Which type of duraplasty is best for Chiari type I malformation surgery?

Abstract

Objective: This study investigated whether the selection of different dural substitutes and distinct dural repair techniques correlates with the incidence rate of postoperative CSF leak in a mixed population of adults and children with Chiari type I malformation (CM-I) who underwent posterior fossa decompression with enlargement duraplasty (PFDD) as the first surgical approach.

Methods: A retrospective analysis was conducted on all patients admitted to the authors' institution between 2006 and 2023 for PFDD to treat syringomyelia and/or symptoms due to CM-I. Clinical, radiological, and surgical data were extracted from a prospectively maintained database. Demographic information was collected from medical records. Surgical procedures were also scrutinized, specifically focusing on the type of dural graft used for duraplasty, alongside perioperative complications and the necessity for subsequent surgeries. Lastly, during follow-up, the occurrence of a CSF leak was assessed and analyzed in relation to the type of dural graft used during surgery. The type of dural substitute chosen changed over the years to reduce CSF fistulas, while the technique of PFDD remained the same. Consequently, large sequential homogeneous groups differing only by dural substitutes were available for comparison.

Results: The data from 409 patients with CM-I undergoing PFDD were analyzed. A total of 368 cases had complete surgical data and were included. Thirty patients received autologous duraplasty. The remaining 338 cases with heterologous duraplasty from equine and bovine pericardium were considered for the comparative statistical analysis. The mean follow-up duration ranged from 39 months in adults to 45 months in children. The CSF complication rate requiring revision was 6.5% in the total cohort, with a higher incidence in children (10.5%) compared with adults (3.9%). There was no significant difference in adverse events (CSF leak, revision surgery, or ventriculoperitoneal shunt placement) between the different dural patches by univariate analysis if applied to the total cohort, although the trend neared significance (p = 0.06). In pediatric cases, this value was significant (p = 0.01) in favor of equine pericardium, particularly when combined with a collagen matrix inlay graft.

Conclusions: This study on a large and homogeneous series of patients with CM-I undergoing PFDD with heterologous duraplasty demonstrated that CSF complications may be kept low. The dural substitutes derived from equine pericardium, particularly when combined with a collagen matrix inlay graft, exhibited a reduced rate of CSF leaks compared with substitutes derived from bovine pericardium.

Keywords: CSF collection; CSF leak; Chiari type I malformation; duraplasty; posterior fossa decompression; postoperative fistula.