Congenital malformations of the ureter - Congenital disorders of the kidney

Congenital malformations of the ureter

Definition

Developmental abnormalities of the ureter are relatively common.

Aetiology

Often sporadic, but increased risk in those with a positive family history.

·        Agenesis: This occurs with renal agenesis.

·        Atresia: Failure of the ureteric bud to canalise, associated with renal dysplasia.

·        Ectopic ureteric orifice: The ureter normally enters the bladder outside the area of the trigone. An ectopic ureter often arises from a duplex kidney, which may be associated with vesicoureteric reflux. Occasionally the ureter can drain into the vagina or seminal vesicle. Surgical reimplantation of the ureter may be indicated.

·        Ureterocele: The ureteric orifice is tiny, so that the ureter dilates to form a cyst by the bladder wall. If not surgically dilated, the obstruction leads to hydronephrosis.

·        Primary obstructive megaureter: The cause of this condition is unknown. The whole ureter becomes dilated, apart from the terminal segment. If the stenosis is causing obstruction, treatment is with surgical reimplantation of the ureter.

Clinical features

Many are asymptomatic. Obstruction is chronic and therefore usually painless. Urinary stasis or reflux can lead to repeated urinary tract infections, which in children may cause non-specific fevers, malaise, failure to thrive and abdominal symptoms.

Management and prognosis

In recurrent infections, renal scarring results unless the condition is diagnosed and treated with prevention and early detection of UTI’s and surgical repair where indicated. Unrelieved obstruction can also lead to irreversible loss of renal function.