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Idiopathic fourth ventricle outlet obstruction successfully treated by endoscopic third ventriculostomy: a case
Yukitomo Ishi1, Katsuyuki Asaoka2, Hiroyuki Kobayashi3
1Department of Neurosurgery, Teine Keijinkai Hospital, 1-40, Maeda 1-12, Teine-ku, Sapporo, 006-8555 Japan ; Department of Neurosurgery, Hokkaido University Graduate School of Medicine, North 15 West 7, Kita-ku, Sapporo, 060-8638 Japan.
Introduction:
Fourth ventricle outlet obstruction (FVOO) is a rare cause of obstructive hydrocephalus. We describe a case of idiopathic FVOO that was successfully treated with endoscopic third ventriculostomy (ETV).
Case Report:
A 3-year old boy without any remarkable medical history presented with a headache and vomiting. Computed tomography (CT) images, which had incidentally been taken 2 years previously due to a minor head injury, showed no abnormality. Magnetic resonance imaging on admission showed tetra-ventricular hydrocephalus associated with the dilatation of the fourth ventricle outlets, without any obstructive lesions. However, CT ventriculography, involving contrast medium injection through a ventricular catheter, suggested mechanical obstruction of the cerebrospinal fluid (CSF) at the fourth ventricle outlets. Thus, the patient was diagnosed with FVOO and ETV was performed; the hydrocephalus was subsequently resolved. Although hydrocephalus recurred 1 year postoperatively, re-ETV for the highly stenosed fenestration successfully resolved this condition.
Conclusions:
ETV should be considered for FVOO treatment, particularly in idiopathic cases without CSF malabsorption.
