Membranous occlusion of the foramen of Monro following ventriculoperitoneal shunt insertion: A role for endoscopic foraminoplasty

We report two cases of lateral ventricle dilatation due to membranous occlusion of the foramen of Monro following ventriculoperitoneal shunt insertion. Both cases were treated successfully by endoscopic foraminoplasty of the obstructed foramen of Monro and III ventriculostomy. One child had meningomyelocele and hydrocephalus. She had CSF infection after repair of the back lesion. Isolated left lateral ventricle occurred after insertion of a right ventriculoperitoneal shunt for hydrocephalus when the girl was 2 months old. A right ventriculoperitoneal shunt was then inserted. Chronic shunt infection with abdominal pseudocyst was found 8 years later. The shunts were exteriorized. Membranous obstruction of the foramen of Monro was found endoscopically. Fenestration of the membranous obstruction along with a III ventriculostomy was performed. After the endoscopic procedure, the exteriorized ventriculoperitoneal shunt was removed 2 weeks later. The patient was still symptom free without shunting 14 months after the operation. The other child had hydrocephalus after a premature birth and hemorrhage. Repeated ventriculoperitoneal shunt infections contributed to membranous obstruction of bilateral foramen of Monro. After the shunt infection was treated this patient's shunting procedure was simplified by endoscopic foraminoplasty of the left and right foramen of Monro along with a III ventriculostomy. He was symptom free with a new ventriculoperitoneal shunt 9 months after the operation.