Table 3. Special considerations in the selection of PCF reconstruction of clival dural defects.

Considerations	Descriptions
Are there any better reconstruction options?	Nasoseptal and inferior turbinate flaps should be unavailable.
What is the most appropriate length of PCF for clival defects?	Since clivus is an extended application of PCF, dissection must be directed posteriorly from the bicoronal incision, to be able to harvest the longest possible flap.
Which incision should be used to harvest a PCF?	Since this is an extended application of the PCF, bicoronal incision may be a better choice.
Bilaterally or unilaterally based	Unilaterally based flap should be preferred since it is easier to transfer through ethmoidectomy cavity and has a wider angle of rotation. Bilaterally based flaps are reserved for wider defects.
When should it be harvested, in the beginning or at the end of surgery?	Harvest after scalp elevation is preferred since the vascular supply is better visualized.
What should be the lateral and medial border of the PCF and its pedicle?	Medial border should not pass the midline. Lateral border is the superior temporal line.
Where is the most suitable place to create bony window to transfer PCF into nasal cavity?	Just inferior to glabella at nasofrontal junction, at least 10 mm height and 15 mm width to protect pedicle from compression.
What are the additional surgeries necessary to transfer PCF to the clivus?	Total ethmoidectomy should be on the ipsilateral side with the flap. The mucosa should be removed to expose bone. Either an extended Draf-II or Draf-III frontal sinusotomy can be performed in unilaterally based flaps, whereas Draf-III must be performed in bilaterally based flaps.

Abbreviation: PCF, pericranial flaps.