Complex Type Split Cord Malformation: A Two-Center Study

Complex spinal dysraphism is the condition where multiple dysraphic pathologies are observed in the same patient. Complex type split cord malformation (SCM) is a compound dysraphic phenotype involving disruptions at multiple developmental stages, characterized by the co-occurrence of SCM and spina bifida aperta. This study aimed to understand the differences between complex SCMs from classical SCM cases in terms of embryological aspects, perioperative management, and follow-up.

Patients with SCM associated with spina bifida aperta who were treated at Dicle University and Kocaeli University, Departments of Neurosurgery, between 2011 and 2025 were included in the study. Patient age (months), gender, presenting clinic, lesion localization, SCM type, number of affected vertebrae, neurological status, presence of tethered cord, presence of kyphoscoliosis, spina bifida aperta type, Chiari malformation, syringomyelia, presence of posterior fusion defect number of vertebrae with defect, hydrocephalus, accompanying intracranial pathologies, and additional anomalies were included in the study.

The study included 44 patients who underwent surgery for complex SCM. Of the patients, 81.8% were operated on during the neonatal period in the same session with spina bifida aperta surgery. Surgery was planned for 11.4% of patients for follow-up purposes and for 6.8% following detection of SCM on MRI performed due to gait disturbances. It was observed that 68.2% of patients were plegic/severely paretic, 22.7% had moderate paresis, and 9.1% had mild paresis/normally. Regarding the type of spina bifida aperta, 72.7% of patients had myelomeningocele, and 27.3% had myeloschisis. Type 1 SCM was detected in 79.5% of patients, type 2 SCM in 13.6%, and type 1.5 SCM in 6.8%. Additionally, 93.2% had tethered cord/thickened-fatty filum terminale, 90.9% had posterior fusion defects, 77.3% had hydrocephalus, 68.2% had kyphoscoliosis, 65.9% had Chiari malformation, 54.5% had syringomyelia, 45.5% had intracranial pathologies other than hydrocephalus, and 4.6% had lipoma.

Complex SCMs should not be viewed solely as a spinal pathology; they should be evaluated multidisciplinarily in the perioperative period in terms of anomalies accompanying spina bifida aperta. In these cases that are diagnosed at a younger age, the incidence of type 1 SCM increases, while the frequency of occurrence in the lumbar region decreases and increases in the thoracic region. Furthermore, it has been determined that additional anomalies accompanying spina bifida aperta occur more frequently with complex SCMs.