Objectives: To systematically review the literature concerning techniques of closure of endoscopically created skull base defects based on site of skull base defect and flow rate of cerebrospinal fluid (CSF).
Data sources: PubMed, SCOPUS, and Cochrane databases.
Review methods: A comprehensive systematic literature review.
Results: The literature search produced a total of 1708 studies. Of these, 1585 studies were excluded based on title and/or abstract review. A total of 123 articles remained for full-text review, 101 of which were subsequently excluded primarily because of lack of detailed information as to the reconstructive techniques used or clinical outcomes. Of the 22 studies remaining for final analysis, all were case series. A total of 673 patients were included in the analysis, with an overall postoperative CSF leak rate of 8.5%. Subgroup analysis was performed based on location of the skull base defect and presence and quality of intraoperative CSF leak.
Conclusions: Based on level 4 evidence, in cases of low-flow intraoperative CSF leaks, skull base reconstruction with multilayered free grafts and synthetic materials offers similar outcomes to vascularized flaps. In cases of high-flow intraoperative CSF leaks, pedicled vascularized flaps appear to be superior. Location of the defect does not seem to be a significant factor in determining successful closure, with the exception of clival defects. In all other sites, good closure may be achieved by multiple reconstructive approaches. More consistency in data reporting and higher levels of evidence will ultimately be necessary to make definitive recommendations.
Keywords: CSF leak; endoscopic skull base surgery; high-flow CSF leak; low-flow CSF leak; skull base reconstruction; skull base repair; systematic review.