Patterns of spinal cord malformation in cloacal exstrophy

The objective of this study was to assess the prevalence and spectrum of spinal dysraphism in a cohort of children with cloacal exstrophy (CEX) using MRI.

Children with CEX presenting between 1999 and 2019 with baseline spinal MRI were included. The images were reviewed in consensus to assess the type of dysraphism. The dysraphisms were initially reviewed and described based on their descriptive anatomy, and then classified according to anomalies of gastrulation, primary neurulation, or secondary neurulation.

Thirty-four children were included. Thirty-three of these children had closed spinal dysraphism, and 1 had a normal spine. Of the 33 cases of closed spinal dysraphism, the conus and/or filum terminale were involved in all cases. The most common malformations were spinal lipoma (n = 20) and terminal myelocystocele (n = 11). The lipomas were heterogeneous: 4 dorsal, 9 transitional, 4 chaotic, and 3 terminal. A large subgroup (10/20, 50%) within the lipomas had an unusual morphology of noncontiguous double lipomas, the proximal fat related to the conus and the distal fat within the filum. These were difficult to characterize using existing classifications. In 2 cases, only a thickened filum was noted. The majority of these malformations were compatible with a disorder of secondary neurulation.

Complex spinal dysraphisms are consistently associated with CEX. The unusual dysraphism patterns found in this group of patients highlight the limitations of current embryological classifications. Given the propensity for neurological deterioration in this group of patients, spinal MRI should be routinely performed. The type and distribution of malformations seen have implications for the wider understanding of the pathogenesis and classification of lumbosacral lipomas.