SPINAL DYSRAPHISM DETECTED BY MAGNETIC-RESONANCE-IMAGING IN PATIENTS WITH ANORECTAL ANOMALIES - INCIDENCE AND CLINICAL-SIGNIFICANCE

Though the concept of caudal regression, suggested in 1961 by Duhamel, could explain the association between anorectal anomalies (ARA) and s pinal dysraphism (SD), its real incidence may be underestimated and it s clinical significance is debatable. From 1988 to 1993, 111 patients with ARA were treated at the authors' institution. Associated anomalie s were present in 36% of cases, with the exception of vesicoureteral r eflux, which was considered functional rather than anatomical. In view of the late (1 to 2 years after surgical treatment) onset of vesical dysfunction and/or orthopaedic symptoms in some of these patients, a s creening protocol was started in 1991, using magnetic resonance imagin g (MRI) in all patients with ARA. Fifty patients, 29 boys and 21 girls , underwent a spinal cord MRI, with pathological findings in 25 cases (50%), 13 boys and 12 girls. The authors did not find any significant difference in incidence with respect to high, low, or cloacal malforma tions. A thickened filum, with or without fibrolipoma, was the most fr equent finding, but even tethered cord, syringomyelia, and sac morphol ogical alterations were present. MRI was also able to detect osteoarti cular and/or muscular anomalies. Even when a urodynamic study and a ne urological and orthopaedic workup were performed in 20 patients underg oing MRI, the clinical significance of these findings remained unclear . However, accurate follow-up of these patients is mandatory in order to detect early neurological symptoms, because currently it is not adv isable to refer for neurosurgery all the patients with ARA presenting with anomalies of the spinal cord.