Vesicoureteral Reflux (VUR)

Definition

Vesicoureteral reflux (VUR) is an abnormal movement of urine from the bladder into ureters or kidneys. Urine normally travels from the kidneys via the ureters to the bladder. In vesicoureteral reflux the direction of urine flow is reversed (retrograde).

Causes

·         Primary VUR

Insufficient submucosal length of the ureter relative to its diameter causes inadequacy of the valvular mechanism.

·         Secondary VUR

Valvular mechanism is intact.

But, overwhelmed by raised vesicular pressures associated with obstruction, which distorts the ureterovesical junction.

Futher divided into:

1.      Anatomical: Posterior urethral valves; urethral or meatal stenosis.

These causes are treated surgically when possible.

2.      Functional: Bladder instability, neurogenic bladder and non-neurogenic neurogenic bladder urinary tract infections may cause reflux due to the elevated pressures associated with inflammation.

Resolution of functional VUR will usually occur if the precipitating cause is treated and resolved. Medical and/or surgical treatment may be indicated.

International Classification of Vesicoureteral Reflux

Grade I – reflux into non-dilated ureter

Grade II – reflux into the renal pelvis and calyces without dilatation

Grade III – mild/moderate dilatation of the ureter, renal pelvis and calyces with minimal blunting of the fornices

Grade IV – dilation of the renal pelvis and calyces with moderate ureteral tortuosity

Grade V – gross dilatation of the ureter, pelvis and calyces; ureteral tortuosity; loss of papillary impressions

Diagnosis

The following procedures may be used to diagnose VUR:

1.      Nuclear cystogram (RNC)

2.      Fluoroscopic voiding cystourethrogram (VCUG)

3.      Ultrasonic cystography

4.      Abdominal ultrasound