickle cell beta thalassemia and rarely in those with sickle cell trait.
•Priapism may occur as an isolated episode or as part of generalized SCA vasoocclusive crisis.
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23 Priapism in Children |
|
|
Red blood cells hemolysis
Free hemoglobin |
Arginase |
|
No consumption
L-Arginine |
Polyamines |
|
and proline |
No NO synthesis
Deficient NO
Smooth muscle cell growth
and collagen synthesis
•Endothelial cell activation
•Up-regulation of the potent vasoconstrictor endothelin-1
•Vasoconstriction
•Platelet activation
Proliferative vasculopathy
•Increased tissue factor
•Activation of coagulation
•Priapism may occur also during sleep or following an active sexual intercourse.
•These patients usually present with an erect painful penis and on palpation, the penis is hard in consistency while the glans penis is soft.
•Many of these patients are not aware of this as a complication of SCA and this leads to delay in seeking medical advice.
•The mean duration of symptoms was reported to range from 6 to 70 h (mean 22 h). Some of these patients may resort to sexual intercourse in an attempt to relieve the pain.
•Stuttering priapism:
–An episode of priapism lasting more than a few minutes but less than 3 h.
–Stuttering priapism typically occur in clusters, approximately two to three times per week for several weeks.
–About 60 % of those who develop stuttering priapism will develop an attack of acute priapism in the future.
•The majority of patients with SCD report intermittent episodes preceding an acute episode.
•This emphasizes the need to investigate stuttering episodes in sickle cell outpatients, in order to actively prevent acute episodes and educate the patients.
•The most common precipitants of priapism are sexual activity (including masturbation), dehydration, fever and exposition to a cold environment.
23.9 Priapism and Sickle Cell Disease |
519 |
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23.9.6 Treatment
•Priapism is a serious complication of SCD.
•There are no definitive guidelines available for the treatment of SCD-related priapism.
•Although conservative management has commonly been advocated, most experts advocate emergent surgical decompression when conservative management fails.
•Patients with SCD should be educated regarding the need to seek prompt specialized treatment for any episode of priapism that lasts longer than 2 h.
•Numerous therapeutic options have been attempted, including blood transfusion, exchange blood transfusion, diethylstilbestrol, gonadotropin-releasing hormone analogues, various adrenergic agonists, and hydroxyurea.
•Few agents have actually been examined in a controlled clinical trial, making it difficult for practitioners to treat this complication.
•The parents of children with SCD should be educated about priapism and how to treat it initially.
•Some educated and willing parents could also be taught how to aspirate the cavernosa and then inject intracavernosal epinephrine or phenylephrine for prolonged episodes or for those not relieved with oral pseudoephedrine.
•It is recommended that treatment should be conservative initially.
•The patient is encouraged to drink extra fluids, urinate, exercise, and take oral analgesics. These simple measures have occasionally been sufficient enough to produce detumescence.
•If the episode of priapism persists beyond 2 h, the patient should report to the emergency department.
–The patient is assessed clinically
–The patient should be started on intravenous fluids at 1.5 their maintenance requirements.
–The patient should be given analgesics to relive the discomfort and pain.
–Anxiolytics, such as lorazepam, midazolam, or hydroxyzine pamoate, and supplemental oxygen may also be given if needed.
•If priapism persists beyond 4 h, intracaverno-
sal blood aspiration and instillation of an α-agonist should be performed under local or
regional anesthesia and repeated as needed.
•Alpha-agonists act as vasoconstrictors and are thought to induce contraction of the smooth muscle of the penile arteries of the corpora cavernosa, forcing blood out of the corpora cavernosa and into the venous system.
•Beta-agonists, on the other hand, act as vasodilators by blocking β-receptors, resulting in
smooth muscle relaxation of the vasculature. This allows oxygenated arterial blood to enter the cavernosa, washing out stagnant, already damaged sickle cells.
•Various adrenergic agonists have been used in the treatment of priapism, including:
–Pure α-agonists (e.g., metaraminol)
–Mixed α- and β-agonists (e.g., etilefrine, phenylephrine, and epinephrine)
–Pure β-agonists (e.g., terbutaline)
–Etilefrine is the ideal α-agonist to use
–Phenylephrine (preferable, since it is more selective) or epinephrine can be used also.
–Metaraminol is associated with side effects including transient but severe hypertension.
•The procedure consist of intracavernosal aspiration followed by irrigation with 10 mL of a 1:1,000,000 solution of epinephrine. Aspiration continued until detumescence occurred. If detumescence lasts for at least 30 min, the patient is discharged from the emergency department.
•Others use intracavernosal aspiration and irrigation with diluted epinephrine (20 mL of a solution of 1 mL 1:1,000 epinephrine in 1 L of 0.9 % sodium chloride) are performed.
–Irrigation and aspiration are performed until sustained detumescence was achieved or a maximum of 200 mL of solution was used, after which an emergency shunt is performed.
–If irrigation was successful, the patient is observed for 24 h and then discharged home.
•The procedure of aspiration and irrigation (Figs. 23.9, 23.10, 23.11, 23.12, and 23.13):
–Apply local anesthetic blockade
–A 21-gauge needle is used for children.
520 |
23 Priapism in Children |
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|
Figs. 23.9 and 23.10 Clinical photographs showing priapism in a child with SCA being treated with aspiration and irrigation
Fig. 23.11 Clinical photograph showing a child with sickle cell disease and priapism being treated with aspiration and irrigation
–Puncture one of the corpora cavernosa, usually via the glans
–In the majority of cases it is not necessary to puncture the two corpora cavernosa.
–Blood should be collected for gas analysis and confirmation of the diagnosis.
–Thereafter the corpora cavernosa are drained.
–Irrigation and drainage of the full extension of the corpora is more efficient.
–The volume of blood removed in the aspiration:
•This should be limited to a maximum of 7.5 mL/kg (10 % of the blood volume in children >1 year of age), because of the risk of provoking hypovolemia or shock.
–Alpha-adrenergic agonists (etilefrine, phenylephrine, epinephrine, metaraminol) are then injected.
–Injection of adrenergic agents is known to be associated with complications including:
•Infection
•Hematomas
•Urethral injury
•Fibrosis at the injection site
•Rarely, penile necrosis.
–The proposed dosages are:
•10 ml of adrenaline 1:1,000,000
– The overall success rate is 87 %
– A 100 % success was reported in those <24 h duration of priapism
– In 20 % of cases it was necessary to repeat the injection.
•Other authors propose diluting 1 mL of adrenaline 1:1,000 solution in 1 L of