Diagnostic accuracy of ascending cystourethrogram for localising recto-urinary fistulas in non-colostomized male neonates with high anorectal malformations: Cairo University paediatric surgery experience

Accurate preoperative identification of recto-urinary fistulas in male neonates with high anorectal malformations (ARMs) is essential for surgical planning, especially when considering single-stage repair. The ascending cystourethrogram (ACU) provides a simple, minimally invasive approach that eliminates the need for a preliminary colostomy. This study explored the feasibility and early clinical value of ACU in defining recto-urinary fistula anatomy in selected neonates. This prospective study included 35 male neonates with high ARM who underwent ACU before definitive repair. The presence and level of recto-urinary fistulas were recorded and compared with intraoperative findings. When imaging did not demonstrate the fistula, distal colostography was performed to confirm the diagnosis. ACU identified recto-urinary fistulas in 30 of 35 neonates (85.7%; 95% CI: 70.6–94.1%). Detected fistulas included recto-bladder neck (14.3%), recto-prostatic (42.9%), and recto-bulbar (28.6%) types. In five cases (14.3%), a fistula was not visualised on ACU; however, distal colostogram confirmed the diagnosis in four. Relative to intraoperative findings, ACU demonstrated a sensitivity of 85.7% and a positive predictive value of 100%. ACU is a reliable, minimally invasive, and readily available technique for early localisation of recto-urinary fistulas in male neonates with high ARM, demonstrating close correlation with intraoperative findings. It can be safely performed within the first 24 h of life, enabling prompt anatomical assessment and supporting the appropriate selection of candidates for single-stage repair. These findings reinforce ACU’s role as a practical first-line diagnostic tool in the management of high anorectal malformations.