Endoscopic Fenestration of Suprasellar Arachnoid Cyst: Preoperative Aqueductal Peak Flow Change without Hydrocephalus

An 8-year-old patient presented with mild headaches and was diagnosed with a suprasellar arachnoid cyst (SAC). Patency of the cerebral aqueduct was confirmed using cine magnetic resonance imaging (MRI), and the patient was initially managed with outpatient observation without surgical intervention. However, with worsening headaches and the new onset of bitemporal hemianopsia, a sudden increase in aqueductal peak flow was detected on follow-up cine MRI. Notably, no change in cyst volume or evidence of hydrocephalus was observed on the second MRI. Endoscopic surgery was subsequently performed via the right Kocher’s point, and both the rostral and caudal membranes of the SAC were fenestrated. Following the procedure, the patient’s symptoms improved, and normalization of aqueductal peak flow was confirmed on postoperative cine MRI.