Does lamina terminalis fenestration reduce the incidence of chronic hydrocephalus after subarachnoid hemorrhage?

OBJECTIVE: The incidence of chronic hydrocephalus requiring cerebrospinal f luid shunting was analyzed for a prospective series of 52 consecutive patie nts with ruptured cerebral aneurysms who underwent fenestration of the lami na terminalis during early microsurgical aneurysm repair. We hypothesized t hat, by creating an anterior ventriculocisternostomy, fenestration of the l amina terminalis would facilitate cerebrospinal fluid dynamics and decrease the risk of subsequent hydrocephalus. METHODS: Patients were enrolled according to the following criteria: 1) age more than 40 years; 2) admission Hunt and Hess Grade 2 to 4; 3) initial su barachnoid hemorrhage severity of Fisher Grade 3 or 4; and 4) early microsu rgical repair of an anterior circulation aneurysm. RESULTS: The mortality rate in this series was 9.6%. Of the 47 surviving pa tients, 32 (68%) were discharged with a Glasgow Outcome Scale score of 5, 1 0 (21%) with a Glasgow Outcome Scale score of 4, and 5 (11%) with a Glasgow Outcome Scale score of 3. The follow-up period ranged from 12 to 60 months . Chronic hydrocephalus was radiographically and clinically evident in 3.8% of the total population. Shunt surgery was performed for two patients who exhibited symptoms resulting from hydrocephalus, corresponding to 4.2% of t he surviving patients. CONCLUSION: Estimates from the most recently published studies indicate tha t an incidence of chronic post-subarachnoid hemorrhage hydrocephalus (requi ring shunt surgery) of 15 to 20% is representative for an average contempor ary population of patients with aneurysmal subarachnoid hemorrhage. The low er incidence of chronic hydrocephalus observed in this series possibly refl ects the favorable effect of lamina terminalis fenestration on cerebrospina l fluid dynamics.