Authors: Macfarlane, Michael T.
Title: Urology, 4th Edition
Copyright 2006 Lippincott Williams & Wilkins
> Table of Contents > Part One - Chief Presentations > Chapter 9 - Penile Complaints
Priapism is an abnormally prolonged penile erection (>6 hours) that does not result from sexual desire. It generally involves only the corpora cavernosa and not the spongiosum. It is often associated with pain and difficulty urinating. It can occur at any age and may last for several days to several weeks if left untreated.
Priapism can be classified into two distinct types: low-flow (ischemic) veno-occlusive and high-flow (nonischemic) arterial priapism. Low-flow ischemic priapism is secondary to failure of the detumescence mechanism and obstruction of the venous drainage of the corpora cavernosa. Ischemic priapism is associated with acidotic cavernosal blood gases. High-flow priapism is generally the result of trauma that causes laceration or rupture of the cavernous artery within the corpora cavernosa.
Many cases are classified as primary or idiopathic because the etiology is unknown. Other major causes of priapism include drug and alcohol abuse, erectile-dysfunction drug therapy, sickle cell disease, neoplastic diseases, and trauma. Drugs that affect the neurovascular or central nervous system can potentially cause priapism. These include psychotropics (e.g., chlorpromazine or trazodone), antihypertensives (especially hydralazine, guanethidine, and prazosin), and alcohol. Anticoagulants (e.g., heparin) also have been associated with cases of priapism. Pharmacologic injection therapy to treat erectile dysfunction, such as intracavernous injection of papaverine or prostaglandin E1, have become the most common causes of priapism.
Sickle cell disease and trait are common etiologies in boys and account for about 10% to 20% of cases overall. Attacks often occur during sleep with sludging of red cells in the corpora cavernosa after a normal physiologic nocturnal erection.
Neoplastic diseases can obstruct corporal outflow. Leukemias are the most common cause of priapism in boys.
Trauma can result in priapism secondary to hematoma formation and compression of venous drainage or injury to the cavernous artery and high-flow priapism.
The diagnosis of priapism is straightforward. Patients are first seen with a persistent erection (>6 hours) without sexual desire. Pain and fever may be present along with difficulty voiding. On physical examination, the corpora cavernosa are fully rigid in low-flow priapism and partially to fully rigid in high-flow priapism. The glans penis is generally flaccid. Patients will often delay seeking attention because of embarrassment. Recognition of any underlying etiology, such as neoplasm or sickle cell disease, is important because it may affect the plan of treatment. A sickle cell preparation for hemoglobin S should be performed on all black patients with priapism. A complete blood count should be obtained to rule out leukemia. A thorough drug history is essential. Intracavernosal injection therapy complications will be evident from the history. Cavernosal blood gases and duplex ultrasound scanning can be helpful in differentiating ischemic and nonischemic priapism.
Priapism can result in impotence in up to 50% of cases, and early treatment can reduce but not eliminate the risk. Patients using pharmacologic injection therapy should be instructed to use pseudoephedrine, an over-the-counter decongestant, if their erection lasts longer than 4 hours, possibly to avert a more serious priapism. Conservative management in other forms of priapism is often unsuccessful; however, an initial intramuscular injection of a narcotic analgesic is reasonable. Definitive therapy should not be delayed because the risk of permanent impotence increases significantly if treatment is not started within 24 to 48 hours. Remember that the penis in priapism is usually ischemic, despite being engorged with blood, and that pain is usually a good indication that tissue ischemia has occurred. Intracorporal blood-gas determinations can be used to monitor hypoxemia and acidosis.
Medical management should be exhausted before resorting to surgical treatments.
Aspiration of 50 to 100 mL of stagnant blood through a small needle placed directly in the corporal body or through the glans into the corpora cavernosa should be tried initially. The patient must be sedated first and the glans anesthetized with local lidocaine (Xylocaine) 1%, without epinephrine. After aspiration, gentle irrigation of the corpora with normal saline is sometimes helpful. Alternatively, the dark blood can be squeezed out until bright-red blood returns. Use of prophylactic antibiotics is recommended with aspiration.
After aspiration, intracavernous injection with an -adrenergic agonist should be attempted in low-flow non sickle cell patients. Pharmacotherapy with -adrenergic agents is the treatment of choice for priapism secondary to intracavernous injection therapy (e.g., papaverine or prostaglandin E1). This injection should be cautiously performed because -agonists may prolong tissue ischemia. Aspiration of 10 to 20 mL of blood followed by injection of epinephrine (10 20 g diluted in 1 mL normal saline) or phenylephrine (100 200 g diluted in 1 mL normal saline) has been successful. This can be repeated every 5 minutes until detumescence occurs. A transient increase in blood pressure can be expected. Caution should be exercised in patients with a history of severe cardiac or cerebrovascular disease.
