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HYPOSPADIAS AND EPISPADIAS


HYPOSPADIAS AND EPISPADIAS
Hypospadias is a birth defect of the male urethra that involves an abnormally placed urethral meatus. Instead of opening at the tip of the glans penis, a hypospadic urethra opens anywhere along a line (the urethral groove) from the penile tip along the ventral shaft to the junction of the penis and scrotum or perineum. This is among the most common birth defects of the male genitalia, second only to cryptorchidism, but the incidence varies widely from country to country, from as low as 1 in 4000 to as high as 1 in 125 boys. Hypospadias can occur as an isolated defect or it can be observed in a complex syndrome of multiple malformations. The global incidence of hypospadias has increased since the 1980s and this has been attributed to the wider application of assisted reproductive techniques and to endocrine disruptors. As it is considered to represent a degree of feminization or male pseudohermaphroditism (see Plate 1-13), hypospadias has also been associated with hypogonadism.

In hypospadias, the genital folds (see Plate 1-3) that normally unite over the urethral groove from the penoscrotal junction fail to close fully, thus creating a urethral meatus in a more proximal than normal location. The urethral meatus in one-half of cases is located just proximal to the normal meatus but still on the glans penis and is referred to as glanular or first-degree hypospadias. In penile or second-degree hypospadias, the urethral meatus is situated more proximally on the penile shaft. In perineal or third-degree hypospadias, the urethral opening is proximal to the penile shaft and is observed on the scrotal or perineal skin.
periurethral glands

With hypospadias, the prepuce is usually redundant and forms a hood over the glans. In most cases, the urethra and corpus spongiosum fail to form normally, which results in a downward penile curvature (chordee) due to fibrous bands on the ventral undersurface. The scrotum may be bifid, with maldescended testes in some instances. Early correction of the chordee is important so that the penis and corporal bodies may grow straight. Androgens may be a valuable adjunct before surgery. Circumcision should not be performed because the hooded foreskin may be of use later as a source of flap tissue in urethral reconstruction.
Epispadias is a rare anomaly of the male urethra and is usually associated with exstrophy of the bladder (exstrophy–epispadias complex). It occurs in around 1 in 120,000 male and 1 in 500,000 female births. In this condition, the urethral orifice is observed on the dorsal penis just proximal to the glans (glanular epispadias) or is observed as an opening under the symphysis pubis in complete epispadias. Epispadias is a partial form of a spectrum of failures of abdominal and pelvic fusion in early embryogenesis. While epispadias occurs in all cases of exstrophy, it can also appear in isolation as the least severe form of the complex. It occurs as a result of defective migration of the genital tubercle primordia to the cloacal membrane during the fifth week of gestation.
In this condition, the floor of the urethra is observed as a groove on the dorsum of the penis that is lined by mucosa and demonstrates openings of the periurethral glands (see Plate 2-12). The partial prepuce is located on the ventral penis. The epispadiac penis tends to curve upward and press against the mons pubis. The membranous and prostatic urethrae in most cases of complete epispadias are widely patent with incomplete development of the external sphincter muscle so that patients are commonly incontinent. The symphysis pubis may be well formed or may only be a fibrous band of tissue. Causes of epispadias are still unknown but theories that postulate endocrine disruption, polygenetic predisposition, and viral infection have been put forth. Urinary tract reconstruction is necessary to restore continence and full penile function.