Endoscopic third ventriculostomy through the interfornicial space.

Endoscopic third ventriculostomy (ETV) is the most common cranial endoscopic surgery being done worldwide for a variety of conditions resulting in hydrocephalus. We report ETV in a case of congenital hydrocephalus with deficient third ventricular roof and wide interfornicial space. A 6-month-old male child presented with gradual progressive head enlargement and signs of raised intracranial pressure. Computed tomography of the head showed aqueductal stenosis with enlargement of third and lateral ventricles. The patient was operated under general anesthesia with endotracheal intubation. A right coronal burr hole and free-hand entry were made into the right lateral ventricle. The anterior part of the septum and the third ventricular roof were deficient with a narrow Monro's foramen and the third ventricular floor was visible through the space between both fornices. ETV was done in standard fashion. Postoperatively the patient showed uneventful recovery clinicoradiologically. We review the literature and discuss the findings and technique of ETV in this rare entity.