"Why children with anorectal malformations need urological evaluation: Insights from a retrospective study"

Traditionally, patients with high anorectal malformations (ARM) are considered to have a worse associated urological functional prognosis and are actively managed in pediatric urology units. However, the evidence supporting this risk-based stratification remains limited. This study aimed to determine whether the height of the malformation or the presence of associated anomalies influences the risk of lower urinary tract dysfunction (LUTD) in a large cohort of children with ARM, in order to assess the need for systematic urological surveillance.

We conducted a retrospective cohort study of ARM patients followed by the "Multidisciplinary URIMAR clinic" (pediatric colorectal and urology) from January 2017 to December 2024. Demographic and clinical data, as well as current bladder function, were collected from medical records. Patients with cloacal malformations were excluded. Patients were divided into groups according to the presence of dysraphism and height of ARM. Bivariate analyses were performed using LUTD symptom variables (DVISS), urodynamic tests (both invasive and non-invasive), and treatment requirements.

From a general registry of 108 patients with ARM, a total of 58 (63.8% male) patients met inclusión criteria. Spinal anomalies and congenital anomalies of kidney and urinary tract (CAKUT) were present in 27.5% and 41.3% of patients, respectively. Urinary symptoms were reported in 41.4% of patients, most commonly urinary hesitancy (19%), daytime incontinence (15.5%), and urinary urgency (12.1%). Urodynamic abnormalities were found in 55.1%, with plateau curve being the most frequent finding (93%) followed by significant postvoid residue (40.6%) and electromyographic activity (15.6%). Notably, 72% of asymptomatic patients showed abnormal flowmetry. No significant differences in the prevalence of urinary symptoms (p = 0.392), urodynamic abnormalities (p = 0.501), or pharmacological requirements (p = 0.512) were observed according to the height of the malformation. Similarly, no significant differences were found according to the presence of spinal anomalies in the prevalence of urinary symptoms (p = 0.52) or urodynamic abnormalities (p = 0.448). However, patients with ARM and spinal defects were more likely to require clean intermittent catheterization (p = 0.02) and showed a tendency toward requiring anticholinergic drugs (p = 0.1).

LUTD was observed across all anatomical subtypes of ARM, including patients with low malformations and no spinal dysraphism. Although the severity of LUTD was magnified by the presence of spinal anomalies, no anatomical subtype guaranteed normal bladder function. Notably, almost 50% of asymptomatic patients with a normal spine exhibited abnormal uroflowmetry patterns. These findings challenge the traditional risk stratification based on malformation height and support the universal indication for urological follow-up in all patients with ARM, regardless of anatomical subtype or the presence of spinal defects.

LUTD constitutes a fundamental concern for the entire population of children with ARM, regardless of the height of malformation. Although patients with associated spinal anomalies face a disproportionately higher risk, the absence of such anomalies does not rule out the possibility of LUTD. These findings support the implementation of systematic and mandatory urological surveillance programs for all ARM patients to ensure early detection and intervention.