Purpose or Case Report: The purpose of this study was to determine if concavity of the basiocciput and concavity of the posterior atlanto-occipital membrane are correlated with the need for future hydrocephalus surgical intervention.
Methods & Materials: A retrospective review was performed of brain CTs or MRIs obtained in the first six-months of life among children diagnosed with open myelomeningocele/myelocele who underwent postnatal repair from Jan 2014 through Sep 2022 at a single tertiary care hospital. Radiology assessment by a single neuroradiologist included the basiocciput length, presence and severity of basiocciput concavity and posterior atlanto-occipital membrane concavity, and assessment of hydrocephalus severity, posterior fossa size, Chiari II grade, and presence or absence of ventriculoperitoneal shunting or endoscopic third ventriculostomy/choroid plexus coagulation.
Results: A total of 52 patients met inclusion criteria. Among the 42 patients who underwent surgical intervention, the average radial depth of basiocciput curvature was 2.78 mm (range 1-4 mm) compared to 2.3 mm (range 1-3 mm) without surgical intervention (p-value=0.14). Average curvature of the posterior atlanto-occipital membrane was 2.71 mm (range 0-6 mm) among patients with surgical intervention compared to 2.2 mm (range 0-4 mm) without surgical intervention (p-value=0.36). The size of the posterior fossa area measured on sagittal plane was 10.49 cm2 (range 3-23 cm2) among patients with surgical intervention compared to 14.5 cm2 (range 6-28 cm2) without surgical intervention (p-value=0.006). Average Chiari II grade was 2.28 among patients with surgical intervention compared to 1.9 without surgical intervention (p-value=0.046). The average lateral ventricle atria size on coronal plane was 30.0 mm among patients with surgical intervention compared to 30.1 without surgical intervention (p-value=0.99).
Conclusions: In pediatric patients with Chiari II malformation, the severity of the concavity of the basiocciput and posterior atlanto-occipital membrane were not significantly correlated with future need for VP shunt or ETV/CPC, though concavity of the basiocciput does show a trend towards significance. Future ongoing directions include expansion of this dataset to include analysis of pediatric patients with in utero repaired open spinal dysraphisms.