Table 1. Clinical features of the patients, their clival dural defects, and PCF.

Patient	Age	Primary diagnosis	Prior treatments	Number of prior unsuccessful CSF leak surgeries	Indication for PCF	Prior radiation therapy	Frontal sinus surgery	Lumbar drain	PCF side	Width of clival dural defect (cm) a	Length of the clival dural defect (cm) a	Level of the inferior border of the clival defect	Estimated length of PCF needed (cm) a b
1	14	Recurrent Chordoma	Chordoma surgery, CSF leak surgery	1	CSF leak (failed graft)	Yes	N/A	Yes	Right	2,15	1,99	Inferior border of C1	17.74
2	22	Recurrent Chordoma	Chordoma surgery, CSF leak surgery, RT	1	CSF leak (necrotic ITF)	Yes	Draf-II	Yes	Right	1,77	3,28	Inferior one third of clivus	18.99
3	8	Primary Chordoma	CSF leak surgery	2	CSF leak (necrotic ITF, TPF)	No	N/A	No	Bilateral	3,01	3,62	Inferior border of C1	17.89
4	52	Recurrent Chordoma	Chordoma surgery, CSF leak surgery, RT	1	CSF leak (necrotic ITF)	Yes	Draf-III	Yes	Right	2,45	4,19	Inferior one third of clivus	18.34
5	64	Recurrent chordoma	Chordoma surgery, CSF leak surgery, RT	1	CSF leak (failed ITF)	Yes	Draf-III	No	Right	1,94	3,23	Inferior one third of clivus	20.59
6	15	Primary chordoma	CSF leak surgery	3	CSF leak (failed ITF)	No	Draf-III	Yes	Bilateral	3,42	4,82	Inferior one third of clivus	20.54
7	60	Primary chordoma	CSF leak surgery	1	CSF leak (necrotic NSF, ITF)	No	Draf-II	Yes	Left	2,95	5,45	Inferior one third of clivus	20.50

Abbreviations: CSF, cerebrospinal fluid; ITF, inferior turbinate flap; PCF, pericranial flaps; NSF, nasoseptal flap; RT, radiation therapy; TPF, temporoparietal flap.

^aMeasurements were done on preoperative CT scans and sagittal and axial sections.

^b From nasion to the most inferior part of the anticipated defect + external pedicle length + 3 cm. ⁸