Challenging reconstructive techniques for skull base defect following endoscopic endonasal approaches

Objective: We assessed the outcomes of various reconstructive methods for skull base defect after endoscopic endonasal approaches (EEA) depending on the degree of intraoperative cerebrospinal fluid (CSF) leaks. Methods: Between Jan. 2008 and Sep. 2009, 122 consecutive patients underwent 124 EEA for sellar and extra-sellar lesions. Intraoperative CSF leaks were classified as grade 0, no intraoperative CSF leak; grade 1, low output; and grade 2, high-output based on the degree of CSF leakage and size of opening in the arachnoid membrane (<5 or ≥5 mm). Results: Postoperative CSF leaks or meningitis occurred in 13 of 124 cases (10.5%). In 77 patients with grade 0, there was no postoperative CSF leak. Among 20 patients with grade 1 CSF leaks, four patients developed meningitis or postoperative CSF leak. Postoperative CSF leaks occurred in nine of 26 patients (34.6%) with grade 2 leaks. Comparison of reconstructive methods revealed that gasket-seal method provided better control of CSF leaks than free-fat graft in patients with grade 2 leaks (11.8% vs. 66.7%, p=0.028). However, in grades 0 and 1, we found no difference among the various reconstructive methods. Conclusion: The selection of reconstructive methods for skull base defects should be determined by the degree of CSF leaks. Although grade 0 or 1 leak requires relatively conservative management such as simple closure or free-tissue grafting, a more aggressive reconstructive technique is required to prevent postoperative complication in grade 2 CSF leak.