Anorectal prolapse after anorectal reconstruction: Incidence and risk factors according to the ARM-Net Consortium

There is a knowledge gap regarding which patients with anorectal malformations (ARMs) are at highest risk of anorectal prolapse (AP), and which risk factors predispose to AP in ARM. The aims of the study were to define the frequency of AP after ARM reconstruction, and explore risk factors.

Data from the ARM-Net registry inserted between 2007 and 2023 were used. Inclusion criteria were the reconstruction performed, no stoma at 1-year follow-up and all data available at 1-year follow-up. The statistics used were univariable and multivariable logistic regression models.

After exclusions the incidence of AP was 163 in 1117 patients (14.6%) in data inserted by 31 centres from 12 countries. The AP incidence was unevenly distributed between the centres (interquartile range 6.3%-21.7%). AP was more frequent in boys than girls (20.9% vs. 8.1%; P < 0.001). In both sexes the incidence of AP was higher in complex ARM subtypes (P < 0.001). AP was most frequent after laparotomy- and laparoscopic-assisted reconstructions (50.0% and 37.5%, respectively). Spinal and sacral anomalies constituted risk factors for AP in univariable analyses, while tethered cord did not. Adjusted risk factors for AP were severity of ARM subtype (40% in long-channel cloaca and bladder neck fistula, OR 3.1, 95% CI 1.0-10.2), laparotomy-assisted posterior sagittal anorectoplasty (50%, OR 3.7, 95% CI 1.6-8.4) and larger neo-anus at 1-year follow-up (Hegar 13.6 vs. 13.1; OR 1.2, 95% CI 1.1-1.4). Constipation was not a risk factor for AP.

Anorectal prolapse is a frequent postoperative sequela. Adjusted analyses indicate that severity of ARM, abdominal open access during reconstruction and larger size of anus are risk factors.