Ureteropelvic junction obstruction (UPJO) and vesicoureteral reflux (VUR) are the most common uropathies. The co-occurrence of both anomalies has led to the practice of screening for VUR in children with UPJO to prevent deterioration of kidney function due to renal scarring following urinary tract infections (UTIs). We determined the prevalence of VUR in children with UPJO for a critical assessment of VUR screening by voiding cystourethrography (VCUG). A systematic search strategy in MEDLINE, EMBASE, and CENTRAL was carried out for all articles that included VCUG, and renal scintigraphy or any other appropriate imaging technique for the diagnosis of UPJO. Twenty studies were eligible for inclusion. We found a pooled prevalence for VUR of 8.2 % (95 % CI = 3.6-12.7), about a threefold increase compared to the general pediatric population. VUR occurred bilateral or contralateral to the kidney with UPJO in 5.7 % (95 % CI = 3.0-8.5), equivalent to 75 % of all children with VUR. Considering the effect size of VUR treatment with antibiotics, about 207 and 278 children would need to undergo VCUG to prevent one febrile UTI and one case of renal scarring by 1-2 years, respectively.
Against this background, screening for VUR needs to be scrutinized and restricted to selected risk groups. What is known: • Screening of patients with ureteropelvic junction obstruction (UPJO) for vesicoureteral reflux (VUR) is recommended based on a small number of repeatedly cited studies. • The lack of conclusive evidence results in different treatment strategies and leads to difficulties when communicating diagnoses and treatment options to parents. What is new: • A robust prevalence for VUR in children with UPJO based on all published evidence and the resulting number needed to screen are given for decision-making in daily clinical practice. • The results may be a precursor for implementation into guidelines.