Congenital anomalies of the urethra in boys usually involve anatomic abnormalities of the penis and vice versa. In girls, urethral anomalies may exist without other external genital abnormalities. Surgical repair is needed when function is impaired or cosmetic correction is desired.
This anomaly is ventral or rotational curvature of the penis, which is most apparent with erection and is caused by fibrous tissue along the usual course of the corpus spongiosum. It is often associated with hypospadias.
The urethra opens on the dorsum of the glans or penile shaft, or at the penopubic junction. In girls, the urethra opens between the clitoris and labia or in the abdomen. Epispadias can be partial (in 15%) or complete; the most severe form occurs with bladder exstrophy (see Congenital Renal and Genitourinary Anomalies: Exstrophy). Symptoms and signs are incontinence, reflux, and UTIs. Treatment is surgical. In partial epispadias, prognosis for continence with treatment is good. In the complete form, surgical reconstruction of the penis alone may lead to persistent incontinence; bladder outlet reconstruction is required to achieve complete urinary control.
This anomaly is caused by failure of tubularization and fusion of the urethral groove. It almost always occurs in boys, in whom the urethra opens onto the underside of the penile shaft, at the penoscrotal junction, between the scrotal folds, or in the perineum. The foreskin fails to become circumferential and appears as a dorsal hood. Hypospadias is frequently associated with chordee.
Prognosis for functional and cosmetic correction is good. Outpatient surgery at about 6 mo of age involves construction of a neourethra using penile shaft skin or foreskin and repair of the chordee.
Hypospadias is extremely rare in girls; the urethra opens into the vaginal introitus.
Phimosis and paraphimosis:
Phimosis, the most common penile abnormality, is constriction of the foreskin with inability to retract over the glans; it may be congenital or acquired. Paraphimosis is inability of the retracted constricting foreskin to be reduced distally over the glans. (See full discussion on p. discussed in Penile and Scrotal Disorders: Phimosis and Paraphimosis.)
Phimosis may respond to topical corticosteroids and gentle stretching; some patients require circumcision.
Paraphimosis should be reduced immediately because the constricting foreskin functions as a tourniquet, causing edema and pain. Firm circumferential compression of the edematous foreskin with the fingers may reduce edema sufficiently to allow the foreskin to be restored to its normal position by pushing the glans back through the tight foreskin using both thumbs. If this technique is ineffective, a dorsal slit done using a local anesthetic relieves the condition temporarily. Circumcision is then done when edema has resolved.
Other penile anomalies:
Less common anomalies include penile agenesis, duplication, and lymphedema. Many anomalies also involve urethral abnormality, or other anomalies, such as exstrophy. Treatment of most anomalies is surgical and may include complete removal of the genitals with sex reassignment.
Microphallus results from androgen deficiency or insensitivity; in boys with deficiency, treatment is testosterone supplementation.
Urethral meatal stenosis:
Most commonly acquired after newborn circumcision in boys, urethral meatal stenosis is occasionally congenital and associated with hypospadias. Meatotomy is needed for a significantly deflected stream or for a pinpoint stream.
Urethral stricture causes obstruction along some part of the length of the urethra. It almost always occurs in boys, is usually acquired, and typically results from a crush injury after straddle trauma. Congenital urethral stricture may manifest similarly to urethral valves and may be diagnosed by prenatal ultrasonography, or postnatally by symptoms and signs of outlet obstruction or patent urachus and is confirmed by retrograde urethrography. Initial management is often with endoscopic urethrotomy, although open urethroplasty may be necessary.
In boys, folds in the posterior urethra may act as valves impairing urine flow. Urethral valves can cause urinary hesitancy and a weak urinary stream, UTI, overflow incontinence, myogenic bladder malfunction, vesicoureteral reflux, upper urinary tract damage, and renal insufficiency. They occasionally occur with a patent urachus. Diagnosis is often made by routine prenatal ultrasonography; cases suspected postnatally are confirmed by voiding cystourethrography. Surgery (usually via endoscopy) is done at time of diagnosis to prevent progressive renal deterioration.
A much less common anomaly, diverticulum of the anterior urethra, may act as a valve (anterior urethral valve) and is also treated endoscopically.
Last full review/revision January 2010 by Ronald Rabinowitz, MD
Content last modified February 2012