Risk Factors and Management of Intraoperative Cerebrospinal Fluid Leaks in Endoscopic Treatment of Pituitary Adenoma: Analysis of 492 Patients.

OBJECTIVES:To determine risk factors and management of intraoperative cerebrospinal fluid (CSF) leakage in endoscopic endonasal transsphenoidal pituitary adenoma surgery. METHODS:We conducted a retrospective review of 492 patients who, between April 2012 and August 2015, underwent endoscopic endonasal transsphenoidal surgeries for resection of pituitary adenoma. A multivariate statistical analysis was performed to investigate the association of some risk factors with intraoperative CSF leakage. Intraoperative CSF leaks were classified as grade 0, no leak observed; grade 1, small leak without obvious diaphragmatic defect; grade 2, moderate leak; or grade 3, large diaphragmatic defect. Repair methods were based on the CSF leak grade. RESULTS:Intraoperative CSF leakage occurred in 86 cases (17.5%). On univariate analysis, there were 3 factors associated with an increased intraoperative CSF leak rate: 1) repeat surgery (repeat 30.0% vs. primary 16.4%; P = 0.033), 2) consistency of the adenoma (tenacious, 27.3% vs. soft, 13.5%; P = 0.000), and 3) tumor size (22.0 ± 9.7mm vs. 25.4 ± 11.5 mm; P = 0.007). However, on multivariate analysis, only tumor consistency (P = 0.001; odds ratio, 2.379) and tumor size (P = 0.026; odds ratio, 1.032) were independently associated with intraoperative CSF leaks. In the 86 cases with intraoperative CSF leaks, the degree of intraoperative CSF leakage was categorized grade 1 in 30 cases, grade 2 in 25 cases, and grade 3 in 31 cases. Postoperative CSF leak repair failures occurred in 6 cases (1.2%). CONCLUSIONS:Intraoperative CSF leaks have a propensity to occur in cases with fibrous or large tumors. Once an intraoperative leak is identified, our graded cranial base repair method is safe and reliable.