Reduced differential renal function in scintigraphy predicted high-grade vesicoureteral reflux in children with antenatal hydronephrosiss.

AIM: A top-down approach is widely used for detecting vesicoureteral reflux (VUR) in children with febrile urinary tract infections. We evaluated the diagnostic value of renal scintigraphy in predicting VUR in children with antenatal hydronephrosis (AHN). METHODS: The voiding cystourethrogram (VCUG) and renal scintigraphy results of 125 AHN patients (76% male) admitted to the Children's Hospital of Helsinki University, Finland, from 2003 to 2013 were analysed. Of those, 94 had nonrefluxing hydronephrosis, nine had low-grade VUR and 22 had high-grade VUR. RESULTS: Scintigraphy was performed at a median age of 1.4 (0.8-15.6) months. In patients with high-grade VUR, the differential renal function (DRF) of the worse kidney was significantly lower than in patients without VUR, with a median of 35% and interquartile range (IQR) of 20-45 versus 47% (IQR: 44-49), (p < 0.001). There was no difference between patients with low-grade VUR and patients without VUR (p = 0.181). DRFs below 44% showed a sensitivity of 73% and specificity of 79% and predicted significantly high-grade VUR (odds ratio 9.82, 95% confidence interval 3.44-28.05, p < 0.001) in the univariate analysis. CONCLUSION: A DRF below 44% predicted high-grade VUR in patients with AHN and supported the decision to perform VCUG.

Correction to: Postnatal imaging of prenatally detected hydronephrosis-when is voiding cystourethrogram necessary?

The original publication contained an erroneous version of Table 3 with incorrect data regarding ureteral visibility. The authors apologize for any inconvenience caused by their mistake and are pleased to present the corrected table here.

Postnatal imaging of prenatally detected hydronephrosis-when is voiding cystourethrogram necessary?

OBJECTIVE: To evaluate whether grade 4-5 vesicoureteral reflux (VUR) can be predicted from renal ultrasound (RUS) findings and perform voiding cystourethrograms (VCUGs) only on high-risk patients. METHODS: The RUS and VCUG images of infants with prenatally detected hydronephrosis admitted to our institution between 2003 and 2013 were re-evaluated. The UTI episodes were collected retrospectively from patient journals. Patients with complex urinary tract anomalies were excluded. RESULTS: One hundred eighty, 44 female and 136 male, patients (352 renal units (RU)), 23 (30 RU) of them having grade 4-5 VUR, were included. The median age of the patients at the time of the RUS was 1.3 (0.1-3.0) months and the median follow-up time was 2.0 (0.1-11.2) years. In multivariate analysis, a visible ureter (OR 12.72; CI 5.33-32.04, p < 0.001) and shorter renal length (OR 2.67; CR 1.50-4.86, p < 0.001) in RUS predicted grade 4-5 VUR while a visible ureter predicted UTIs (OR 5.75; CI 2.59-12.66, p < 0.001). A three-grade risk score for high-grade VUR was developed based on the RUS findings and the patients were categorized into low-, intermediate-, and high-risk groups. The incidence of grade 4-5 VUR was 2.9% in the low-risk, 12.2% in the intermediate-risk, and 52.2% in the high-risk group. The sensitivity and specificity for detecting grade 4-5 VUR were 79 and 82%, respectively. CONCLUSIONS: In patients with antenatally detected hydronephrosis, a visible ureter and reduced renal length in RUS are significant risk factors for high-grade VUR. A RUS-based risk scoring would probably reduce the proportion of unnecessary VCUGs.

Prenatal complicated duplex collecting system and ureterocele-Important risk factors for urinary tract infection.

PURPOSE: To evaluate the risk of urinary tract infections (UTIs) in infants with prenatally detected complicated duplex collecting system (CDS) or ureterocele. MATERIALS AND METHODS: All patients with prenatally detected CDS (n=34) or single system ureterocele (n=7) who were admitted to our institution between 2003 and 2013 were enrolled in this retrospective analysis. Duplex collecting systems with ureterocele (n=13), vesicoureteral reflux (VUR) (n=20) or nonrefluxing megaureter without ureterocele (n=7) were determined as complicated. Twenty-six (63%) patients were females. The prevalence of UTI was compared to 66 controls. RESULTS: The median follow-up time was 5.5 (1.7-12.2) years. Eighteen (44%) patients and 3 (5%) controls had at least one UTI (p<0.001) at the median age of 0.8 and 0.4years, respectively (p=0.481). Fifty-seven percent of the UTIs were breakthrough infections and 82% of those were non-Escherichia coli infections. UTIs occurred prior to any surgical intervention in 4/13 (31%) patients with ureterocele, in 2/14 (14%) patients with VUR, in 4/7 (57%) patients with both ureterocele and VUR, and in 3/7 (43%) patients with nonrefluxing megaureter without VUR or ureterocele (p-values 0.012, 0.209, 0.001 and 0.010, respectively, compared to controls). Postoperative UTIs were observed in 29% of the girls and in none of the 11 boys (p=0.072). The incidence of UTI after perforation of ureterocele was only 14%. CONCLUSIONS: Children with prenatally detected ureterocele or duplex collecting system associated with nonrefluxing megaureter are at high risk of UTI despite prophylactic antibiotics. In case of prenatally detected ureterocele we suggest to consider early endoscopic perforation. LEVEL OF EVIDENCE: III.

Incidence of urinary tract infections in infants with antenatally diagnosed hydronephrosis-A retrospective single center study.

OBJECTIVE: To evaluate the incidence of urinary tract infections (UTIs) in infants with antenatal hydronephrosis (AHN). MATERIALS AND METHODS: A cohort of AHN patients admitted to our institution between 2003 and 2013 were identified. Altogether 192 patients with nonrefluxing hydronephrosis (HN, n=135), nonrefluxing hydroureteronephrosis (HUN, n=21), or vesicoureteral reflux (VUR, n=36) were identified. Patients with complex anomalies or neonatal decompression of the urinary tract were excluded. Information about UTIs diagnosed among the AHN patients was collected and compared with data from 58 controls. RESULTS: During the median follow-up time of 2.6 (0.3-11.2) years, 24 (13%) patients (15 (10%) males and 9 (19%) females) and 2 (3%) controls experienced at least one UTI (p=0.033). Eighteen (69%) UTIs were febrile. The males had the first UTI at significantly younger age than the females (0.3, 0.0-1.7years vs. 1.0, 0.4-4.8years, p=0.010). UTI was detected in 15 (63%) patients with grade 4-5 VUR, in 8 (6%) patients with HN, and in one (5%) patient with HUN (p-values <0.001, 0.726 and >0.999 against the controls). None of the patients with grade≤3 VUR had UTI. Fifty-eight percent of the patients with UTI were on antimicrobial prophylaxis. In five (12%) cases UTI appeared within one week after voiding cystourethrography (VCUG). CONCLUSIONS: Infants with AHN and grade 4-5 VUR had the highest risk of UTI. UTIs tented to be more common in females than in males; however, males experienced UTI at younger age than females. VCUG caused UTI in 2.3% in our material. LEVEL OF EVIDENCE: III.