What is primary Vesicoureteral reflux?
VUR occurs either primarily or secondarily. Primary VUR is due to “immaturity” or abnormality of the ureterovesical junction (UVJ), which allows urine to ascend into the ureters during bladder filling or voiding. Generally, reflux is related to ureteral orifice size and the length of the ureter as it tunnels into the bladder.
What is secondary Vesicoureteral reflux?
Secondary VUR occurs as the result of an abnormality of the UVJ, such as with presence of a distal paraureteral diverticulum or ureterocele (an outpouching of the ureter that extends into the bladder). Secondary VUR may also occur as a result of bladder outlet obstruction or secondary to a neurogenic bladder.
How is primary Vesicoureteral reflux graded?
Primary VUR is graded on a scale of 1 to 5, based on the degree of ureteral and pyelocalyceal (renal collecting system) filling and dilation. In addition to providing the referring physician with a visual description of the degree of reflux, assigning a grade also gives the clinician an idea of the likelihood of spontaneous resolution (e.g., 80% of cases of grade 2 reflux resolve within 3 years).