Subdural Fluid Collection Following Ruptured Aneurysm Surgery as a Manifestation of Disturbed Cerebrospinal Fluid Circulation

Park, Hyeon Seon; Kim, Sun Ho; Lee, Kyu Chang

Abstract

The authors analyzed 197 consecutive cases of ruptured aneurysm surgery and investigated the incidence of postoperative subdural fluid(SDF) collection according to patient's age, amount of subarachnoid hemorrhage, preoperative ventricular dilatation, and combined surgical procedures such as ventricular or spinal fluid drainage, and opening of the lamina terminalis and/or the Lilliequist's membrane. We also evaluated the postoperative course for each patient with regard to the development of hydrocephalus. The results were as follows; incidence of SDF collection after aneurysm surgery was 20.8% and it correlated well with patient's age, initial CT grade, preoperative ventricular dilatation and opening of major cerebrospinal fluid(CSF) space. Especially, in patients with a preoperative dilated ventricle that had not been corrected(with preoperative shunting procedure), the incidence of postoperative SDF collection was very high(53.8%). In contrast, postoperative SDF collection didn't develop in six patients whose ventricle had dilated and it had been corrected with preoperative shunting procedures(two cases) or intraoperative external ventricular drainage followed by internalization(four cases). Patients wth postoperative SDF collection had a higher incidence of hydrocephalus than the other group. Hydrocephalus developed more frequently in the large SDF collection group than in the small one. On the basis of the above findings, we presumed postoperative SDF collection to be a manifestation of disturbed CSF circulation in ruptured aneurysm surgery. Because of the risk of rebleeding after preoperative shunting procedures, intraoperative diversion of CSF followed by early internalization should be recommended for preventing the development of postoperative SDF collection in patients with disturbed CSF circulation. We also discussed possible mechanisms of the conversion of postoperative SDF into hydrocephalus in relation to disturbed CSF circulation.