To estimate intracranial volume-buffering capacity in the event of shunt occlusion, the reexpandabilty of the lateral ventricles and clinical manifestations were examined in shunt-dependent hydrocephalic children.Material and methods
This retrospective study was performed in 38 children who displayed acute deterioration due to spontaneous shunt obstruction. At the time of shunt obstruction, patients with small lateral ventricles [small ventricle (SV) group: Evans' index ≤35, n=13] showed significantly more rapid deterioration into lethargy after onset than those with large lateral ventricles [lateral ventricle (LV) group: Evans' index >0.35, n=25]. All patients in the SV group were 3 years or older at the time of shunt obstruction or had a long period (5.2 years) between initial shunting and shunt occlusion. Their Evans' index was less than 0.33 prior to shunt obstruction.Conclusions
While a shunt is functioning, the factors predictive of reduced ventricular reexpandability include (1) a lateral ventricular size smaller than 0.33 on the Evans' index and (2) either an age of more than 3 years in children who have undergone initial shunting at less than 1 year of age or over 5 years of the period after initial shunting.