Clinical utility of voiding cystourethrogramfollowing kidney abscess in children.

Abstract

Abstract Background: Limited research on paediatric kidney abscesses exists, and international guidelines on whether this should be an indication for systematic voiding cystourethrogram (VCUG) are lacking. This study evaluates VCUG’s clinical utility after initial kidney abscess presentation in otherwise healthy children. Methods: This retrospective study included all children presenting to a tertiary paediatric reference centre with a first kidney abscess over one decade (2011-2022). Results: Among the 17 patients (median age 9 months, IQR; 6 months-6 years), VCUG identified vesicoureteral reflux (VUR) in five (29%; 95%CI: 13-53%), including two with grade IV-V. Treatment consisted of 10-21 days of intravenous antibiotics (5 days of bitherapy) followed by oral treatment for 2-6 weeks. Median abscess size was 19mm (IQR; 14-27). 8/17 (47%) children presented focal areas of hypoperfusion on ultrasound, including one case of renal atrophy. Three of six children with DMSA scan showed hypofunctioning (33-44%), and one had a non-functioning kidney. The proportion of children with scars on the DMSA scan was similar, regardless of identified VUR. Seven children had subsequent pyelonephritis; three with uropathy underwent surgery (one circumcision, one ureteric reimplantation, and one nephrectomy). 10/17 had no subsequent pyelonephritis, including three with VUR grade I-III. Conclusions: Among initial kidney abscess cases, 29% had VUR, similar to children experiencing their first uncomplicated pyelonephritis. Surgery was mainly indicated for recurrent pyelonephritis with kidney scarring, regardless of VCUG results. Conversely, VCUG guided prophylactic antibiotherapy. We recommend employing similar VCUG indications for pyelonephritis or abscess after a second febrile UTI or if imaging suggests high-grade VUR or kidney scaring.