Correlation of Renal Scarring to Urinary Tract Infections and Vesicoureteral Reflux in Children

Abstract

Objective. To study the association of the grade of vesicoureteral reflux (VUR) and urinary tract infections (UTI) with renal scarring at the first clinical presentation of patients who underwent antireflux surgery. Materials and methods. Between 2015 and 2020, 150 patients (194 units) who underwent antireflux surgery had dimercaptosuccinic acid (DMSA) renal scans preoperatively. Patients were classified into the nonscar and scar groups according to DMSA scan results. Moreover, cases were classified into afebrile UTI, febrile UTI, and antenatal hydronephrosis (ANH) according to the mode of presentation. We correlated the mode of presentation and the grade of VUR to the presence/absence of renal scars in both groups. Results. The mean follow-up was 45 months preoperatively. The mode of presentation was afebrile, febrile UTIs, and antenatal hydronephrosis in (50, 14), (20, 46), and (10, 10) patients in the nonscar and scar groups, respectively. Of the 20 patients who presented ANH, 10 (50%) had scars. Clinical presentation was correlated to the presence of renal scarring and its degree. The scar group had significantly higher grades of VUR than the nonscar group (grades I–II (50 units versus 10 units), grade III (28 units versus 40 units), and grade IV–V (22 units versus 44 units) for the nonscar versus scar groups, respectively ( p value <0.001). Conclusion. Renal scarring is associated with higher grades of reflux and urinary tract infections. We advocate further research investigating infants who had UTIs with or without fever for early detection of reflux.

Risk factors for new renal scarring in children with vesicoureteral reflux receiving continuous antibiotic prophylaxis

“…After receiving an intravenous injection of 22.2–185.0 MBq imaging agent (1.85 MBq/kg body weight) for 3–4 h, children were placed in the supine position, and static imaging in the anteroposterior view was performed using a low-energy high-resolution parallel-hole collimator with a field of view that included both kidneys and the bladder, energy peak 140 keV, window width 20%, matrix 512 × 512, magnification 2.19, and radioactivity count 1.8 × 106. The 99mTc-DMSA renal imaging protocol and result assessment followed the clinical guideline of the Society of Nuclear Medicine and Molecular Imaging 10 , 11 . The time between index UTI and first DMSA was 1 (0.6) months.…”

“…The percentage of renal function on each side (differential renal function) was calculated by delineating the kidney regions of interest and background using computer, and a differential renal function greater than 10% was considered renal impairment. One or more focal radioactivity reductions or defects in the renal cortex, with contraction or volume reduction of the affected cortex, or wedge-shaped defects denoted renal scarring 11 . NRS was defined as the occurrence of new renal scarring or aggravation of existing renal scarring on a DMSA re-scan while receiving CAP 11 (Fig.…”

“…One or more focal radioactivity reductions or defects in the renal cortex, with contraction or volume reduction of the affected cortex, or wedge-shaped defects denoted renal scarring 11 . NRS was defined as the occurrence of new renal scarring or aggravation of existing renal scarring on a DMSA re-scan while receiving CAP 11 (Fig. 2 ).…”

Efficacy and safety of Hyadex for treatment of vesicoureteral reflux: a multicenter experience

“… 1 Approximately 30% of children with urinary tract infections (UTIs) are diagnosed with VUR, and such children may experience recurring UTIs and long-term renal scarring. 2 There are several possible causes of VUR, including congenital anomalies at the ureterovesical junction, pathological conditions that may cause voiding dysfunction, or illnesses that disturb the function of the ureterovesical junction or bladder. 3 Voiding cystourethrography (VCUG) is the imaging modality of choice for diagnosing VUR, and the diagnosis is confirmed by observing the movement of contrast dye through the ureters and kidneys.…”