Long-term evolution of renal damage associated with unilateral vesicoureteral reflux

Imaging studies and biomarkers to detect clinically meaningful vesicoureteral reflux

The work-up of a febrile urinary tract infection is generally performed to detect vesicoureteral reflux (VUR) and its possible complications. The imaging modalities most commonly used for this purpose are renal-bladder ultrasound, voiding cystourethrogram and dimercapto-succinic acid scan. These studies each contribute valuable information, but carry individual benefits and limitations that may impact their efficacy. Biochemical markers are not commonly used in pediatric urology to diagnose or differentiate high-risk disease, but this is the emerging frontier, which will hopefully change our approach to VUR in the future. As it becomes more apparent that there is tremendous clinical variation within grades of VUR, the need to distinguish clinically significant from insignificant disease grows. The unfortunate truth about VUR is that recommendations for treatment may be inconsistent. Nuances in clinical decision-making will always exist, but opinions for medical versus surgical intervention should be more standardized, based on risk of injury to the kidney.

Predictive Factors of Chronic Kidney Disease in Patients with Vesicoureteral Reflux Treated Surgically and Followed after Puberty

PURPOSE

We delineated clinical features and determined predictors of chronic kidney disease during long-term postpubertal followup in patients with vesicoureteral reflux treated surgically.

MATERIALS AND METHODS

We analyzed the data of 101 patients who were surgically treated for vesicoureteral reflux and had gone through puberty. Patients underwent preoperative and postoperative voiding cystourethrography to assess reflux status, and dimercaptosuccinic acid scan to assess renal cortical defects. We compared several variables preoperatively and postpubertally, including body mass index; blood urea nitrogen, creatinine and uric acid levels; estimated glomerular filtration rate; microalbuminuria; blood pressure; renal function and renal scarring. Kaplan-Meier analysis was used to predict chronic kidney disease-free survival rates throughout the followup periods. Cox regression model was adopted to identify independent predictors of chronic kidney disease. We defined chronic kidney disease as estimated glomerular filtration rate less than 60 ml/minute/1.73 m(2).

RESULTS

Median followup was 100.0 months (IQR 69.0 to 136.5). Median age was 16 years at last followup (IQR 14 to 18). A total of 11 patients (10.9%) were diagnosed with de novo chronic kidney disease during postpubertal followup. It is noteworthy that serum uric acid levels (HR 1.96) and presence of high grade reflux (HR 7.40) were significant predictors of chronic kidney disease on multivariate analysis.

CONCLUSIONS

In children who were treated surgically for vesicoureteral reflux preoperative uric acid levels and high grade reflux were independent predictors of de novo chronic kidney disease during postpubertal followup. Our results offer valuable information for predicting long-term renal outcomes in patients with vesicoureteral reflux treated surgically.

The relative function of damaged kidneys in children does not deteriorate further at 3-year follow-up

PURPOSE

It is thought that the function of a damaged kidney will deteriorate further with time because of impaired maturation and compensatory hyperfiltration. The aim of this study was to determine changes in relative renal function (RRF) over time in children with vesicoureteric reflux (VUR) and/or urinary tract infection (UTI) where the unilaterally scarred kidney was found to contribute 30% or less to overall function.

PATIENTS AND METHODS

Children who met the inclusion criteria and had multiple radionuclide studies during a 12-year period were identified, and RRF was compared.

RESULTS

Twenty-seven boys and 3 girls with a median age of 0.8 years (0.08-13.05 years) were included. Eight patients had unilateral VUR, 21 patients had bilateral VUR, and 1 patient had UTIs without VUR. Twenty-one patients underwent reimplantation surgery, and 9 were managed conservatively.At a mean follow-up of 2.64 years (0.26-6.77 years), there was a nonsignificant mean decrease in RRF from 19% (11%-28%) to 18% (9%-29%). The mean change in renal function was not affected by the severity of the initial RRF.

CONCLUSIONS

In the medium term, there is no deterioration of RRF of unilaterally severely damaged kidneys associated with either VUR or UTI managed either surgically or conservatively. Boys are at a much greater risk of severe reflux nephropathy.

