Voiding Cystourethrography in the Diagnosis of Anorectal Malformations

Abstract

Introduction In a newborn with an anorectal malformation (ARM), it is vital to determine the anatomy of the underlying defect. After a colostomy has been created, distal colostography (DCG) is currently the chosen modality for the detection of fistulas. The role of voiding cystourethrography (VCU) is unexplored. Aim The aim of this study was to analyze the reproducibility of DCG and VCU in assessing the underlying malformation in ARM, and to evaluate any degree of concordance among them. Materials and Methods A retrospective evaluation was undertaken comparing DCG and VCU findings with definitive surgical findings in children who received both investigations for the initial management of ARM. Results In this study, 26 boys were included. Malformations were classified according to Krickenbeck classification. Four boys with perineal fistula were excluded from the analysis, as none of them needed a colostomy; therefore, comparison between both methods was not possible. VCU identified a rectourethral fistula in 12 cases, a rectovesical fistula in 4 cases, and excluded a fistula in 6 cases. VCU was false negative for a rectovesical fistula in one case. VCU showed a vesicoureteral reflux in 16 patients. Results obtained by VCU were compared with DCG. DCG showed a rectourethral fistula in 11 cases, a rectovesical in 3 cases, and excluded a fistula in 6 cases correctly. DCG was false negative in two cases, a rectoprostatic and a rectovesical fistula. The diagnostic accuracy, measuring the sensitivity was 95% in VCU (range: 76.18-99.88%) and 90% (range: 68.30-98.77%) in colostogram. Conclusion VCU can be as accurate as distal colostogram in the evaluation of male patients with ARM. VCU uses a natural orifice, without the need of a colostomy. VCU can be performed as an initial modality to determine the type of malformation and to decide on the type of early surgical management.