Unilateral endoscopic fenestration for symptomatic cavum septum pellucidum cysts without hydrocephalus: a pediatric case series and surgical considerations

BACKGROUND: Cavum septum pellucidum (CSP) cysts are uncommon and usually asymptomatic midline lesions. While surgical management is well established in the presence of hydrocephalus, the indication for treatment in patients with symptoms but without hydrocephalus remains controversial. METHODS: We retrospectively reviewed three pediatric patients with lasting clinical manifestations and CSP cysts without hydrocephalus. They underwent a neuronavigation-assisted unilateral endoscopic fenestration between 2017 and 2024. Clinical and radiological outcomes were assessed, including interwall distance measured on MRI scans. RESULTS: All patients presented with headaches, associated with neurobehavioral symptoms in two cases. Interwall distance decreased in all patients, with a sustained mean reduction of 69.1% one year after the surgery. Clinical symptoms improved in all cases, with complete resolution of headaches. Mean follow-up was 2.8 years, with no recurrence. CONCLUSION: Unilateral neuronavigation-assisted endoscopic fenestration appears to be a safe and effective minimally invasive treatment option in selected pediatric patients with clinically manifest CSP cysts without hydrocephalus.