Does every patient with ureteropelvic junction obstruction need voiding cystourethrography?

Co-Existing Pediatric Ureteropelvic Junction Obstruction and Vesicoureteric Reflux: Prevalence and Implications

Purpose

The purpose of this study is to ascertain the coexistence of ipsilateral vesicoureteric reflux (VUR) with ureteropelvic junction obstruction (UPJO) and to compare postpyeloplasty outcome in patients with and without associated VUR.

Materials and Methods

Prospective study from 2014 to 2016 of consecutive children (n = 135) undergoing pyeloplasty. Data of patients without (Group 1) and with (Group 2) associated ipsilateral VUR were compared.

Results

Thirty-five patients (25.9%) had ipsilateral VUR along with UPJO (Group 2). This group showed the following unique features: (1) Higher percentage of infants (31/35) compared to Group 1 (62/100) (P = 0.003) (2) VUR in the contralateral (normal) kidney in 21/35 (60%) cases and nil in Group 1 (3) Significantly less preoperative differential renal function in children above 1 year (P = 0.007) (4) Presence of renal scars (18 units) and pyelonephritic changes (6 units) in Group 2 at the 1-year follow-up dimercaptosuccinic acid renal scan. Both groups showed improvement in function 3 months after pyeloplasty with no statistically significant difference. Improvement in drainage on the renal scan was better in Group 1 at 3 months postoperative (P = 0.015) as well as between 3 months and 1-year follow-up (P = 0.052).

Conclusion

The prevalence of VUR was 25.9% in this study and 33.3% in ≤1 year age group. There was a loss of function in delayed presenters with associated ipsilateral VUR. There was delayed drainage postpyeloplasty in patients with VUR. A preoperative voiding cystourethrogram should be done in children <1 year age before pyeloplasty so that associated VUR if detected can be concurrently managed along with pyeloplasty and preserve nephrons affected by the dual pathology.

Influence of postnatal hydroureter in determining the need for voiding cystourethrogram in children with high-grade hydronephrosis

Objective

To evaluate the utility of hydroureter (HU) to identify high-grade vesico-ureteric reflux (VUR) in patients with high-grade postnatal hydronephrosis (PH).

Patients and methods

We retrospectively reviewed patients’ charts that had antenatal hydronephrosis from 2008 to 2014. Patients were excluded if they presented with febrile urinary tract infection (fUTI), neurogenic bladder, posterior urethral valve, multi-cystic dysplastic kidney, and multiple congenital malformations. We reviewed postnatal ultrasonography images and patients with Society of Fetal Urology (SFU) Grades 3 and 4 hydronephrosis with a renal pelvic antero-posterior diameter of ≥10 mm were included. The ureter was assessed and considered dilated if the ureteric diameter was  ≥4 mm. The voiding cystourethrogram (VCUG) studies, fUTI incidence, and surgical reports were reviewed.

Results

Of the 654 patients reviewed, we included 148 patients (164 renal units) of whom 113 (76.4%) were male and 35 (23.6%) female. SFU Grade 3 PH was identified in 49% of the renal units, with the remaining 51% being SFU Grade 4. HU was found in 50/164 renal units and was not detected in the remaining 114 units. VUR was diagnosed in four units (3.5%) without HU (low-grade VUR); whilst it was detected in 19 units (38%) with HU (72.7% were high-grade VUR) (P < 0.001). VUR was diagnosed on the contralateral side in four/105 patients with PH without HU and diagnosed in 10/43 patients with PH with HU (P < 0.001). During a median follow-up of 25.9 months, none of the renal units that had VUR without HU developed UTI or had surgeries.

Conclusion

Low-grade uncomplicated VUR was diagnosed in 3.5% of renal units without HU. Our results support limiting the use of VCUG to renal units with PH if associated with HU.

To screen or not to screen for vesicoureteral reflux in children with ureteropelvic junction obstruction: a systematic review

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.

CONCLUSION

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.

Pediatric urologic interventional radiology

Interventional radiologists are playing an increasingly important role in pediatric urologic intervention, working closely with the pediatric urologist. Interventional radiologists are frequently asked to establish percutaneous access to the renal collecting system prior to nephrolithotomy. Additionally, procedures such as percutaneous nephrostomy, ureteral stent placement and exchange, and renal parenchymal biopsy are frequently encountered requests. This article will review these common procedures and highlight techniques and pathology that are unique to the pediatric population.