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Ureteral anomalies frequently occur with renal anomalies but may occur independently. Complications include obstruction and infection and calculus formation from urinary stasis. Urinary incontinence occurs if the ureter bypasses the bladder and terminates in the urethra, perineum, or vagina. Diagnosis typically involves ultrasonography and voiding cystourethrography; some conditions may present on routine fetal ultrasonography. Treatments are surgical.
Duplication
anomalies:
Partial or complete duplication of one or both ureters may occur with duplication of the ipsilateral renal pelvis. The ureter from the upper pole of the kidney opens at a more caudal location than the orifice of the lower pole ureter. Ectopia or stenosis of one or both orifices, vesicoureteral reflux into the lower ureter or both ureters, and ureterocele may occur. Surgery may be necessary if there is obstruction, vesicoureteral reflux, or urinary incontinence.
Ectopic
orifices:
Malpositioned openings of single or duplicated ureters may occur on the lateral bladder wall, distally along the trigone, in the bladder neck, in the female urethra distal to the sphincter (leading to continuous incontinence), in the genital system (prostate and seminal vesicle in the male, uterus or vagina in the female), or externally. Lateral ectopic orifices frequently lead to vesicoureteral reflux, whereas distal ectopic orifices more often cause obstruction and incontinence. Surgery is needed for obstruction and incontinence and sometimes for vesicoureteral reflux.
Retrocaval
ureter:
Anomalous development of the vena cava (pre-ureteric vena cava) allows the infrarenal vena cava to form anterior to the ureter (usually the right); a retrocaval ureter on the left occurs only with persistence of the left cardinal vein system or with complete situs inversus. Retrocaval ureter can cause ureteral obstruction. For significant ureteral obstruction, the ureter is surgically divided with uretero-ureteral anastomosis anterior to the vena cava or iliac vessel.
Stenosis:
Narrowing may occur at any location in the ureter, most frequently at the ureteropelvic junction and less commonly at the ureterovesical junction (primary megaureter). Consequences include infection, hematuria, and obstruction. Stenoses often diminish as the child grows. In primary megaureter, ureteral tapering and reimplantation may be needed when dilation increases or infection or obstruction occurs.
Ureterocele:
Prolapse of the lower end of the ureter into the bladder with pinpoint obstruction may produce progressive ureterectasis, hydronephrosis, infection, occasional calculus formation, and impaired renal function. Treatment options include endoscopic transurethral incision and open repair.
When a ureterocele involves the upper pole of duplex ureters, treatment depends on function in that renal segment, because of the significant incidence of renal dysplasia. Removal of the affected renal segment and ureter may be preferable to obstruction repair if no segmental renal function is found or if significant renal dysplasia is suspected.
Vesicoureteral
reflux:
Reflux is retrograde passage of urine from the bladder back into the collecting system. It is most often due to congenital anomalous development of the ureterovesical junction. Incomplete development of the intramural ureteral tunnel causes failure of the normal flap valve mechanism at the ureterovesical junction that permits reflux of bladder urine into the ureter and renal pelvis. Reflux can occur even when the tunnel is ordinarily sufficient if bladder outlet obstruction increases intravesical pressures.
Reflux of urine from the bladder into the ureter may damage the upper urinary tract by bacterial infection and occasionally by increased hydrostatic pressure. Bacteria in the lower urinary tract can easily be transmitted by reflux to the upper tract, leading to recurrent parenchymal infection with potential scarring and renal dysfunction. Chronically elevated emptying pressures (> 40 cm H2O) and increased bladder volume and pressure often cause progressive kidney damage, even without infection or reflux.
Symptoms and signs are typically those of UTI; these may include fever, abdominal or flank pain, dysuria or flank pain with voiding, frequency, and urgency. Pyuria, hematuria, proteinuria, and bacteriuria may be present on urinalysis.
Tests for reflux include filling and voiding cystourethrogram (which is best to diagnose bladder outlet obstruction) and radioisotope cystogram. Renal ultrasonography evaluates for size, hydronephrosis, and scarring. Renal cortical involvement with acute infection or scarring is precisely delineated with succimer (dimercaptosuccinic acid) nuclear scans, when indicated. Urodynamic studies may demonstrate elevated filling and voiding pressures in the bladder.
Vesicoureteral reflux is usually mild to moderate (with little or no calyceal dilatation—see grading system see Table 4: Infections in Infants and Children: Grades of Vesicoureteral Reflux* ) and often resolves spontaneously over months to several years while daily antibacterial prophylaxis (eg, with trimethoprim-sulfamethoxazole , amoxicillin , nitrofurantoin , sulfisoxazole ) is maintained. Reflux accompanied by high-pressure storage of urine in the bladder or high intravesical pressures with voiding is treated by lowering bladder pressures with drugs (eg, oxybutynin ), behavioral modification using perineal electromyography, or both. Reflux with complications (eg, infection, impaired renal growth, renal scarring) is treated with endoscopic subtrigonal injection of a bulking agent or ureteral reimplantation. Obstruction is also surgically repaired.
Last full review/revision November 2005
Content last modified November 2005
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