Oral terbutaline (5 10 mg PO) has been shown to be effective in patients with priapism secondary to intracavernous injection therapy for erectile dysfunction.
Patients with sickle cell disease should be treated conservatively with prompt aggressive hydration, oxygenation, and metabolic alkalinization to reduce further sickling. Aspiration and irrigation of the corpora should be performed. Transfusion and erythropheresis may be necessary.
Fistula creation between spongiosum of the glans and cavernosa by using a Travenol Tru-Cut biopsy needle (Winter's procedure) is a reasonable next step after failure of medical management. This will provide additional continuous drainage of the cavernosa via the corpus spongiosum.
Formal shunt creation may be necessary with an open surgical procedure:
A side-to-side anastomotic shunt between the corpus spongiosum and cavernosum at the base of the penis may be successful;
Alternatively, a saphenous vein corpus cavernosum shunt may be necessary for difficult cases.
Patients with high-flow priapism may require arteriography with embolization of the internal pudendal artery.
Tight circumferential dressings around the penis should be avoided.
Phimosis is a narrowing or constriction of the distal penile foreskin that prevents its normal retraction over the glans. Phimosis is most commonly acquired as a result of poor hygiene and chronic infection. Phimosis rarely occurs with a normal foreskin. The inability to retract the foreskin is normal during early infancy. These congenital adhesions will naturally separate during the first 1 to 2 years of life and are not an indication for circumcision. Complications of phimosis include balanitis, posthitis, paraphimosis, and penile carcinoma.
Minor phimosis can be managed with hygiene alone; however, more advanced phimosis will require circumcision. If significant infection is present (balanoposthitis), an immediate dorsal slit may be necessary to provide proper drainage and to allow resolution of the infection before attempting circumcision.
In paraphimosis, the retracted foreskin remains trapped behind the glans penis, with secondary swelling, pain, and inflammation. Untreated, it can progress through major infection and eventual ischemia of the glans to gangrene. Paraphimosis is frequently the result of a partially phimotic foreskin that has been retracted and not released. It also can frequently occur in a patient with a urethral catheter in place and the foreskin retracted.
An initial attempt at manual reduction should be made. The patient should first be premedicated with meperidine (Demerol)
Balanitis refers to an inflammation of the superficial layers of the glans penis, whereas posthitis is an inflammation of the prepuce. The two conditions commonly occur together and are often associated with poor hygiene and phimosis.
Meticulous hygiene is the key to treatment and prevention. Patients must be instructed to retract the foreskin several times a day for cleansing with mild soap and water and thorough drying. Local application of antibiotic ointments (e.g., Bacitracin or Neosporin) or steroid-based creams (e.g., Kenalog or Mycolog) may be beneficial. Oral antibiotics or antifungal agents [e.g., fluconazole (Diflucan)] also can aid resolution. In severe cases, a dorsal slit may be necessary to establish drainage and to allow proper cleansing. Circumcision should be considered after inflammation has subsided.
Peyronie's disease is characterized by scarlike lesions of the tunica albuginea of the penis. Once thought to be a primarily inflammatory or autoimmune disease, it is now believed to be the result of trauma to the penis during sexual activity. The trauma causes collagen deposition and scar formation, resulting in curvature and functional shortening of the penis. Painful erection also is characteristic early in the disease. Erectile dysfunction is common and usually precedes the development of Peyronie's disease. Spontaneous resolution can be expected in up to 50% of patients; however, extensive plaques with calcification may not resolve.
The mainstay of treatment is to discontinue trauma to the site, limiting further injury and allowing time for natural healing and resolution.
Many nonsurgical treatments have been tried for Peyronie's disease, most with limited success.
Vitamin E 400 mg twice a day PO.
Potassium para-aminobenzoate (Potaba) 12 g/day, in four to six divided doses, is expensive and of uncertain benefit.
Intralesional steroid injection is probably of little benefit and may worsen the lesions.
Small-dose radiation can alleviate pain but does not correct the bending deformity.
Other medical interventions, such as colchicine or calcium channel blockers, are unproven.
Surgical intervention to correct penile curvature should be delayed for at least 1 year to allow adequate time for spontaneous resolution or medical therapy to take effect.