A case of rapid deterioration in a subacute period after endoscopic third ventriculostomy

Background: Although generally a safe procedure, serious postoperative complications after endoscopic third ventriculostomy (ETV) for obstructive hydrocephaly have been rarely reported, such as delayed obstruction of the stoma at the third ventricle floor.Case description: A 20-year-old male was referred to our department because of severe headache and diplopia. A pineal tumour and obstructive hydrocephaly were detected in preoperative imaging. After tumour biopsy and ETV, the reduction of ventricle size and improvement of headaches were immediately observed. On the seventh day, however, he developed a rapidly progressing consciousness disturbance due to severe hydrocephalus leading to urgent secondary ETV. The original ventriculostomy stoma at the third ventricle floor was completely occluded by scar adhesion. The patient recovered well as previously and received additional treatment.Conclusion: Although very rare, occlusion of the ventriculostomy stoma can postoperatively occur in the subacute period. Patients undergoing ETV for obstructive hydrocephalus due to a pineal tumour should be carefully monitored to avoid serious consequences.