Risk of meningitis after posterior fossa decompression with duraplasty using different graft types in patients with Chiari malformation type I and syringomyelia: a systematic review and meta-analysis

Several complications have been reported after the use of grafts for duraplasty following posterior fossa decompression for the treatment of Chiari malformation type I. This study aims to investigate the rate of meningitis after posterior fossa decompression using different types of grafts in patients with Chiari malformation type I and associated syringomyelia. The search was conducted using multiple databases, including PubMed, Scopus, Web of Science, and Embase. Data on the rate of meningitis, syrinx change, and rate of reoperation were extracted and investigated. Quality of evidence was assessed using the Newcastle–Ottawa scale. Nineteen studies were included in the final meta-analysis, encompassing 1404 patients and investigating autografts, synthetic grafts, allografts, and xenografts (bovine collagen, bovine pericardium, and pig pericardium). Autografts were associated with the lowest rate of meningitis (1%) compared to allografts, synthetic grafts, and xenografts (2%, 5%, and 8% respectively). Autografts were also associated with the lowest rate of reoperation followed by xenografts, allografts, and synthetic grafts (4%, 5%, 9%, and 10% respectively). On the other hand, allografts were associated with the highest rate of syrinx improvement (83%) in comparison to autografts and synthetic grafts (77%, and 79% respectively). Autografts were associated with the lowest meningitis, reoperation, and syrinx improvement rates. Furthermore, synthetic grafts were associated with the highest reoperation and xenografts with the highest rate of meningitis, whereas allografts were associated with the best syrinx improvement rate and second-best meningitis rate. Future studies comparing autografts and allografts are warranted to determine which carries the best clinical outcome.