Atlas of pathophysiology, 2 Edition

Part II - Disorders

Genital Diseases

Hypospadias and Epispadias

Among the most common birth defects, congenital anomalies of the ureter, bladder, and urethra occur in about 5% of all births. The abnormality may be obvious at birth or may go unrecognized until symptoms appear.

Hypospadias is a congenital abnormality in which the urethral meatus is located on the ventral side, or undersurface of the penis. It may be on the glans, the base of the penis, the penoscrotal sac, or the perineum. The defect may be slight to extreme, and it occurs in 1 of 300 live male births. Epispadias occurs in 1 in 200,000 infant boys and 1 in 400,000 infant girls. In males, the urethral opening is on the dorsal aspect of the penis; in females, a cleft along the ventral urethral opening extends to the bladder neck.

Causes

·   Congenital malformation

·   Genetic factors

·   Hormonal variations

Pathophysiology

In hypospadias, the urethral opening is on the ventral surface of the penis. A genetic factor is suspected in less severe cases. It's usually associated with a downward bowing of the penis (chordee), making normal urination with the penis elevated impossible. The ventral prepuce may be absent or defective, and the genitalia may be ambiguous. In the rare case of hypospadias in a female, the urethral opening is in the vagina, and vaginal discharge may be present.

Epispadias occurs more commonly in males than in females and often accompanies bladder exstrophy, in which a portion of posterior bladder wall protrudes through a defect in the lower abdominal and anterior bladder wall. In mild cases, the orifice is on the dorsum of the glans; in severe cases, on the dorsum of the penis. Affected females have a bifid (cleft into two parts) clitoris and a short, wide urethra. Total urinary incontinence occurs when the urethral opening is proximal to the sphincter.

Signs and symptoms

·   Displaced urethral opening

·   Altered voiding patterns due to displaced opening of the urethra

·   Chordee, or bending of the penis (in hypospadias)

·   Ejaculatory dysfunction due to displaced penile opening

Diagnostic test results

·   None are necessary if sexual identification is clear.

·   If sexual identification is unclear, buccal smears or karyotyping determines gender.

Treatment

·   Mild, asymptomatic hypospadias: no treatment

·   Severe hypospadias: surgery, preferably before child reaches school age

·   Epispadias: multistage surgical repair, almost always necessary

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DIFFERENTIATING HYPOSPADIAS AND EPISPADIAS

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