Congenital Anomalies of Ureters

Congenital anomalies of the ureters are common, and include duplications (double and bifid ureters) and ectopic ureteral orifices ("ectopic ureters"), which frequently occur together. Ureteral duplications increase the risk of hydronephrosis, pyelonephritis, and lithiasis ("stones"). Ectopic ureteral orifices (i.e., openings other than into the bladder) usually causes urinary incontinence in affected females.

Types

• Ureteral Duplications
  • Complete duplications (double ureters)
  • Incomplete duplications (bifid ureters)
• Ectopic Ureters

Ureteral Duplications

Ureteral duplications are common (about 0.8% of autopsies). 15% of cases are bilateral. Rarely, the upper urinary tract duplication includes a supernumerary kidney. Hydronephrosis, pyelonephritis and lithiasis are common complications of ureteral duplications.
Incomplete and complete duplications (i.e., double and bifid ureters, respectively) are equally common. Ureteral duplication is considered to caused by early bifurcation of the ureteric bud, with incomplete duplications representing more distal bifurcations than complete duplications.

Ectopic Ureter

A ureter that opens anywhere but into the trigone is ectopic. Clinical ureteral ectopia opens anywhere but into the bladder. Ureteral ectopia usually causes incontinence in females but not in males. Therefore, discovery is far more likely in females than in males.
Ectopic ureter and ureteral duplication are associated:

• 80% of ectopic ureters occur with ureteral duplication.
• 15% of ureteral duplications occur with ectopic ureters.
  

The sites of ectopic ureteral orifices (openings) differs between males and females:

• Females:
  • Urethra (36%)
  • Vestibule (34%)
  • Vagina (25%)
  • Uterus (5%)
• Males:
  • Prostatic urethra (47%)
  • Seminal vesicle (33%)
  • Prostatic utricle (10%)
  • Ductus deferens or Ejaculatory duct (10%)