Graded repair of cranial base defects and cerebrospinal fluid leaks in transsphenoidal surgery

OBJECTIVE: A graded approach to cerebrospinal fluid (CSF) leak repair after transsphenoidal surgery is presented. METHODS:Patients undergoing endonasal tumor removal during an 8-year period were reviewed. 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/dural defect. Cranial base repair was tailored to the leak grade as Grade 0, collagen sponge; Grade 1, two-layered collagen sponge repair with intrasellar titanium mesh buttress; Grade 2, intrasellar and sphenoid sinus fat grafts with collagen sponge overlay and titanium buttress; and Grade 3, same as Grade 2 with CSF diversion in most cases. A provocative tilt test was performed before patient discharge to assess the integrity of the CSF leak repair. Protocol modifications adopted in 2003 included an intrasellar fat graft in Grade 1 leaks with a large intrasellar dead space, frequent use of BioGlue (CryoLife, Inc., Atlanta, GA) in Grade 1, 2, and 3 leaks, and CSF diversion for all Grade 3 leaks. RESULTS: Among 668 cases in 620 patients (475 pituitary adenomas and 145 other lesions), an intraoperative CSF leak was observed in 57% of the cases: 32.5% Grade 1, 15% Grade 2, and 8.7% Grade 3. Postoperative repair failures occurred in 17 cases (2.5%), including 0.7, 3, 1, and 12% of Grade 0, 1, 2, and 3 CSF leaks, respectively. Bacterial meningitis occurred in three patients (0.45%). After protocol modifications in 2003, repair failures decreased from 4 to 1.2% (P = 0.02). CONCLUSION: A graded repair approach to CSF leaks in transsphenoidal surgery avoids tissue grafts and CSF diversion in more than 60% of patients. Protocol modifications adopted in the last 340 cases have reduced the failure rate to 1% overall and 7% for Grade 3 leaks. Provocative tilt testing before patient discharge is helpful in the timely diagnosis of postoperative CSF leaks.