Clinical course of prenatally detected primary vesicoureteral reflux

Abstract

The purpose of this study was to report the clinical course of medium-long-term follow-up of children with prenatally detected vesicoureteral reflux (VUR). Between 1986 and 2004, 53 (41 males) children with VUR detected by investigation of prenatal hydronephrosis were followed up for a mean time of 66 months (range: 6-200 months). Newborns were investigated by ultrasound, voiding cystourethrogram (VCUG) and DMSA scan. Follow-up clinical visits were performed at 6-month intervals. After 24 months patients were investigated by conventional VCUG or direct isotope cystogram. Survival analysis was performed in order to evaluate the resolution of the reflux. Differences between subgroups (mild vs moderate/severe reflux) were assessed by the two-sided log rank test. Thirty (58%) infants presented bilateral VUR, for a total of 83 renal units. There was a predominance of severe reflux (54%). Renal damage was detected in 33.7% of the units on first renal scan. There was a significant correlation between severe reflux and renal damage scars (RR=3.4, 95% confidence interval [CI], 1.4-8, p=0.002). Forty-seven patients were treated with continuous prophylaxis. One patient developed systolic hypertension. Urinary tract infection occurred in 12 (25%) children conservatively managed. VUR resolution was evaluated in 56 renal units. Spontaneous resolution was observed in 25 units (45%). At 48 months after diagnosis, 75% of the cases of mild reflux (I-III) and 37% of severe reflux (IV-V) had resolved (log-rank, 5.6, p=0.017). There was an improvement of nutritional parameters between admission and the end of follow-up. In conclusion, the clinical course of prenatally detected VUR followed up on a medium-long-term basis is relatively benign. Our study corroborates the results obtained in other series of infants with reflux that emphasized the heterogeneity of this disorder.

Randomized Intervention for Children With Vesicoureteral Reflux (RIVUR): Background Commentary of RIVUR Investigators

“…Other concerns about current diagnostic and therapeutic strategies include the cost and potential psychological harm of studies to detect VUR and its follow-up to resolution, 5, 11, 22, 23 and the development of antimicrobial resistance with long-term prophylactic antibiotic use 24, 25 . Doubts have arisen concerning the role of VUR in renal scarring and the efficacy of current therapeutic strategies in comparison to prompt evaluation and treatment of UTI 2, 7, 8, 26 .…”

“…Another issue for consideration is that primary VUR may be discovered during follow-up investigations for prenatal ultrasound findings or after a UTI 8, 26, 31 . Because our interest is in patients with primary rather than secondary VUR, the timing of the discovery of reflux is less important.…”

“…Because our interest is in patients with primary rather than secondary VUR, the timing of the discovery of reflux is less important. Put differently, all primary VUR exists on an embryologic basis 13, 26 . The main differences between pre- and post-natal disease are therapeutic approaches, including the choice of antimicrobials, the organisms encountered, and a greater spontaneous remission rate in younger children.…”

Independent risk factors for renal damage in a series of primary vesicoureteral reflux: A multivariate analysis

“…Most of the children (501 out of 549; 91.3%) were admitted after the first episode of urinary tract infection. The remaining 48 patients had antenatal hydronephrosis and no episode of urinary tract infection had occurred when the diagnosis of VUR was established 12 . In our series, the median age at diagnosis of the first urinary tract infection was 8.9 months (interquartile range (IQ), 4.4–20.3 months) and the median age at diagnosis of VUR was 19 months (IQ, 9–38 months).…”

“…Nevertheless, VUR increases the risk of post‐pyelonephritic renal scars in children 8,9 . On the other hand, data from series of VUR obtained in the investigation of foetal hydronephrosis have shown that renal damage can occur in the absence of infection 10–12 . Therefore, when considering the pathogenesis of renal damage, it is essential to distinguish between the acquired segmental scarring associated with VUR and infection and the primary renal damage seen congenitally whose aetiology is very different and linked to abnormal metanephric development 4,13 …”