Vesicoureteral reflux (VUR)
Vesicoureteral reflux (VUR): The retrograde flow of urine from the bladder to the kidneys. This is an abnormal condition in humans and is a congenital anomaly caused by shortening of the part of the ureter (taking urine from the kidney into the bladder) that is located in the bladder wall. This leads to an incompetent valve mechanism and allows urine to flow back towards the kidneys.
Signs and symptoms: – can be identified in newborns that were noted to have hydronephrosis on prenatal ultrasound. Usually it is diagnosed in infants and children presenting with a urinary tract infection. Not associated with pain unless the child has pyelonephritis.
Evaluation: – the diagnosis is suspected on ultrasound that shows the presence of hydronephrosis and a voiding cystourethrogram (VCUG) indicating the presence of VUR. VUR is graded from I – V, based on the VCUG. Grade I is the lowest grade and has high potential to resolve spontaneously. Grade V is the highest grade and has low potential to resolve spontaneously.
Management: – the goal for management has been the prevention of urinary tract infections and therefore the prevention of potential damage to the kidneys. This has been done with the use of long term prophylactic antibiotics, with surgery reserved for those failing the use of prophylaxis. There is significant debate today on the benefit of long term prophylaxis in the prevention of urinary tract infections and therefore impacting scarring. The largest study to evaluate the benefit of prophylaxis (the Randomized Intervention for children with Vesicoureteral Reflux Trial – NIH/NIDDK) indicated that there was a marked reduction in infections in children on prophylaxis, but the impact on scarring on the kidneys, was not able to be demonstrated. The study, however, was only two years in duration, which may have been too short to determine an impact on scarring.
Surgical management has been with the use of injectable agents or ureteral reimplantation.
Megaureter: Enlargement of the ureter. May be secondary to obstruction at the ureterovesical junction (UVJ obstruction) or high grade vesicoureteral reflux. At times may just be congenitally dilated with no evidence of obstruction or reflux.
Signs and symptoms: – can be identified on prenatal ultrasound and may be associated with hydronephrosis. May also be identified following a urinary tract infection. May rarely present with pain secondary to obstruction.
Evaluation: – can be seen on ultrasound evaluation, however identification of obstruction requires evaluation with a diuretic renal scan. The presence of obstruction can lead to reduction in function of the affected kidney.
Management: – Once obstruction or vesicoureteral reflux has been identified, management is with ureteral reimplantation. If there is no evidence of obstruction or vesicoureteral reflux, then ongoing conservative management with follow-up ultrasound evaluation may be all that is needed.