Preoperative imaging contributes to pathologically complete resection of the urachal remnant by determining an appropriate surgical approach without unnecessary and excessive surgical invasion: a retrospective study

BACKGROUND: The urachus is an embryonic structure that connects the bladder to the allantois during early embryonic development. Occasionally, it fails to disappear at birth, leading to a case of urachal remnant (UR). This study aimed to determine whether our policy for selecting an appropriate UR resection approach is valid. We performed preoperative imaging to examine whether UR continued toward the bladder apex. If so, the UR and bladder apex were excised using the trans-umbilical approach, in addition to laparoscopy, if necessary. If preoperative imaging indicated that the UR ended near the umbilicus, the UR from the umbilicus to the duct end was resected. Pathological evaluations were performed to determine the appropriateness of the surgical approach indicated by preoperative imaging. METHODS: We retrospectively reviewed pediatric patients with UR who underwent surgery between 2015 and 2021. Their background characteristics and surgical outcomes were evaluated. RESULTS: Twenty patients with UR were included (median age, 7 [interquartile range, 2–10.25] years). UR continued toward the bladder apex in 10 patients and ended near the umbilicus in 10 patients. Urachus tissue at the bladder site was observed when the UR and bladder apex were excised. When UR was resected from the umbilicus to the duct end, urachus tissue was not pathologically detected at the resection margin. CONCLUSION: Our policy results in complete resection without excessive surgical invasion.