The male urethra

The most common congenital abnormalities of the male urethra are:

  meatal stenosis;

  congenital urethral stricture;

  congenital valves;

  hypospadias;

   epispadias.

Meatal stenosis

A congenital stenosis of the external urinary meatus, normally the narrowest part of the male urethra, is associated with phimosis. After circumcision, meatal ulceration may lead to stricturing of the meatus. When the meatal opening is reduced to a pinhole there may be chronic retention of urine with back-pressure effects and eventually chronic renal failure. Lesser degrees of stenosis lead to loss of the normal urinary stream with spraying or dribbling.

Treatment by meatotomy or meatal dilatation is indicated for symptomatic stenosis, if the stricture is sufficient to prevent free drainage of discharge in a patient with urethritis or there is a need to pass endoscopic instruments transurethrally.

Meatotomy

The tightened meatus is opened by cutting down on to a fine probe placed in the anterior urethra. The cut edges of urothelium and skin are sewn together with absorbable suture. If the stenosis recurs a skin flap can be laid in as a meatoplasty to widen the meatus (Fig. 67.1).

Congenital urethral stricture

This condition is rare. Some cases are associated with duplication of the urethra. Usually symptoms are delayed until adolescence, when it may be difficult to be sure that a supposedly congenital stricture of the bulbar urethra is not due to unrecognised urethral injury in childhood. A single treatment by optical urethrotomy or dilatation is usually effective.

Congenital valves of the posterior urethra

These are symmetrical folds of urothelium which can cause obstruction to the urethra of boys. They are usually found just distal to the verumontanum but they may be within the prostatic urethra. They behave as flap valves so, although urine does not flow normally, a urethral catheter can be passed without difficulty. In some instances, the valves are incomplete and the patient remains without symptoms until adolescence or adulthood. In such cases the prostatic urethra is grossly dilated and saccules and diverticula are present within it.

The valves are difficult to see on urethroscopy because the flow of irrigant sweeps them into the open position. If the bladder is filled with contrast medium, the dilatation of the urethra above the valves can be demonstrated on a voiding cystogram.

Treatment

A suprapubic catheter is inserted to relieve the back pressure and allow the effects of renal failure to subside before definitive treatment by transurethral resection of the valves using a paediatric resectoscope.

Hypospadias

Hypospadias occurs in one in 350 male births and is the most common congenital malformation of the urethra. The external meatus opens on the underside of the penis or the perineum, and the inferior aspect of the prepuce is poorly developed (‘hooded prepuce’).

Hypospadias is classified according to position of the meatus.

Glandular hypospadias — this is the most common type and does not usually require treatment. The normal site of the external meatus is marked by a blind pit, although it occasionally connects by a channel to the ectopic opening on the underside of the glans.

  Coronal hypospadias — the meatus is placed at the junction of the underside of the glans and the body of the penis.

  Penile and penoscrotal hypospadias — the opening is on the underside of the penile shaft (Fig. 67.2).

  Perineal hypospadias — this is the most severe abnormality. The scrotum is split and the urethra opens between its two halves. There may be testicular maldescent which may make it difficult to determine the sex of the child.

The more severe varieties of hypospadias represent an absence of the urethra and corpus spongiosum distal to the ectopic opening. The absent structures are represented by a fibrous cord which deforms the penis in a downward. direction (chordee). The more distant the opening from its normal position, the more pronounced the bowing.

Treatment

Glandular hypospadias does not need treatment unless the meatus is stenosed, in which case a meatotomy is performed. Surgery is indicated for other forms of hypospadias to improve sexual function and for cosmetic reasons. A bewil­dering variety of plastic surgical procedures is described to correct the chordee and to bring the urethra to an opening at the tip of the penis. Most of these procedures make use of prepuceal skin and so circumcision should be avoided until the hypospadias has been repaired. Operations for hypospa­dias are best performed by a specialist paediatric urologist and will not be detailed here.

Epispadias

Epispadias is very rare, occurring in one in 30000 males and one in 400000 females. In penile epispadias the opening on the dorsum is associated with upward curvature of the penis (Fig. 67.3). Total epispadias usually goes with ectopia vesicae and other severe developmental defects.