Systematic Analysis of Cerebrospinal Fluid Leak after Endoscopic Skull Base Surgery: Tumor Location, Closure Method, and Pathology.

Objective: Endoscope-assisted cranial base surgery provides a direct, minimally invasive alternative to traditional transcranial approaches. One of the greatest challenges of endoscopic anterior base surgery is avoidance of postoperative CSF leaks, which may be associated with significant morbidity including meningitis, pneumocephalus, and death. Considering postoperative CSF leak rate as a potential barrier to the widespread acceptance of endoscopic anterior cranial base surgery, it is important to identify the indications, techniques, and limitations of the various approaches to reconstruction to minimize this complication and improve outcomes. To this end, we performed a systematic analysis of the endoscopic endonasal skull base approach to assess factors associated with postoperative CSF leaks.

Methods: We performed a MEDLINE search (from years 1950–2010) to identify relevant studies. Included studies were reviewed and data were extracted for demographics, closure method, incidence of CSF leak, complications, and reoperation. Additionally, outcomes were assessed based on the number of patients treated at an institution.

Results: One hundred studies involving 3,880 patients treated with the endoscopic endonasal approach were included. Meningiomas and craniopharyngiomas had significantly higher postoperative CSF leak rates (33.3% and 26.0%, respectively) than pituitary adenomas and clival chordomas (4.9% and 12.3%, respectively). Gasket-seal closure had a lower postoperative CSF leak rate (0.0%) than fat graft, multilayer, or isolated nasoseptal flap (6.5%, 7.5%, and 19.2%, respectively). Sellar lesions had a lower postoperative CSF leak rate (4.5%) than suprasellar, clival, or anterior skull base lesions (14.6%, 10.8%, and 10.0%, respectively). Patients treated at larger institutions were significantly less likely to have CSF leaks or have repeat operations.

Conclusion: Our systematic analysis supports the conclusion that low rates of postoperative CSF leaks (<5%) may be obtained with appropriate patient selection, meticulous multilayer closure techniques, and surgical experience. In high-risk patients, surgeons should have a low threshold for spinal drainage and use meticulous multilayer closure in combination with a vascularized nasoseptal pedicled flap. Critical to obtaining optimal results is the use of an experienced multidisciplinary surgical team with prior exposure to a wide breath of endoscopic skull base lesions.