Bilateral occlusion of the foramina of Monro after third ventriculostomy.

Occlusion of both foramina of Monro following third ventriculostomy is a very rare complication. The authors present the case of a 30-year-old female who underwent endoscopic third ventriculostomy (ETV) for occlusive hydrocephalus due to aqueductal stenosis. Thirty months after the ETV, she reported recurrent headaches. Magnetic resonance imaging demonstrated bilateral enlargement of the lateral ventricles with a collapsed third ventricle caused by bilateral stenosis of the foramina of Monro. Left-sided endoscopic foraminoplasty and stenting of the left foramen of Monro were performed with immediate neurological improvement.