Slit ventricle syndrome (SVS) is a delayed complication of shunt insertion and occurs only in children with slitlike ventricles after shunt placement. Although SVS appears to be related to early shunt placement, its predisposing factors are largely unknown.
Baseline data in 737 children who had received shunts were obtained from the databases of two previous clinical trials. Ventricular size before shunt placement and at the last routine follow up was measured using the fronto-occipital horn ratio (FOHR). Ventricles with an FOHR less than or equal to 0.2 at follow up were classified as slitlike ventricles. A univariate analysis was performed on data obtained in children with more than 1 year of clinical and radiographic follow up to identify risk factors for developing slitlike ventricles. These results were entered into a multivariate analysis to identify independent predictors of slitlike ventricles.
Two hundred forty-four children had more than 1 year of clinical and radiographic follow-up data. The 23 patients (9.4%) who developed slitlike ventricles had shunts inserted at a younger age (42 compared with 134 days, p = 0.09) and were more likely to have developed hydrocephalus secondary to infection (37.5%), head injury (25.0%), or aqueductal stenosis (22.2%). Slitlike ventricles were seen in 10.8% of patients with differential-pressure valves, 10.5% of patients with Delta valves, and 3.6% of patients with Orbis-Sigma valves (p = 0.007). Regression analysis supported the role of the valve type in developing slitlike ventricles.
Age at shunt insertion and valve type appear to be the modifiable risk factors for developing slitlike ventricles. If the authors of subsequent studies can further validate these conclusions, slow-draining valves and delayed shunt insertion might be used to decrease the incidence of slitlike ventricles and SVS.