Predictive risk factors in childhood urinary tract infection, vesicoureteral reflux, and renal scarring management

Approaches to the management of children with urinary tract infection (UTI), vesicoureteral reflux (VUR), and renal scars have been challenged and have become controversial over the past decade. It is difficult to determine when, how, and which patients will benefit from the diagnosis and management of this condition. Therefore, the issues of diagnostic imaging, observation, follow-up, and intervention tend to be decided more on a case-by-case basis, rather than by using an algorithm. Over the past few years, there have been advances in the identification of risk factors that predispose patients with UTI to present with VUR, to develop recurrent UTIs and renal scars, to have deteriorating renal function, to show VUR improvement and/or spontaneous resolution, and to be candidates for and benefit from early surgical intervention.

Risk factors for renal scarring and deterioration of renal function in primary vesico-ureteral reflux children: a long-term follow-up retrospective cohort study

BACKGROUND AND PURPOSE

The aim was to identify the risk factors for renal scarring and deteriorating renal function in children with primary vesico-ureteral reflux (VUR).

MATERIALS AND METHODS

Patients with primary VUR admitted to the National Cheng Kung University Hospital were retrospectively analyzed. The outcomes were renal scarring, assessed by technetium-99 m dimercaptosuccinic acid scanning, and renal function, assessed by estimated glomerular filtration rate. Univariate and multivariate models were applied to identify the corresponding independent predictors.

RESULTS

A total of 173 patients with primary VUR were recruited. The median age of VUR diagnosis was 10.0 months (IQR: 4.0-43.0 months). After adjusting for confounding factors, it was found that older age of VUR diagnosis (≥5 years vs. <1 year, adjusted OR = 2.78, 95% CI = 1.00-7.70, p = 0.049), higher grade of VUR (high grade [IV-V] vs. none, adjusted OR = 15.17, 95% CI = 5.33-43.19, p<0.0001; low grade [I-III] vs. none, adjusted OR = 5.72, 95% CI = 2.43-13.45, p<0.0001), and higher number of UTI (≥2 vs. 0, adjusted OR = 3.21, 95% CI = 1.06-9.76, p = 0.039) were risk factors for renal scarring, whereas a younger age of VUR diagnosis (≥5 years vs. <1 year, adjusted HR = 0.16, 95% CI: 0.05-0.51, p = 0.002), renal scarring (yes vs. no, adjusted HR = 3.66, 95% CI: 1.32-10.16, p = 0.013), and APN (yes vs. no, adjusted HR = 3.10, 95% CI: 1.05-9.14, p = 0.041) were risk factors for developing chronic kidney disease stage 2 or higher.

CONCLUSIONS

Our findings expand on the current knowledge of risk factors for renal scarring and deteriorating renal function, and this information can be used to modify the management and treatment of VUR.

Radiographic evaluation of children with febrile urinary tract infection: bottom-up, top-down, or none of the above?

The proper algorithm for the radiographic evaluation of children with febrile urinary tract infection (FUTI) is hotly debated. Three studies are commonly administered: renal-bladder ultrasound (RUS), voiding cystourethrogram (VCUG), and dimercapto-succinic acid (DMSA) scan. However, the order in which these tests are obtained depends on the methodology followed: bottom-up or top-down. Each strategy carries advantages and disadvantages, and some groups now advocate even less of a workup (none of the above) due to the current controversies about treatment when abnormalities are diagnosed. New technology is available and still under investigation, but it may help to clarify the interplay between vesicoureteral reflux, renal scarring, and dysfunctional elimination in the future.

Chronic pyelonephritis presenting as a renal sinus tumor with retroperitoneal extension: a case report

Introduction

Chronic pyelonephritis is associated with progressive renal scarring and occurs, most of the time, in patients with major anatomical anomalies, including urinary tract obstruction, calculi, renal dysplasia or vesicoureteric reflux. We report the computed tomography imaging findings of a patient with chronic pyelonephritis appearing as a renal sinus mass. To our knowledge, it is the first time that such a case has been published in the literature.

Case presentation

We present a case of a 68-year-old woman who underwent a computed tomography scan of the abdomen in the work-up for recently diagnosed hypertension. A non-enhancing left renal sinus mass was detected extending to the para-aortic space. The initial diagnosis was that of a tumor of the collecting system. Nephro-ureterectomy was performed and the pathology results revealed changes of chronic pyelonephritis.

Conclusion

Chronic pyelonephritis presenting as a renal sinus mass is reported for the first time in the literature. This may lead to the conclusion that diagnostic ureteropyeloscopy and biopsy should be performed prior to radical surgery for possible upper tract urothelial tumors.