Intraoperative endoscopic video of the lamina terminalis fenestration procedure. The video starts with the neuroendoscope in the third ventricle looking at the tuber cinerum and optic chiasm. After identifying the optic chiasm, the tip of the flexible neuroendoscope is bent anteriorly, the suprachiasmatic recess and the lamina terminalis are identified next. Once in position, with a closed grasping forceps, the lamina terminalis is perforated. The ostomy is slowly enlarged with the grasping forceps or with the neuroendoscope itself. The anterior communicating artery complex and its branches are identified. The ostomy is further enlarged if necessary. The free edges of the ostomy move with the pulsation of the brain indicating CSF flow. The purpose of this second video is to show that the position of the anterior communicating artery may vary, in this case the ostomy was made closer to the artery but still below it.