Navigator system-assisted endoscopic fenestration of a symptomatic cyst in the septum pellucidum--technique and cases report.

Expanding cysts of the septum pellucidum are rare and frequently manifest as intermittent headaches. Although the technique of endoscopic fenestration has been used since 1999, only a limited number of cases have been reported. We have added the use of a navigator system to guide keyhole creation and endoscopic access.