Endoscopic options in the management of isolated fourth ventricles

Isolation of the fourth ventricle is occasionally observed after shunt treatment of the lateral ventricles for obstructive panventricular hydrocephalus. Of the various surgical options currently available, placement of shunts in the fourth ventricle has remained as the mainstay of treatment. These shunts are difficult to place, however, and have been associated with higher complication rates. With the advent of neuroendoscopic techniques, the treatment of this condition has shifted from shunt therapy to endoscopic third ventriculostomy (ETV) and aqueductal reconstruction. The authors report on four patients (age range 11-28 years old) who had undergone fourth ventricular shunt placement earlier in childhood to treat panventricular hydrocephalus and who presented with an isolated fourth ventricle (IFV) during the follow-up period. All patients underwent magnetic resonance imaging to identify the extent of the stenosed aqueduct. Symptoms improved in all and the size of the fourth ventricle decreased as well, indicating a functioning stent. The ETV failed in two patients, however, and they required placement of a ventriculoperitoneal (VP) shunt. Aqueductal stenting with an ETV or a VP shunt is a promising option in the management of IFVs.