Ectopic Ureter

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Definition of Ectopic Ureter

An ectopic ureter is a ureter with an abnormally located ureteral orifice. Instead of draining into the bladder, the ureteral orifice is located in the urethra, vagina or in structures of the mesonephric duct (ductus deferens or seminal vesicles).

Epidemiology

1:2000, more girls than boys.

Etiology

See etiology of ureteral duplication.

Pathology of Ectopic Ureter

80% of ectopic ureters are associated with an ureteral duplication, especially in girls. In boys, the ectopic ureter may also drain a single renal system. In girls, the ectopic ureter drains into the urethra (35%), vulval vestibule (34%), vagina (25%) or uterus (5%). In boys, the ectopic ureter drains into the prostatic urethra (47%), seminal vesicles (33%), prostatic utricle (10%) or vas deferens (10%).

The further the distance of the ureteral opening from its normal position, the higher the likelihood of a renal malformation (renal dysplasia, renal hypoplasia) and dysfunction. If the ectopic ureter is associated with a duplex system, the ectopic ureter drains the upper pole of the kidney.

Signs and Symptoms of an Ectopic Ureter

Recurrent urinary tract infections, flank pain, fever. Additionally and depending on gender and location of the ureteral orifice:

• Girls: urinary incontinence (day and night, but sometimes also intermittent), vaginal discharge.
• Boys: LUTS, epididymitis.

Diagnosis of Ureteral Ectopia

Pelvic examination:

Pelvic examination is indicated in girls with urinary incontinence, sometimes the orifice of the ureter can be identified in the vagina or vulval vestibule.

Cystoscopy and retrograde pyelography:

Cystoscopy and retrograde pyelography to search for ureteral orifices.

Ultrasound imaging:

Ureteral ectopia may cause hydronephrosis. If a duplex kidney is present, urinary obstruction of the upper kidney portion may be visible. A dilated ureter may be detectable behind the bladder.

Intravenous Urography:

Intravenous urography is increasingly replaced by MR urography or in adults by CT. Urography often lacks to image in the upper part of the duplex kidney due to poor renal function. Hints for a non-contrasting upper portion is obtained from the small number of calices shown and the greater distance of the renal system to the spine. Late images after 1–3 hours may however contrast the upper renal portion.

Voiding Cysturethrography:

VCUG may detect reflux into the lower renal pole, if a duplex kidney is present.

Renal scintigraphy:

Renal scintigraphy is indicated to determine the renal function on the side of the ectopic ureter. If a duplex system is present, the renal function of the upper and lower pole must be analyzed separately.

MRI Urography or CT:

MRI urography is the most accurate imaging tool and indicated for imaging in children, especially if unclear findings in previous investigations are present and an ectopic ureter is suspected. CT is an imaging alternative in adults which is more sensitive compared to intravenous urography.

Treatment of Ectopic Ureter

Treatment of ectopic ureter is only necessary in patients with complaints (see signs and symptoms).

Ectopic ureter with a nonfunctioning kidney:

Heminephrectomy for a duplex kidney (upper pole partial nephrectomy) or nephrectomy in a single system, surgery is possible with laparoscopy. If reflux is present into the ectopic ureter, ureterectomy is also necessary. If significant vesicoureteral reflux is present into the lower pole of a duplex kidney, ureterocystoneostomy of the lower pole ureter is necessary.