Frequency and long-term follow-up of trapped fourth ventricle following neonatal posthemorrhagic hydrocephalus.

OBJECTIVE Intraventricular hemorrhage (IVH) is a common complication of premature neonates with small birth weight, which often leads to hydrocephalus and treatment with ventriculoperitoneal (VP) shunting procedures. Trapped fourth ventricle (TFV) can be a devastating consequence of the subsequent occlusion of the cerebral aqueduct and foramina of Luschka and Magendie. METHODS The authors retrospectively reviewed 8 consecutive cases involving pediatric patients with TFV following VP shunting for IVH due to prematurity between 2003 and 2012. The patients ranged in gestational age from 23.0 to 32.0 weeks, with an average age at first shunting procedure of 6.1 weeks (range 3.1-12.7 weeks). Three patients were managed with surgery. Patients received long-term radiographic (mean 7.1 years; range 3.4-12.2 years) and clinical (mean 7.8 years; range 4.6-12.2 years) follow-up. RESULTS The frequency of TFV following VP shunting for neonatal posthemorrhagic hydrocephalus was found to be 15.4%. Three (37.5%) patients presented with symptoms of posterior fossa compression and were treated surgically. All of these patients showed signs of radiographic improvement with stable or improved clinical examinations during postoperative follow-up. Of the 5 patients treated conservatively, 80% experienced stable ventricular size and 1 patient experienced a slight increase (3 mm) on imaging. All of the nonsurgical patients showed stable to improved clinical examinations over the follow-up period. CONCLUSIONS The frequency of TFV among premature IVH patients is relatively high. Most patients with TFV are asymptomatic at presentation and can be managed without surgery. Symptomatic patients may be treated surgically for decompression of the fourth ventricle.