Incidence and management of postoperative pseudomeningocele and cerebrospinal fluid leak after Chiari malformation type I decompression.

Objective: The optimal surgical management of Chiari malformation type I (CM-I) remains controversial and heterogeneous. The authors sought to investigate patient-specific, technical, and perioperative features that may affect the incidence of CSF-related complications including pseudomeningocele and CSF leak at their institution.
Methods: The authors performed a single-center, retrospective review of all adult patients with CM-I who underwent posterior fossa decompression. Patient demographics, operative details, and perioperative factors were collected via electronic medical record review. The authors performed Fisher's exact test and independent Student t-tests for categorical and continuous variables, respectively. Univariate regression analysis was performed to determine odds ratios. A multivariable regression analysis was performed for those factors with p < 0.10 or large effect sizes (OR ≥ 2.0 or ≤ 0.50) by univariate analysis. The STROBE guidelines for observational studies were followed.
Results: A total of 59 adult patients were included. Most patients were female (78.0%), and the mean body mass index was 32.2 (± 9.0). Almost one-third (30.5%) of patients had a syrinx on preoperative imaging. All patients underwent expansile duraplasty, of which 47 (79.7%) were from autologous pericranium. Arachnoid opening for fourth ventricular inspection was performed in 26 (44.1%) cases. CSF-related complications were identified in 18 (30.5%) of cases. Thirteen (22.0%) patients required readmission and 11 (18.6%) required intervention such as wound revision (n = 5), wound revision with CSF diversion (n = 4), CSF diversion alone (n = 1), or blood patch (n = 1). Three (5.1%) patients required permanent CSF diversion. Male sex (OR 3.495), diabetes mellitus (OR 0.249), tobacco use (OR 2.53), body mass index more than 30 (OR 2.45), preoperative syrinx (OR 1.733), autologous duraplasty (OR 0.331), and postoperative steroids (OR 2.825) were included in the multivariable analysis. No factors achieved significance by univariate or multivariable analysis (all p > 0.05).
Conclusions: The authors report a single-center, retrospective experience of posterior fossa decompression for 59 adults with CM-I. No perioperative or technical features were found to affect the CSF-related complication rate. More standardized practices within centers are necessary to better delineate the true risk factors and potential protective factors against CSF-related complications.