Traumatic basilar aneurysm after endoscopic third ventriculostomy: Case report

OBJECTIVE AND IMPORTANCE: This case illustrates thai although endoscopic third ventriculostomy for patients with aqueductal stenosis is successful and minimally invasive, it can have severe, life-threatening complications. CLINICAL PRESENTATION: A 3-year-old girl presented with hydrocephalus and aqueductal stenosis. She underwent endoscopic third ventriculostomy with laser fenestration of the third ventricular floor. During the procedure, she developed a severe intraventricular hemorrhage that required prolonged external ventricular drainage and ultimately ventriculoperitoneal shunting. Despite having a negative angiogram after the procedure, she presented 1 month later with a subarachnoid hemorrhage and a traumatic basilar tip aneurysm. INTERVENTION: The patient underwent a right subtemporal approach with clip ligation of the aneurysm and subsequently had a good recovery. CONCLUSION: Hemorrhagic complications after endoscopic third ventriculostomy are rare. The formation of a traumatic basilar tip aneurysm after this procedure has not been reported in the literature, Laser fenestration of the third ventricular floor may increase the risk of this event.