Fig. 2.

Illustrations for steps of the multiple onlayers watertight reconstruction in trans-tuberculum approaches. A and B : Intraoperative (A) and sagittal (B) view of the skull base defect. C and D : The complete onlayer sealing of bony defect with FSPs achieved a temporary watertight barrier. E and F : The HAC were injected and layered on the FSPs and surrounding denuded skull base bone along the margin of the FSP. G and H : The consolidated HAC in the dry state was covered by the PNF, and the attachment of the PNF to the denuded bone around the HAC was confirmed. FSP : fibrin sealant patch, HAC : hydroxyapatite cement, PNF : pedicled nasoseptal flap.