gms | German Medical Science

Objective: While endoscopic management of midline arachnoid cysts has emerged as the treatment of choice in recent years, the body of knowledge on tailoring the approach to individual aspects of these lesions and on the outcome is still slim and distributed among case reports and small series.

Methods: Retrospective evaluation of a single-institution series of patients with midline arachnoid cysts treated consecutively with endoscopic procedures from 1996 to 2018.

Results: Of 85 patients treated, 79 were under 18 years of age. In 30 cases, the cyst originated in the interhemispheric fissure. 24 of these were under 2 years of age. Males predominated with 20 cases. The cysts became symptomatic with cyst size progression, accelerated head circumference growth and signs of ICP elevation that were caused by CSF pathway obstruction in half of the cases. Treatment requires fenestration among cyst compartments and towards the ventricular system. 6 patients needed stents, ventriculo- or subdural shunts. 37 patients had suprasellar cysts, 33 of which were pediatric cases with an average age below 4 years and no gender preponderance. Most patients became symptomatic with hydrocephalus due to obstruction of the Foramen of Monro, one third had endocrine symptoms. The latter deficiencies remained unchanged, the CSF obstruction was resolved in all cases, but 4 infants needed shunting despite of that for remaining communicating hydrocephalus. The remaining cysts were located in the quadrigeminal cistern (12 cases), the transverse fissure (2 cases) and midline retrocerebellar (4 cases). Salient features of these locations will be detailed as well. One quadrigeminal cyst recurred and needed a second endoscopic fenestration. Overall, complication rate was low and no mortality or permanent morbidity occurred. 75 patients remain shunt-free.

Conclusion: Endoscopic treatment of midline arachnoid cysts is efficient with low complication rate and excellent outcome.