Abstract
The cervical syrinx cavity in a 27-year-old male with Chiari 1 malformation was inspected with a flexible small-caliber endoscope during syringosubarachnoid shunting. A cleft was observed in the midline on the ventral wall of the cavity, from which blood vessels emerged and ran along the wall. Several strands accompanying the blood vessels passed from one wall to another. The endoscope was also used to evaluate whether any obstacles to the passage of a shunt tube were present in the subarachnoid space. Endoscopic observation of the syrinx cavity is helpful in performing the shunt operation.