Imaging Characteristics of Pre-operative Augmented Pressure Colostography in Anorectal Malformations without a Perineal Opening

Anorectal Malformations without a Perineal Opening

Abstract

Accuracy in diagnosing an internal fistula between the rectum and adjacent organs by transanal contrast catheterization in patients with congenital rectal malformations is critical for planning corrective surgery. The objective of this diagnostic research was to investigate pre-operative predictive fluoroscopic characteristics of the internal fistulas in children with imperforate anus. From January 2009 to December 2022, a total image of 45 children with anorectal malformation (ARM) without a perineal opening underwent augmented pressure colostography prior to corrective surgery were reviewed. Diagnostic types were done according to Krickenbeck classification. Differential imaging features between surgically proven fistula and non-fistula groups were analyzed using multivariable regression models. Twenty-nine out of 45 children with ARM had surgically confirmed fistulas. Fluoroscopic features including beak appearance of the rectal pouch, high-type ARM, and visible fistula were identified as significant variables for predictive fistula, contributing to two prediction models. It was found to have a high accuracy in diagnosing internal weld penetrations (AUC = 0.95, 95%CI 0.89-1.00). When comparing the predictions with the model using all characteristics, it was found that the accuracy decreased slightly (AUC = 0.97, 95%CI:0.93-1.00). It can be concluded that specific diagnostic imaging characteristics, including beak appearance of the rectal pouch and high-type ARM, help to predict the diagnosis of internal fistulas between the blocked rectum and adjacent organs with high accuracy. Although no radiopaque substance was detected through the weld hole