A retrospective case cohort study of managements and outcomes of pediatric patients with intracranial arachnoid cysts

Background: Intracranial arachnoid cysts are benign developmental lesions with CSF-like fluid collection inside. As the exact pathogenesis and natural history are still unclear, there has been no treatment guideline of intracranial arachnoid cysts so far.Methods: We have analyzed medical records of pediatric patients below the age of 14 years old with intracranial arachnoid cysts managed in our department from January 2011 to September 2016. A total of 134 cases were enrolled in this study. We have investigated and discussed the clinical data with a literature review. Results: 134 pediatric patients were admitted in our department in the past 5 years, aged 1 month-14 years (averaged 5.3 years). Surgeries were performed in 91 cases, of which 71 cases underwent cyst fenestration or resection, 17 cases received cystoperitoneal shunt and 3 cases underwent subdural drainage. 70 cases (77%) were symptom-free after surgeries or had minor complaints at follow-up. Notably, 9 cases (6 cases under 2 years old, 3 cases older than 2 years old) undergoing prior cyst fenestration or resection developed hydrocephalus and/or subdural hygroma that necessitated secondary shunt surgeries, and 2 cases treated with primary CP shunt developed shunt dependency 2 and 4 years later respectively, which was resolved by keyhole resection of the shrunken cyst walls. 18/23 children with giant intracranial arachnoid cysts who were diagnosed incidentally without any definite symptom had satisfactory outcomes after surgical interventions. Conclusions: CP shunt with a programmable valve is recommended for patients aged 2 years or below with giant arachnoid cysts. Shunt dependency syndrome after CP shunt could be resolved by minimally invasive resection of the shrunken cyst wall. Giant intracranial arachnoid cysts, even lack of symptoms, could be considered for surgical interventions.