Spinal cord anomalies in children with anorectal malformations: Ultrasound is a good screening test.

PURPOSE: The purpose of this study is to correlate spinal ultrasound (US) and magnetic resonance imaging (MRI) findings in patients with anorectal malformations (ARMs).

METHODS: A retrospective analysis of records was performed for children with ARM presenting to two major pediatric hospitals between 2009 and 2017. The primary outcome analyzed was detection of spinal cord anomalies. Spinal US was performed up to 4 months and MRI within the first year of life. The conus medullaris was considered normal if it had a tapering contour and terminated at or above the Lumbar 2-3 disk space.

RESULTS: One hundred ninety-three patients with ARM presented during the study period with a slight male preponderance (108, 56%). Spinal imaging was performed in 157(82%) - 137(87%) had US, 64(41%) had MRI and 44 (28%) had both. Of the 44 who had both; US was abnormal in 25 children-confirmed by MRI in 20 (80%). US was normal in 17 children- MRI showed a filum cyst in 1 and a lipoma in 2 children and was inconclusive in 2 children (p<0.001). All who required surgery except one child, were reported on spinal US to have a low lying cord, borderline low cord or tethered cord (p<.05). No child who was reported to have a normal spinal US required de-tethering at a later stage. Spinal US had an overall sensitivity of 91% and specificity of 75% compared to MRI for detecting spinal cord anomalies in children with ARM CONCLUSIONS: Spinal US performed in a tertiary pediatric imaging department was a good screening test for spinal cord anomalies in children with ARM. The finding of a low, borderline low or tethered cord on US mandates an MRI to confirm the findings and correlates with the need for operative correction of spinal cord tethering.

STUDY TYPE: Clinical research paper.

LEVEL OF EVIDENCE: 2.