Introduction: Endoscopic endonasal transclival approach is a useful method for skull base pathologies. Postoperative cerebrospinal fluid (CSF) leakage is one of the concerns for transclival approach because high-flow CSF leakage is always followed. This study introduces our skull base reconstruction strategy according to the location of pathologies.
Methods: Between Jan. 2015 and Feb. 2022, 35 patients underwent surgical resection via endoscopic endonasal transclival approach. We classified tumor location into three groups; upper, middle, and lower groups based on the level at the clivus (Figure 1). Skull base reconstruction was tailored for each level. Upper and middle clivus were reconstructed with intradural fat, artificial dura substitute inlay, tachosil onlay, with or without Megaderm onlay, and nasoseptal flap (Figure 2). For lower clivus lesion, intradural fat graft, artificial dura substitute inlay, and primary suture of tectal membrane and nasopharynx wall was performed (Figure 3).
Results: Twenty males and fifteen females were included. There were 25 chordomas, 4 meningiomas, 4 metastasis, and 2 primary malignancies. Thirteen (37%) patients had pathologies at middle clivus, and six (17%) patients had lesion at lower clivus. Sixteen patients were involving at least two levels of clivus. Two patients involved whole clivus. Seven (20%) patients had CSF leakage and all patients underwent revisional surgery because they were not solved by lumbar drain. Moreover, 3 patients had surgical repair over 2 times. All patients who had whole clival lesion or underwent radiotherapy received revisional surgery. Multi-level involvement was one of the risk factors for CSF leakage. Mid-clivus lesion was higher rate of CSF leakage than upper or lower clival lesion. In lower-clivus lesion which we performed primary closure with surrounding soft tissues, no CSF leakage was occurred.
Conclusion: Clival lesion is prone to occur CSF leakage after endoscopic endonasal approach. We recommend that reconstruction strategy is tailored to the level of involvement. Moreover, we suggest that lower clivus lesion can be reconstructed by approximation of fascia and nasopharyngeal wall rather than nasoseptal flap.
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