Fig. 1

Schematic diagram of the surgical procedure. a, b The medial margin of the skin incision was at the supraorbital notch. From the supraorbital notch, about 3 cm incision was considered sufficient for the pericranial flap. After skin retraction, the periosteal layer was dissected superiorly under endoscopic view. An additional incision was made at the point where dissection was not possible due to the natural skull curvature (red line). c, d Through the burr-hole on the supraorbital area, the pericranial flap was inserted in the medial direction via the extradural or intradural pathway. The pericranial flap could cover the sellar and anterior skull base defects