Endoscopic approach for quadrigeminal cistern arachnoid cyst.

Objectives Quadrigeminal cistern arachnoid cysts (QCACs), which are usually asymptomatic and may be accidental findings during radiological evaluation, are rare, comprising 5-10% of all intracranial arachnoid cysts (ACs). We report a series of eight patients with QCACs treated with neuroendoscopic intervention and try to discuss the different endoscopic approaches according to the different types of QCACs. Materials and methods Between October 2007 and January 2013, eight patients affected by QCACs were endoscopically treated. All the endoscopic procedures were completed uneventfully (infratentorial approaches in four cases and supratentorial approaches in four cases), which included ventriculocystostomy in seven cases (lateral ventriculocystostomy in one case, third ventricle cystostomy in five cases and both in one case), endoscopic third ventriculostomy in three cases and cystocisternostomy in one case. Results Five patients achieved complete cure after the endoscopic procedure alone; nevertheless, in none of the patients did the cyst totally collapse following the endoscopic procedure during follow-up. The number of episodes decreased significantly even after cessation of all medications and headache disappeared in one patient and the two patients who had unsteady gait together with visual complaints showed remarkable improvement. Conclusion QCAC is one kind of pineal region ACs and it is advisable to plan the operative approach before the endoscopic procedure according to the different types of pineal region ACs. Pineal region ACs and the associated hydrocephalus can be successfully treated with simple, minimally invasive endoscopic procedure.