Embryological and clinical implications of the association between anorectal malformations and spinal dysraphisms

To describe the association of anorectal malformation (ARM) and spinal dysraphism (SD) in terms of impact on the management of SD and embryogenetic implications. Patients with SD associated with (A) or without (B) ARM were included. The two groups were further divided into operated on (A1/B1) or not (A2/B2) for SD. Groups A and B were compared for type of SD (embryogenetic classification) and prevalence of neurosurgery; Groups A1 vs. A2 for type of ARM (Wingspread classification); Groups A1 vs. B1 for age at neurosurgery, neurophysiology, and clinical symptoms. One hundred twenty-one patients with SD, 83 with and 38 without ARM were consecutively treated (1999-2015). Group A was associated only with SDs developing after primary neurulation, corresponding to the period of cloacal septation and organogenesis (p = 0.0007). Untethering surgery was significantly less frequent in Group A (p < 0.0001 and p = 0.04, respectively). Higher ARMs were not associated with increased risk for neurosurgery. No other significant differences were detected. In our series, ARMs were associated only with SD developing after primary neurulation, suggesting a single insult leading to both SD and the associated ARM. Neurosurgery is indicated less frequently in patients with ARM-associated SD, despite the similar preoperative clinical features.