Surgical Management of Vesicoureteral Reflux - Statistical Data Included

AORN Journal, March, 2000 by Pamela I. Ellsworth, Marc Cendron, MAUREEN F. McCULLOUGH

Vesicoureteral reflux (VUR) is a urologic condition in which there is a retrograde flow of urine from the bladder through the ureter back up to the upper urinary tract. Vesicoureteral reflux may be classified as primary or secondary. Primary reflux, a congenital anomaly of the ureterovesical junction, is due to a deficiency of the longitudinal muscle of the intravesical ureter, which results in an inadequate flap valve mechanism. Secondary reflux is a result of decompensation of the valvular mechanism as a result of elevated intravesical pressures associated with voiding dysfunction and bladder outlet obstruction.(1)

The incidence of VUR ranges from 1% to 18.5% in children and is as high as 70% in infants who present for treatment with symptomatic urinary tract infections.(2) Eighty-five percent of children are females, with Caucasian females most frequently affected.(3) The definitive reason that VUR occurs more frequently in Caucasian females is unknown, but it is believed to be genetic.

Vesicoureteral reflux appears to have a multifactorial origin. It appears that the genetic component exists, and this is supported by the increased incidence (ie, 45%) of VUR among siblings.(4) Sterile reflux after birth does not appear to cause significant renal damage; however, reflux of infected urine may lead to pyelonephritis, renal scarring, and in severe cases, significant loss of renal function and subsequent hypertension. The primary goal in the management of VUR is the prevention of pyelonephritis and subsequent renal scarring.

HISTORICAL PERSPECTIVES

Vesicoureteral reflux and the concept of an incompetent ureterovesical junction were first described by Leonardo da Vinci and Galen.(5) One researcher noted that renal infection may be the result of an abnormal ureterovesical configuration.(6) Another researcher was the first to demonstrate that the length of the intravesical ureter and the muscular development of the trigone affected the incidence of VUR.(7) In 1952, it was proposed that there was a causal relationship between reflux and pyelonephritis and renal scarring.(8) Restoration of a normal length submucosal tunnel, which was five times the diameter of the ureter, became the focus of surgical repair.

In 1967, researchers demonstrated that the normal ureteral diameter ranges from 1.4 mm to 2.0 mm and varies in size at the ureterovesical junction with the child's age. The normal intravesical ureteral length varies from 7 mm to 12 mm and also varies with the child's age. In children with reflux, the ureter is often dilated up to several millimeters in diameter, varying with the degree of reflux. Based on these findings, restoration of a normal submucosal (ie, intramural) tunnel, five times the diameter of the ureter, became the focus of the repair.(9)

The excellent success of open procedures (ie, 98%), fueled the interest in devising less invasive techniques to surgically correct VUR.(10) Currently, a variety of surgical techniques are used to treat VUR, including laparoscopic, endoscopic, and open techniques.

EVALUATION AND MANAGEMENT

Most children with VUR present with symptoms of a urinary tract infection (UTI). Newborns often are diagnosed with a febrile illness, failure to thrive, or a history of pelvicaliectasis (ie, dilation of the renal pelvis and calyces) on a prenatal ultrasound.(11) Complete evaluation, including a voiding cystourethrogram (VCUG) and renal ultrasound, is indicated in four groups of children. The first group consists of any child less than five years of age with a documented UTI. In the second group are children with a febrile UTI, regardless of their age. The third group consists of male children with a UTI, unless the male child is sexually active or has a significant urologic history.(12) The fourth group consists of newborns with a history of prenatal pelvicaliectasis.(13)

Vesicoureteral reflux may be identified on a contrast VCUG or by radionuclide VCUG. Both VCUGs are performed in the radiology department. The contrast VCUG is performed in the fluoroscopy suite, and the radionuclide VCUG is performed in the nuclear medicine department. Preparation for both studies involves antiseptic cleansing of the glans and perimeatal area and the placement of a small caliber lubricated feeding tube into the bladder. Usually, a 5-Fr catheter is used in newborns and infants, and an 8-Fr catheter is used in children. The postvoid urine residual is recorded, and a urine sample is sent for urine culture. The child's expected bladder capacity is determined using the formula of the child's age in years plus two, times 30.

For the contrast study, diluted water-soluble contrast is instilled into the catheter by gravity that does not exceed 100 ml water. An x-ray is obtained before instilling the contrast to confirm catheter position and to rule out any abnormalities of the lower spine (eg, sacral agenesis, spina bifida occulta). While the contrast medium is being instilled, intermittent fluoroscopic scanning is performed to assess for reflux during the filling. Fluoroscopic scanning also is performed while the child is voiding. If reflux is present, films are taken at intervals (ie, delayed) to assess upper urinary tract drainage. A postvoid film also is obtained to assess bladder emptying. Repeating the filling and voiding cycle during the same examination increases the accuracy of the contrast voiding cystourethrogram VCUG by 12%.(14) A contrast VCUG usually is used for the initial radiologic study as it allows for grading of the reflux and visualization of the urethral and bladder anatomy. Reflux is routinely graded according to the International Classification of VUR (Table 1, Figure 1).(15)