The role of endoscopic third ventriculostomy in the treatment of triventricular hydrocephalus seen in children with achondroplasia.

The authors of this paper describe two patients with achondroplasia in whom triventricular hydrocephalus has been successfully treated using endoscopic third ventriculostomy (ETV). The authors performed ETVs in two children with achondroplasia involving a moderate macrocranium and enlarged lateral and third ventricles with intermittent clinical evidence of increased intracranial pressure. The endoscopic procedure revealed a significant deformation of the floor of the third ventricle in both patients caused by longstanding hydrocephalus. Because of the anatomical variations such as empty sella and the persistence of the infundibular recess, the ETV procedure became technically demanding. The standard ventriculostomy on the tuber cinereum was not possible. Ventriculostomies were performed on the part of the third ventricular floor that was hanging ventral to the pons. Both patients became symptom free postoperatively, and phase-contrast cine magnetic resonance (MR) imaging studies confirmed the patency and effectivity of the ventriculostomy sites. The authors suggest that ETVs may constitute an alternative for ventriculoperitoneal shunt therapy as the treatment of choice for patients with achondroplasia who have triventricular hydrocephalus and clinical symptoms. Attention should be paid to the shape of the floor of the third ventricle, however, especially in cases of longstanding hydrocephalus. An association of the empty sella or the persistence of the infundibular recess must be carefully evaluated using MR imaging studies before attempting ETVs in such patients.