Arachnoid Cysts Associated With Subdural Hematomas And Hydromas: Analysis Of Treatment, Long-term Follow-up, And Cause Of Disease

OBJECTIVE: Subdural hematomas and hygromas are infrequently encountered complications of arachnoid cysts of the middle cranial fossa and are particularly rare with cysts of other regions. Reports in the literature focus on casuistic observations. Therapeutic recommendations often include fenestration or extirpation of the cyst wall, in addition to evacuation of the space-occupying lesion. This study evaluates the results of and rationale for fenestration and extirpation of the cyst wall. METHODS: 10 cases of complicated arachnoid cysts with subdural hematomas or hygromas, were analyzed retrospectively together with 10 other cases with simple arachnoid cyst. Additionally, magnetic resonance imaging scans from these patients with arachnoid cysts, were reviewed for signs of hemorrhagic complications. RESULTS: chronic subdural hematomas or hygromas were found in 2.43% of patient with arachnoid cysts of the middle cranial fossa. This indicated a 0.04% prevalence of arachnoid cysts with chronic subdural hematomas or hygromas. Only two patients with untreated cysts showed signs of hemorrhage in magnetic resonance imaging scans. An excellent or good therapeutic result was achieved with evacuation of the subdural fluid by drainage or craniotomy in 1 case and with evacuation of the subdural fluid and fenestration of cyst wall by craniotomy in 9 cases. No additional symptoms from the arachnoid cysts occurred in a follow-up period of up to 3 yearsafter therapy.CONCLUSIONS: we generally consider it necessary to perform cyst fenestration atthe time of drainage of a hematoma or hygroma in previously asymptomaticarachnoid cysts. Fenestration of cyst wall is a better therapy compared withextirpation.