Surgical Management of Frontal Skull Base CSF Fistulas: Results of a Skull Base Team Approach

Objective: Frontal skull base CSF fistulas are lesions with differing pathomechanism and complex treatment strategies. These strategies are defined and evaluated within the interdisciplinary skull base team at skull base conferences. We report on the results of the re-evaluation of our treatment strategy.

Methods: We retrospectively analyzed the medical files of 18 patients treated interdisciplinary by the skull base team from 2010 until 2015.

Results: Of the 18 patient with frontal skull base CSF fistula, 13 (72%) were males and 5 (28%) were females. The causes of the CSF fistulas were trauma 10 (55%), iatrogenic 6 (33%), and congenital 2 (11%). The localization of the defects varied: frontal sinus 8 (44%), ethmoid sinus 4 (22%), sphenoid sinus 3 (17%), olfactory groove 3 (17%). The surgical approach was transcranial in 8 (44%), endoscopic transnasal in 8 (44%) and combined (in sequence) in 2 (12%). Six (33%) patients were additionally treated with CSF lumbar drainage (2 intraoperatively, 4 delayed). Four patients required revision surgery (4/8 endonasal group, 0/8 transcranial group, 0/2 combined group; p = 0.037 log rank Mantel Cox). Three (17%) of the patients developed pneumococcal meningitis (no residuals). Olfaction was preserved in 14 and reduced in 1 out of 15 patients (no information in 3 cases).

Conclusion: Both, cause and anatomical localization of the skull base defect, define the surgical strategy to treat CSF fistulas. Frontal sinus defects caused by trauma demand either a transcranial or combined approaches with very good results. Sphenoid and ethmoid sinus defects are managed transnasally but with a high revision rate. Continuous reevaluations of interdisciplinary strategies are important.